Talk and powerpoint by Tony Holmes on fossils, 12 Sept 2011
About 3/4 hour talk , break, 3/4 hour Q&A, 18 people
Since I retired I've taken up fossils again. I'm not a professional , I haven't got any qualifications .
I buy the occassional fossil , I certainly don't sell fosssils. I don't deal in fossils , I
don't collect fossils for other people except museums. As an amateur, following in the steps
of the likes of Mary Anning and other people , although Mary Anning had to make a living
out of it, I don't. I'm lucky enough to have a pension and manage to get along the coast
To collect fossils is not an easy thing. For a start, when you go from here it costs you
25 quid to get to Dorset and back. By the time you've bought yourself a bacon sandwich
its not a cheap day out. But. if I find anything spectacular or if i find duplicates, I
do give fossils to museums. I mainly give to the Oxford university museum . Their
natural history museum is one of the finest in the country, far better than the London
natural history museum . Its well laid out, only one thats better that I know of
and that is the Sedgewick museum at Cambridge. They have better fioosils but the history of
geology is more aligned with Oxford uni museum. The museum its self is quite fantastic
in that the whole building is made to collect fossils and natural history . When you go up
onto the roof and look down you can see the rocks and fossils built into the building itself,
the infrastructure. A few people give me fossils occassionally but to collect fossils you have
to be relatively fit. You've got to be able to walk 2 or 3 miles with a couple of hundredweight
of rock on your back. Its not easy . My mate had 80 pounds of rock in his rucksack and
another 100 pounds of rock on his shoulder, when we went up to Somerset.
After collecting them you have to extract them from the rock, I do that myseff with a series
of special tools. Driven by compressed air, air scribes that run at something like 20,000
impacts per minute. They just take the rock away from the fossils. I also use air abrasive.
I have a small but specialised collection, by small I mean about 1200 items. Ranges from
pleisiosaurs through to very small trace fossils. All collected by myself and all
cleaned up by myself. I collect from sections along the Dorset coast , Atherfield on
the IOW from a band of very hard rock and clay, difficult to get fossils out of. I also go to
the Sussex coast which is chalk so nice and easy . The main site that I collect from is
the Dorset coast
Painting by Henry de la Beche. Done about 150 years ago and it shows all the main
animals that you find now. The pleisiosaurs, crocodiles, ictheosaur , cuttle fish, fish, squid
turtles and so forth. The only thing it doesn't depict is what is happening on the sea floor
which is quite important.
The section that I collect from is Eype, Dorset coast, a section about 183 to 175 million years old
, a thin band about 3m thick there but if you go up to the Yorkshire coast the same band is
hundreds of feet thick. They are very compressed beds, been laid down, eroded , laid down ,
eroded and the fossils that you see , amonites have been sheared off by the erossion , fallen into the
sediment, bottom side has been preserved . The sea has retreated or the land has come up , one or the other.
Its been erroded away and then another layer, dropped back down and another series of layers on top.
Some of the layers are completely missing in Dorset. You have a landmass up at London and
another land mass in Cornwall or so and there is shallow to deep seas in between. It goes
up and down like a yo-yo. The whole country was then situated about where SW Spain is now so
quite warm seas but at that time the air temperature was a bit cooler so compare the sea
with something like norther Spain , ie relatively warm.
Picture showing Seatown to the west ,Eype, Burton Bradstock and W Bay to the east. You have to
walk either from Seatown or Eype. At Eype there is a fault and the land drops 20m .
Picture is taken in the summer and the beach is nicely covered with tourists, shingle and maybe sand
and a reef just off shore means fairly warm and safe sea bathing unlike Burton Bradstock. There the
beach just drops and long-shore drift/rip one of the most dangerous beaches on the south coast.
Picture wintertime, nov to march , of Eype when all the shingle has gone and all the fossil bearing rocks are
exposed. There are flat boulders but turn around and look west there is a large boulder spread that you
have to clamber over. The fossils are in this lot, very hard going, very difficult. Not something I'd
recommend for families, most people only get a couple of hundred yards and they give up.
If you find a foissil around the headland you have to clamber over all the boulders to bring
Q: How do you actually look for them do you end up moving the boulders round?
No, you just walk along and see what you can see. When looking for foossils, there are 2
ways for looking. One is to walk along and keep moving , its difficult to explain , but when looking
for fossils you just see them. I used to walk along with my daughters and i used to
say ther's a shark's tooth there, amonite there etc and she used to look at me saying where?
she couldn't see them.
Another pic with Burton Bradstock looking eastwards and look for boulders and hammer them
out. The Germans come across to this site and they come with mini buses and bring
sledge hammers with them. When they've been along the beach they've broken it up
and its a real mess. I go along with a 2.5 pound hammer and if I can't get it out with 2.5 pound
then it stays. If its too big it doesn't get taken.
Last year I was invited by the Oxford university museum to go a quarry because it was the same
age beds as at Eype and they knew that ultimately that they would get my collection. A quarry
just north of Oxford . Although a big site, the fossils were only in 2 small places and we went back
]5 times before we were able to identify where the fossils were. You have to find the beds and its not
easy. Part of a farm, excavating into a hillside to put in grain silos. They brought in a quarrying company
to extract the rock for road aggregate. We were allowed in occassionally and reluctantly , they never are
keen these days. The rock is sandstones and limestones, can be hard or soft or indifferent
but on that site the fossiliferous beds 4 foot thick in Dorset , hundreds of feet thick on
Yorkshire coast but on that site only inches thick. They vary much so across the country.
On the sea floor you get worms and other animals living there .
Picture of a worm cast , in the food chain somewhere near the bottom , food for fish.
You can see where the worm moved back and forth up the branches filtering out the
sediment . You only rarely see the organism that did it. I've only ever found one and Oxford Uni
immediately took it off me as soon as I showed it to them. We led the field trip, we're having that.
Fossil about 4 inches long but not that common. The fossilisation occurs in mainly 2 ways.
When an animal dies it falls to the sea floor . Dying and falling maybe for not enough oxygen
in the sea . As in the Black Sea bands with no oxygen, fish swims in there and suffocates .
At Kimmerage you can see where fish have dived into the sea floor and then something else has come
along when oxygen levels have risen, and eaten the back of the fish, leaving the skull in the ooze.
Fossilisation can happen immediately and the skin gets preserved , other times just bones
from a slow process.
This is an echinoid pic, a unique echinoid , the only one known of from this site. It has a trace
fossil boring into it. Something has gone into it immediately on falling to the sea floor and eaten partially
or went into it accidentally burrowing along the sea floor. I doubt anyone else will find another one.
Pic sea lilies, crenoids or featherstars differnt names . The preservation is quite unique ,
to find them like this in Dorset is very unusual. They are preserved 3D. You see them in
Lyme Regis as squashed slabs , perhaps 30 quid for a small piece. Couple of thousand for
a big piece. But you never see 3D ones. If you could take them out of the rock and stand them up
they would stand just like modern feather stars. When under attack they fall over and they drag
themselves along the sea floor. They use the "arms" to drag themselves along to get away
from the attckers , normally starfish. Maybe the crinoids were trying to escape and got covered in sediment
. Every fossil tells a story.
A crinoid looks like a plant on the sea floor but its an animal and feeds as corrals do,
filtering organisms out of the sea. These at Eype have been preserved so well thgat the fine detail
has been preserved. When I first fond one of these I cleaned it up with a toothbrush and I
lost all this as I didn't know it existed. It was in a very fine sand. It wasn't until I got a
microblaster , a pencil that fires a talcum powder like substance at the rock and
slowly errodes it.
Another unusual fossil , a shrimp, again unique. Saw just a small part, knocked it off the rock,
stuck it in my pocket. It turned out to be a small shrimp, crustacean, the head is not exposed yey.
Whether its there I don't know, I didn't like to do any more. To get the legs preserved is
Sometimes when fossils are preserved, the water filtering through the rocks then
dissolve the outer shell. This fossil is the indside of a gastropod , rare along there.
2 bands of marginals along there where tht's from. Its the fact the outer shell has been
dissolved away . Some people would take all the surround away , leaving the hole,
take a cast of it and say that's the fossil.I think that is a bit destructive.
This is a scllop , a pectin, they lived on the sea floor. You see film of them opening and
closing to get away from enemies. Nothing has changed in 200 million years, they are
exactly the same.
From my bag of goodies, this is an amonite . This come out of block of stone about 10 x 15 inches
about a hundredweight. My friend started to clean it up but he ruined it so I took the rock
off the back and this is the result, taking 2 weeks. Even the ribs on the amonite are preserved .
Unusually it was preserved in 3D , not sheared off or erroded.
Q: is any of the original material in the fossil?
that is the actual shell. What sometimes happens is that the amonite drops to the sea floor
and , there is a lot of discussion and argument about this, but this bit becomes filled with
sediment , the middle doesn't and it crushes. So you only get the outer whorl.
Another amonite , a different sort, there are about 30 or 40 different types on this site.
Again its been preserved right to the centre , even the keel around the edge is there,
Another amonite , important along the Dorset coast , especially the tourist industry.
If you go into any of the Lyme Regis fossil shops you see amonites everywhere.
They are important parts of the food chain, again discussion and dispute, but this is how I see it.
They lived midwater and were able to go up and down in the water by filling these
chambers with air , so either neutrally boyant , positive or negative , and had an octopus like
feeding mechanism at the front. And they squirted away from enemies.
Another amonite, all different shapes, they all live in different parts of the environment.
Some close to the surface , some close to the bottom , Some may have crawled along the sea bottom,
who knows. The air process is a bit like a swim bladder of a fish.
The differnce between modern day nautalus and amonites are that the internal compartment
lines of the shell . On a nautulus they are straight , on an amonite they are all over the place.
The ones on a nautulus are stronger , but on amonites they are corrugated probably to give extra strength.
Again loads of professional arguments over this. The amonites died out at the end of the cretaceous,
nautaluses didn't. Same animal , different shape, nobody knows why. The amonies adopted different
shapes for different conditions but they died out.
It took me years to find a decent amonite.
This is a worm-tube a circalid worm tube , still around today, they've not changed much.
But to find one that well preserved is most unusual. I took a photo of it , sent it to the Natural History
Museum , they told me it was an amonite. I didn't take too much notice of that.
Then I sent it to a german chap and the Stutgart museum identified it. You get to see people
and people get to know you. It is a corral, a solitary corral, about the only place on the Dorset
coast that you can find corrals, where the sea levels were shallow, noit in great numbers.
There is a band of corrals at Kimmeridge at Rimstead Bay but no solitary corrals.
The fauna on the Dorset coast is very small compared to say Yorksfire eg ichtheosaurs, crocodiles ,
not in Dorset.
This is a starfish , the dream that every fossil collector wants. The professionals go along a beach
just to collect starfish, not interested in anything else, they cannot sell anything else.
This is a pic I found showing ictheosaurs and I think they are eating an amonite. Its quite
recognised that ictheosaurs eat amonites, you have seaweeds here , tend not to be preserved
in the fossil record . A couple of years ago I went to the Munich museum where the have a recoinstruction
of an ichtheosaur , the fattest ichtheosaur that I have ever seen. Likr a dolphin it breaths air
and a parallet evolution , feeding in the same way, the only difference is the tail goes the other way
and the icth has bloomin big teeth. How does the german icth go through the water? very slowly I
should think. This pic is an icth skull that I found the bottom section. On the same day I found
a pleaiseosaur so we left the icth skull to pick it up the next day - I didn't find it for another
3 years. Nobody else found it. It came out in about 1000 pieces and I had to glue it all
back together. Some bits I had to remake, using a prioduct called miliput, not unusual for collectors
to repair fossils and there is a whole industry in Doret where they actually make foissils -
but we won't go there. I've seen some of them, I turn them over and I can't tell the difference.
If I do it you can tell. This jaw with ribs, vertebra . In icth vertebra from the bag of goodies
and a piece of turtle. This took weeks and weeks to clean up .
This is part of the pleiseosaur that I found. If you feel your shoulder blades , there is a rib running through near.
Southampton Mineral and Fossil society have an annual competition and this won best fossil.
Again some more of this pleis, it is six feet long. I haven't got the skull or the tail . You've got the
vertebra, the ribs, and the neural arches . The series of nodules running your fingers up your
back , thats the top of the neural arch. Under that Y shaped bit attaches to the vertebra , the nerves
run through that. I didn't find the flippers of the pleis . When one of these beasts dies, because of its
long neck , the head falls off and so does the tail, they are somewhere else. A skull of one looks
very ferrocious but it is quite a fragile skull and just falls to pieces. One was found on the Somerset
coast , complete, about 6 feet long. To get it out of the ledges they cut it into squares and
then took it out. They think the Loch Ness monster is a pleis . No a pleis would not have the
strength to lift its neck up like that .
A cartoon by Joe Jusco , but that just could not happen , but the skull is about right , those teeth
were really like that. Nothing around that has evolved like that since.
A few years ago I found out about a quarry near Swindon and after much cajouling we managed
to get ourselves in there . All was mud but we found a crocodile skull and numerous else.
This pic shows similar, but these from the Fleet, behind Chessil Beach. Fish jaw, shark fin spine
the bit that goes through the water in Jaws, the only bone in a shark , the leading edge of
that fin. Sharks tooth, rabbet fish .
Steve Etches has one of the finest private collections of fossils in the world. When he opens his
museum to the public in a few years time , it will be worth a visit.
When I went to Munich I went to the fossil and mineral show. They were selling fossil fish,
complete 3D , about 25,000 dollars for those weeks of work.
A pic from the Munich museum , a fossil sponge from the cretaceous. The cleaning up is
miraculous , the sponge here is stood on its stalk with its roots , in 3D and standing up.
Isle of Wight and Atherfield Point , the fossils there lobsters, gastropods, little shells called
trigonias and corrals with all the individual cells preserved .
Cartoon depicting how fossil collecting used to be , in the days of Mary Anning in the 1800s .
If they found something in the cliff they used to take the cliff down. She used black
powder , they blasted the cliffs down to get to them . They levered up the ledges to take it
out . These days you'd have do-ggoders on your neck . Its not allowed, digging into cliffs,
sledge hammers etc. They came up with the fossil collecting code, and we all abide by it.
We just collect off beaches , no wanton destruction. Last year 2 people were prosecuted and
banned from Dorset for levering up the ledges.
Get a storm and all you see on the beaches is people's backsides and all you hear is
tapping of hammers. Cartoon from 1857 Punch and nothing has changed , see of backsides.
Even the number of fossils being found has not changed , not been over-collected.
A slide of Burton Bradstock on a winter's evening , the beach just drops away , so long-shore
tide. Along the top is a band of oolite and very fossiliferous.
Q: Is it oolitic limestone that produces the most fossils?
At Eype there are oolitic bands but not particularly rich. At Barton Bradstock there is but
not generally. I would say theat oolitic is indicative of a Caribbean type climate and only
seem to form in those conditions.
Q: What proportion of fossils found in Brittain would be from marine flora or fauna.
Most of them
You haven't talked about terrestrial ones.
I don't really look for them. And in any case where are you going to put a dinosaur. If you go to
the IOW there is a hipsolonadon , about 3 feet long . One dinosaur leg is 4 feet long , in 3
pieces and I can't lift any of them. Because they are preserved in iron , as iron.
Q: Going to the other scale , dependent on grain size , can you get fossilised nematode
worms, as distinct from garden worm sizes. ?
At Kimmeridge you get very fine sediments so you get dragonflies preserved , fine enough to
preserve anything and everything as long as the conditions are right when that animal dies.
Only a small proportion that die get preserved , very small . the chemicals have to be present to preserve
them. So I don't collect dinosaurs and terresstrial animals tend to be fairly big. Even the skull that
we found in that quarry - the block that we got it in was the size of a table and 18 inches thick.
It went to Lymme Regis and Chris Moore to be put in an acid bath to eat the limestone away
but after starting to eat away, a skin formed and no more dissolving so he had to do it by hand.
Q: When you say you use this air thing with talc is that like a micro shot blaster?
Yes, its exactly that. The equipment for that isn't very expensive , but you have to have a blast
cabinet and a dust extractor. The dust extractor system can be expensive though.
Q: Is there aids in the form of staining, short term, for increasing the contrast between
fossil and rock to help the cleaning process?
Yes there is. People down at Lyme Regis use coffee and some use wood stain for appearance.
With unstained , the detail doesn't show up but add a slight colour is all thats needed
to bring out the details.
Q: Have the broken fossils broken in historical times or in the extraction proces?
When you take some fossils out, the shales break up
I thought shales cleaved nicely so would help.
Not necessarily , when exposed to the sea they tend to fracture. So remove in thick segments
to avoid cracking and when processed mount in high density foam . Normally an expensive
foam , a 2 x 4 foot sheet is about 30 quid but the Natural History Museum told me that if you
use camping foam , the rolls, its exactly the same but 3 or 4 quid. To excavate 2.5 feet wide
and 6 foot long by 18 inches deep took about 4 months. Blocks can move up and down a beach
so can get covered over with rock or sand.
Q: Shouldn't you be going there by boat to make extraction easier?
