Cafe Scientific, Southampton, UK, past talks

Latest update of this file 21 May , 2015

Some details on past SWA science cafe talks in 2010 , including transcripts of talks and Q&A
Some details on SWA science cafe talks of later 2011
Some details on SWA science cafe talks of early 2011
Some details on SWA science cafe talks of early 2012
Some details on SWA science cafe talks of mid 2012
Some details on SWA science cafe talks of end 2012, including transcripts of talks and Q&A
Some details on SWA science cafe talks of early 2013, including transcripts of talks and Q&A
Some details on SWA science cafe talks of mid 2013, including transcripts of talks and Q&A
Some details on SWA science cafe talks of late 2013, including transcripts of talks and Q&A
Some details on SWA science cafe talks of early 2014, including transcripts of talks and Q&A
Some details on SWA science cafe talks of mid 2014, including transcripts of talks and Q&A
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Some details on SWA science cafe talks of early 2015, including transcripts of talks and Q&A
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Some summaries etc of past talks held at the venue, The Southwestern Arms (upstairs room) , 36 Adelaide Rd, St Denys, SO17 2HW
Some hosts are not alowing remote linking now , so to view a "forbidden" picture you have to right click on the mouse and select "view". Not verbatim, and there will be homonyms, transcription, transliteration, typing and spelling errors and misattributions in the following write-ups. Q&A , grouped under one "Q" or ? terminator tend to be dialogue with / multiple questions from one enquirer. ? for unheard / masked words , ??? for phrases.




12 Jan 2015 Matthew Proctor , Soton Uni Title: "Moving beyond TV: new developments in liquid crystal devices" Synopsis: "This talk will introduce the exciting world of liquid crystals, describing the strange materials themselves as well as how they are being used in modern devices." 30 people, 1 1/4 hour I'm interested in studying materials that react in a certain way with light. Optically active materials. One is where you shine light on them and they will heat up, they will absorb the light energy and change it into thermal energy. Another is a photoconductive material where you shine light on thgem and they'll change their electrical conductivity. Another is a photochemical material , shine a light on them and change the chemical structure and change it back after shining light. With these materials I produce devices , very small , that are liquid crystal cells that in someway incorporate those materials. Think of the liquid crystal {LC}displays that you personally own, TVs, laptops, mobile phones. Some one has shown there are more LC devices out there than there are human beings. Its ubiquitous and in a way the materials are victims of their own success. You have someone over there doing research into carbon nanotubes , someone over there doing powerful lasers , all very sexy and exciting and LC come across as a bit ordinary. Some of you will have an awareness of these materials and some sort of understanding of them. Its a bit of a shame because these things are completely unique , completely strange in the way they react to light and electric fields . They find their way into chemistry , physics and biology. Examples involving LC , perhaps you're not so familiar with. Soap, beer, skin , TV and insects all involve LC. The beer here is not LC but the foam on top is a LC material. Your skin is made of a polymer which uses LC molecules. Washing up liquid itself is not a LC but add to water, it becomes a LC. Kytin the material of the exoskeleton of lots of insects is made of LCs. Spider silk is another one , we know as a fascinating material because of its tensile strength , that is made of LC. They are all over the place. We at the uni are developing future materials that will be involved in a lot of optical networking and optical computing. What is a LC. Firstly a disclaimer. Some are themotropic LC which you achieve by heating something up and some are liatropic? crystals got from mixing a chemical into a solvent. Fairy liquid in water becomes a LC , that is liatropic. They are used a lot in the food industry for example , cakes like Mr Kipling use them. But the technological #aspects of them are not so interesting. So I will restrict myself to thermotropic LCs. I did have a demo for this but technical problems. A Fredrich Reinitzer? in 1888 had a chemical he'd derrived from cholesterol that he'd extracted from carrot. Scince, as it was back then. He could look and play around wiht this material. Try lots of things until something intersting happens. It doesn't work quite like that these days you'd not get the funding. It was solid at room temperature , he applied heat to it and it melted into a cloudy liquid , no surprises, plenty of reasions to being cloudy. He went on heating it until it went clear , completely clear at another distinct temperature. There was no real chemical reaction going on , one component only. It wasn't an oxidation reaction because it went clear. He made the quite fantastic logical leap that what he was looking at , what he'd observed was a second melting point. We are familiar with a solid, a liquid and a gas. Reading his paper I'm not entirely sure he knew what was going on, but he'd got it spot on. Using Xray difraction a bit later on , they found he was correct and he'd found a new phase of matter. To demonstrate this new phase. I'd like you to imagine you ar e each holding a straw above you, that represents a LC molecule. For now you are cold and solid . You can't move , you can vibrate a bit but you can't move around the room. in a solid molecules a re fixed relative to their neighbours and can't move around. All the straws would be pointing in the same direction . Lining up with your neighbours. This designates a crystaline solid. If I applied enough heat , you would turn into an isotropic liquid . Everyone now can stand up and run around . In such an isotropic liquid the molecules can move around , they can be in any direction you like, that characterises a liquid. Now a LC is still a liquid , you would still be running around the room but all the LC molecules would be pointing in the same direction. That alignment is a crystaline parameter , that why they are called LC, they have some aspects of a liquid and some aspects of a solid. Which is odd and there is really no other material that does this. We have a few states of matter other than solid, liquid and gas , we have plasmas at very high energies , we have Bozon ? condensate if we cool down a lot . In my straw analogy, if you heated up even more then you would fly out of the room as you would become a gas A schematic of nematic? crystals, long thin molecules, all over the place, disordered but all pointing in the same direction. Not very interesting in itself, it doesn't do much. You can form them into LC cells. If you have 2 sheets of glass that you rub with a cloth , you can put some LC between the glass , a planar LC cell. You can cause the molecules to line up in whatever direction you like, they are still moving around. I need to introduce 2 physical concepts to do wiht light. One is the refractive index and the other is polarisation. Light passing through a transparent material will slow down and the amount it slows down by, is cxalled the refractive index. Something optically dense may be an index of 3 or 4, a quarter of the speed in air or vacuum. 2 polaroid films here, as in some sunglasses. Light is a wave, an electric field oscilating up and down, or side to side, unpolarised light travels in all sorts of planes. Ignore the people who say its particles for the moment. Polarisation is the orientation of that oscillation. Polaroid film forces light , that passes through it , to give it a certain polarisation. If I put a second such film so they cross at 90 degrees, the transmitted light goes dark. LC cells are birefringent in that they have a different refractive index according to how light is polarised. Light passing through such a cell, in one direction will slow down a different amount , to light passing through in another direction. Refractive index used to be called refringence, so 2 refringence. There is maths giving how much light you'd expect to come out of a LC cell. Either it slows down as passing and comes out the other side, with no change or a polarisation rotation. Come in in one direction and come out in another direction. So we can turn light on or off, but one more aspect to make them more useful. When you apply a voltage the LC cells will reorientate, they are no longer birefringent and no longer let light through between the 2 polarizors. They do this very efficiently , very quickly, changing from a light area to a dark area by applying a voltage, no moving parts. You can get them down to micron sizes. So they started to be used in TVs, because if you can have a pixel that can turn red, green or blue light on or off , efficiently, quiclkly, and in a small space then you end up with a display. LC is used optically these days in lenses. Curved face on one side and flat on the other. Light will go through and focus to a point. By aplying a voltage you can change the RI , do the maths, and work out where the lens will refocus to. In a normal camera there are 2 lenses move closer or farther apart to change focus. In a mobile phone, say, you want something smaller as moving parts tend to take up space. Much more efficient and quicker than that. New stuff with LC. Photo-conductive materials, materials that change electrical conductivity dependent on the light shone on them. Make a LC cell with a layer of this material in it , change the applied voltage , depending on the amount of light . You can change the RI of the cell depending on the light. You can slow down the light depending on how bright it is. To make a hologram , in simple terms, shine light at an object , reflect that light through a plate of glass with silver compound on it . Develop it and the bits where the light were , there will be a different RI to where there was no light shone. Shine light back through and you get back the original image , a hologram. LC can do the same thing but more dynamicly. Shine light on it and change the rI where there is a lot of light and keep the same where there is no light. Imagine a sheet of glass between me and you with one of these LC light valves in it. Its perfectly transparent . Someone over there gets a laser pen and shines it in my eyes. The light will hit the LC light valve , change the conductivity , allow the LC to switch and go from a bright state to a dark state. So blocking the light just in that tiny area. So protecting my eyes . I think they are being trialled with the MOD for pilots to defeat kids or enemies with lasers. They will be able to