Over at Kimmeridge a chap found an icth , we started helping him and we walked away ,
and he hired a boat to take it out , but he took the skull , flippers and backbone and left the ribs and
all the important evidence that goes with it.
Q: Is there a central record of what people find?
There is a fossil code where if you find anything unusual , it must be recorded. The crustacean that
I found , the shrimp, I took it to Charmouth and said it was very rare, do you want to record it. They
said we'll take a photo of it but its not importan. So a few weeks ago, as I am involved in
rewriting the fossil code , I said to the chap doing this , about this event and he said it should be
recorded. It is very important. I sent a pic down to Charmouth and they're attitude had changed
over the intervening years.
Q:What about studyoing really small things?
I don't do that, I like things I can pick up. I have a mate over in Scholing who does microfosils, he gets
out his microscope and says look at this and it looks wonderful under the microscope , you'd think they
were badly preserved but they are better preserved than my sort of thing. But you can't pick
it up as its in a test tube.
Q: Can you easily mislead yourself like that "Martian" life that was found in an Antarctic meteor?
are we talking of that sort of scale?
Yes its possible, she came down here to give us a talk
Q: of fraud ?
Take Moroccan trilobytes like giant woodlice. They find one , take a mold of it , rub bbot polish
in the mold , poor resin into the mould, get a block of stone . When its set they turn it over
peel the mold off and there is a 30 quid trilobyte. And the same next day and the next.
Q: What got you started?
Somebody told me you could find shark's teeth .
There's a shark's tooth . You can find shark's teeth in the local chalk pits , I was 8 or 9.
I spent all of a summer holiday in this chalk pit with a spade and a trowel and I found
2. You collect fossiles then you get to 15 and girls come along. You used to find shark's teeth
at Lee on Solent but sea defence work has destroyed that. It was a SSI site but they covered it over.
At Ringstead in Dorset there was an important fossil band and they did the same.
Q: You mentioned about the difference in fossiliferous bed thickness between Dorset
and the east coast, why is that?
If you think of the south with a land mass near London and a landmass near Cornwall and the
sea levels are going up and down , the sea is shallower , so you get less deposition, you get more erossion .
There may well have been the same thickness of beds but they were erroded. There are 15 layers within
the beds and along Yorkshire they are very thick but along Dorset they are either intermittant
or just a foot thick.
Q: You haven't filed the tips of that shark's tooth to make them that sharp.
No. That one came from the Isle of Sheppey. They shed them, if you look at a shark's jaw
the teeth are laid back and as the front fall out there are more coming forward the whaole time. If
you look at icth the teeth are in channels, get damaged, come forward to replace them.
Q: Do you get any strange requests from the Portsmouth Creationist Museum?
Museums tend not to ask for things. I'm reluctant to give stuff to the NHM because if you go there
and a chance to go round the back. The paleantological curators aren't paid to talk to the public .
If you go through the drawers , I took an unknown fossil up there for identification . We went through drawer
after drawer , trying to find an example and they said none of this has been curated or looked at
properly. In fact a few years ago when they had the old store they found a Brontasaur .
Q: So how do you index fossils, someone identifies it and then indexed by that category
or done morphologically in more general terms?
Everyoone does it differently. I just number them sequentially with a description, where
it was found , with a grid reference, the bed if I know the bed although that is not quite so
important despite what people say and give as much info as I can. Quite often I
write it on the back of the fossil. Info stored on a database . Used to be a computer database
but you put it on a floppy disc, then CD , forever trying new media. The Americans put their whole
archive database on punched tape and then threw away most of the paper records and then
they threw away the punched tape readers. In Southampton there is another collecter with myself
, a couple of people who collect to sell and then a couple of people in the New Forest. Some people
get very irate about fossil collcting , You are allowed to collect, as long as you're not on
private land and not being destructive. There is too much money involved in it.
A few months ago there was a Pleiseosaur jaw found in Dorset. The chap who said he found it ,
he sold it for 20,000 pounds. He found part of it. The chap who I mentioned with the private
museum , he found the rest of it and gave it to him. The buyer then told the landowner that it had
come out of his land , in a slip. So the landowner said he wanted 20, 000 as well. But it did not
belong to him as it was on a slip on the beach. They paid him to keep him quiet. If it gets too
bad then ultimately it will stop people collecting. When you find a fossil and show someone , the first thing they
say is what's it worth?.
Q: So there is nothing like the portable antiquities scheme as in archaeology or metal detecting rather.
There is the fossil code and thats it. Steve is setting up a museum, half of my collection will go into it
and the other half will go to Oxford. Some private owners look after the finds better than museums.
If you go to his museum , he creates merry hell if you're in there more than 10 minutes because
the humidity levels rise and his de-humidifiers cut in. He keeps it at 40 percent humidity
and 68 degrees.
Q: Why when its just a form of rock, rock is pretty stable stuff isn't it?
No , some of these fossils have a high iron content , when it gets humid the pyrite forms acid inside
and self destructs. And destruct by expansion and contraction.
Q: Would you like to visit the badlands of the USA or where the archeopterix etc were found in China?
I would love to . But if you move into another area of collecting, what do you
do with it all. My mate reckoned he had 5 tons of fossils to clean up. He is 60, when
is he going to clean up that amount of rock.
Q: Did you say the amonites died of in the creataceous?
They died at the end of the cretaceous, a lot of organisms died off at the same time as the
dinosaurs . If you talk to the Americans they say it is the asteroid that his the Yucatan Peninsular.
If you talk to the Indians it is the amount of lava that came out over the Steppes. For the South
Americans , the dinosaurs didn't die out, they were still alive after the asteroid. Its
accepted now that birds are the descendants of dinosaurs because the way their hips are
orientated. But now they say no , birds and dinosaurs are from the same source animal back in
the triassic but they diverged and the bird hipped dinosaurs are different from the sauropods.
Whatever you are doing in paleantology there are people saying you are wrong.
Q: Were there bird-hipped creatures around after the Triassic?
There were bird-hipped dinosaurs and there were birds . If you talk to the South
americans they will say there were birds in the triassic , so going back before archeopterix
which is the earliest one we know of. Feathered dinosaurs are a different matter all
together. When they put veloceraptors in the film Jurassic Park they knew they
should exist but none ad been found. They knew roughly what they should look like .
The Jurassic Park veloceraptors are about 5 feet tall but is actually the size of
a turkey and covered in feathers . In China the feathers are preserved.
10 Oct, 2011 Prof Nick Evans , Southampton High Energy Physics at the uni
, a followup powerpoint and talk (from his 2008 sci caf 'Soul Cellar' talk)
on recent developements with the CERN Large Hadron Collider .
3/4 hr talk, 1 1/4 hr Q&A, 43 people
The LHC has kicked off, lots of exciting things going on. But I have to give you the slight spoiler that
we have not yet found the Big Thing that we were hoping to find. Which isn't to say its too late ,
and we aren't going to - its early days , but i shouldn't raise your hopes too much.
The first half of this talk will be like the previous talk , motivating what the physics is we are
trying to do , telling you a bit about the machine , and the second half , what the status is ,
how well its working, what we've looked for, what we haven't found etc.
What are particle physicists about. We try to understand how the universe works at the most
fundamental level. So we're not very sophisticated guys, we just like to smash stuff up, work
out what those basic Lego blocks , that make up the universe and why do they stick together in
the ways that they do, to make you and me and tables etc.
If you chop up a piece of wood you get two pieces of wood, you can keep going and
eventually you don't get a bit of wood , you get down to molecules and atoms. Then
you get to discover what atoms are made of . You get a positively charged nucleus .
Like a Solar system with a sun , that's the nucleus and going around them like planets are the
electrons - the first example of a fundamental particle. No one has managed to break one
of those guys up. We think they are one of the fundamental constituents , as far as we have
been able to tell today. Moving these things between different atoms is how chemistry works,
shuffling them around in a piece of metal is electricity. All pretty dull, what we like to do
is nuclear physics, getting down into the core of those atoms and smashing up what is
going on in there, to find out what that is made of. First we discovered that the nucleus was made
of things we called protons, that have positive charge and neutrons which are neutral and stick together
by something we call the strong nuclear force. So that what keeps those guys in the middle , electons don't
feel it so they fly around further away. You can tell that its strong because that nucleus is about ten thousand times
smaller than an atom so something is grabbing them in. In the 1960s people started bashing protons and
neutrons together in Stanford , USA. They managed to break up protons and neutons , at least to
some degree and we discovered they were made of particles that we call quarks. It was the 1960s ,
so silly names were allowed , up quarks and down quarks . A proton is made up of 2 up quarks and
a down quark and a neutron is made of 2 down quarks and an up quark.
Everything that you have seen or interacted with is made of electrons, upquarks and downquarks
which given the variety of stuff in the universe is pretty impressive. One of the major achievements
of science to understand so much concerning so few constituents. There is one more guy that
goes along with that family of stuff that makes up the universe , called a neutrino. They are very
elusive guys, only involved with what is called the weak nuclear force , which is an extra force
that happens within the nuclei of atoms. Its responsible for one kind of radioactive decay called
beta-decay. What happens in there is all rather peculiar becuase neutrons suddenly
decide they will become protons , spitting out an electron . Then it turned out if you wanted
to understand the enegy of these things , these guys did not have enough energy to explain
the energy of the original starting guy. We had to assume something else was heading off into
the universe - originally proposed by Pauli. These things are called neutrinos and they only
interact by this weak nuclear force and weak is the key word. These things are very weakly
interacting - they can go through light-years of lead before they will interact once.
So how do we know they exist - we have to have a very big source , the Sun is an example of
that , all the nuclear interactions in th esun are producing billions of neutrinos, flooding
through us every second. Then you need a big tank of water , the size of a swimming
pool and a mountain to put it under . They do this in Japan at the Superkankandeo experiment .
Basically you sit there for a long time, with the protons in the water nuclei and eventually one
of these neutrinos will bash it and do some version of this interaction. Then eventually you
can see some light come out . Surround your tank with photomultiplier tubes , sit
around for several months and eventually you can take a picture of the sun in neutrino
Those are the 4 guys that basically make up everything. What makes particle physics fun for me
is that these particles have very strange laws. They are not like cricket balls that you just chuck around.
They don't follow Newton's laws. Relativity is a big part of what is going on .
When things are going very fast, almost at the speed of light , all the rules change and this is
what Einstein spent his time working out . 2 key things from that, first E=mc^2 that is what we use to
make particles , we try to crush energy into a small bit of space so that we can convert it into the mass of particles
and make those particles. The other thing is that space and time became one . Paul Dirac in the 1940s,
where an electron emits or absorbs some light , then scatters as a result. If you believe that space
and time are kind of the same you can can rotate the picture and imagine the process where 2
particles , say like an electron come together and they anihilate into light. Took a long time to
understand what that might mean as one guy is apparently going back in time. In the end people
concluded that this was what is called anti-matter. There are anti versions of the 4 particles that I
mentioned. If an electron and its anti particle , the positron , come together and anihilate all
into some light . So that doubles the spectrum of what we know of the particles in the universe.
We now have all the elements we need for accelorator physics . We take electrons and positrons ,
bring them together and given as much energy as possible , moving really fast. When they come together
all their mass and kinetic energy is dumped into light for a short period and then the reverse can
happen. That energy can be used to make new particles. What we hope to do by changing the amount
of energy in the middle stage is to slowly create all the particles that make up the universe.
This collision of electron and positron is the cleanest tidiest thing you can do, what we
did in the LHC tunnels till about 10 years ago. There was an accelerator called the large electron
positron collider .
What is it we've found by doing this .
Just puzzles. What we've found is essentially heavy copies of what we already know. For example there
is a heavy copy of the electron called the muon , exactly the same as an electron in all respects
, in all its interactions, but its about 100 times heavier . The universe doesn't really use it, if
you make one of these it will decay into an electron , the lowest energy state. You make these
things and they just disappear in a fraction of a second. You think why is the universe doing this to
us. There are quarks associated with it , we call generations. I told you of the first generation, now this
muon is the first guy we found in the second generation but there is a version of the upquark
and the down quark , again exactly the same just heavier and as the 60s they were called charm
and strange , doesn't mean anyhting , you have to call them something. Again a neutrino
called the muon neutrino associated with the interactions with the muon like our previous
neutrinos associated with electrons. And it all happened again, we found something called the
Tau which is something 1500 times heavier than an electron but in other respects is
just identical. Wh ts it for. Then with the bottom quark a copy of the down quark . Finally
we found the top quark which is about 1 million times heavier than the electron or up or
down quarks. We don't know what they're there for , we don't know if we've finished or more things to find.
But here is the biggest quation in particle physics at the moment. We beleive energy and mass are
equivalent . Now energy is all to do with interactions . If you haver a candle burning, what is going on in there
is that electrons are moving up by the chemical reactions into orbits a long way from their nuclei .
They don't like that, they move in to a less energetic state , giving energy out . How is it
possible that the electron, muon and tau have all the same interactions but have different masses,
where is that different energy coming from . That suggests that out there is a new force that we
don't know about yet that is distinguishing these particles. There is anothe rconfusion
concerning antimatter. We are just made of matter , we don't walk down the street and bump into
an antiversion of yourself and anihilate. So where is all the antimatter. Whenever I create or
destroy a particle, an aniparticle is involdved. So when the universe was created were there an
equal number of matter and antimatter particles, we don't know. But matter and antimatter
must have differences in their interactions in some way , so that we can be left with hte matter
that we're made of, whilst all the antimatter is gone. his is the single thing that anyone has managed to write down to give
those particles their masses. We introduce a new force, with a particle associated with it,
called the Higgs Boson. Named after Peter Higgs , now emiritus prof in Edinburgh.
I will give a simple explanation , put forward by David Millar, when William Waldergrave was science
minister and he challenged people to tell him what the HB was all about.
This is his explanation. We believe that the universe is full of these particles . By analogy consider
a room of people , there is a door. Through that door will come a famous person, someone
like Stephen Hawkin. All these people want to speak to the famous person , so they cluster around
causing a blob , and this is how the particle is supposed to get its mass. It interacts with
stuff filling space and that interaction is what leads to the ernergy that is the mass of that particle.
So that means we are going to postulate that the electron, muon, and the tau , the heavy versions
of the same thing, all speak to this new stuff differently. Another analogy for what the HB is.
Somebody comes to the door of this room and they whisper in to the crowd - Stephen Hawkin
is coming, but he isn't really. What happens is a great excitement goes through the room
with a lot of people clustering around - is he with you?. That sort of cluster is the equivalent of the HB.
The idea is that if you can put some energy into the vacuum which we believe is full of these guys
in a sort of static state , you can kind of excite it and produce something that looks like a lump,
and thats what we call the HB. This is a very simplistic model . This is a straw man we go out and
look for. We expect there to be many possible variants of this theory which may explain things in more detail
and we are really hoping to find those.
That is all the background, let me tell you about our kit. This is a pic around Geneva , a 27 Km
round ring and our kit is under the ground about 100m down under houses and fields. This
is our tunnel where we are doing our experiment. Inside the tunnel is a pipe , from which you
pump all the air out of. The particles inside will be kicked by magnets and electric fields
to make them go where you want and faster and faster. Electrons and positrons are very clean
and is what we used before. This is actually a proton collider. Its easier to give protons a
lot of energy than it is electrons. To see whats out there with the maximum amount of energy
you can do a better job with protons. Its less clean, in fact its very messy.
We will try and collide protons together with 10 times higher energy than we've ever
collided them before. We talk about 14 terra electron volts 14TeV thats about the energy
of 14,000 protons. To get them to go where you want you have to use magnets to go in a
circle and put them exactly where you want them to be. There are 1232 superconducting
magnets down there with 36 thousand tons of liquid helium coolant to keep them at superconducting
temperatures. That is about half the world's stock of coolant.
These particles are very small and you have to bring them together and make them hit
each other. You have to worry about the tides, where the moon is . You have to worry about
the geneva underground system . I'm a theorist, not an experimentalist , so I will glow
about these guys. Protons are hydrogen atom nuclei . Are we going to collide 2 protons together
really hard - no we're not. We are taking bunches of about 100 billion protons. When those
cross there will be about 20 collisions every time . Eventually crossing them evey 25 nS
and for about 10 years. 600 million collisions a second. So why are we doing so many.
If you take 2 protons, they are quite big things , made of quarks and most of the time
they just go blurph- the energy is just scattered every where. What you want to look for
is very singular events where a single quark in each of those protons go
head to head. All that energy crammed down into a small space so you can use it to make stuff.
Doesn't happen very often. This is an astonishing data rate and 600 million of them evey
second. Its more data than its possible to build hard drives to store. You have to know
what you are looking for and you don't want to see the blurphs. Actually in the hardware ,
the electronics rejecting the routine events, and only about 1 in 100 events make it to the
next level. Where a very quick computer decides yet again to select or reject. Again only
passes about 1 in 100 on to where you are really dong some serious analysis for whether
that was an interesting event.
You're interested in events where quarks come in and electrons come out, or photons
so light comes out . Things where quarks go in and quarks come out happen all the time
and its hard to get any info out of them . As a theorist it is our job to try and guess all the things
that could possibly happen at the LHC to make sure we wern't throwing away the
crucial informations. At 4 places there are some detectors around the ring. The main 2 are
called Atlas and CMS . Tiny particles , how big does your detector have to be - bigger than
a hose And its not really very subtle stuff. In the middle you have an area around the collision point
there is a grid of wires and as the particles go past they excite the wires and you can tell where they were
and get the tracks. Then after that you try and stop the things with lead. To stop muon things you
need battleship size lumps of lead, thats what the exterior of these detectors are.
Stop them and then how much the metal has heated up gives the energy of the incoming particle.
People compare this with what is going on in a watch by bashing them together at 100 mph
and watching all the bits coming out. All you have is the tracks , the energy and what direction they're
travelling in - the momentum. There is also the LHC-B concerning matter/anti-matter problem.
ALICE is interested in even bigger bangs where collide lead and gold nuclei together.
What are we hoping to find. We've seen one generation, 2 generations , 3 generations, shouldn't there
be a heavier version of the electron and the quarks and thats a possibility. New forces, the higgs is
a new force , there may be others that may show up . We suddenly may discover that we can smash
an electon in two and is made out of things. Matter/antimatter asymmetry - we may see a force
that differentiates between them. Dark matter - astronomers tell you how things interact
gravitationally on a universe scale , 95 percent of the matter out there is not the matter of which we
are made. Its something else and they don't know what it is. Weird and whacky stuff - we might find weird
laws of nature , relativity might stop working or whatever, extra dimensions etc.
Whats been going on , what state is it in.
We started in 2008 , going for a short period of time and unfortunately 100 nano-ohms of resistance
set into a faulty weld between 2 magnets. Because superconducting you should have zero
ohms and the result was an arc even with such a small amout of resistance - even that would have
been ok. Unfortunately the arc punctured one of the liquid helium containers. And a few minutes
later whan the Geneva fire brigade turned up , they were told not to go down there as 30,000
cu m of helium gas in the tunnels, you won't be able to breathe. They were not impressed by that.
Required about a year to fix it. Amusing how they did this. How do you find in a 27Km
tunnel which of the magnets have a problem. Take table tennis balls , put them in , then a big
fan and you can hear the broken ones. In 2009 bag operating and a small beam smashed into
lead, splash events. Then Nov 2009 the first collisions with 900 GeV energy. In Dec upped the
energy and then in March 2010 the first collision at half the eventual design energy.
That is as much as they are able to do at the moment given the getby jobs on the welds.
They will stop in 2013 and do a seriously good job to get up to the 14 TeV. You can do a lot
with this reduced energy and people did not want to wait.
I was at Abingdon for a set of talks - and will summarize.
The machine guys who built the machine and run it , they just produce the beams
and they are very happy. These are extremely dangerous experiments. For example early
on when only 1 percent of the energy possible in the beam , it touched the edge of the pipe
and it produced a scratch several cm long. When they have the full energy in that beam you
would not want to be hit by it. At the end of the day they do beam dumping prior to
switching off, they have a large lump of lead and they bang the beam into it.
If you stand near it you can hear it - a real thud. They stress how dangerous it is and how careful
they have to be. They wanted to do crossings every 25 nS , 3564 bunches going around the 27 Km
at any one time. They started with 50 isolated bunches and now to 1380 . Tht close and they
start talking to each other , impressive at this stage into the project that they are that close to the eventual
of double that. Half the energy and half the number of collisions isn't bad going.
They talk of luminosity , the number times these guys are hit. If you increase the nmber of
bunches you get more collisions. If you increase the number of protons in each bunch
you get more collisions. If you make them go round the tube faster , you get more collisions.
But if you make the bunches bigger , more spread out , you get fewer collisions.
Plot of the peak luminosity , the number of collisions per second against time.
Wobbling along at a low rate during 2010 then suddenly they knew what they were doing
and whacked up by a very large proportion. They had 4 worries.
Electon clouds - the beam going around the track interects with the beam pipe and
kicks out electrons that get i nthe way, like firing the beam through background dust.
So much energy i nthe beam that its tending to heat things up. You're trying to use superconducting
magnets at 2 deg K , if they start to get warm then you have to consider your cooling.
Tyeir biggest problem is UFOs - Unididentified Falling Objects, about 35 times , while running,
something just fell into the beam and knocked it about and they have to stop things fast to make
sure that all that energy does not end up somewhere that they're not expecting . There is an honest
worry what these things are. Probably just dust , any volunterrs to dust out the LHC. Very hard to eliminate
every bit of dust that may be in there.
The amount of radiation that comes off things , from stray hits on the beam pipe etc, tend to produce
radioactive atoms within the wall. That is then heating things up and in experiments when
deliberately hitting beams onto lead. They keep going down there and adding more lead shielding .
They are extremely happy with where they are. A sign of that is that the integrated illuminosity , the total
number of collisions, has reached the 2011 target with 16 weeks still to go. They're still betting on
themselves to increase the intensity and collision rate . They now plan running until the end of 2012
. Some discussion that they may up the energy a luittle bit , but my guess is they won't , too
scared about blowing the thing up again. We are doing good physics at the moment.
In 2013 there will be a long shut down while they really sort out those magnet junctions
so they can go up to the full energy.
What have they found. They are looking for everything you can think off. So a bunch of things .
New quarks - is there a fourth family , producing lots of plots like these . Yellow bands on them
, thats where people expect the data to lie based on what we already know . There is a line
down the middle , which is where you should be , tossing coins in effect so some random variation .
So should lie in the yellow band . The black points are the data , so get excited in one area but that
is not possible as other experiments have shown that there can't be new quarks with such low
energy. So drop that. Then up the top , lines on one side , so few data points little to learn. Elsewhere
they are potentially seeing something. But the majority lie exactly where you want it to be , huge
success for our model of the universe, sad if you want it to break.
Atlas excludes quarks with mass less than 1290 times the proton mass , CMS is excluding
those above 1140 times the proton mass. They are beating the Tevatron limits which was 870 times
the proton mass. Pushing the searches but unfortunately as yet have not found anything yet.
But they will push these plots out considerably higher , so some good chance yet.
New forces. Quark and quark collisions , all that energy going into perhaps a photon,
associated with electricity and magnetism. There are othe rpossibilities , you could find a new
version of the photon a new way to pump energy into something.
Again you want to see youself in the yellow band , the black line is jiggling around
in there up to the point they run out of datapoints, there is no deviation from what you already
know. They pushed up the limits on a new photon, it cannot have a mass less than
1800 to 1900 times the proton mass. Using the Standard Model, applying it the data and they
have seen agreement, shame they didn't find anything.
Lets look for the HB something that should be out there , or something like it to explain
the mass of all these particles . 2 things you have to do - make a Higgs , photon coming together
and fusing to make a Higgs in a collision or some quarks emitting some force carrying particles
that then give a Higgs. Lots of ways to make it so you have to calculate which of these is the best rate
, add up the results and so the heavier the Higgs is the less likely you are to make it ,
of course it takes more energy and fewer events are going to have enough head to make it.
Then you have to fold that in with how it will decay. Its supposed to give things mass , means it inteacts
mostly with hte heaviest things. So it likes to decay into the top quark, sometinmes not enough energy
to do that. So the bottom quark is the next most energetic thing that it likes to go for.
Then the W and Z , equivalent to the photon but for the weak nuclear force and it quite
likes to go into those guys. There are a lot of ways this can decay, you're looking at lots
of different channels, and you're not expecting to see a vast number of events in any one.
Whan you combine those channels all together you hope that you will have a few more events
than you're expecting , and then be able to say we're seeing this HB. The most distinctive
signature is actually the Higgs can decay to 2 photons and that is really easy to see.
Lots of protons come in, lots of stuff with quarks come out and coming out amidst of it
all are 2 beautiful photon tracks which adds up the energy of the HB. As yet no one has sen
this. More exclusion plots , so again , where we expect to be the black dotted line in the
middle of the prediction. The data wobbles around under it. If abopve the red line you have
not enough events , you haven't seen any and you didn't expect any . Here we can't yet
put limits but between 440 down to 130 times the proton mass, they have not seen anything
that looks like the HB. There are some people excited about this , there a re a small number
of events above what they are expecting in the low mass limit around 120 to 130, so
maybe about to find something there. Two more experimets and similar exclusions.
Either its very heavy or its just light and in either case we haven't seen it.
When its light , its decay channels are harder to see, why peculiarly ???.
Something else is super-symmetry , an ambitious proposal put forward by theorists who
wanted to double the particle spectrum again, saying that every particle we know about should
have a partner , with a different amount of spin . Like little tops they spin on their axes.
This theory says there are millions of things to look for and is a great way of checking that you're
looking in lots of different channels, for all the possibles. This is their exclusion plot for
the partners of the quarks , against partners of things like the photon . If these things exist
then they must have a mass greater than 1000 times proton mass , but no sign in this
large area .
Overview of the conclusions.
Particle physics has a very concise and precise theory of nature, I hope it breaks soon
as I want to find something new. But it is impressive how our Standard Model has gone
into a totally new energy regime and is still doing a super job.
A lot of things clearly we do not understand , why are these different particles looking the
samre but having different masses. Why is there matter and not anti-matter in the
universe. We are still hopeful that the LHC will provide answers . There is a No-Loose Theorem
there are some experiments where you can take the W particles , scatter them together ,
our current understanding of the universe says the probabality that they interact goes
greater than 1 - and that is rubbish. We know the theory that we have at the moment must break
in this machine, we muiust see something new. The simplest thing that we could find is the HB.
We must find something, even in a few years if it really tries to hide just in that process.
For the machine guys, they are delighted , running beautifully, ahead of where they were
hoping to be this year. So plenty of opportunity to find lots of funny stuff.
Q: Whats the reason for trying to ??? super-symmetry?
One of the reasons we don't beleive the simplest Higgs model is that it is kind of
sick . In Quantum Theory it interacts with all sorts of other particles and what those interactions
tend to do is to make its mass get bigger and bigger. No one can make out its mass at a level
where we can find it at the LHC and do the job its supposed to do. One way to stop all thos e
effects coming in, is to have ? that enter into that calculation with a minus sign. So the things that tend
to make it heavy just don't happen because there is a cancellation. That is the motifiation to make this
Higgs theory make any sense. Its also getting awkward as you needed it to be light , for those cancellations
to set in early. So that is probably not going to be an explanation.
Q: Could there be a family of Higgs particles like the other generations?
Absolutely, in fact having one is somewhat unnatural. Its more natural to have one associated
with the top-quark and one associated with the bottom-quark . So there are 2 Higgs doublets models.
You can imagine having a separate Higgs that speaks to every particle, that is why they have different
masses . All of these things are possible . You just want to find something so you can start sheeding
Q: How do you ? ineract a Higgs, they don't emit with or absorb a H.
The idea is that the universe is filled with this static background of these things. Like
going through treacle, these particles just keep banging off them and the interaction energy
is what gives them mass. Yes they could emit H , but they don't in day to day life as the H
is very heavy. They don't have enough energy to be able to do it. Give them enough energy and they
would just chuck these things off .
Q: The speed of light, are you with the crowd that there is just a mistake somewhere, the details will
reveal why they are wrong?
Concerning recent experiments and the speed of light. I don't think there is a scientist on the planet who would
not bet that that is the case. But that is ot the point , what we would love is something that really does undo
the laws that we know. That is what people like me just dream of. Its hard to believe as it would mean
relativity is wrong and relativity is unbe,ievably well tested. Every time you use a satellite you are testing relativity
because without relativity you would not get a signal . So is it possible that relativity is just broken in
the neutrino sector - maybe. In Quantum Theory everything talks to everything else and so that breaking
of relativity there would feed into what we know about electrons and so on . So it seems unlikely.
Added to that there is a lot of theorists try t oexplain it and nobody really can . You can have outlandish
ideas - we live on the surface of this book , the book lives in higher dimensions , CERN is here
and the detector is here. Then it just so happens that neutrinos can convert into something
that just goes this way , like the light, but goes across the gap and it just so hapens that that is
just the right distance for them to go into something else and come back to being neutrinos then
you could perhaps explain it. That is an idea of the outlandishly weird things you have to do to
explain it. It would be brilliant if that was true of course , but extraordinary claims need
extraordinary backing. So until a lot of other experiments come along showingg the same thing most people don't bet against it.
Q: Could you say briefly how the measurement of that speedy neutrino was carried out as it
may give us some idea whether we can trust it or not. ? and what they were aiming to do , what they wanted to find,
prove or disprove with htat particular move.?
The experiment was all about one species of neutrino chaging into another. This is called neutrino
oscillations , known to happen. The sort of neutrinos made in the sun change into other sorts
of neutrinos . 30 years of history of people discovering this. They are just looking for different examples
for one guy converting into another guy. I'm afraid I don't know what goes into their measurements.
Somehow they have measured the distance and time and I just don't know. There have been papers
whether they've taken into account rotation of the Earth properly and things like that. There are
real issues in there
Q: What would happen if they repeated the experiment at a six month interval? I know it was done
3 years ago but if it was done in January could they do it in August when the earth was facing the
othe rway in its orbit?
I don't know if they could do that on the ground. That tunnel has 3 experiments in there all are
reporting observations that are at odds with other experiments or expectations. That makes me
nervous as well. The reason I brought that up is the other experments are specifically looking for dark matter. The
way they do it , they look for an annual variation in the number of events in the detector.
What they are hoping is that the earth's motion relative to the dark matter will show up as an
annual modulation . There are a lot of things that are annually modulated like the temperature,
and those sorts of things - hard to do those sorts of experiments. 2 experiments in that tunnel that
are predicting things that are already ruled out by other experiments so so you wonder
what is in the mindset there.
Q: Isn't there some result/s that do show an annual variation ?
The 2 experiments are called DARMA and the other I cannot remember the name of. They have a
detector , looking for flashes of light hoping are due to dark matter and looking for annual
variation. Due to differing interactions due to relative speed differences of the dark matter
and the earth. 2 experiments have had a signal and both disagree with each other and they
disagree with others that show it is impossible to be a detection there at that point in
parameter space - go figure! They may be right and the other guys wrong but at this point you
just have to wait for other experiments to come in.
Q: You showed a diagram earlier on of a positron and electron colliding creating a photon,. that
photon then changed to other particles. It seemed strange that a photon could change to
The photons that you're used to just don't have enough energy. At high energies light does
this all the time , you have to have enough energy in there to make the final products.
Doesn't happen in day to day life. How did we first encounter all of this. If you scatter 2
electrons off one another, the simplest way they interact is to change the smallest lump of energy
which is a photon. So you have these 2 guys and a photon goes between them , scatter off each other.
If you do that you get the wrong answer at about the 1 percent level. The reason is that you have to
include that from the fact that from time to time that photon will become an electon and a positron and then
reanhilate into a photon. If you take that into account you get the right answer to 10 decimal
places or so. These effects are really well understood.
Q: Does that mean a photon has a ? ?
At high enough energies they can decay into other particles . There is some kinematic things there ,
a free photon travelling in space cannot suddenly become an electron and a positron because that
does not conserve energy and momentum. If they interact with something in space then it can
happen. In quantum theory yhese things can happen all the time. If you have a laser beam in
empty space , it won't happen.
Q: They do not spontaneously decay, there does need to be an event that causes this to happen?
Thts basically correct, There is this quantum theory that I've not told you about, A basic
concept there is that energy is not conserved over very short periods of time. The sort of time for light
to travel across an atom. Over those periods of time you are allowed to muck about with Newtonian
physics ideas. In those short times a photon can become an electron and a positron but
it will go back to being a photon in the end.
Q: Stephen Hawkin has a bet that H won't be found ? Why does he think it won't be found, does he have
another theory for mass?
I think that one is just him being argumentative. Something has to exist. There are things we can
do at the LHC where we do not know the answer , something has to give anf the H is the simplest thing
that anyone has written down that explains it. There are many variants of that theory. The HB may
not be a fundamental particle but may be made out of things and you can make theorums
of that sort. So I don't even know what he means by doesn't exist.
Q: We need something to ensure that the photon and the W/Z Bosons have different ?, different
masses than the HB does. ?
Q: Is there any sort of idea of th estatus of this idea of ?matter. Matter spins only one way.
there is a peculiar thing about the weak nuclear force , there are electrons like little tops and
some guys spin this way and some that way. Peculiarly only the guys that spin like a left handed
guy , only interact by the weak nuclear force. That means the left-handed/ right-handed symetry
of th euniverse is broken. No good explanation again , we just observe it to be true. I think there is a
friend of yours who has a theory that there is an entire copy of our universe . Where its exactly the
same and people are sat around in a pub and going that why is it the right-handed guys are
feeling this version of the weak force. But at high enough energies these 2 universes will talk
to each other. I think Robert has a theory that some of the impacts by things from outer space
that have anhilated bits of the earth might be a collision from matter from this other world.
All thes ethings are possible and we're looking for thjem , new forces , new particles but
not found them, as yet, but they could be there.
Q: One of the things that get him is that the scientific establishment favours certain experiments .
He as experiments he would like done and for instance woul the LHC have any input into
his particulatr theories?