see normally and just a small area of window will darken. With a hologram you can store a huge amount of computer information, so a sort of USB flashdrive but for light. But you can only write to it once, for traditional holograms. For LC lightvalves you can store for a time, not hours maybe a couple of minutes. You can store a huge amount of info on a very small space and retrieve it by shining light back through and erase the original info. The first time holographic data storage has been possible , involving beatiful mathematical algorythms. LC can make laser beams brighter . The area I'm working on measuring the electrical characteristics of LC cells using a laser beam. Metamaterials. They come about when you can create electrodes on plates which are smaller than the wavelength of light. So in the microwave region and so wavelengths in cm region, not too difficult. Visible light is down to the nm scale. A nm is the length that if you have an aircraft carrier and a seagull lands on it then the carrier will sink by 1nm. Engineering on that scale is really difficult, we have fantastic facilities at Soton uni for doing this . We can get down to 400nm , below blue light and create structures called metamaterials and do wonderful things. You can get negative RIs, you can #break Snell's Law , you can trap light , all sorts of beautifual science. You can use LC in conjunction with these materials to switch them on and off , to change the the operational wavelength , switching absorption peaks etc. There is no other material that can do that as efficiently and as quickly as LC. Beam-coupling. Using LC lightvalves , shine 2 beams of light on them and you'll get a diffraction grating and multiple beams of light coming out. Very useful for information processong . The internet signals these days tend to be light, no longer electricity . It is converted to electricity either at the exchange or at a cabinet in your road. Eventually we will be using light only, no electricity in our computers at all. For that you need to manipulate light in novel ways and LCs seem to be the way to do that. Q&A What are quantum dots and are they used LC displys ? A nono-crystal particle and the size of the particle determines the colour that comes out of it. They are used but I don't think they'll be in any display yoiu see in the shops. First there was organic LEDs and quantum dots will be the next technology. LED TVs are just to do with the backlights, but however the back light is generated, the RGB light would go through a LC cell. Even with OLED TVs we're still using LCD to switch the light on and off. Later OLED will be pixel size light sources , even micron size , emit light controllably. They did not work for a long time because they could not get the blue type working, giving out after about 6 months. The screen of this smart phone is OLED, LC is only used in the camera. You've not given us any chemistry, I'm not a chemisdt , I'm a biologist. Can you explain chemically what happens, why yhe molecules line up, positive charges on one end and negative on the other or what? This sample is LC known as E7, actually leaking. Contains mainly a molecule known as 5CB ? the first LC developed at Hull university , that is LC at room temp. E7 has just a couple of things added to it to make it melt at 80 deg C or so. 5Cb as a molecule consists of 2 rings of carbon atoms, known as phenyl groups, connected to each other. That bit is very rigid then a hydrocarbon base chain coming out the other end that is a bit more flexible. When 2 of these molecules get close to each other you get pi-pi bonding ? The phenyl rings in the middle whan they meet another they want to line up parallel to each other, to stack like dish plates. In a normal liquid of these , given enough heat energy , the bonding is quite strong but not strong enough to overcome heat energy. The forces of heat move them apart but when in the LC state that bonding is just about powerful enough to overcome it. They'll still be moving and moving away , but when they are in contact , 2 adjascent, then the whole thing will line up together. There are electronegative and electropositive groups at each end. Then shining a light on causes the energy state to change? It can do, one way , but we tend to do it by using the extra photoconductive material and change the voltage dropped across it. With certain other molecules you can make them bend when you shine light on them, tend to be used in displays now. We've been playing with a lightfield? camera . It uses a conventional camera sensor , in front of that is a piece of magic , described to me as a hemispherical ? in front of the sensor , scanned in such a way as to effectively develop a 3D mathematical model , like a cube of light, representing the depth of field of the view. Process that and then scan the picture so you can move the focal point within the resulting picture. What you said about the lenses there might kind of fit with how the're manipulating that filter .? I don't think this is a scan , its a single shot these lightfield units. With a LC you can scan a voltage and as you do that you will very quickly change the focal point. If you are taking information at each point as a function of the voltage. My understanding is its a single shot and its something to do with the optics itself. The optics are supposed to be very simple , and the processing is done in software? In that case it probably is LC , with such a scan you would be able to get very high resolution as well. Wheras with a moving part , cogs etc, then only a certain amount. They generate a 16 megabit file from which is generated a 6 megapixel image. ? It must be a scanning process in that case. I've brought along , what I often see in repairing electronic stuff, black bleeding within a 7-segment LC display. All I know is the problem seems to develop from being excessively cold or hot and I'm assuming the 2 glass plates cleave apart , then the LC bleeds across but I've never found out why the numbers fail to register anything although there is LC everywhwere? All such LC displays have polarizors in them , light going in through one and out through another . If we remove the LC from the situation entirely all you get is something that light cannot go through. You can only get this birefringent effect with 2 glass plates , normally coated with some kind of plastic , stick them close to one another , the gap can go up to about 0.5mm if your lucky. In a TV they are usually about 5 micron or so. As you say , in this numeric LC display, the plates have moved apart slightly and the LC is no longer ordered properly. You get something that is cloudy again, its not birefringent. You have small area htere where the LC is lined up but lots of these microdomains where there is no order as to the direction of the domains and the light is scattered . The LC is no longer being aligned by the polymer and what you have instead is something that is not doing anything significant to the light and you have 2 polarizors and so black. I forgot to say how thick this layer is . It has to be carefully controlled depending on what colour you want to come through. If you change the thickness of that layer a bit, then you'll change the colour of the light that comes through it. If you poke a LCD with a finger and see rainbow fringing that is what is happening there, you are flexing the display, changing the thickness , and changing the wavelength of light its letting through, as you have RG and B light behind it. With large flat pieces of glass on laptop screens , how can they guarantee absolutely rigorous separation, until you poke your finger at it, anyway, it seems impossible? They are very very good engineers, very good at what they do. The things we make in the lab , tend to sag in the middle , so about 2 microns thinner than at the edges. Something we ar einvestigating as its often ignored in hte literature. Really thin, tiny electrodes , so carefully designed to get these things working. Generally on new monitors these days, you will not get a single pixel breaking for years. Generally what sort of compounds can form LC, is carbon a requirrement and what LC types are used in common devices? Tyey're certainly asll organic. Tobacco mosaic virus , TMV, if you smoke and then touch a tomato plant, your tomatoes will die because of this virus from tobacco. This virus is also LC, then main thing is the morphology , the shape of the molecules, have to be long and thin with a couple of exceptions. You can get some similar effects in some metal structures but its much harder to achieve. The liatropics I spoke of at the beginning they consist of a hydrophobic tail and hydrophilic head. They form structures where the hydrophilic bit is on hte outside and hydrophobic in the middle. I lied a bit about soap as you only form LC structure only with certain concentrations . At other concentrations it will form just balls. The ones used in displays. A lot of them, engineering them is huge. And you'd think I'd be allowed to know about any of these molecules , very closely guarded secret, how they are made. Are there natural molecules that do it? Cholesterol is one. There are liatropics on your skin, chitin, silk, normally not at room temperature they are in these states. When you spill oil on water , the rainbow shimmering , that is LC setting up on the surface. Cholisterics , the LC that Reinitz? found out about. They curl round, the are chiral as you move up the material. They reflect light of a certain wavelength . You can unwind those helices or make them smaller depending on how hot they are. A hot one will unravel a bit and reflect a different colour of light, so used in simple card thermometers. A lot of cholosteric crystals exist in nature which have an extra group coming out of the biphenyl. You're saying these molecules occur in nature , is it purte coincidence they happen to be LC or is there any evidence they are LC as its characteristics are of evolutionary advantage to the organisms that possess them? Yes, but again not my area. Kitin and spider silk are both LC polymers, so not crystaline . Polymer chains made of LC molecules. LC polymers have their own material properties which are fascinating but outside my area. There is an evolutionary advantage to using them, that kind of material. How stable are these LC structures. If you go smaller and smaller I guess there will be local heating effects that may change the orientation of cells causing ??? Yes you do. LCs don't tend to absorb light by themselves. You can sometimes put metal in them , to absorb light and do interesting things but they don't tend to be very absorbtive by themselves. So shining enough light on them and heating up that happens with a lot of materials. Doesn't tend to happen so much with LC, again why they are so useful. You don't want them absorbing light in your tV