It could do. You could imagine an infinite number of other universes , living in the same
space as us but cannot interact as the forces are extremely weak. It could be at the LHC
when you hav3e enough energy in there , you start to see those new interactions ,
you start to speak to that dark matter. There is an infinite number of possibilities, what you want
to do is find something. But another universe that restores left and right handedness makes sense
but no evidence yet
Q:Assuming you get the power level of th eLHC up to 14TeV is there any plans for a
very large hadron collider on the drawing board? a ring that goes right round th eworld?
What comes beyond. There are likely to be upgrades to the LHC . A very serious proposal
after that is a very large linear collider which will be an electron-positron collider , that is
much cleaner environment. None of the quark stuff from proton collisions and can do more
precise measurements. We can't start planning that until we know what the LHC finds.
If the money is out there. Beyond that there is some really fantastic ideas. You can collide
muons together which is much more energetically favourable , you loose energy less than
electrons so you don't have to put so much in to accelerate them to high energies.
The problem is that muons only live for (remembered ) 10^-7 seconds , so you have to make
the things, make them go at the speed of light then relativity says time is dilated and they
live for a long time. Really difficult to make them , accelerate them, in the numbers that you
need to do a muan collider . If I had 50 billion pounds thats what I would spend
my money on as that would take us an order of magnitude beyond the LHC. There are people working
on it and the technology may develop , probably not in my lifetime though.
Beyond that there are some people doing some fantastic accelerator research . One of the problems,
you want to accelerate these charged particles and you use an electric field to do that but
if you take a very strong electric field and put it on this table then all th eelectons and
protons want to be over there and the whole thing blows apart. So one of the restrictions
is building stuff with big electric fields in. One way around that is to have your stuff to do the
acceleration, already to be ionised. The electrons and the nuclei to be stripped apart and a gas
of these whizzing around. In those materials you can set up extremely powerful electric fields.
Some guys in Stamford, USA are taking the 60s accelerator that looked at protons. It is 3Km long
and on one end they put 1 metre of plasma and they punched a beam through it. Some of
the particles in that beam had their energy doubled in that metre because of the electric
fields you can set up in th e plasma. Twice the gain for just a metre of stuff. The problem
with that technology is that you need a lot of these particles and no one has managed to get the
number that you need out of them. Somone may make the advance and so make much
shorter machines and then we're in business again.
Is the Tevitron closing because of the LHC or just that it is the end of its lifetime.
These machines have an energy limit, whatever it is . the Tevitron about a factor of 10
less than the LHC , it was always envisaged it would stop when the LHC took over.
The LHC has had a long time getting the funding an d the building of it. The Tevitron
was run hard trying to steal discoveries from the LHC , basically reached the point that
they are bust.
If the LHC doesn't find anything new will Peter Higgs get sent the bill?
There are these experiments where we are convinced we have got to see something.
Whether it will be decisive , I don't know. From my point of view if we don't
find the H and we don't find anything else , I'm pretty interested in that as a result.
Its not a great one to sell to the politiciuans. Floating around under this is the moiney.
This thing is costing something like 5 or 7 billion pounds . Putting that in perspective, Sky
TV paid 10 billion to air premiership football for 3 years. The film Titanic, people around
the world spend a billion pounds on seeing that film. Everyone in the EU has paid the price of
cup of coffee to do this experiment. I think that is a price worth paying to find out
how the universe works.
What sort of practical benefits , in terms of new technologies and that sort of thing can you see
coming from running thes eexperiments?
What is certaiinly true you will not have an LHC in your kitchen. Doing this frontier stuff
is really driving frontier technologies. Your forcing the firms that make superconducting magnets ,
the hardware to process that much data so quickly. You are promoting these frontiers.
Going back to LEP, the biggest thing to come out of it was the internet. If we just had a small
tax on Amazon's profits we would be in business. Things spin out of this because we
are pushing computing and hardware. Particle accelerators from 50 years ago ar ein
hospitals curing cancer. You never know what the uses will be.
Do you have a defense for the accusation that unproven or unsubstantiated theories are driving
the direction of research? Is there any independent evidence for H for example?
That is insulting to the experimentalists. They don't listen to what people like me say.
They simply go into this with a new energy regime, we've never been here before -
look for everything. Theorists like me go in looking for things they are not looking for is damn hard.
What is I think certainly true is that we have been and still in an era where the theorists are ahead
of experiments. Our best model just works when they switch on the machine. What does that mean
the theorists are doing. We are exploring the possibilities of what might yey come, we explore
the mathematical space of what we ar edoing, that is what we ought to be doing. Yet we
chuck up weird and wonderful ideas , the reason we are doing that is to challenge the
experimentalists sayiong - don't miss anything.
Wasn't that considered pseudo science just a few years ago?
The Higgs particle has 4 bits to it , 4 degrees of freedom, we have found 3 of them .
Theyare part of th eW & Z particles that we have found
No we've observed them . You're certainly right that theorists are speculating what is
the completion of that theory. But thats our job , we don't want to miss things. There is no
theorist on the planet whao wouldn't be in heaven if they show that everything that
we've done is wrong. We would love that. We want to go back to the 60s era when
experiments had thousands of particles that we knew not where they had come from. We would love that.
We want nature to teach us. In the gap where we are ahead of th eexperimtors we do what we can
to explore the mathematical structures .
You said the people in Abingdon said it was dangerous , how dangerous is this business ,
what is the casualty rate?
I think a couple of people did die in the tunnel construtions . Its not dangerous if your not in
the tunnels. Its dangerous in the sense that you could fill the tunnels with helium gas that
you can't breathe. I don't think any personel are in any danger.
You said that half the world's stock of helium . When ther ewas the leak, did they manage
to recover it or did 1/4 of the world stock go back into the atmosphere.?
It was just 1 or 2 of the 1322 or whatever magnets that had the problem of helium loss and it
was lost into the atmosphere.
Helium is a finite resource and we need it in hospitals ???
What we need is room temperature supeconductors, that many of my colleagues are
working on , if we could make it work then we would not have to worry about helium use.
There are real problems with taking the LHC technology and just saying lets do it
bigger. Thats always been the case , you could never envisage making the next one
10 times bigger without some significant improvements in technology. We're some
of the guys pushing this technology, one of the benefits of doing this.
At one time electrons and protons had charges based on 1 , everything semed in balance.
Now you've been knocking protons about and quarks seem to be based on 2/3
is there some component of an electon that may be based on 1/3 or 2/3 ? It
doesn't sem to balance now.
One can imagine theories where the elctron is composite, there is some theoretical
issues with that. If you crush things down int a very small space , they tend to become very
masive . In a sense that is how you understrand proton mass , crushing these quarks
into a space. Its hard to understand but is not impossible. There are theoretical examples
of composite particles that are mass-less or whatever , so yes it could happen - great
if it did. I don't believe it in a purely functional sense . We haven't broken them
apart yet so we have to treat them as being fundamental. But the moment I go to
higher energy and bash them they could fall apart. I'd love that to happen but as of the
moment not seen.
You keep mentioning energy, there must be huge amounts of energy required to power this ,
wher edoes it all come from?
There ar erestrictions, certain times in the winter CERN does not run because the electricity costs too much.
They don't have their own power station , they come off the grid. It is a significant addition
to Geneva's power usage. Not restricted to night-time oly use say.
This spin , that is just a name like colour? or have they got spin because it you look at it from the
top it is one way but the other from veiwing from the bottom. ?
They have angular momentum , the same stuff that a rotating ball has . You could imagine a lot
of these guys spinning , you could transfer some of that spin to a ball. You can't see these things
so how you choose to see them is an issue. They are point particles but are they , if not then they could
have real spin moving around. We don't know , but we do know they do have angular momentum .
The Higgs field is all pervasive and is kind of reminisent of the aether. Is that a sensible analogy. ?
and where does that field come from and what justification is there for a field?Before relativity people were imagining
that light was like water waves , so there must be something filling the space between us and the sun
for example, that was waving about for light to get to us. In the end that went away , we now think
of light being to do with electric and magnetic fields . There is some similarity to the idea that we
are now filling the whole of space again with something. We are doing it in a way that is compatible
with relativity , thats the bit I'm not sure how to say in this environ. Its quite a bold statement but
not as bold as you may think. We understand most of the mass in the universe
of protons and neutrons and that is generated by the strong nuclear force . In Quantum mechanics
energy is not conserved over short periods of time and energy can be used to make particles E=mc^2.
So what happens over short periods of time particles come in and out of existense i nthe
universe. The strong nuclear force is unbeleivably strong and what happens is if you create
a quark and an anti-quark those guys start interacting so strongly that the energy is less than
it took to create them. So free-lunch, and creates quarks and the space between us is full
of quarks. Your body is full of particles that essentially are massless but they , the protons and
neutrons in your body find it hard moving through that quarky muck and its that that gives them
their mass and why you are able to sit in this room and not disperse into the far ends of the
galaxy. We already beleive strongly that the universe is full of stuff and we are just adding
stuff to explain masses that we don't understand. It is speculation, we could
be wrong, that is why we are doing the experiments. We are proper scientists we do speculate but
in the end we are tied to these experiments and we want to fnd something.
The stuff, the mass , the mass-energy equivalent, where does the energy come from ? is it just there
in the background everywhere .
The least energetic state of the universe is to have it there because of the interactions of the strong force .
If particles and anti-particles are generated randomly , where does that energy come from ?
These questions probably come back to when the universe was created, wht wa sthe net energy state.
A tricky question that requires that you understand the origins of th euniverse. I'm not going there
tonight -cosmologist theorising. We just state this is what the universe is full of, these
are the theories that describe it, what is the lowest energy state - and the universe is like the ball
the rolls down a hill.
Where does string theory come in and what is the situation with the LHC helping that
One of the big problems is that in order to make gravity between 2 electrons as strong as the othe r
forces between 2 electrons, we would have to give those 2 electrons an enormous amout of energy.
Hundreds of thousands mor eenergy than the LHC can put out. We have very little experimental
data on gravity below about 1 mm in length. Put any 2 things closer together than 1mm the electric
forces overpower gravity and its very hard to measure. So we know very little about gravity.
People try to put gravity together into quantum theory that work at the LHC , it didn't work.
you get rubbish that is th eanswer. Some clever guys came up with a theory that
things are not point particles but little extended bits of string , it works. It is a theory of quantum
gravity , that does not mean it is The Theory of Quantum Gravity that works in our world. So
what you want to do is test it but I just said it is basically impossible. So in string theory people
have leant over backwards to make themseves testable. There are versions of that where you could
suddenly discover tha tgravity was important at the LHC. There is no reason for it to be true but it
could be true. So string theory has nothing to say about the LHC
but if we are lucky the LHC could have something to say about string theory. Most likely it wnn't ,
thats the extra dimensions idea. Gravity spreads out through space and it dilutes by an inverse square
law . If you have more dimensions it gets weaker stronger . So if making gravity stronger by making
it live in extra dimensions and that comes back to whare I was saying before. We live on the surface
of this piece of paper but gravity knows about coming out this way. So gravity would look
weaker to us than it really is. It could be that you can set up theories like that , where the LHC
suddenly becomes as strong as it really and suddenly ?. Unlikely but it could happen.
Things in space, processes like black holes , must have interesting quantum phenomena
within them , do you ever think think we will have technology to allow us to examine these quantum processes?
Its hard to beleive we ever will observe quantum effectes in black holes in other galaxies. There are
some clever things people are doing. You can make analogues of black holes in the lab. There
are some materials , like where light changes its speed in different materials. These materials can
really slow light down massively to a metre a second or so. People dream of using ,
within thos ematerials something to make a version of a black hole in that material. Then you
might be able to start examining the quantum properties of them. 5 or 10 years ago there was
a bunch of articles about this concept but I'm not aware anyone has managed it. Maybe a
50 year tiescale for such systems.
Is it a case of mass isn't an inherent thing, we need something like HB to explain it ?
We have an extremely good theory of the photon and that theory absolutely predicts that the
photon is massless . It correctly predicts the properties of the elctron to 11 decimal places -
extremely good physics. When we discovered other forces we took that as out prototype
and we applied it to those other forces , particularly the weak nuclear force . Its immediate
prediction would be the W and Z particles , the equivalent of the photon for that force should be
mass-less. We found that they are not but many aspects of what we took across have been tested
and have been correct. So we need an add-on that in this case the particles can have mass.
And thats what the H is. We are doing tests at the 1 percent level . There is a beautiful structure
there, from LEP, we've gone to a higher energy regime , new data nad we are right on the money. So we really do
believe that the theoretical structure is right but you need an add on for the non mass-less situation.
I think its very robust . These guys feel a force and these guys don't. Its about how these 2 things are combined
by mass into a theory of how this guy feels a force and this one doesn't. somehow they
o need a HB to do that . There is a strong understanding that you cannot understand any
of the maths without this force.
I was at a lecture on relativity theory and I challenged him to derrive the ? to be massless from the 2
assumptions from special relativity and he said it was just another assumption added on. You've
taken the mass away by an assumption and now you're adding it back. ?
No your not. The theory of the photon makes an unbelievable number of predictions
and some of them are tested to 11 decimal places. Its an astonishing theory, its the best physical
theory that we've had. Relativity is now part of the bigger structure which explains where
the photon comes from - its called gauge invariance . Its our guiding principle, we beleive it
because basically we are being forced to by the univrse. All this vast number of measurements,
anything to do with electric charge forces us to this conclusion. If its not true its not true
to a very tiny amount. And that is hard to explain.
You add one thing and then you try to derrive 10 things and you go and test those 10 things.
If for every measurement you make you add an assumption , you're not doing science.
We make far more predictions than we have assumptions. Every seminar I go to
I'm asked that question. How many assumptions are you making, how many predictions
are you making.
??? (too quiet) ?
If you're travelling at the speed of light is supposed to be still. A student asked me this recently
and I said I'd go back and think about it. I think I'm reight that photons see light as static.
I would like to think about it from the photon's point of view as well, its very confusing.
Relativity is a theory that is very un-intuitive , you can spend a lot of your time being confused.
When light enters a lens , it slows down and when it comes out the other side it speeds up again ,
if it had mass would it have to store the energy somewhere so it got it back again when it
came out again. ?
How do you give a photon mass and the answer is a supercondutor - a material in which a
photon has some mass. Its there that we nicked the Higgs theory from , it is the theory
of superconductance . You can do this . You have a photon coming along it has some
energy, it enters the superconductor , some of its energy has to become its mass . It doesn't
penetrate it basically comes to a halt. The classic thing is that magnetic fields are expelled
from a superconductor and that is because the photon has a mass . The photon
rapidly fades away and stops existing and gives its energy to the Higgs background
or to the superconducting background.
Then it has to come back in again ?
If its a superconductor it won't come out the other side . In a lens it isn't that the photons are
getting a mass its just being absorbed and emitted. The slowing down is just an absorbtion and
re-emission process rather than having a mass.
Does the Higgs mass theory help us in where the equivalence comes from , inertial and
Thats all general relativity. Something that naturally emerges from general relativity.
It is gravity coupled to energy rather than mass , E=mc^2 intrinsic . There is a problem with
general rel'ativity getting to talk to these theories and gravity.
With the hardware filters that knock out 99 percent of the information coming to it before its
passed on . If someone suspects we may be throwing the baby out with the bath-water
can people go in there and change the hardware?
Basically no, its extremely difficult. Theorists and experimentalists have spent 25
years thinking about being careful not to chuck away. Most of what you are chucking
away, you could not hope to get any info out of anyway. Protons in and lots of quarky
type stuff coming out . Even if there was a signal in there, there would be so many events
that looked like the signal from random scattering protons, that you would
not be able to see the signal through this background . You are just looking at events
where something comes in and something special comes out , something that is
really distinct. Even some of that will happen in proton-proton collisions , maybe
powerful jet-like structures , out of the quarks. But you can concentrate on some event
for some reason. I think they've domne a pretty good job looking for the stuff that
is potentially interesting.
They did that with the Voyager spacecraft, went out looking at the planets and then in the
outer planets it was the moons that were most interesting rather than the planets .
They got all that wrong despite all the effort they put into it. ?
Absolutely. No one is in any doubt that something unexpected could come along ,
what we would be most excted about. What we try to do , all these theories that theorists
have come up with , part of their job is to suggest things that you may see . The experimentalists
sit there , we have this detector, what could we see. They are looking for things say 5 minutes
after the collision , looking for everything they can possibly think of, that might be a signal
for something. They started building some of this hardware 10 years ago .
Are they trying to collide other things, say various nuclei?
The ALICE experiment colliding lead and gold nuclei , they have done some. If you have
2 electrons and they are near each other , they interact strongly. You send that one up
over there . There is a 1/r^2 and the other one stops caringg, its too far away and I don't
really know about it. Quarks are completely the opposite , 2 quarks on top of each
othe rdon't interact , they start to separate , they interact more and more. Its called
confinement. If you go into a proton , grab a quark and try and pull it out , eventually you have to give
up and it goes back in, You can never end up with a quark in your hand. So people have imagined,
if only you could crush protons and neutrons close enough the quarks would be so close to each
other , they'd stop interacting, stop being protons and neutrons and become a gas of free quarks.
That is called the quark-gluon plasma, the gluons are the equivalent of the photon for
the strong force. Alice is about that taking 2 nuclei of atoms and crushing them so hard
that they form that other form of matter.
Why do we need to postulate the Higgs field, the HB, to explain mass? as we don't need
to explain charge?
It comes down to gauge invariance where we have a theoretical thing we bring to bear to create
a theory which we then use to make these predictions. That theoretical beast that is coming
down is saying , this is a special problem, you need to have an answer for why some of my
predictions aren't right. Thats the hifallutin theory end but there is also simply this thing that if
I scatter these W particles off one another , I get nonsense as the answer unless there is
something else there. The H is the simplest thing you can put in there that then makes it
make sense. Special in the sense of an experiment you can imagine doing that is unique
and can rely on. Why is the electron charge the exact opposite of the proton charge.
It really is, its unbelievable , and all sorts of GUT to explain it. But they predict things at enormous
energies which we can't probe so you're not hearing about it. The mass generation is
here and now , we can do an experiment on that and probe it.
Do you see a future where we can take control of whether something has mass or not be
manipulating the Higgs field? and then implications of getting things into space.
On the scale of the size of the nucleus , you might be able to play this game but
the energy involved in converting a real area of space is energy that you cannot conceive,
way beyond anything that fusion could do. Fusion is about the remnants of nuclear forces
insid a nucleus. The strong nuclear force that holds quarks together is thousands of
time stronger . On a real scale , I think no . Quantum theory does all these things iself
and we know that we don't see things behaving as though they are massless rockets
at all , that it is just impossible. Limited to very small scale and very high energies. Only
in the big bang.
A year or two ago there wa sconcern in the press that firing up the Star Chamber
and create a black hole then the end of the world. Are you still hopeful of creating
any black holes?
Comes back to the people who were trying to make gravity relevant at the LHC. Its an extremely
long shot. No reason to believe it is true though it may be. If it were true and you create a
black hole , would it then eat the universe. No, the reason is that although at the LHC we are
doing things for the first time, out htere in the universe , where there are black holes
producing highly energetic particles and so on. These sorts of high energy collissions have occured many
times over , the LHC has been done thousands of times over . anything catastrophic on a
universal scale is certainly ruled out. A black hole is simply somewhere that the amount
of energy in some region of space is so great that its gravitational attraction on a photon
stops the photon escaping. If gravity came much stronger than you might niaively think
at the LHC then the energy of the collision would be enough to cause that. The basic
argument about any of these things being worrying is that the universe is doing these things all the
time and there is no evidence for catastrophes. I compare it to cavemen , caveman and
his wife sat around in a cold cave. And the caveman says he is going to bang these rocks
together and make fire. And his wife say you'd better not do that or you might burn the
planet down. But you know thats not right because you've seen a lightening strike cause a fire
and its not burnt the planet down.
If we ramp up energies in things like the LHC would we then have enough energy to create
We are way way off that . We believe what Stephen Hawkin tells us that from quantum
effects that black holes actually evaporate , the smaller they are, the quicker they evaporate.
So very small black holes wouldn't last very long.
14 Nov 2011
The "Sound of Music", exploring the physics of various musical
instruments and showing how musicality is determined by their physical properties.
A talk with powerpoint and demos including video-projected
oscilloscope/spectrum analyser, by Robert Stansbridge, Teaching Fellow at
the Institute of Sound and Vibration Research, University of Southampton .
3/4 hour talk, 1 1/4 hour Q&A, 40 people
A lot of the content is musical and also live graphical display , only transcript here.
I've lots of toys here, I will do a selection of them. Lets start with the voice - a
musical instrument you can all play. The human ear isn't designed for listening to music.
It is designed to gather information , warnings , natural dangers and to communicate by speach
and so on. From a young age we have baby talk , a lot of the communication is from the pitch,
rising and falling and the rythm. Marching music, working songs , are communication of
sorts, to do with social organisation between humans. Our ears are tuned to that sort of
thing. So when we listen to music we are absorbing the information that is carried i nthe
rythm, pitch and harmonies etc. If I whisper , I can communicate without using any
pitch whatsoever. I cannot whisper and convey pitch variation. Because I'm not using
my vocal cords . The vocal cords are what gives the voice pitch. Where does the vibration caome from
, what is the source of the sound. Think it , open your mouth and out it comes.
The cords work like this , , simulating vocal cords , the flap cut off a rubber balloon.
You take air from your lungs , the pressure builds and eventually it forces
the vocal cords apart . A puff of air comes out, the pressure drops, the cords slam shut
and then builds up again. Then the vowel sounds from shaping the mouth.
Video graphical tracing with , in lower trace, time along the horizontal and sound
pressure along the vertical then at the top, a spectum analysis with low frequency
to the left and high frequency to the right.
Lots of frequencies being generated by this ballon flap compared to whistling
which is a fairly pure sine wave. We see 2 peaks, the main one I am trying to make and another one
I'm trying not to make. As I go up in pitch it moves across. If I open my mouth I get 4
peaks. Making an "e" sound gives a different spectrum . My throat is generating a lot
of noises and then my mouth is suppressing some frequencies and amplifying others.
Another toy a tiny mouth sized electronic sound generator, generating lots of frequencies small
enough to place in the mouth and then moving my mouth shape changes to sound
emerging. That is what musical instruments do .
You can build a mathematical model of the vocal tract . A high note then tension the
vocal cords. A low note, let them go slack. Pythagoras had some ideas on music .
Metal workers bashing metal . He noticed that when hitting with a big hammer
made a booming gong sound and when doing delicate work , deduced it was the
size of the hammer that made the difference. Luckily a simple experinment showed that
it was the size of the piece of metal. As in a xylophone and a hammer. Same hammer, different
metal, different sound. Very pure sine wave sound, just a single peak in the spectrum, due to the physics but why.
Why should the little ones be higher frequency than the big pieces of metal. An
animated graphic. When you bash
it with a hammer you compress the molecules in the lump of steel , each molecule
pushing against its neighbour , pushing down and out so the bar will bend. The force moves
out to the outside , the molecules cannot fly off, they return to there rest posistion ,
but overshoot. At thge supports they cannot move and so tend to twist the structure.
The position of these supports is not just anywhere. There is a point where the
suports are where it hardly moves at all. If I bash a xylophone key and touch it in the
middle it will stop. It can feel like an electric shock when you touch it because of
so much energy in th evibration. If I touch the ends it dies. If I touch it where the supports
are, it carries on ringing, called the nodes. The other points are called the antinodes.
If I bash a key with the hard end of the hammer , it gives a chaotic ring. Vibrations going
in all directions but most are killed by the rubber supports. Only one vibration is not
killed and its the one that creates nodes at those positions. So the pitch is decided
by the speed of sound in the metal and the size of the bars . The speed of the sound in
the metal is constant for that metal.
Moving to strings - Mersenne, the formula for the relationship between the length of a
string L. T is the tesion and mu is the mass per unit length. Long string gives a low
note and short one, high note. Altering the tension will also change the pitch - something
you just accept. The bass strings have brass wrapped around them to make them heavier
to increase mu.
Long rope simulating a guitar string , setting up a non-flexible boundary condition,
ie held by hand at one end rigidly (nut end). The other end pulled tight (bridge) and cross-wise pulled
away from the natural line , like a plectrum, and released. The peak travels along the string ,
hitting the immovable object at the other end and reflected back and go round again.
Tight rope/string and this peak travels fast or slack rope then slower.
The pitch is then given by the time to make this round path. When the vibration hits the
bridge it passes the sound to the body of the guitar. If the string was heavier it would
go more slowly. If we shorten the string it goes faster as not so far to go.
We have to make a compromise. To make that wave going round and round , lots of
sustain , we don't want to loose anything at the bridge, so solid at both ends and we don't
loose any energy. But no movement of the bridge means we won't hear any sound.
The second requirement to make a guitar sound, the soundboard. When that force
hits the bridge it forces downwards and makes the body vibrate. Diagrams of laser
interferometry of a guitar body subjected to different precise frequencies and
different patterns. At low frequencies the main part of the body will be like a
big drum. At the smaller end of the body at both sides then like 2 smaller
drums. With a moved string , the air just moves from one side around to the other
side, moving around the string and not moving outwards , like an electric
guitar not plugged into an amplifier. So not efficient. What you want is the body
to move a lot and so a big sound and the sound cannot come around it fast enough
to suppress it and the wavefront moves outward so you can hear it.
Why the box and not just a plate . The box does 2 things - a Helmhotz resonator
like an empty milk bottle and blowing over the top. The air inside is in 2 parts
the bit in the neck is acting as a mass and the air in the body acting as a spring.
Blowing over the top, the air swirls around like when you open a car window and there
is a swish noise because the air is going around in circles. Blowing over the top
some wants to carry on and some wants to stay so twists the air.
Spinning air is what makes the air in the neck bounce up and down and bouncing on
a spring which is the air inside the bottle. A pressure wave travelling through .
So with a guitar body a mass of air in the sound hole and a spring of the air inside
the body. Also acting like a set of bellows because the front is going backwards
and forwards and squeezing the air like bellows. Puting the microphone in
different close up posistions one gives the bottom end of frequencies and other position
it is more even across the spectrum. So if recording and a mic placed at the sound
hole will sound boomy . High frequencies if th emic is placed near the strings.
An audience does not hear the same sound as the guitarist , in fact they get a better
sound than the guitarist. If you play a guitar and place your ear at different parts
of the guitar you can hear how different parts radiate different parts of the spectrum.
So distant miking is going to get a better sound but you pick up extraneous sounds
as well. and the acoustics of the room. If close-micing then the room reflections are
Musicality. In something like a flute the puffs of air are making a swirling round ,
or this penny whistle. About 30cm long and the speed of sound about 340metres per second
and distance covered from open hole along the barrel, to the end, some is transmitted , some comes
back, hits the original end and bounces back and that to and fro determines
the pitch . Blowing hard rather than soft gives a different pattern.
Back to guitar strings. Playing E soft low note in one position played and twang
in another position. Putting my finger on th e12th fret, half way along the string, it
makes a hiugher note. Seventh fret another note, or fifth another .. etc.
Back to the rope rotating fast the peak doesn't reach the other end and in another mode
and behaves as if half the length with a node in the middle and hardly moving.
Faster still and 2 nodes , like 3 shorter nodes and up to 5
On a guitar string it does all of these modes so when playing one note it includes a
number of notes all lumped in together. If I play another note with it that is the same
but a differnt string, they sound harmonious. Once you start with the low note it sets
the key for what you are playing, in E here. Play with the fret next to previous harmonic one
and not so good , or the other way , also bad. The reason is that you are already
playing the second one included in the first in the good sounding pair of notes.
The high note is going twice the frequency of the low fundamental note, play the
bad note with it and the ratio will be something like 1.96 and the other bad note then 2.32
ratio or something messy. If its 2 it sounds nice. All very clear on the scope and
spectrum displays. The patterns repeats itself quite quickly for the good pair and
a continuous pattern. The bad pair shows a lot of spurious traces and your ears are
trying to resolve whats going on . THey are always trying to spot patterns, easily
find the pattern in the good 2 but not for the bad pair which is why so annoying.
Hearing is about communication and the unharmonious pair are just communicating
chaos. The harmonious pair is communicating tranquility - all is right with the world.
Hence my referenc eto the physics giving the music.
The next one up , a third way along, is a B , so play a B alongside E it sounds quite nice
but try Bb or C and it doesn't. E nd C sound quite horrible.
A quarter of the way along is another E, a high E, so in harmony the high reinforcing the low one.
If its out of tune, detuning, then the traces look a mess, they don't line up.
And a chord sounds terrible. Thats what being in tune means - the top string is a multiple
of the bottom string, in harmony. Its easier to tell whether the guitar is out of tune so I
so I distinctly detune slacker and flatter so I know I have to go tighter until it
sounds nice. The strings are locked in to the bottom note.
A fifth of the way along is Ab , a bit weak. I can play a low E , a middle E , high E , a B
and an Ab and play all together and they all reinforce the bottom string and that makes
all the spectra line up and that is the chord of E major. That is what a major chord is,
all the notes are in harmony with each other . Same with a C with a G ,etc . That is what a
chord is 6 sings in harmony with each other. Mojor chords used for simple music like
nursery rhymes, C&W, very confident sounding. In rock music they are the heavy power chords
big fat major chords locked in together and speak assertiveness.
In fact Walt Disney banned minor chords as they put in a slight disharmony. A bit more
whistful and you put in a slight dischord , all the notes are the same but one is slightly out.
Disney was listening to some of the music someone had composed for one of his cartoons
saying that sounds funny, whats that. Musicians there could not understand what was wrong
and eventually realised he was objecting to a minor chord and after that no minor chords
were allowed in Disney product. A minor chord is less confident than the solid majors.
Demo of beginning of Bruce Springstein , The River, on hearing the first chord you
know its not going to be a happy song, sort of telling you don't go to the river. Just
because the relationship between the strings isn't right, slightly dodgey whimsical , serious
or uncertainty . Dream,dream,dream and the second chord is minor - a bit of whimsey or dreamy
Another one is the seventh is a D and is not so strongly in harmony so makes it a bit
more interesting. Put in that small bit of disharmony and that has the message hurry up,
lets get going, an irritation or spur.
Another disharmony, difficult on E, so I do it on a C. You can break the sound, soften it
by changing one note and you have C major seventh , breaking up the strong harmonic
structure and difficult to tell exactly what note you have , more difficult to analyse .
There are sixths , an A sixth , has a vagueness. Ninths are jazzy chords . Its my theory
that the harmonic structure is broken down , some of the relationships are moved
and jazz players like to play out of key. If you play solid majors and play it out
of key it will sound horrible. But if its not very obvious what the key is to start with
then what key is that in. It hasn't the harmonic relationship so the sax player , or heaven
forbid the trumpet player , can do all sorts of things over it and it won't sound really
Another example, when you want to be really bad, dis-harmony, completely disonant
ais , example A augmented fifth. Its an A with one note changed up one fret . You then know
there will be a monster or an axeman in the cellar. When that chord appears is when the axeman
Final guitarpiece demonstrating all these musical effects.
Q: Why is the minor third ???
I tried finding the physics behind the minor third and got stuck. The minor third you slightly
break away from the structure of the major , a slight deviation. In other cultures its not
particularly regarded as sad. These things a re a bit like a language so when you hear Russian
for the first time its just nonsense , you cannot get the intonation etc, but when you've been
there a few days , you start to get the rythm and pitch and so on . The minor third is thought
to be just a learnt thing. In a similar way that children's songs are all majors , you get bored
with these simple melodies as you get older , you want something more intriguing.
In jazz people play things more disonant, less harmonious relationships between the melodies
and the chord structures. Like a child drinking real ale , they don't like it, it is a learnt thing.
A conoisseur can find interest in the complications of jazz that are not fathomable by the
uneducated mind. The harmonies aren#t there to show you the way. I can't give a physics
Its not the note itself but the relationship to the other notes that is behind it. A thing about
blues is they are usually in major keys , not sad chords, but the melodies people sing
over the top . Only 5 notes in the scale for blues so a clash between the melody lines
and the chord structures. And the two are crossing each other. I can play a melody with the
same chords and if I play as majors it sounds jolly . If you have a blues solo to do,
especially if you haven't many songs , like Cream and Eric Clapton famous for doing long
guitar solos because they had few numbers, padding out the set. But one thing you can
do is do part of it in the major scale and part in the minor.
Q: You showed us a slide earlier of various vibrational modes on a guitar body. So
why is it you can play any note on a guitar and not hear obvious peaks ?
Especially on a violin they have peaks all over the place in the spectrum and in fact
big gaps also. There is a big hollow between what is produced from the large
body part and the smaller body part. the reason is because there is so many harmonics
a spectrum for the box and a spectrum for the sound production. Some of them are going
to be amplified and some will be reduced . You play the next note and different ones
are going to be amplified and reduced and they cover the area. Also the human brain is
clever at interpreting. This is the spectrum of the box , the body and this is the spectrum
of the strings . If I plug the pickup straight into the analyser , the red trace is from the piezo
so the forces transmitted to the body and the microphone is the blue trace.
They coincide to some extent but some of the peaks in the red are being reduced by the
body shape and some are enhanced. The blue is what is coming out of the guitar body ,
the sound that you here. One is a modulated version of the other. There are subtle
differences. With the human brain, even if you don't play the fundamental . I heard a virtuoso
double bass player on the radio giving a demonstration of the wonderous things he
could do . I was listening in a car with little speakers that is impossible to reproduce
the sound of the double bass. But from the harmonic information the brain can deduce the
missing fumdamental. Its called the missing root, the brain does this with no effort
at all. If a chord has not the root , the lowest note, people still hear it , a sort of psycho
acoustic phenomenon. Your ears don;t do it but your brain does.
In this room if I do a pure sine wave it would run around the room and be reflected
from surfaces and there will be points in the room where you get cancellation
and you can walk around the room monitoring peaks and troughs. This is happening
all the time but our voice does not hold a sustained note and we don't notice.