say, as you won't have a clear picture. What does matter , is if you have 2 LC molecules next to each other . If you're trying to switch them using light as in ligh valves and you want them to switch in a very small area there is a contention. LC molecules really want to be lined up with one another , your not letting them, you're shining light at high resolution at them. That leads to all sorts of interesting problems . It affects all the molecules around them and affects the optical quality of the whole system. Basically how small you can get your pixels is a limitation of LC. We are just about art the limit in TVs at the moment, go any smaller then crazy horrible things would start happening because you are trying to make them do things they don't really want to do. How do you get colour from LCs? That is because you have red green and blue light behind them. Simple as that? Yess. There are reflective displays that work on cholesterics where they can change colour but its difficult to get them black. Almost impossible to get a true white also. When I'm taliking of something colourful like kitin , bubbles , shimmering colours then its nearly always a cholersteric windy ones. Is there any long term degradation problems with LC. If you have a TV display or an instrumental 7 segment display , it requires a certain amount of voltage for a certain amount of contrast. If the voltage step stays the same , 20 years time, will it produce the same contrast? You do get a degradation. Known as image sticking . Its not actually LC fault . We like to think that we've only put molecules in there that we want , but we process them in a factory , transpported , stored them and we introduce impurities. Some of these impurities are going to be charged within the LC. I apply a voltage so a positive voltage over here and negative over there that attacts charged material to either side. Bits of rubbish here and bits of rubbish there . Generally if you turn it off it will all relax back intio the system and no problem except for something called charge-screening?. However you have a polymer on the surface and you can get a chemical interaction wiht the rubbish and stay s locked in when turned off, that contributes to inmage-sticking. So switched off there is still an electric field . Especially in the early days , if I displayed a still picture and leave it on for just 3 or 4 hours then the image will stay there even when turned off. Are we lucky that these things happen around room temperature, or are there ones outside room temperature that we just have not developed yet.? We've had to be very clever to design these things to work at room temperature. I think even in the 1930s LC was posited to be useful in all these sorts of devices like displays after someone later than Reinitzer put out a seminal paper in German on the physics of this. The problem was that nothing could be made to work anywhere near to room temperature. Mostly operative at about 80 deg C. Most of these early developement guys were at Hull University. I think Hull should be a bit more recognised for that as they have a fantastic LC department. Its difficult for a physicist to see the problem when he requests a molecule that looks like this and does this, I know that will be useful, go on chemists, bring it to me. But its incredibly difficult and complex , some real geniuses working there, some still there, managed to get that to work. Is Hull still doing wonderful things? Yes, very much so. Now its such a big industry , the most exciting things have been done by industry, problems solved by industry , but not being published by industry, because thats industry. Early days used a LC called TL205 developed by MERK chemicals , was used in all displays. Nowadays every company and basically every line will have their own LC . Some of the cells are twisted, called twisted nematic (TN) , some are aligned on the surface called Vertical Alignment VA, and some In-plane Switching where they change state in a different manner requiring very cleverly designed electrodes. Do they have any problems with using these things in space? cosmic rays etc hitting the crystals. I'm not sure they've tried it much, there would be a boiling issue if the pressure is too low. A lot of 7 or 16 segment displays are just LEDs as they don't need to be clever. Do they use LC in electronic paper ? No . e-paper and ink is difficult to tie down as its a marketing phrase. Used in such as the Kindle. A lot of people say they don't like reading off a screen. But if you look at a Kindle , reading off it, it is exactly the same as paper. No different, ther's no light there its all done with reflected light and looks identical to a paper book. They use electrophoretics , a lot of liquid with black liquid inside it , which forms droplets within the clear liquid . Those droplets can move dependent on an electric field. Again , if smart with the electrode engineering , you can make the ink move , form images and words . At that point you can switch off the display, they don't move , thats the beauty , you don't need to keep updating it. Very efficient, no strain on the eyes as black against white or tan background. But it takes milliseconds to form a new image, long enough that you notice the change-over. Wheras LC are much faster, can go down to 5 microseconds switching speed. I seem to remember that early forms of industrial LC, were disctinctly toxic . Was that the case, or some toxic. Seeing that your sample was leaking out of the bottle, got me thinking.? The molecules contain things like cyanide and benzine but when bonded they don't necessarily form hazardous chemicals. We developed a LC display at the labs I used to work at , very small one, essentially a replacement for a photographic slide , put in an old Kodak slide projector . Then able to project computer images on a screen. The only way we could get it to work was by using gamma radiation , so failing environmental impact assessment on eventual disposal. We had to abandon the project. For its time was high definition, very small display, back 20 years or so. ? Interesting



16 Feb 2015 Unfortunately the scheduled speaker , archaeologist Dr Fraser Sturt has a family emergency and cannot give his talk. I, Nigel Cook , organiser of these talks have a prepared presentation with a bit of an archaeological context I will be giving instead. This talk, I'm scheduled to give to the City of Southampton Society
title: Mathematical Tiles in Southampton and Hampshire. The what, the where and most intriguingly , the why. New technology of the 1700s that still has the power to perplex and intrigue archaeologists, architects and infuriate building owners in the 21 century. By the end of the talk hopefully we can, now informed on their detection etc, decide on the evidence so far, whether there is a second example of these tiles in Southampton. So far not in the historic buildings records of such examples, despite being in full public view for over 200 years, such is their ability to misrepresent themselves. Very photogenic powerpoint and despite the title, absolutely no equations. Become some of perhaps fewer than a hundred people in the UK who have had a chance to handle some complete examples of these rare artefacts, rather than the shards found in archaeological digs, otherwise handled by just a few people, such as specialist historic buildings renovators and conservators. Learn the secrets of them, 35 villages , towns and cities in Hampshire have them and about 50 examples in total, and rising. Powerpoint based on my page A Small Study on Mathematical Tiles
rejigged with full resolution pics and an HD video projector. Gallery of examples in Hampshire, followd by the main talk. Background to what they are, then using the example on Tudor House Museum , Southampton to show the main diagnostic features, in depth analysis of a few representative Hampshire examples, ending with the evidence , so far, for 49 Bugle St being an undiscovered example in Southampton. Only the Q&A , transcribed here, interspersed through the 1.5 hour talk. Why did they construct using these tiles? There isa lot of unknowns in this subject, its open to the audience when it comes to the rationale behing them , because no one actually knows, a lot of theories but no certainty. When was that lablel, mathematical tile (MT), get put on them. They've always been called MT even if you looked in the early editions of the digital Times Newspaper resource. If you looked into what the term mathematical meant in the 1700s , then it meant precision. A main rationale behind these tiles is the skill in making them flat, you will hardly ever see a flat roof tile, and consistency in colour and shape. So anyone relatively unskilled on site could lay up a complete wall of these in a day. Compared to laying bricks which requiires a lot of skill. Lay them adjascent, level in 2 senses , progress a wall vertically keeping planeness in 2 senses and having to keep stopping to let the mortar go off. You have to mount them on something? Yes, that's where they start to fail. They're not structural, they're a cladding. (Tudor House) There is brick behind the tiles? Yes, very common. No one knows for sure , why. You can understand where you have a timber frame building , with wattle and daub or plaster that's seen better days - then clad it up with tiles. Why clad tiles over brickwork that may be perfectly good brickwork. With the Havant chemist shop example, they have builders in at the moment. There is serious cracking of the underlying brickwork , one and a half bricks thick, header and stretcher thick, plus 2 1/8 ins of MT. That cracking due to a massive beam , 2 burgage plots long, behind, now sagging 7 inches and has cracked the brickwork, maybe the original justification for MT covering over the cracks. My own property hasn't got tiles on the outside but you said why would there be bricks in there. In this the timber framing ofa wall , for some reason has bricks filled in at some unknwn period. Then subsequently anothe rwall was built just beyond by an inch from the original wall with the timber framing. Whether simply because it was loosing structural integrity. ? Probably the same structure in Tudor House as its been rebuilt and added to many times over the centuries Its a funny mixture of lengths and widths and everything on that (tudor house) wall.? Over time they must have got different batches to patch up repairs , with the large pink patch to the right they must have given up and placed some brick slips or terracota slips or somesuch. More like dry-stone wall construction, different shapes and sizes, fitting them in where they can.? The angle of the photo doesn't help . Would the (Brockenhurst) tiles have to be made specially? Yes. I've no idea of cost. In the 1700s plain MTs were of the order of 3 GBP per thousand, in the 1980s about 80p