We do not hear this cancellation effect. Similarly our brains concentrate on the first
5 or 10 milliseconds or so . Compared with trying to monitor with a computer, it gets
swamped by all the reflected information. One of the great problems with hard of hearing
people and electronic processors in their ears. In a noisey pub we can pick out
an individual voice and what they are saying. We have advanced knowledge of context,
vocabulary etc. Similarly we know the vocabulary of chords and music and we know what
it should be , though our ears aren't hearing it , we do.
Q: In Indian music say the harmonies are different, can you retune your guitar so
it was the same.?
No. We have the fundamental , 12th fret , in Indian music they have the half-way
12th fret . They also have the third harmonic . The guitar is basically designed to
play in E and that is fine, it has 2 Es. If you play in C or G then some of the harmonics don't work.
In Western music they came up with this logarythmic scale , the distance between each of these
frets is 1.059 wider than its neaighbour. That was decided artificially, it was a way round
the problems . The tempered scale. The harmonic scale is different for different instruments.
Pianos are slightly different to guitars because they slightly detune the lower
notes . On a guitar the top E is 4 times the frequency of the bottom E. A is 440 Hz , another A
is 220 Hz and the A string is 110 Hz, all very neat and elegant. On a piano you
have an extra octave at the bottom and a bit more at the top and they are not exact
multiples of each other because it sounds wrong. If you tune them according to the strict
physics , it sounds wrong. So tuning to middle C on the piano means the errors
are going to be spread out more evenly. If you started at the bottom and multiplied the
frequencies exactly as the physics then it sounds wrong at the top.
Western scale is arbitrarily set as this but other scales are available, hence Indian
Q: If someone tok the Tocatta and Fugue in D minor and transposed it to D major
it would still be recognisable as the same piece of music but would be different, could you define
what that difference is?
They would flatten the thirds right through . It is quite a jolly piece of music, if you flattened throughout
it would be a bit of a downer. It could be done as a variation on the same theme ,
comes round. You woulfd notice a different feel.
Q: On recording technology. People say that vinyl LPs , old valve amplifiers give a warm
sound . Can you bottle that warm sound .
The warm sound is a difference between valve and transistor amplifiers. They have
softer distortion characteristics when driving speakers but I don;t think that is what
you are asking. People say that old vinyl sounds better than CDs. There is a phenomenon
that can explain this. If you do a microphone recording of say a violin player as part of
an ensemble . You could have 2 microphones, one in each ear . This ear hears it first , the
spatial signal is being given by the difference by the 2 paths , one has to go round your head,
so subtle differences. The microphones will pick that up and you can reproduce those
subtle differences. What do you do then , you put it on your stereo and you
play it from 2 speakers so a new set of subtle differences . If you put headphones
on then the sound is inside your head, it doesn't sound as though its coming from
outside. Its to do with the interation of your ear flaps, pinnea?. There is another thing
particularly relating to vinyl. The pressure waves from a woofer can be metres long in
wavelength , higher frequencies if wavelength about the size of the speaker it projects
it nicely . The low frequencies are not so directed, they go round the sides. You can very
easily focus a high frequency sound but a low frequency sound wil lspread out. That is
why your 5.1 stereo no one cares where the woofer sits, the whole room gets that.
But the high frequencies are directed. So your violinist is recorded at this position
with 2 microphones . Not too much trouble if he is in the miiddle but if off to the side
then put it on a CD all perfect reproduction . When it goes through your speakers the
high frequency sounds go in one direction , the lower go in another direction.
If someone is blind tested and replay the violin as a single tone. If its 50/50
then they will say its in the middle. If its 25/75 and a pure tone they will accurately
point to a specific posistion. But play another pure tone , because the way speakers radiate
and the perceived position will change. They will put higher frequencies nearer the middle.
So the same violinist will appear to be moving. The sound is smeared . But it has been found
that on a vinyl record there is cross-coupling because of inadequacies of the vinyl tracks , needle and pickup
, one groove but 2 bits of information , undulations in 2 planes. But because the system
is not that good, you get cross coupling. When the needle is being modulated by one
side , some leaks to the other side. It just so happens that this effect near enough
cancels out the effect of the speaker dispersion problem and you get better localisation
of the sound from vinyl. 2 wrongs making a right. You get a clearer reproduction starting
from vinyl rather than CD. I've seen a demo about 3 years ago of an electronic cross-couple to add this
effect and at the flick of a switch you can spatially place individual instruments.
Just like the conversation in a noisey room you can then concentrate on one individual
instrument. Not on the market yet but you'd think it would take the world by storm.
Q: Why as a singer do we have to hear ourselves to be able to pitch properly. If on
stage and no foldback - its a nightmare.
You are self-adjusting all the time. Something like pointing a hosepipe at a plant , while turning
on the water supply , you home in on the spot. If you cannot hear yourself you tend to
tune into something else and that is often the echo off a far wall .
Q: on chord creation, how arbitrary the frequency of a note is . Could you have it 219 Hz
rather than 220 Hz as long as you have the right ratios.
You can do exactly that . The A is now standard in Western music at 440Hz, but not always
so , it has been 436 , moved through history.
In olden days you didn;t have electronic tuners , so tuned to another instrument,
whatever sounds right. I can take this guitar and detune all the strings and you would
not perhaps notice any difference. Oce you have the root note everything follows from that.
Q: Is there a special relationship for the notes of a chord?
Yes, that is the physics of it. With a string fixed at both ends you cannot have
vibrations with half a loop, only full loops. You can in a whistle, you've got to have
half loops. There is no 3.5 , 3.2 pattern , whole numers only.
Q: Will all the major chords fit those strict patterns?
Yes , if I play a B. Now the Circle of Fifths , the most fabulous thing ever for a musician.
If I start from the E, the chord that will sound best with it , harmony point of view,
is the B , because of the string vibrations. The chord that will sound best with a
B is an F# a perfect fifth the next one along clockwise around the circle. If you are
playing in C , for all the white notes on a piano , then the chord that goes best with it is
G the perfect fifth. If the E sounds good with a B , then a B is going to sound good with an E,
the second best chord that would go ewith a B is an A because B is a perfect fifth of A.
The 3 chords that go best with an E are E, A and B. That is the basis of the blues,
rock and roll and modern music .
If the tune is going to be in C you know, 3 chord trick, the other chords will likely be the F and
the G from the physics. If its in A , the relative minor of C, the notes of the C scale are
the same as A minor , sound good together. Thats a bit jolly, if you want something more
wistful, more serious you go to A minor . It could be E minor , could be D minor , its
going to be from that segment of the circle. Its the physics of song composition, the notes
that sound best together. If you can't sing it in C and lift it up a bit to D, every F change to
a G etc. If you want to change the whole song you move it all round
by 2 notches of this circle. With the circle of fifths you can play any song in any key .
Thats how people can come up on stage and sit in with the band. So a song in G and a key change
to D , then F its all in the circle of fifths.
Q: Could you explain the function of sympathetic strings and drones?
A sympathetic resonance is hitting one piece of this xylophone and another one stated
up of its own accord, if there is a harmonic relationship between them. Reinforcing
one another. Its a harmonic, enrichment thing rather than for amplification. A high drone demonstrated on the guitar . On a banjo they have
a drone G. Banjos are in the key of G so sounds good overall as its harmonious.
Q: the high drum of the tabla is tuned to the drones of a sittar
All sounds good together.
Q: Some people cannot tolerate certain instruments, I know someone who cannot
stand bagpipes but I quite like them , single or massed, what is going on there. ?
Harmonicas generate a lot of harmonics , dogs don't like them because of ultrasonic content.
Bagpipes are often out of tune, a drone, difficult to tune and difficult to keep them in
Q: Pianos not being in tune through the octaves, do you think they were more in tune
before equal tempering came in ?
They could be perfect but just for the one key, therin lies the problem. There is reams and reams
of material on that history, lots of variations of tempering. Quite an esoteric subject,
when you conside rthat you do not have to have 12 notes to the scale. 12 divides nicely by
2,3 and 4 but you could have 11 or 13 say.
Q: Why vibrato and tremolo ?
Subtly moving the pitch. Gliding across the spectrum of the instrument. You could have the
situation with a violin playing a straight pure note which you don't do on a violin
, there are deep troughs in the resonances and you can fall in them and if you hit one it would be
noticeable. By vibrato the fundamentals are moving over these troughs and the harmonics
are also moving over them and then the ear does not detect the failings.
If you play an A on a violin , as an open string , it is inditinguishable from the organ sound
but put the vibrato on , and the way it is applied, then it becomes distinctly a violin.
12 Dec 2011, Presentation and talk on epigenetics by Dr Deborah Mackay ,
Senior lecturer in Human Genetics, Wessex Regional Genetics Laboratory ,
Salisbury District Hospital
Title: Epigenetics and imprinting - the enigma of non-genetic inheritance.
Human beings are >99% genetically identical, and every cell in our bodies
has common DNA blueprint. So how do different cells and different people
end up tracing such diverse pathways through life?
Deborah Mackay has a ten-year history of investigating the medical causes
and consequences of epigenetic mutations. Here she sets out the
biological nuts and bolts of epigenetics, gives some examples of
epigenetic diseases, and considers the apocalyptic risks of being what our
1 hr presentation, 1/4 hr break, 3/4 hr Q&A, 21 people (nasty weather)
I'm paid by Soton Uni and work in Salisbury Hospital on medical epigenetics, specifically human diseases
when something has gone wrong, not necessarily with your genetics , but a sequence based mutation.
A mutation in the way a sequence is used. So a very medical geneticist, working on patients,
specifically the patients that the NHS can't sort out. "We are sure this child is ill but we don't
know why , but we think he may be one of your's" - and I get it. The longest time to sort out
what was wrong with a patient was about 13 years. Unlike the NHS I've got all the time in the
world, I just keep trying. In order to make sense of my talk on epigenetics I have to start
with genetics. Genetics is pretty damn hard and epigenetics is anothe rlayer on top of
that. In a way it is an hour long apology for why we don't know the answers to all
this. Basically you are encoded in your genes. But on the other hand you are a product of
your genes and your environment. Influences that were acting on you during your
developement. So you have to explain how you progress from an egg , through the first
tentative cell divisions . 2 , 4... 32 cell ... a morulla , from the latin for a mullberry. How
you get from that to an embryo to a human being. We know this is all encoded i nthe
genes and epigenetics is sort of the study of how that happens. People are made of cells
and proteins . If you blew me up you would find a variety of organ systems , with
different kinds of cells doing what those cells do. If you take any one of those cells
you find that every cell is performing the 7 processes of life- sensitivity, respiration, growth ,
reproduction, excretion and nutrition . The instruction for every cell to do every function
are encoded in the DNA . Classic image of the DNA parked inside the cell. Cell, nucleus
containing chromosomes, not looking like Xs but pairs of socks tied together in the middle.
Unwide them and like socks they are knitted from DNA , fantastically tightly coiled.
Pulling out fully and they make a DNA code. You get 2 copies of every chromosome, one from your mother and one
from your father , both alike in principle , but the great thing is you have a spare.
So oif you bust one copy of either chromosome you've got anothe rone you can refer to.
This is the system, that is why ladies why we mate, if you've ever wondered , why we do it .
DNA is a 4 letter code, effectively a library. Like a citadel in a mediaeval city, parked in th ecell,
not doing anything. Books in the library are not ain a 26 letter code but a 4 letter code.
ACGT, 4 different chemicals. The human DNA code isn't 3,000 letters but 3 billion
in every cell of your body , except for ???.. 100 trillion cells , that are in you contain 3 billion bases
of DNA . Every cell in your body , say 10 to 15 microns across , contains 2m of DNA.
Every second in your body 1 million cells drop dead and anothe rmillion has to take their
place. That means if each one of those contains 2m of DNA, every second you are making 6,000
km of DNA . The DNA in your body will go to the sun and back 150 times.
Lets pretend it doesn't look like a plate of spaghetti and is organised into genes, that is
individual books in the DNA library, each one confers an individual function.
DNA makes genes, makes proteins, makes cells. A 4 letter code is not very good for making
proteins so taking 3 letters at a time, its very degenerate, say ACG ACG GAT and each one of those
can encode for an amino acid, quite degenerate enough to do that. 20 different flavours
of amino acids which are all , polymeric blocks you can assemble in different orders
and they make proteins. The proteins , by virtue of their chemical structure, fold themselves
up spontaneously into their lowest free energy confirmations and go to wherever they are
meant to be in the cell. So the DNA makes the genes that encodes the proteins that nake the
cells work that make you work. So simply that is the basis of genetics. You can imagine the
DNA blocked into genes, each of which has a function , that makes proteins, that go into cells
that make you. I pass my time looking for spelling mistakes. If you get that encoding wrong
then the code is incorrectly read , either the wrong amino acid gets put in or
may abort the protein and throw it away. That is not just a spelling mistake.
This is an example of one of the disorders that I work on.
This child effectively has no functioning insulin in his body. They are born weighing approximately 3 pounds and
no subcutaneous fat. They are entirely dependent on insulin or they just die. That is the
severity. If you have destroyed the protein function , that function is not available to the
body. So a genetic mistake affects the entire soma, its a serious issue.
An example of a genetic mutation . A normal sequence but alongside it it is the same with an
A to G transition. Much clearer is a difference plot where the normal is subtracted
from the test sequence. That represents a change, one copy of that DNA is wrong.
This is what I pass my time looking for. This lady had 2 babies who died.
A lot of genetic conditions are quite rare , some you've heard of , everybody knows some.
The reason you know some is that individually they are rare but collectively they are
rather common. In fact 3 to 5 percent of new borns are affected by something which
can be attributed to being some kind of genetic problem. These problems cause
25 percent of hospitalisations. Genetic changes cause problems that continue to afflict
people and a significant fraction of later health problems. This gene is H19 .
The fact that people get genetic mutations and we've got this absolutely enormous genetic
code to look them , provoked one of the great enterprises of the last century.
To read the DNA code to find out what it is in the instructions to get you from a one
cell embryo to being a human being. The human genome project started in 1990 ,
with what I used to use, slab gels . Pouring acrylimide gel , down ,separating it by
electic charge. If you work well and do'nt get bubbles in them you can force oyut 2,000
letters of DNA in a day's work. You feel a bit tired and a bit radioactive . These days we
are about to take delivery of one of these babies, reassuringly expensive. They will do 300
million bases per run. That means you can get all the important functioning sequence in
a human being, out, in a week. I'm doing that to a few patients at the moment.
What this means in understanding the basis of genetic disease , going from 10Kbases per
day per machine to 10 million per day . It is getting to the stage where we can feed a single DNA
molecule through nanopores and with DNA sequence by electric charge , based in differences
of charge between the different bases. We are getting fast at this. It means the secrets of the
genome are being laid bare. We can read the whole genome, able to get at what gets us
from being a one cell individual to a human and all the kinds of thing that can go wrong
in between. Its like being on the Starship Enterprise. We can point at someone and know
their DNA . So why are we still struggling with genetics. This is the key question.
as Dr Mckoy says I'm a doctor, not a computer programmer. Because the DNA sequence
is not actually simply a code. And that is what I've come to talk about, the rest
has been preamble up to now.
Now epigenetics. Implicit in everything I've been telling you up until now.
What makes cells different. While every cell in your body has to perform the functions
of life, but also different functions as well. There is no point eye cells trying to look
like toenail cells, it won't go well, or vice versa. The simple answer is that different cells are
making different proteins . Eye cells make cornea proteins and jelly toenail cells make keratins.
Cell 1 is expressing comlement 1 of genes, cell 2 is expressing complemnt 2, cell 3 complent 3.
The same code in different cells is being used in different ways. To set this in context, when I say
this is a kind of map of a small group of genes and how they actualy interact in a bunch of cells,
I'm interested in. Its very complicated the interactions between proteins, some have many
interacting points and a vast influence on the way the cell works. Some have relatively few points
of interaction, on the periphery of the diagram . A fantastically complicated emergent system
, understanding those is key to what makes the cells work properly.
Epigenetics is the study of the interaction of the genetic code and its environment that brings
its function into being. The dNA code is the same in every cell of you , approx 99.5%
similar between you and your neighbour but different cells, different organisms use that code
in different ways. Now explore the different ways that the code can be regulated so your
eyes can be eyes and toenails be toenails and all in between. The things that make DNA work
differently are its own sequence , exactly how its put together, exactly where it is , exactly
when you're trying to read it , where you got it from and the conditions under which
you're using it - these are the factors.
Regulation by sequence - A few slides back I said DNA divided up into genes , and we know this particular gene
encodes a protein , read that in 3 letter increments and that will encode a protein
with a function - sorry I was fibbing. If you look at the code , read from one end to the other
you can detect that 1.5% of it encodes proteins , all the rest is doing something else , it
used to be called junk DNA in the 1980s. 30 million bases of the DNA are encoding for proteins
, what is the rest of it doing. The average gene is not simply a string of letters and you read your
way along it. There are 27,500 proteins available , 27,500 genes in the human genome and that
came as a surprise as 27,500 proteins is not enough to make all the variation that is implicit
in you . It became apparent that any particular gene must be able to be read in different
A schematic of a "vanilla" gene , a small number of them are read simply from one end
to the other , the boring ones. Your average gene will almost certainly contain the following
useful items. Reading , for historical reasons from 5` to 3` in that direction, some are encoding
for protein , bits called introns between the coding seqences are not junk , that join one
code to another. Start sites and stop sites , promoters - encouraging DNA to be read ,
enhancers - encouraging the DNA to be read as the dynamic range between of and on
for any given protein is about 10,000fold . Which is more dynamic range than your average loudpeaker or car.