each. But those external angle and tapered probably had a lot of failures along the way and much more expensive. Presumably why only one type was made for one taper angle of octagonal spire. The mixture of the old lichen covered tiles and the new whiter ones looks very good. (Preston Candover) are those vertical sections over the windows, tile as well? Traditionally it would be wood, could be brick slips or anything. Brick slips? Bricks cut down into slices on a Clipper Saw or made as such slivers. Is Keymer the only supplier? no there isa number of them but the quality varies widely. If a building is listed and has MT and they fail, do they have to put MT back again? Yes (Romsey) Re-tiled, so earlier tiles removed? Yes and not salvageable presumably, new ones replacing them. It cost a fortune is the only figure I can find for this restoration. The bugle st example , were there some tiles protruding an inch? No that pseudo string course is neither brick or tile but stucco or plaster. I'll never be allowed to get up there and poke around to confirm though. So no "bucket-handling" underneath in the wet plaster? No just flat trowelled off surface like the initial front face before bucket-handle incising the brick patterning on it. On the right hand edge of 49 are they external tiles? Its so well painted over render probably its not possible to say what the return section is made of, certainly no MT edges exposed, unfortunately. Does someone do this nowadays. I don't know anyone professionally who deals with this but there are certainly people who do. So they were called Hampshire or Southampton tiles but were they used widely around the whole country? Yes. It started in London, a famous architect of the time Soane or Hollande . Because by that time red bricks had become common-place , too common, used even for farm outbuildings. So the fashionista of the time declared that the new brick should be white , so pushing the fashion for white/yellow brick. So white MT were clad over existing red brick walls. In Kent you can find white MT. Nothern counties as well? No , very much Sussex is the capital of MT about 300 examples and then Home Counties. Wiltshire has 30 or 40 examples just in Salisbury, and just 2 elsewhere in Wiltshire . One example in Wales and a few in Norfolk but thats as far north as they go. I don't think even Dorset has any examples. You need a special type of clay and the Weald , Hampshire and somewhere in Norfolk seemed to have the only suitable clays. Even for ordinary clay roof tiles you have to be more selective of the clay than for making bricks, how you prepare the clay , how you mould it , the drying and firing stages are just a bit more involved than roof tiles or bricks. Sagging of clay roof tiles is part of the attraction of traditional tiles, but you don't want saggy MT

09 Mar 2015, Dr Martin Gregory, Industrial Archaeology and Twyford Waterworks 31 people, 1.5 hour I'll start with Southampton because all the south Hamsphire area is essentially sitting on one large ball of chalk. The chalk is permeable, when it rains , it soaks into this reservoir, that is our water sup[ply. Nearly all the water you drink is pumped out of wells in the chalk. You sink wells into this chalk, pump water out of those wells into small brick reservoirs on the tops of hills and that then gravity feeds the surrounding area. Twyford is one of the places , how it operates. Southampton startrd pumped water supply in 1851 . The first plant was at Mansbridge. 2 engine houses, now sort of under the M27 now. They took water out of the Itchen. That led to problems as if you take river water you can't just pump it round , there are creepy crawlies and you need filtration and treatment. The company was in competition with Southampton . The 1866 sanitation act required local authiorities to arrange a wholesome supply of drinking water . With Soton they decided to do it themselves for the city and Portswood area but the rest of S Hampshire had other companies, Winchester its own private company and the rest was the South Hants Water Company. The chairman was William Erasmus Darwin , Charles' Darwin elder son and the offices were 2 High St, adjoining the Bargate. Its first pumping plant was at Timsbury, north Romsey. That pumped water out of wells in hte chalk to Michelmersch which then gravity supplied Romsey , they gradually extened out until they were supplying Shirley with a depot on Winchester Rd , Soton. Shirley was then a village , in the 1870s. Soton demolished its Mansbridge plant and moved it to Otterbourne . A much larger plant with 4 beam engines in the 1880s. That pumped water out of wells to a brick reservoir on the top of Otterborne Hill and that gravity fed Soton. The pipes following the railway line, presumably going past this place. 1890s the South Hants company was expanding , got to Shirley was looking to the enlarged villages of Eastleigh and FairOak and Bishops Stoke. They commissioned their engineer to look into a pumping operation based in the Itchen Valley rather than the Test Valley. He was Baldwin Latham , one of the great waterworks engineers of the UK. Something like 30 UK towns where Latham designed the waterworks. He also did Cairo, Danzig , Bombay, Calcutta and many more. The plant he built at Twyford, the beginnings of the plant there today. The low single story plant of 1898/1900. The taller building is 1905 extension and also on the hill, lime kilns for water softening. The argument was that if we wanted to sell the water , the customers liked it softened, the medics didn't . Otterborne had softening , the competition. Around 1909. 1905 the first of the triple expansion engines at Twyford. Built by Richson Wesgarth?, marine engineer builder in Hartlepool. the only stationary engine they ever built, but short of work then in 1905. Fairly typical of engine building of the tim,e. That plant was the biggest employer in Twyford village. In the Edwardian times about 20 people. The reservoir is less than 24 hours supply so has to be 3 shift 24 hour a day working. Everything is 3 shift and everything is backed up and duplicated. The engine there taday was built by Haythorn Davey, a specialist pumping engine manufacturer , the "Rolls Royce" of pumping engines. One of Henry Davey's last designs , he startred in the 1850s , still designing in 1914. The crusade throuhg hte latter bit of the 19C was to improve the efficiency of the steam engine. If you could get more work out of the steam then you would improve the efficiency. Put the high pressure steam from the boiler into the high pressure cylinder , let it expand and do some work ,re-heat it and put in the next cylinder , expand more doing more work , reheat and put in a third cylinder, you are getting more work out of the steam. There were even quadruple expansion engines built. The efficiency of energy input to water pumped , is as good as the electric pumps that are down there today. The difference is that you're not employing 20 people, unattended and remotely controlled. Still providing water from the same well , forced to the same little reservoir through the same pipes to youy and others down the Itchen valley. The same applies to Otterbourne and Timsbury. The Twyford engine was 100 years old last year. One of the biggest problems with reciprocating engines , whether beam engine, formula1 grand prix car or your runabout. One is getting fuel or steam into the cylinders and the other is getting exhaust out of them. The rest is fairly simple. This has a very efficient system of valve-gear which gives control over both of inlet and outlet parts of the cycle , independently of each other. Infinite adjustment of the running conditions, allowing tweaks for a very efficient engine. The valvegear is Corless, by American George Corless in the 1840s and it remains standard on reciprocating steam plant to the end of the steam era. The reheaters are just heat exchangers, high pressure hot steam goes through the tubes and the steam being reheated is around the outside, in the drum. Gauge board, tells you the pressures in the various parts of the engine. In the middle a stroke counter, you need to know how much water you've delivered, count the number of strokes and know the volume of water displaced in each stroke and make a guess at the leakage (small). Engine is at ground level , below it are some ram pumps that push the water out to the reservoir . The wells are operated off a set of lift pumps , to one side, so the engine is driving 2 sets of pumps. The Twyford wells are about 40m deep with about 1km of adets driven out from the bottom of them. How do you dig them? The chalk is saturated with water, the water level is about 10m down. So how did they dig the last 30m because it was not done by divers. We don't know. All we know is the contractor went bust because he paid the men too much. He paid ther gang a pound per foot run to share out to the gang. Similarly for the adets. These days you could freeze the ground. They are lined for only about the first 10 metres, after that you're hoping water will come in. The adets are to collect water. The chalk is the filter, its super water. The only treatment at the 3 local plant was to put chlorine in, to remove bacteria. Same today, no water treatment done because whaen water softening ceased , the medics were thrilled , hard water is good for you. After that there was no purpose in water softening in water treatment. One time Twyford had a bottling plant, called Hazely Down water. When the French bought Southern Water in 2003, theyb closed the bottling plant because they wanted to sell Avien. in terms of bacterial count, minerals Twyford is 10 times better than Avian. An engine needs boilers. I find it depressing that the vast majority of "preserved" steam plants you go to, the steam engine is original but a modern package boiler around the back, eg Bursledon Brickworks, original steam engine from 1870s but a modern boiler you just press a button. At Twyford we decided to restore one of the old boilers back to steam, then you can see the whole plant. 3 boilers , Babcock & Wilcox , the preeminent boilermakers of the 20C these are the last 3, they've not survived well in preservation. An elegant design, a steam drum at the top about half water, half steam and banks of tubes suspended below it, the water is inside the tubes. So unlike a railway locomotive where the combustion products are in the tubes and water around the outside, here its water in the tubes and the fire around the outside. Which means the brick firebox that surrounds it has no pressure difference across it , just need to keep it airtight , so no smoke in the boiler room, just a decent draught on the chimney. September 2014, boiler 1 the one being restored. The boiler next to it still has tubes in it . One of the big arguments in the preservation movement and museums, very fiercely fought argument, is do you conserve or do you restore? The conservationists say you mustn't restore it , you change it , don't do anything to it other than stop it going rusty. Corrossion inhibition and keep the roof watertight but your job as a conservationist is to preserve it for future generations. The restoration people say its no fun if its not working , we want to see it working. The are people with unique items and are not allowed to restore it as the conservationists have won there. They say can't conserve it by restoring it. We are lucky at Twyford , we have 3 boilers, so we are restoring 1 , conserving 1, and leaving 1 exposed so the public can see out its made. We're considered extraordinarily lucky to have that option. We've now got the firebrick wall on one side of the firebox, still no tubes. You need the scaffolding around because the whole thing is suspended from a portal frame, that frame carries the steam drum and all the tube banks. It sits in cast iron pads on the floor and they're not attached . The verticals sit in cast iron sockets . So if you take the scaffolding away , with no brickwork, you can move the whole thing around. March 2015 we now have the tube banks back . All metal to metal contact , all expanded. The tubes go into a socket, place an expander up it , to roll the tube out until it grips , nothing welded, no rivets, very clever. You only need one size of expander to do the whole lot, all 4 inch tube . Thats a problem as you can't get 4 inch tube now as its all metric but our boilermakers solved that problem. All the tubes, so you can sweep and clean them out have caps over them, cast iron caps screwed on. Both ends of the tubes will have those caps on. The superheater headers, the top one goes straight into the bottom of the steam drum and the other has pipes along the side to the valves. There will be lots of superheater tubes expanded into those, different size expander for the superheaters. The next job. Twyford was the second last one to remain in steam, after Otterborne. When that happened Soton University Industrial Archaeology group lobbied to have the site scheduled andin 1973/4 it was scheduled as an ancient monument. English Heritage has 2 systems, scheduled ancient monuments and listed buildings. Its more difficult to change scheduled ancient monuments than change listed buildings. Both have 3 levels grade 1, 2* and 2 or scheduled 1,2 or 3. 1 is national importance like Stonehenge and Twyford, its the most complete set of waterworks kit in the country. So in EH view its of national importance site. Sadely EH don't have lots of money these days . So all this work at Twyford we've been fortunate with a Heritage Lottery Fund to return to steam. Everything at Twyford is operable under steam once you have a live boiler. The feedpumps to provide high pressure water to the boiler, and 2 of them because of the back-up problem of having a smalll reservouir. There is an air compressor , 2 of them, a dynamo for lighting , DC lighting originally , 2 of them. One of them the Reader is a steam engine the other a Russel-Newbury Diesel which was the backup. Done about 25 hours according to its log book in 75 years because the steam engine was fairly reliable. It was run up occassionally to make sure it worked. The population expanded and Soton Corporation did not get on well with the South Hants Company. Their spheres of influence met roughly along Winchester Rd, Soton. They threatened a compulsory purchase order on the S Hants Company. The argument was the Water Rate that you paid to Soton was half the rate you paid as a customer to the private company, that was making considerable profits. All residents of greater Soton should have the same water rate. So in 1910 the difference between private and council utilities existed already. After the First World War they did take over the S hants company, which is why Southampton Corporation is over the door of Twyford now, the first thing they did was pay a local stonemason 27s 6d to chisel the change of name. 1930s they built a diesel house , wanting more pumping capacity , Chandlers Ford growing. Otterborne got more steam engines, Twyford got diesel engines . So we have examples of steam and diesel plant. 1934 , the depths of the depression, Soton Corporation has a lot of civic pride, building the civic centre. The new Twyford building has stone facings etc. Otterborne fared even better, they got stained glass windows with hte Soton coat of arms in them. Diesels driving centifical pumps . Such pumps need to go round fast , wheras reciprocating need to go slowly. Steam engines 20 RPM, 23 is top speed. The diesels are about 400 RPM which is rather slow for centrifical so there is a step-up gearbox to 1000RPM. The other problem with diesel is centrifical pumps have a very considerable slip , loss of water that depends on speed. So you can't have 1 engine driving 2 pumps , from the well and out to the customers. Because you don't know how much the water will slip and have to match them as there is no storage in between. So 2 diesels to replace . 1950s electricity came to Twyford. The grid came with an 11KV supply and some electric pumps . A centrifical pump in the ground and a DC motor at ground level. You want to know how much water you are supplying. A Venturi, a constriction in a pipe , htere is a resulting pressure drop , know the diameters of the pipe and the pressure drop, you can work out the pumping rate. A venturi-meter ,U-tube at the bottom measures the pressure difference and the top has a brass drum driven by a clock and a pen controlled by a float in the U-tube. So a graph on the drum of pumping rate v time. All our pumps have these venturi meters, whether steam, diesel or electric to measure their output over time. There is aso a set of dials that measure the total amount pumped, integrated pumping rate and time. To do that mechanically requires non uniform cams , mangle drives and nasty gear wheels. There seems to have been no standaed way of doing it. No 2 meters that we have, have the same box of gear wheels and cams to integrate it. No 2 meters that we have , have the same size drum, so the supeintendent needed different sizes of graph paper for evey meter, all printed Southampton Corporation Waterworks. So someone in Soton was printing 50 sheets this size and 50 that size, and 50 another, one a week use. Water softening. Otterborne,Timsbury, and Twyford did it by O level chemistry. Water coming out of the chalk is saturated with Calcium Hydrogen Carbonate. Add an alkali to that , any alkali, you precipitate out the hydrogen carbonate as carbonate sludge. Why not choose Calcium Hydroxide as the alkali as we have chalk on site . If we put up a lime kiln we can bake the chalk to make quicklime , slake the quicklime with eater we get slaked lime Calcium Hydroxide. Add that to the water from the well we will precipitate out Calcium Carbonate and we can sell that . Invented in the 1840s ,by a man called Clarke only done in the south of England chalk areas. It ran at Twyford from 1902 to 1969. Think of 1902 and Soton Docks, its the era of the big liners, so millions of gallons of softened water wanted. The Queens of the 1930s took on 1.5 million gallons a voyage. No desalination plant on board then. Now the Soton based liners tsake on no water at Soton as they have there own desalination plant . There was a large market for softened water and it was that that really paid for the softening plant. Thats left us with the last surviving set of bottle lime kilns. These were 50 years out of date when they were built. Why not a continuous feed top loading one that everyone else was using, we don't know why. So we have a set of beatiful botltle lime kilns. The loading floor and the little railway. A chalk quarry on site. The lime kilns are up the hill which keeps the fumes away from the rest of the works. So a railway incline to get there. Everything in the softening plant is driven by hydraulic motors , as you have free high pressure water on site, no electricity to 1950 and never any gas. Too far from the boiler house as condensation in any steam pipes. Used to be common for things like opening dock gates and dockyard cranes. You have to mix the quicklime with water to make slaked lime and then into a softening tank. Most of the carbonate settles out in the tank. Once a fortnight every man on site is given a broom , go in the drained taknk and brush out all the sediment into a culvert that runs under the road to a sludge pit. They sold the calcium carbonate to toothpaste manucfacturers, 95% by volume , of toothpaste , is a mild abrasive to polish your teeth what better than calcium carbonate precipitated out of pure Hampshire chalk water. They removed the last 5% or so with cloth filters. A row of steel tanks and in each tank . System patented by Charlie Haynes of Soton Corporation Waterworks only used at Twyford, Otterborne and Wimborne Dorset. Each steel tank has 20 filters, a flat perforated metal box with a cloth sleeve around it . If you have cloth filters in the public water supply sooner or later you will get Legionaires Disease . So once a week , every tank was taken out of circuit , steam cleaned and sterilised and put back in use. 2 tanks per day and 1 on Sundays. Hence 20 people over 3 shifts to keep it going. Any sludge not sold was pumped on to a lagoon and settled out. We need money and volunteers to get the railway incline back into use. And to convince Health & Safety that you can have an incline of about 40 degrees safely operating with the public around. There were no locos a tthe waterworks proper, they pushed skips around and a hawser to raise up the incline . We've imported a little diesel loco to help us aging volunteers. The filter house has some spare space in it and we've used that to preservr/restore some offsite local water pumping plant. A gas engine came from a livery stables in Portsea where they had a private well, driven off the town gas supply. Our entry kiosk was the bus shelter at the library in Jewry St, Winchester, made in the 1920s for Hants and Dorset. Q&A Could you explain why medics preferred one process and not the other? Calcium ions in the water is good for your cardio-vascular system In 1900 when they built the softening plant they said the customers liked it because hard water produces a lot of scum with traditional stearate soaps. so trying to do your laundry and its a problem. That meant customers were prepared to pay the extra water rate to have it softened. By the 1960s modern detergents would cope with the scum problem , so thats gone. The medics had always lobbied for hard water. So they were only too delighted. As far as the docks were concerned steam demand had gone. In the 60s and 70s there was very little passenger shipping from Southampton. How often are the waterworks open to the public? The normal regime, this coming year , is the first Sunday of the month from May to October inclusive. So we open on May bank holiday weekend . Can't tell you when we get back to steam , things are going well at the moment . However once everything is sorted out you then need various training runs and only 2 or 3 of us who have had experience of running the site under steam, before. So we have to train up people, we've got to debug it all. I would have said we are likely to be in steam for the general public, possibly October, the last one of the year. Maybe earlier. On the restored boiler we have to fulfill all present day pressure vessel regulations. Every rivet has been ultrasounded and Xrayed, all the tubes have been replaced. Why, because modern pressure vessel regulation says all tubes used must have a pedigree, you must be able to go to the paperwork and say this was rolled at this steelworks from that batch of steel, you can't do that with hundred year old steel. H&S aspects. It has no automatic water level control. There are 2 gauge glasses , even in the 19C you had to have 2 in case one broke . But present day regulations say its not good enough to have a human being and keeping an eye on the water level and do something if it drops below there. You must have something that is computerised and an electronic water level on it, an electronic pressure gauge . Borden gauges, a flat tube rolled up, increase the pressure and it tries to straighten itself out . Been around since the 1840s , very reliable , every oxygen cylinder in the world has a Bordon gauge on the top of it , but the H&S says there must bre an electronic readout. I don't believe the electronic readout will be as reliable but we shall have both. A Bordon because we have one and that was what was originally fitted with and a discrete , round the corner, readout. We just don't know how long that process will take, debugging , satisfying insurance people and H&S. Why do the tubes have to be set at that angle? The cold end of the boiler , the chimney end , is the lowest bit of the tube , so the cold water seeps down the downcomers at the back and as it comes up the tube its heated, boils and steam comes up into the short tubes at the front of the steam drum and that keeps a circulation around the system. Actually very efficient. Invented in the 1850s by 2 Americans. I still cant figure out why its more efficient at an angle? Because when you start up , the hottest part of thre fire is at the top, the water hotter there, so steam initially produced there , goes into the steam drum and displace water down the pipes at the back. Once that circulation is going , it will keep going. Do you have any trouble getting hold of coal? No, its just rather expensive. I don't know the early coal consumption figures but in the second world war when it also had diesel plant helping it. |It was allocated by the Ministry of Coal, a thousand tons a year. That was all hand fired , so 3 tons a day. Was that nice looking building at Mansbridge, designed by an engineer or an architect? The cottages that were alongside it were still there a few years ago. I don't know who designed the main buildings. I think it all got subsumed into the M27. Baldwin Latham was the architect at Twyford. But basically you built what the customer wanted. A private company had to pleas ethe shareholders but it was not a matter of civic pride. Otterborne was Soton Corporation and therfore civic pride. Once you built the town hall or the civic centre, the next thing a lot of cities spent money on , was the waterworks. The most elaborate of all is Nottingham. Hathelwick that has been preserved by Severn Trent Water. The condensing pond for the steam engine had fontains, all really over the top. All the cast iron pillars that support the machinery have brass vine leaves curling round them, and griffins on the capitols. Nottingham mayor wanted to show other mayors that Nottingham did it properly. There is a council chamber just for the waterworks committee that convened just 2 meetings a year. The only other complete Baldwin Latham plant left in the UK is at Wolverhampton. That is Venetian gothic with bartisans at the corners, and turrets, because thats what they asked for. The machinery is basically the same as at Twyford. If you need technical drawings for pumps or engines is there a National resource for that , like Wroughton Science Museum library or local county record offices on the assumption that company records would have ended up locally there? There is a lot at Wroughton. In the case of Twyford, because it was originally taken over by Soton Corporation , part of the engineering records are in Soton Record Office , including drawings, yes. A number of the drawings, we happen to have because Soton Corporation tended to leave a set of drawings on site. Southern Water on the other hand gives drawings and minute books etc to Hampshire Record Office in Winchester. Sothern Water in the 1980s/90s was to photograph all their drawings onto microfiche cards and throw away the drawings. Unfortunately the resolution of those drawing doesn't enable you to read the anotations on the drawings. Although you can see the general layout you can't now get any dimensions . I guess there is an enormous problem coming up for our successors of digitising everything and putting it into a format that the computers of 20 years from now won't be able to read. Then we will have lost everything. Most serious archivists print it out onto paper, that the first thing they do, if you give them a digital file. If they are archaeologists, they send it up to York and hope their distributed systems will keep it live and working uncorupted? On a related thing , is there anyehere local you can go for big engineering. There is one little aluminium foundry down here, is there anywhere for making and machining a big engine block? Not that I know of. You have to go up north every time? No, usually you have to go to either Czechoslovakia or India. Czech because Skoda in Pilsen still have the ability to cast and forge things that are 20 feet long and 10 feet diameter. How much longer and even that will have disappeared? I went around it a few years ago and they reckoned they could keep going for ever because nearly all the shafts of wind turbines and big things like the London Eye , they are now the only people in Europe who will tackle it. They reckoned they could make enough on a few really big jobs . Along with that there must be the human resources as well? after all the Fred Dibnahs of this world have passed away, there are people coming up through who can take on that sort of work? Yes. But it is a sad fact the average age of volunteers is very high. And we've really got to get more young people , we've a couple of 20 yearolds at Twyford, the people we really have to be nice to, because they are the people going to be here in 20 years time. I take it you are on nice friendly terms with the likes of the Watercress Line and related engineering setups? Yes. You do find there are volunteers for both and there are volunteers who have a disagreement with somebody at Twyford and go off to the Mid-Hants railway , then a disagreement at Ropley and then back at Twyford. Then off to Bursledon. Are you in charge of the volunteers? No, I'm just a volunteer. You mentioned a Sanitation Act of Parliament , was there a legal definition of what constituted wholesome water, nationally or left to local authorities to interpret? It was quite an interesting thing. The Act said it was the duty of every local authority to provide a system of sewerage and a suplly of wholesome water. Sewerage is almost entirely local authority driven. But no set time limit , left to the local government boards to enforce it. Soton had a borough engineer who got it organised very effectively. Ten miles up the road at Winchester they had a waterworks in 1851 but no sewerage until 1878. The city council just kept procrastinating in replies to the Secretary of State, saying we are considering it, for 20 years. The water closet has been invented, more and more closets, more people sign up to the water company but what do they do with their effluent. Did the water supply have to meet a set of criteria? Yes, mostly related to things like cholera. Established by Dr John Cross, a waterborne disease , not the miasma of the atmosphere. Cholera and Typhoid there were tests for. Over the years there was no serious problems with any of the local chalk well water supplies. That was organised at national level? Yes, set up by parliament. Was the water quality inspected? With Twyford, Baldwin Latham is not only a major engineer his obitiary says he was no more a familiar face in parliamentary committees. You mentioned the dimensions of the well, is that from drawings or examinations of the well? They have been surveyed, sending down CCTV systems. You've got pictures of the structure? Yes, every year or so it is filmed. There is one bit of film that I have that shows how they were dug. Showed standard skips for perhaps 15 inch gauge railway being rolled along and men in waders and souwesters. Chalk has fissures in it , you would be digging along in hte dry and then knee deep in water as you broke into the next fissure and the water level would rise rapidly. The contractor had a few small pumps . If you take out your 25 million litres of water a day, the level doesn't change, there was certainly not 25 million litres a day pumping capacity when they were sinking it. North of Fareham there was a waterworks for Knowle hospital, that was from chalk, but it was found you could pump that dry in a few hours. So they tried elsewhere to find a better supply. They surveyed all the water levels of all the wells around , every farmer and private house with a well. You find there are hydraulic gradients through the chalk, so hte water is flowing through the chalk. You want to put your well where the level is deepest. The deepest well is at Otterborne, why it was built there, then 2.5 miles away at Twyford there is another sump and so on. Could the adets have been mined by miners under compressed air, still used these days? They could have but no evidence that they did. The technology was there but there was no pics of compressors or air locks and paper documents showing the outline of contracts, dimensions and prices. There was a lot of people that drowned in that sort of period? I guess there were. i don't think anyone turned up in Twyford churchyard having drowned. All much a mystery. When did the diver William Walker rescue Winchester Cathedral? That was around 1905, using full diving rig. Otterborne was drilled rather than dug , adets were dug but the wells were drilled. At the time the largest drilled wells in the country. By drill I mean a large cast iron mass with chisels all over it , raised it , dropped it, breaking the chalk. Then a miser a big spiral auger which