A phenominal subtlety in how much given protein is expressing in any cell at any time.
And there are various other signals , along the DNA, some silences there, acting as break points
, they can slow down expression. An average DNA sequence has a really complicated
strucrture of controlling elements around it. If they didn't have, you wouldn't be able to
turn it on and off. So its like a car engine having a car around it so you can control it.
The sequence around the protein coding stuff is not junk , its controlling.
As a rule of thumb for a geneticist the more crap there is parked around the encoding
sequence, the more I can tell this gene must be under very strong control and so
more likley to be interesting . So 1,2,3,4 coding regions , you don't have to use them all
at any one time. You can control which of these you use and therefore you can control
how big the protein is that you make. So not only how much but exactly how it looks like.
Some of these genes don't produce 1 protein but can produce hundreds under different
control and situations. Thats one of the things that lets your DNA sequence to be as flexible
as it is. 1.5% encodes the genes , approx 27000 of them, the rest isn't junk its regulation.
The next gene regulator is organisation.
If you pull on the sock knitting you can unstrand the DNA , from wbeing wound around proteins
,round one another and then wound around the scaffolding. They tighten themselves up , thats the
only effective way of getting 2m of DNA tidyly into your cells without loosing any of it.
You can control the DNA by exactly how tightly you packed it up. You cannot read genes
if they are tightly packed up. To read the code you have to undo it. In a cell making proteins the
DNA is completely unpacked , it does look like spaghetti . Its another emergent stochastic system
in which proteins ar ediving around , finding the dNA they want to find and doing what they
want to do wioth it. So regulation in space. These genes can be read in different ways
and depending on how open and accessible they are , that will influence how they are read.
They organised in a very flexible way within the nucleus .
A drosophella cell , 6 chromosomes, packed up tidyly , which wants to divide up cells so you
can partition the DNA accurately between daughter cells. Without that you will end up with
cells with the wrong number of chr - thats very bad. The dNA is only packed up when you
want to divide it. In a normal functioning cell , chr 1 in red has its own territory here and here
, chr 2 has territory here and here. A light micrograph image and what its showing , as if you
dive in there and swim around in the DNA , it looks like a somewhat ordered plate of
spaghetti. You can't mix the dNA completely together because in the average cell cycle you would
not have time to get it back apart again. Chr occupy what you might call territories in the nucleus.
Some of the DNA will pack itself down towards the edge of the nucleus and this looks more
like the knitted socks. Much more compact, less useable. Towards the centre is a much more
open structure , you've got proteins that go round in factories of packs about 400 , falling upon
bits of DNA and reading them . Other structures outside are silencing DNA and on the edge of the
nucleus you have DNA that is being turned (draft?). Brilliant piece of work was done recently ,
they took some pieces DNA and inserted them in other chr and showed if you get 1kb of DNA
at one time, the sequence information that is in that DNA is quite sufficient to instruct the
nucleus on its own saying "I'm a silencing piece of DNA , I'm a toenail gene and this is an
eyeball cell, clkearly I need to be at the edge of the nucleus". They were able to track these
pieces of DNA and prove that 1Kb contained enough information to activate or silence
the gene. Its implicit in the sequence , that controlling DNA again.
The next thing you can regulate is time.
An egg is the ultimate multi-tasking female accessory - it contains everything it needs
for the first 8 or 9 cell divisions. Not till it gets to 100 or 200 cells that it will try and implant
on the wall of the uterus. Its got to contain a lot of packed lunches. It contains enough protein to get itself
started, enough energy resources. Sperm , by contrast, is like a little motorboat , just a suitcase of
DNA and virtually nothing else at all. When the sperm DNA turns up inside the egg it
can then undergo the first cell divisions . A bit later you have a lot of programs going
on in different cells . In the moreallar , the cells at the centre of this ball of cells are
beginning to do different things than the outside ones. The outside ones concentrate on gripping their
neighbours and making sure the ball of cells is tight. The inside ones are beginning to
become embryos as opposed to placenta or extra-cellular membranes . They've already
started to do different developemental programs although only 3 days previously there
was only 1 cell in there. Over time you get this diversification of program. It steadily
gets more complicated as cells decide to forget to be toti-potem , able to do anything, and they
choose to be pluri-potem , able to do a lot of things , multi-potent and heading to being
differentiated where they will do one job and do it brilliantly. That is a successive series
of decisions which involves packing up certain bits of DNA and saying I will never use
you again. The same thing carries on for years and years but one critical thing is
happening in that a proportion of the cells in any adult individual has decided to get
its old books back out again. Every person contains germ cells that are then going to
become tote-potent and they will complete the journey back to being egg or sperm.
So you can go from a one cell tote-potent fertilised egg , a zygote, and get continuing
specialisation and then undo that specialisation again in an incredibly controlled way.
Undoing that diversification in an uncontrolled way is the essence of cancer.
The whole point is you don't normally let cells do that. So the generation of the new
egg and sperm cells is a tightly controlled process.
Now we come to mentioning Dolly the sheep. Cloned about 1985 at the Roslyn , Edinburgh.
Normally tou can't take just any specialised cell and say I would like you to make a new
embryo. We cannot clone ourselves. Dolly was the first clone, she had 3 parents. One donated an egg , its
own nucleus was taken out, another sheep donated a breast cell and cultured. The DNA was taken out of those
and put into the egg. This was allowed to develop ot a plastocyst of 100 cells or so
and implanted into a third sheep , in which it grew.
That in principle is easy. Take adult DNA out of one cell one cell , pop it into an egg cell
and go be something new. Dolly was 1 of 277 cloning attempts. 29 resulted in blastocysts
implanted into different sheep , 3 were born , 2 died and only one survived.
It doesn't work. The reason is the specialisation . The breast cell is designed to make
milk and fat etc, its no good at being an egg. In order to make it be an egg you have to
undo every aspect of the epigenitic program that has been stuffed into it .
You have to genetically engineer this cloning process for mammals . Just as well, as
unregulated differentiation causes cancer.
This next area is what I work on . Regulation by inheritance. This is the chief reason why
cloning doesn't work. From a somewhat Dr Strangelove experiment they did in
Cambridge in the 1980s. John Girdon had proved that you could do cloning with frogs .
Take a frog egg , take out the DNA, add in the DNA from an adult , and that would have a good
punt at becoming another frog. So other scientists said we will do that with mice. Took the DNA out of
normal fertilised eggs and tried putting in the DNA from other cells. If you put in DNA
from an egg and DNA from a sperm you could get a good punt at being a mouse embryo.
But they found something peculiar. When they tried stuffing in DNA from 2 eggs they did
not get an embryo , they got a bit of an embryo and a useless placenta. By contrast,
using DNA from 2 sperm , they got a tiny embryo and a huge placenta. So something about
whether the DNA had come from a mother or a father. Even though it was the same DNA ,
it was being used differently, based on where it had been inherited from.
Pic of a one-cell zygote , contains maternal and paternal DNA. The moment the male DNA goes in it fuses
the maternal DNA executes its first ? and shreds the paternal DNA and take off all the markings
that are specific for being a sperm. It reassembles it and gets on with copying it. Your cells can
tell where your DNA came from.
Its not all the DNA that matters but about 99% of the 20,000 genes of your genome ,
one from mum , one from dad, you can use either of them. about 100 genes, it realy matters
from mum or dad, and one of those copies will not be used. The marking stays constant throughout
your life. My work is working on genes, finding out what has happned to the DNA packaging
in children with problems with what is called inprinting which is a special kind of epigenetics.
One copy from mum, one from dad - you've a spare. Why would you use just one copy.
Scientists worry why this happened in the first place. Inprinting came in just about when
mamals started to develop. So cows, rats, mice monkeys etc. There are 2 suggestions ;
the ovarian timebomb - you don't want maternal DNA progressing on its own without
waiting for paternal DNA because that can turn into a cancer. So you have to have some DNA
that has to be provided from elsewhere . The other suggestion is the genetic conflict.
Not humans here, the idea is the female of th especies will have multiple litters but they
won't necessarily have the same father. In evolutionary terms the mother's DNA will say
I will keep my children small so I can share out my resources and no one will have too much
of my attention. The father's genetic contribution says I want my children to be big.
So paternal influences are designed for largeness and maternal for smallness. With a few excepions
fits with what we find. An example Insulin-like Growth Factor 2 ,its parked on the gene
right next to the insulin gene. So food stroage, nourishment and growth. IGF2 is used
to grow from the point about 3 months into gestation , and putting on weight you use
IGF pathway to keep growing until you hit about 1.5 to 2 years old and then growth
hormone cuts in. This is expressed only in your father's copy , your mother's copy is
asleep , never used. You can get certain kinds of genetic mutations , effectively maternalisation ,
you are not making enough IGF2 you end up with a small baby. If you are making too much
IGF2 you end up with a baby who is too big. Not a big difference , in the grand scheme
of things. 2 examples, 1 birthweight about 4 pounds and another of 10 pounds.
There are particular things that are out of proportion in these children. Top of face is fine but the
lower face is undergrown - his eating apparatus is relatively small . Second example cranium
size is right but lower face is over developed. This situation can mean they can choke on their
tongues, when asleep , not just when eating.
They? have so little interest in food, they don't store food , they don't have glycogen
in their livers and so life-threatening hypoglycemia in bed because they run out of food in the
night as so little body fat. So the results of not making the right amount using just one gene
in one phase of your developement.
This occurs in about 1 in 15,000 newborns - Beckworth?. But ART , assisted reproduction ,
is associated with 2 to 4 fold increase in the rate of these errors. Why - because we;ve been interfering
with normal reproductive processes. Reasons could be aRT starts with super-ovulation
so instead of 1 egg ripening per menstrual cycle and ripens about 20 simultaneously due to
administered hormones. Probasbly in a relatively unregulated way and then a doctor
goes in and extracts about 10 near the surface of thew ovary, that look as though they may be ripe.
Whether ripe or not is impossible to tell . There could be genetic reasons why these mothers
were infirtile and the ooercytes not working. ART is associated with an increase in this kind of
programming epigenetic error .
This is the headline grabbing epigenetics. We are a product of our genes and environment.
So when you are an egg you receive your genetic inheritance and some element of epigenetic
inheritance. As you grow up some things happen depending on how you grew in the womb
and some dependent on the environment you experienced and those influence the way your
DNA will be used by the cells in your body, throughout your life.
Oguti mice,an inbred strain of laboratory mice. They have what is called the oguti gene.
Kept in same conditions and fed in the same way . The only difference is what their mothers
were fed while offspring were in utero . The oguti gene is turned on in the presence of
certain food additives like soy ,(genicide?) folic acid , methyl donors. If the mice are starved of those
methyl donors then the oguti gene is mis-expressed youget mice that are more (?) and more prone
to excessive weight gain and metabolic syndrome , blood pressure problems , heart disease
hypoglycemia , diabetes. This is not to do with anything you did to them but the way they're
mothers were fed. You can take these mice and antagonise the folate pathway, the genicite pathway you
can feed them something called Bisphenyl A. If mother is fed with that you get mice
that are oversensitve to the ill effects of over eating . Bisphenol A is a headline grabbing
environmental additive. Its used to stiffen plastics , its present in 99.9 % of the human
population at detective levels. It contaminates all water sources .
There was a recent paper showing 2 groups of individuals
, one group fed on home made soup
, the other group get one meal a day of canned soup for a week and then you take a urine
sample. Then you swap the 2 groups over and after a week take more urine samples.
The guys taking the canned soup had 55 times the level of BisphenylA in their urine rather
than the home-made soup. Thats because we all got worried about aluminium being on the
inside of tin cans . So the insides of cans was coated with plastics which are stiffened with
BisphenolA . We know if we feed mice mothers with BisA its bad for them because you
can see it. We don't know whats going on in humans. Nothing clear from the FDA in the USA etc.
Hayles and Barker , the Thrifty Phenotype Hypothesis , the Hertfordshire Cohort.
1920s keen midwives in Hertfordshire . took the birthweighs of all new borns and at
1 year old. Then 60 years later these records were discovered , how are the kids doing
now. Taking urine , blood samples , life histories, questionaires , weighed and measured.
Babies of 7.5lb / 8.5 lb, now 60 years later BMI is below 27Kg/Lt ie the non fat ones.
Prevalence of the metabolic syndrome , the pre-diabetic syndrome , disregulation of glucose
etc , they are getting a bit fat , those factors sky rocket with individuals with low birth weight.
The smalle rthe children were atr birth the greater their risk of becoming diabetic
in later life, if they did not regulate their weight . 1 in 3 of the guys who were 7.5 lbs
or less at birth, if they got fat , they would get diabetic. This is an environmental
influence , not selected by anything other than midwives in th e1920s.
Proved in different cohorts around the world. There is the Asian time bomb. If you take
children born in certain Asian countries , the natural birth weight is lower at
4 to 5 lbs . If these babies then have a European type diet they are of very high risk
of metabolic syndrome. Nobody is sure what the problem is, Because finding out what the
actual genetic difficulty is because its like finding a needle in a haystack that was there 60 years ago.
Genome wide scans have not found the reason because it is a combination of
genetics and epigenetics and too hard at the moment.
Dutch hunger winter 1944 , north Holland .
After operation Market Garden when the Allies were trying to push down through Arnham.
Dutch resistance helped , bu the Germans pushed the Allies back. In reprisal to the
Dutch they cut off food supplies to north Holland. It was also an unusual and harsh
winter. By the time some food could have got through the canal system was frozen up.
The ration from Nov to May went down to 700 and then 400 calories a day. Reduced to eating tree
bark and poisonous tuilip bulbs. Audrey Hepburn was brought up in Amsterdam in that winter
. She was a trained dancer and entertained the populace. She continued to dance until
too weak to walk, For the rest of her career she was a fundraiser for INICEF.
Back to IGF2 . For children in their mother's wombs at early gestation in the hunger winter,
subsequently have been at much higher risk of getting diabetes. This tremendous enviroinmental
insult giving to this unborn population has had a severe impact on their life course .
Effectively it reprogrammed their bodies to be very thrifty with whatever nourishment was
available. After the war and unlimited nourishment, their bodies were less programmed
to deal with it. In evolutionary terms, this makes sense but in our abundance culture,
that sort of thing is not good for you. There is a body of Dutch researchers trying to understand
the problem of the hunger-winter children. They think there is something going on in the region of
IGF2 . THe IGF2 gene is controlled by various enhancers and promoters , sequencing windows,
particular confirmation, expressed from one allele . The picture is very complicated .
So the journey of epigenetics is the difference between the linear code of the DNA and bases
and using different parts of your code in different ways , in different developemental stages .
That is my apology for why we don't understand why it causes so many problems.
Epigenetics will be at the heart of many life-style diseases. Only last week something on the BBC
that 40% of cancers are environmental . The environment acts on the cells in your body by the
DNA . There are many things here to be discovered as its an astonishingly complex problem .
Questions and Answers
firstly for a sense of scale
Sperm is tiny relative to the egg. Sperm and chr , not an error in scale , the DNA is compressed
down so it it will fit inside a sperm. Red blood cell 8micron, this is why red blood cells throw
out all their chr , they toss out their nuclei at the final stage of differentiation or
they will not get around capillaries.
Q: when you do gene therapy , genetic material is manipulated and then put back, how
is it put back into all the cells of out body?
It can't be , that is why gene therapy is going to have quite limited application.
As I understand it with Cystic Fibrosis , a potassium channel which is not working.
They sit on the outside of the cell and other things control what salts go in and out.
Supposed to run in a fluid something like sea water as far as its salt content, it
reflects our ancestry. To control this, there is a whole bunch of proteins that sit in the lipid
membrane of the cell and acts as gates for potassium , sodium etc and push it out again
if they don't want it. That regulates for the whole body and the kidneys can toss out
the salts you don't want at all. The problem with CF is a particular potassium channel is not
working properly , not secreting enough something. The end cause is the mucuous membranes
particularly tracheal and lung and the gut lining are too viscous , and then traps germs
and then lots of infections. The gene therapy approach is to look after the airways
, they take channel DNA that is correct , package it up , one time into virus but troubles with that,
now put into lipid layers and put in an inhaler. That will coat the lung lining, those lipids
or whatever vector, will deliver the DNA into the cell . Sits in the cystoplasm and uses that
DNA and makes a corrected channel. The moment those cells die and are sloughed off,
you have to have another dose. The point of CF therapy, is its a target that you have a
target at reaching. Maybe also similar for an eye disease , perhaps macular degeneration ,
again because you can get to the eyes . Gene therapy for Parkinsons , say, will be much
more of a challenge. You can't go playing around in that space. The brain is a very diverse
collection of cells , so not disturbing any of those while targetting one cell type is much
more of a challenge.
Q: I was wondering about this working on part of the knitting at one time , does that explain
the aging process. At different stages in life , differnt bits of th eknitting are being
worked on and when you get to the end then thats when you're at the end of your life?