scooped up the broken chalk. Would they have drilled holes along the line of the adet to reduce the water table at that point? I suppose they could have done. The surprising well is the one on Southampton Common. The concrete cap , near Burgess Rd is still there. That is 1500 feet deep , they went down 700 feet by hand . Dug out a couple of feet depth, bricked it up, rather smaller than you dug out. Then puddled clay between the brick and chalk to make it water tight. The brickwork was underneath , not dropping by gravity. hen they got down 700 feet and no water they decided to bore down , got down to 1500 feet and still no water, so they capped it off. The chap who dug it was the most famous well sinker in Hampshire, a Thomas Dockwra , his name survives as Southern Water subcontractors Clancy Dockwra. When I visited Otterborne many years ago they were proud that it was dug by Cornish miners, because the copper and tin mining industry had collapsed? I have some photos of the adets at Otterborne , one of which collapsed and there are people down there in chest high waders. I've heard one theory that the water we get comes from Spain? I doubt its from that far. One of the problems with chalk is the permeation rate is about 1m a year, pretty slow. But the permeation through fissures is a bout 1m per second. So it all depends on how many fissures there are in hte chalk that your adets intercept. A theory is they choose fissure-free chalk , so they could dig the well , then took explosives down there to shatter the chalk, so the water flows in quickly, a bit like fracking. The strangest well I've come across was sunk below Spitsand Fort in the Solent so surrounded by seawater? Is there any desalination plant in Hampshire? Not as far as I know. There is a river intake at Otterborne put in 1940 wartime because they were worried the steam plants at Otterborne and Twyford would be bombing targets. No damage from bombs anywhere near them. After the war that remained and is there to this day. Even in London no serious damage to water or sewerage plant occured in hte Blitz. Again in Berlin no significant pumping plant was damaged by allied bombing

Monday 13 April 2015, Dr. Simon Boxall, National Oceanography Centre, title: Planet Ocean -a guide to the hidden planet in our solar system. synopsis:Known by the locals as planet Earth, planet Ocean is the 3rd planet from the Sun. Covered by water its inhabitants live on the 28% of rock and earth jutting out of the sea. Its environment is ideal for life due to a perfect balance in the composition of its atmosphere and the surface temperature of the Sun. Little is understood about what lies beneath the surface of Planet Ocean and it remains one of the least explored areas of the solar system. Learn more about this mysterious planet with needs more than a Goldilocks' Zone to thrive. 42 people, 1.5 hours The Goldilocks zone. We hear a lot about this planet exists i na special zone, not too hot not too cold, just the right distance from the sun. Actually the oceans have a lot to play for there being life on Earth beyond just a stable planet. Its a lot more complex than you might think. Actually we are not planet Earth, but planet Ocean. We are 72 percent water . If you divide the ocean up so every person on the planet, all 7 billion, have their share of the ocean, we would each own a swimming pool 2m deep and an area of 93 sq km. Its a bit tough if your patch is at 10,000m , a bit cold and a bit high pressured. They are vast and a major part of our planet surface. The Circumstellar Habitable Zone, otherwise known as the Goldilocks zone. Our planet sits in what astronomers call the habitable zone. We are in just the right distance from our sun. You can look at a series of star systems and by looking at the mass of hte star, you get this relationship for any star in the universe, has its GZ. Extra-solar planets there are some that sit in the GZ, eg BS581 ? which sit in the GZ. Astronomers expect for such planets in their GZ, they expect to see water and can expect to see life. The Earth is a bit more special than that, not jus tthe distance from the sun. For a start we have tectonic plates, which is an important factor in making the Earth the way it is. Because thiose plates move round, there is not a rigid crust to the Earth, like Mars for example. It means below the Earth surface there is convection going on. If we look at the mantle, and the core of the Earth, we get convective cells . Because the plates move, the cells can also move. If we had a rigid surface, it would slow down this circulation, ther ewould not be the overturning of the core. This spinning of the iron core is important because it creates a magnetosphere, a magnetic force around the Earth, which stops the Solar wind from literally blowing away the atmosphere. Without the magnetic field the solar winds would rapidly blow away any atmosphere. We get the amazing northern and southern lights. When we first visit a polar region we spend the first night looking up to the sky to watch them. The other main bits of science are down to 2 laws. Stephan and Wien's law . All bodies radiate e-m energy. When we feel the heat of the sun we are feeling light . We can look at the spectrum of em from gamma rays, X-rays , visible, IR, radio and beyond. Dependent on the temp of the body so you radiate energy according to that temp. Wiens Law, wavelength times temp we have a constant. So the sun with surface temp of 6000 deg K, so the optimal wavelength from the sun is about .5 micron which is blue light. Over half the energy from the sun comes in the form of light. If we look at the sea surface, or us in htis room , we are about 300K and so our optimum emission is in the thermal IR about 10 micron. Looking at the spectra from the sun it has a peak at about .4/.5 micron. The energy from the ocean goes right up to the 30 micron end of the spectrum. If I turned the lights off here and was dark outside we would not see each other. But if I had an IR camera , you would all be sitting here glowing. Some of you hot after rushing in, some cool be an exit. A range of temps, picked up by your thermal IR emission. If aliens came to Earth, the assumption is that they would see us as we see us , in light. The chances are that if they saw you in terms of what you gave off , then they would see you as an IR image. Gaussian curves around those peaks, half the Sun energy is in that rainbow of light. Oceans giving energy up in hte thermal IR. It just happens that the atmosphere is perfectly tuned to this. The constituents of the atmosphere, methan, nitrous oxide, oxygen, ozone , CO2, water. Each of those components absorb energy at different parts of the spectrum. The atmosphere has a handy gap at the sun peak wavelengths, not a lot absorbs the light. Oxygen and Ozone absorb a little . Go down to the UV then O3 does a really good job of blocking off the UV. Hence the concern if the ozone layer is diminished because we start to take away the sun-block. We get radiated with harmful UV. We can still get sunburnt, but that is the tail end of the UV, near the visible light. As we go through near IR, 1 to 3 micron, water and eventually CO2 absorb that energy quite well. Then where the ocean gives energy back to space, again a neat gap, a narrow window . When we talk of climate change and greenhouse gases , the concern is if we increase for example methane , CO2, nitrous oxide and water then we start to close the window. At present there is a fairly nice balance between energy coming in as light and energy back out as IR. If we close the greenhouse window we trap that energy in and so we get global warming and climate change. The size of the planet does matter as well. If its too small it cant hold on to its atmosphere, not enough gravitational pull, the gases leak out into space. If we were the size of the moon we would not expect to see an atmosphere if it had not been stripped already by the solar wind. When the energy from the sun hits the planet surface, then some of that energy will be reflected naturally back. Looking at the albedo of the ocean is about 4% goes back out to space, not a lot, 96% goes into the ocean. If our planet was mainly forest then more reflected back, 18 to 25%. If it was desert then about 40%. If an ice or snow covered planet then about 70% goes back out into space. So once you get a snowball planet its very difficult to warm it up. The fact we ar emainly a water planet means the energy coming in isnt lost back out to space, absorbed by the ocean. That gives the perfect GZ effect. If our surface was not water but another material then particularly seawater then that energy hitting the surface would not be stored in the ocean. Looking at the attenuation coefficient going from UV to radio. If 1 then all the energy is absorbed or reflected in hte first metre. A value of 10 means in hte first .1m, a value of 1000 then the first mm. The ocean is really good at reflecting and blocking firstly IR . So early stories in hte press about coral reefs being hit by UV rays from the sun, a myth, as UV does not penetrate more than a few mm of water. To avoid sunburn all you have to do is lie beneath the sea surface. The sea is also good at blocking IR. And go up the red end and penetration again only about 1mm. So the only type of em radiation that penetrates the ocean is light . A very convenient window that sits bang on the peak energy from the sun. If the sun was 1000 degree cooler or warmer then that energy peak would be shifted outside that window. The water would then freeze over very quickly as it would not be absorbingh that energy. The oceans are perfectly tuned to our Sun. Go further up and radio waves are also efficiently absorbed by seawater. To comunicate with subs you have to go to km wavelengths . Some of the big fields of antenae around the country are for comunicating with subs. The down side of that is very little info can be conveyed at ultra low frequencies apart from push the button or don't push the button. Light can penetrate quite a long way in the oceans. In the euphotic zone whwre phytoplankton can develop and although the text books say you can get enough light down to 250m , I reckon 150m is about the limit for photosynthesis. On a clear day about 1000W per sq m of ocean surface, down to about 10W psm at 200m and even down to 800m crustacea can pick up some of that light , its lost its diectionality by that stage, a feint glow. Then 1Km is about the limit for any photons penetrating. Most of the energy is going into that narrow top layer, and in perspective, the ocean is very deep. The average depth is about 4km. So most of the ocean is dark, not as cold as you might think. Typically the deep ocean is about 2 degrees. Its warmed up, not be direct sunlight at the surface but effectively convection. The hot water at the surface , spreads out, moves towards the