Not exactly that but there are related processes. In some ways you've absolutely hit it.
The first thing to say about the aging process is that any given cell in your body is
going to have to replicate itself perhaps 80 or 100 times in order to run long enough.
Some more often , some less. Frankly copying 3 billion bases of DNA , not screwing
it up in the process, is an imense challenge. Generally the cells in your body accumulate
errors and seness . By middle age 70% of your liver has stopped working . We are built
with huge amounts of degeneracy and so you don't get problems until loads of it has
keeled over. Likewise the pancreas , you don't present with type 2 diabetes until
you've only got about 10% of your beta cells left, because they just work a bit harder.
A critical thing in the aging process is accumalating genetic errors .
The thing that controls your aging, the crises of senesis in any given cell is called the
telomeres . I told you the dNA is great long strands , when you're copying the DNA
, what happens when you come to the end, do you just fall off. The DNA is packagged
up so it has to have 2 ends to each chr. You can't put anything of value on the ends because
you might loose it, as not able to accurately copy it as could easily fall off the end.
At the ends there are tens or hundreds of kilobases of garbage , just goes ACACAC......
for ages. A buffer zone at the end that you can safely loose and not matter.
In any new born child these telomeres are quite long. At some point in any given cell line
and errors, its telomere gets critically short and then its too short to thread the apparatus
back on and start copies in the opposite direction. At that point that cell is no longer
able to make the right number of chr. Telomere shortening is an absolute crisis point
in the life of any cell line. There are agents that can reactivate shortened telomeres, they can
make them grow.
There is a suggestion you can use those to reverse the aging process. Its true that you
can intervene in mice and reactivate their telomerase and live another 50% longer
than normal. The absolute risk is that telomere shortening is a great protection against cancer.
Because any canser cell is going to replicate its DNA endlessly and this is a time
bomb built into the process. You don't let cells have short telomeres because if they get
cancerous, they will just keep going. So the answer to lifespan is not what is happening
all along the DNA , except as much as you make mistakes, it is critically what happens at the
end, when you fall off the end.
Q: Ignoring any ethics or technical problems , could you see any any advantage in anyone
who wanted it, to be allowed to have the edited but full medical history of their deceased
parents and grandparents? Just the ordinary GP medical records.
As someone in a family where there were chronic health problems , type 1 and type 2
diabetes in immediate relatives and I can tell you that medical records are astonishingly
poor. Take your average type 1 diabetic child , you take him to a clinic once every 3
months and they will do one measurement, one parameter . Its all the NHS can
afford. For any given situation you do as little as you can afford to do, so more money
to spend on something else. So a medical history is not so good.
What you will be able to get, in everyone here's lifetime is the exome, not
the full human genome, the encoding stuff. It is of the order 500 to 1000 pounds ,
you could buy someone one as a wedding present to predict the future
of their future children . This is the inheritance you have to offer.
The discussion we are having in the NHS at the moment. Effectively the heel prick
on the baby and not doing the foetile ketonuria testing , which is single mutation,
but getting all the exome coding sequence . How does it vary from the concensus .
But what kind of burden would that be on a developing child, to know that on
a little chip is life or death information , Huntingdon's disease , Parkinsons ,
diabetes, blindness or any such. The ethics of genetics at the momnent is that if you feel
you have genetic problems you can refer yourself to a clinical geneticist and say I
have a terrible squint, tell me about my genetics or my leg is falling off , tell me about
my genetics. But you cannot do that to your child unless your child has the problem.
Because you are not to force that knowledge upon them. You can however do it
to an unborn child. eg what is the chance of my child having chr21 trisomy-
Downs Syndrome , testing for maternal anxiety a, a screening test. Every mother
is offered a marvelous collection of biochemical and ultrasound tests and can choose
to end that child's life . The ethical issues are profound and they are going to get worse.
If you know htere is something like Huntingdons Disease in your family - then at what
point are the insurance companies going say we're not going to offer you life insurance.
Science always goes faster than the ethical and legal frameworks.
As you mentioned Huntingdons Chorea , about a year ago we had an archaeologist here
, not a geneticist. He referred to some research done in Papua New Guinea and the
early history of mankind and canibalism. On chr 20 they detected , 2 variants of a marker,
and according to which you got then a high probability or a low probability
of getting kuru as they called Huntingdons disease. Australia came on the scene
, whenever it was, and outlawed canibalism , cleared from the culture all together.
Myself and 2 other people in the audience , on seeing a graphed out plot of the
ballance of these alleles on chr20 , monitoring new offspring blood samples. In 10 years
you could pick up a distinct change in this balance , we expected to see it only after
generations - would that be an epigenetic process. ?
The perceived wisdom is that genetic changes have to occur over a generational basis , slow.
I don't know if anyone has seen anyone with Spina Bifida , probably not. But if this
conversation was 50 years ago then we may have done. SB is a defect whereby in the
developing embryo the neural tube enveloping the spinal cord doesn't close , so what
happens is , depending on where it doesn't close, either its open at the base of the spine
and less control over lower muscles or tetraplegia or the very worst the brain case
does not close and anecephally which is incompatible with life. This used to be quite
prevalent and was thought to be connected with the consumption of potatoes
because it was more prevalent in th enorth and east of the country , Scotland and Northern
Ireland and less so in the south and west. It was due to diet but the eating of folates
which is an epigenetic regulator . These days folates are put in food routinely after
a controlled experiment showed that 400 micrograms of folate when expecting or expecting to expect to
have a baby could dramatically cut the incidence of neural tube defects. Now you don;t
see it - an example of an epigenetic disorder .
With the Papua New Guinians , it was part of their culture , that the brains of the dead were consumed
by the women not the men, would that be contributory. ?
It shouldn't be . A woman's complement of eggs is fixed and set in her ovaries at
5 moinths in her own mother's womb. I don't think it would be a genetic effect, more likely
to be due to prions . The chr markers probably showing a susceptibility or not.
Another example of this is thalosemaea, sickle-cell disease. If you get 2 sickle cell alleles
your blood cells are not healthy round things but have structural defects and they are crumpled up,
get stuck in the blood vessels and sickly children and die quite young. A common disease
in th eMediterranean population , what is it doing there. The answer seems to be that
if you have one allele, the blood cells are not tasty to (tripanosomes?) and is a selective advantage against malaria
to have one copy of that gene - an evolutionary price worth paying having the occassional offspring
that dies. You can treat it , people can come to me of reproductive age .
Its prevalence in the population can change rapidly as its not being stripped out
by death and natural selection .
When you were talking about Dolly the sheep, you say they took the DNA out of an egg
and put the new DNA in and tell it to go . I think was the expression you used - did they
have to sdo something or does the egg not automatically grow.?
It automatically grows. They lay them beside and deliver a mild electric shock , that shocks the lipid
layer and lets the DNA in and that is the signal to start the differentiation process.
But it doesn't get an electric shock normally. Does something stop it and then it needs
something to make it go again.
As I understand it there is a change in membrane polarity in the egg when the sperm head
contacts it properly and passes through. I think the mere arrival of a sperm can trigger
the whole process. You can get 2 sperms arriving simultaneously and the process
will procede with 69 chr, not 46 and that is incompatible with life.
People living at high altitudes are more efficient in their ? of oxygen , would that be due
to epigenetics.? Is it a difference in the DNA, DNA expression or environment. If environment
then does each child have to develop this ability in their own lifetime, or would they inherit it
I don't know the basis of the process. The red cell blood count and the quantity of
haemoglobin in any given red blood cell is higher in such people. That is an adjustment
that your body makes quite rapidly . If you wer eto go into Tibet then within a few
weeks you would acclimatise. You make a rapid change in gene expressions but
i don't know whether the genetic code is different of those people.
There was something on TV a few weeks ago about it, natural selection works over
a few generations.
Does knowing more about the process change the type of advice that might
be given to pregnant mothers? Does it enable us to give more focussed advice rather than
??? for six months .
I think the correct answer is it does. But advice given on a public basis is very
anodyne . There was a study with a group of people who were terribly obsese and type 2
Diabetic were put on a 500 calorie a day diet for 8 weeks. Effectively starvation rations ,
exceedingly hard to do and at the end of the 8 weeks their glycemea was assessed and
they had normalised, not necessarily stayed normalised if they went back to their previous
diet. But if they were sensible they stayed normalised. When this came out all the public
medical advice sites came out saying no way to do this without medical advice because it
could be dangerous. So the answer is yes, we do know an awful lot more about the kind
of things that can affect a growing child but no one is going to go out saying please do
not have children over a certain age , or please don't do HRT because women long to
do certain things and you should not take away their right . Normal child birth
is terribly risky but you would not say don't have children because its dangerous. And likewise
when you have a pregnant mothe ryou would only say make sure you eat a good balanced
diet , be sensible , but specific advice , you will find , is starkly lacking.
Advice that you can guarantee will not harm anybody will scarsely suit anybody - and that
is the essence of public medicine.
Hooray for a reduction in spina bifida , from a simple thing like adding folates ,
did they ever understand the mechanism by which this works?
The answer is half. The thing I didn't go into was explaining the actual molecular changes
to the DNA that ? epigetics because there are various things you can do to DNA so it
will be expressed or screw it up so it will not be expressed. One of the key things for saying
to're staying supressed is sticking methyl groups all over cytozines in CG dinucleotides
of DNA. There are elements that are brilliant at turning on expression , called promoters,
that tend to be quite rich CG dinucleotides but if you slap metal groups over the cytosemes
they will be supressed/controlled. Folate is a methyl donor , its like vitamin B
, it passes methyl groups around from one molecule moiety to another . Methyl is
unreactive H and C , no oxygen or anything. So its hard to donate
methyl groups around the cell . It affects the methylation of something but we're not sure
what. If you supplement folate to ladies the methylation at certain places goes up and
esodyalosmine?-thiamine level goes up . But again its like looking for a needle in a haystack
that was there a year ago. We haven't figured it out yet but its going to be that.
When I was a kid , you never saw kids , adults or anyone going around clutching
bottles of water. Somewhere over the decades something has changed in that any train
passing through here and in any railway carriage half the people have a bottle of
water with them. Concerning Bisphenol A in the plastics and that, is there an addictive
thing going on ? do you have any input as to why so many people are going around with
bottles of water?
Partly due to health advice that we;ve been given, that we need to drink more water.
Have you seen that amazing Fructose - the bitter truth?. A priceless scare-mongering
(toke?) on the internet, Sugar: the bitter truth. He is talking about how through evolutionary
history we are not well adapted to eating sucrose as there is so little of it in a diet that you
can pick off trees or chase,catch and then eat. But our modern diet does contain
a great deal of sucrose . Put that together with in the 1970s there was a great hoohah about
colesterol . Some well meaning scientists measured the total colesterol levels in varios
people. Saying you've got loads of colesterol , we must all eat a low fat diet, fewer eggs,
much less fat. Food has to be made out of something you can't supplement it with
cardboard. If you take out the fat you have to put something in . If you read the labels
, low fat foods tend to be higher in sugar , so our diet has been getting awesomely high
in sugar. Partly because its easily processed, easily stored , a huge sugar diet and our
bodies are not properly adapted to deal with fructose. We don;t have pproper pathways for it
, not like glucose , fructose has to be metabolised by the liver which is not good at it.
So misguided advice has led to something which is not quite right. Like introducing
Japanese knotweed to get rid of something in a pond and it was not a very good idea.
We all want to drink mor ewater but how to carry it around when glass containers ar e
dangerous - we mustn't have those , what we need is nice sturdy plastic bottles. Lined
with bisphenol A. We've been told to drink more water, so we do . We all know
that Lawrence of arabia could survive for 3 days on half a cup of camel's urine or whatever
. It desn't do us any harm to go without extra water but we all think we should have more.
I don't think we are allergic or addicted to bisphenolA but socially we;ve been acclimatised
tio do this. Like 50 years ago we were acclimatised to think that all cool people lit
up at every opportunity. Think what this pub would have been like 50 years ago.
Now we think that anyone who is anybody needs 4 wheels and a petrol engine to get
around . In 50 years time people will ask - did you really drink all that bottled
water , did you seriously drive a petrol car. Its social addiction , I think.
Isn't there something in primary schools called Brain Gym ? actively trying to get children
to drink more water?
A blog in the Guardian and Susan Greenfield but I don't know the truth about it.
This BPA, is that an oestrogen type thing ? so affecting male foetuses ,
males being feminised by this BPA? So no true men any more?
Yes it is a synthetic oestogen, yess there is a suggestion it causes reproductive anomalies
, not just in the offspring of those mothers mothers scoffing BisphenolA but further
down the generations as well . I don't know much about this but I can pass on one
piece. A few years ago at Bristol University animal house and they were doing
experiments on fish or mice or something , they suddenly found that they were all
girls. Could not figure out what was going on as it was ruining the experiments as they
could not mate anything. They tracked it down to a new lab technician had started
and had started washing all the lab plastics and glass ware in a new kind of detergent
which contained a whole pack of synthetic oestrogens which wa sfeminising all the
animals. Now think of all the detergent we use and its additives that smell nice and the
stuff to get through tomatoe and chocolate stains. I don't know . I'm not saying
lets all go and be mediaeval again because we will die by the age of 5. As ever there is
clearly something foing on here but complex and emergent system of the epigenetics of the
cell , we will get to the bottom of it .
Why are skin problems so difficult to treat?
This is scare mongering science. You take a baby whao has nappy rash and a sore botty
and you put nappy cream on it. Nappy creams are oils , a carrier of an oil, they need to be
nice and cheap so they use peanut oil. Peanut lectins are not particularly agreeable
to the human system so you sensitize babies to peanut lectins , probably connected
with the prevalence of peanut allergy these days. Psoriasis , I don't know about.
There is a work coming out of Norwegian ladies where someone kept samples for a long time
and able to check samples of pregnant mothers and 15 or 20 years later. They found that the
mothers who had relatively low levels of vitamin D in their circulation late in pregnancy
, there children were more likely to develop type1 dibetes, by the age of 15. Suggesting
that they wer enot getting enough sunlight in late pregnancy . There are certain disorders including
excsma , asthma , diabetes, MS and a whole package of others where there is a genetic
predisposition combined with environmental insult that we can't grasp because the range
of environmental influences on anyone is too complex . It will take the most fantastic
followup studies .
You mentioned that red blood cells loose their DNA, is that true for all blood cells?
No, white blood cells keep their nuclei , the red blood cels have to squeeze through the
capilliaries. the lymphatic system is for recycling white blood cells, collected into the
lymph nodes and returned.
In a blood bank do they ? DNA from people who've donated blood?
I don't know if they spin the blood and take out the red blood cells. Because some people
ar eplasma donors .
There seems to be a good case for keeping lots of medical records of people so a fantastic
insight for these studies. If everyone had everything stored about them by the NHS
they could be doing all sorts of fantastic things over the decades
Partly Harold Shipman and partly Alderhay scandals there is now astonishingly tight
ethical constraints on what one is entitled to ask and collect and keep. If I had patient
sensitive data on that computer , I'd be sacked without recourse of any kind.
Its a criminal offence to hold data in an unregulated way. In a recent study I've been
involved with of too small and too large babies it took a year and a half to get permission
to use the remainder of the DNA for further research. Ask any rational human being , can I use
any data about you and they will say of course you can.
But for these constraints .
Cameron was going to make NHS data more available for commercial reasons
Depersonalised with care
This is the life blood of what you're doing, lots of data over many years
Yes. If you ask the right question it doesn't take many answers .
Is the politics or culture in Iceland different? Because of that huge multigeneration
accumulation of genetic data. ? A world leader in that area of investigation
They can all trace their lineages . The whole population gave blood samples .
K? Stephansun has been doing genome wide studies and is now doing epigenome wide
studies and because of the power of the data resources of Iceland they are doing
great things. I think the Icelandic population have a more balanced attitude to risks
and rewards. What you're guarding against in the UK is insane people. So you legislate against
the worst thing that can happen. This is quite a challenge sometimes. Sometimes legislation
is puut in place that is too fierce and then gently gets undone later.
I beleive there was something about the children of fathers who had worked at Winscale had
an increased risk of cancer ???
There are some diseases that seem to be more prevalent in the children of ??? and that is to
do with the way eggs and sperm are made. By the time a baby is born there are about 400
eggs parked there and then every month after menarche one egg gets chosen , declares
itself to the world and then it dies. With a boy stem cells start dividing and dividing
and so divide hundreds of times in the man's reproductive life , they accumulate errors.
Certain disorders affect their children when the fathers are old. A prevalence
thing. I think the Winscale thing remains unproven , not enough data to sort that out
yet. Like mobile phones and radiation effects remains unproven.
My professor has told me that having an accessory nipple is really quite complicated.
Its like drugs , if it has the effect that you want its useful, if a bad effect then a side effect.
Genes have effects , a mutation can have no effect, it is silenced or a variation could make you
1 inch taller or smaller , those are variation. An accessory nipple may not send you to a clinic
but something that is embarassing , like say excess hair, will more likely send you to a clinic.
Hold up a baby and say that DNA is bad in assessing the DNA is a very particular subset
of changes. At one end are somewhat insifignificant anomalies and the other extreme there are
changes that are incompatible with life.
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