poles, where its cooled and then sinks. To get from 10m down to 6km rather than the quick journey , more like the equator to the poles and then back down again. That takes about 150 to 200 years. A very long slow process. But that energy eventually does find its way to the deep ocean. We have better maps of the Moon and Venus than we have of our own sea floor. That became very clear in the recent MH370 disaster. More people have walked on the moon than have been to the deepest part of our ocean. The only trip, until 2 years ago, was on the Trieste Picarde and Walsh in 1960, down the Marianus Trunch to 11 km. The pressure at that depth is equivalent to taking an A3 paper sheet and balancing th eEifel Tower on it. They did not spend long down there as they got a crack in the windscreen , only about 10 minutes down there. But they did discover there is a lot down there. We assumed up till then, oceanographers said nothing. Now we know there is a lot down there , one of the main focuses of the NOC is looking at the deep sea environment. Then James Cameron , so the same number as Apollo 11 on the moon. With Deep Sea Challenger he spent about 3 or 4 hours down there . Do we learn anything from sending people down to those depths, no. Its very expensive, very dangerous . I'd opt for going to the Moon each time. We use ROVs and robots these days . ISIS of NOC, capable of about 6.5km. We use this to explore our inner planet. There ar eno plants in the deep ocean , no light, no photosynthesis. So everything in hte deep ocean is basically animal or bacteria. So small angler fish for example. Using bioluminescence to attract prey. They are the only source of light down there. A fish sees a light , wanders over and is then dinner. Deep sea octopus use light to attract mates. In the middle of the deep ocean and not many of you around, you cant see each other so you need some sort of light show to attract your fellow mates. Some really weird creatures down there. Other creatures glow in shallow water. The film Blue Lagoon the swimming in glowing water is not a filmic effect, but real. Not only energy from above but energy from below as well. Deep sea thermal vents , first discovered about 20 years ago. Areas where the deep seabed was teeming with life. These thermal vents provide heat , food for bacteria comes from detritis from above and are the base of a food chain. Creatures such as 'Yeti' crab . White and have furry claws nothing like surface crabs. In the last 5 years we've discovered about 3000 new species of plants and animals in the oceans. Although the big fish are cute and fascinating actually its the bacteria , the phytoplankton the microscopic plants that photosynthesise at the surface that are all so critical. They absorb some of that energy , they absorb CO2 in fact more so than all the terrestrial plantlife and they give oxygen, about 60% of the oxygen we breathe. They keep the balance in the atmosphere , the oxygen , CO2 and so on. A lot of work being carried on today looking at how these plants change as our atmosphere changes. Those plants respond to changes in htose levels . There are concerns. If we mess about with our oceans too much we can upset the balance of these plants and bacteria. Not only do we add CO2 to our atmosphere but we add platics to the ocean. A pic from ISIS in the deep ocean about 3km down , a large sheet of plastic. The most remote parts of the planet and you get pics like this. We've done a lot of work in the Arctic. About every 2 years we go up there with writers , musicians and artists. We do the science and they report on what they see. We do the science on a schooner so its a bit makeshift as far as winches etc. Not only plastics in hte deep ocean but also in the most remote parts of the arctic as well. 3 years ago we were there to sample for plastic particles in hte water. All sorts of filter equipment with us but we set foot on Muffin Island. It is a walrus sanctuary , so we had a license to go there. About 82 degrees north so about 4-500 miles from the pole . One of the land parts before the pole . Apart from the walruses there was huge amounts of marine litter, plastered with plastic bags, rope, bottles . We gathered a full box full of plastic from a 2 metre square, that knee deep in plastic and even the box we gathered it up in , was also on the beach. We are having a dramatic effect on our planet's ocean. A lot of work we've undertsken to see how we can clean up our seas and how we afect our seas. We don't look after our seas or our atmosphere and its those two that keep us alive. If the whales disappeared of fthe planet tomorrow it wouldbe tragic but it would make no difference to the planet. If we disappeared from the planet it would be tragic for us but it would not affect the planet that much. If the microscopic plankton disappeared off the planet , tomorrow, we'd probably all be dead in a couple of months. Not very long, as they keep the very fine balance of the gases in hte atmosphere, the way the planet works. Q&A Did you say 60% of the oxygen for us, comes from sea based conditions ? Its hard to estimate precisely. Certainly over half. Some people say its more than 60%. If you look at the phytoplankton, the plants of the ocean, they give off oxygen , take up CO2. There has been a number of projects in recent years looking at fertilisation of the oceans as a way of dealing with increasing CO2. So if we put micronutrients into the water we can encourage plankton growth and absorb some of the CO2. It is flawed . If you look at the amount of such nutrient to put into the water you are talking fleets of supertankers , pumping nutrient into the water, to create a large enough effect. Projects to bio-engineer the oceans to increase its productivity in absorbtion of CO2, draw the carbon down into the oceans . There are problems. How to ge tthe stuff into the ocean , is it just that one micronutrient that contributes. Pu ttoo much of the wrong one in there , you get the wrong type of plankton. You get cynobacteria growing which can make the situation worse . Also things like toxic algal blooms, leading to shellfish poisoning and de-oxygenate the water. Projects like IroneX ? better ways of doing this in a controlled way. I was out in Brazil last year, up the Amazon. They spoke about the plankton, spreads out into the ocean for more than hundred miles, you can see it. They were saying we need this more than the rain forest . Thats true. We do need both the rain forests and the oceans. We did a big project at Barbados about 15 years ago. Transits and sampling off Barbados and you can see meanders of the Amazon going past. We can see a drop of about 1 to 2 in the PSU salinity level , a significant drop in salintity. You can see those meanders on satellite images. If our planet was entirely water based , no land, would our habitable zone around the sun, move in or out.? The good news is we would be in a job for life. You would change the albedo of the system. One concern at the moment is that as the ice cap is melting near enough halved over the last 10 years in terms of the typical summer ice cover. You're taking away a big reflector, so that energy that was going into space is now coming back into the system. So if you took away the land , at the moment we have a balance of land, sea and ice, where we are replacing the land and deserts with water so the planet as a whole would only reflect back about 4%, so we would heat up. But a chicken and egg. If you heat the planet up , more evaporation, more clouds which would in turn reflect more energy into space. The problem with clouds is tha tthey also trap in energy. There isa myth put about by climate change deniers, great, mor e cloud. Clouds do block some of the sunlight but not as much as you think. On a cloudy day you think not much light getting through . What they do do is trap the IR. Water is very good at blocking the lower parts of the IR spectrum. The clouds keep that energy in. Go out on a cloudy night, its quite warm. Go out on a cloudless night and it will be chilly. Clouds act as a blanket. Although more clouds with more evaporation , they are likely to keep that energy trapped in. Its very difficult to model this, so many variables. If we were totally water-covered , we think we would overheat, that would in theory boil the oceans away . End up wiht a thivck water atmosphere . You would find life growing bu tdifferent to our present life. You could argue that life would adapt, so more moist say, and 30 or 40 degrees hotter, some sort of life of the extremes we get in desert areas. Same with the cold , you can go from -40 to +40 and still find life. Nature is very good at adapting to that. A water covered planet would be an interesting experiment. When I've been flying in an aircraft I've looked down on the clouds and they seem extremely reflective. So they may keep some heat in, the tops must reflect? They do reflect back out to space, not as much as snow and ice but its still substantial, but there is a balance of reflecting and trapping the IR. I was apalled to find that human litter and detritis is in even the remotest parts of the planet. I know its a mamoth task bu tis there any international effort to try and clean up? There are various programs clearing up litter from coastlines and beaches. The problem wiht plastics in the ocean is they break down into microbeads . Those small particles are still active. Most of the plastics ever made are still in existence today. Thousand years to break down, no one is sure. Some plastics are shorter duration than that. There has been a number of articles in Science and Nature about the volume of plastic particles in the ocean. One of the articles I reviewed for the publication said there was abaout 250 million tons of plastic in the ocean, I think that is a serious underesctimate, perhaps by an order of magnitude. How do we clear it up, we can't as its distributed through the ocean. We have 92 sq km of ocean each , 2m deep. You go out to clear up that size of pool , that s a lot. If you do it by trawling nets through , not only picking up the plastic and litter, you're picking up the animals and plants and all else, end up denuding the ocean of its life. A very difficult one, we can certainly stop it happening and we can clean beaches . An interesting university of Miami project. The Pacific Gyre , the huge gyre of plastic , not the media pics of canoing through solid rubbish. The gyres focus or concentrate the plastic , Pacific , Atlantic and Indian oceans all have gyres. There is as much plastic in the Atlantic Gyre as the Pacific one. They've monitored for 15 to 20 years now and they've noticed that in the last 5 years the levels have been incrreasing but have stopped , levelled out. I suspect that is because we are getting better at recycling, better at not dumping stuff in hte oceans. Up till about 15 years ago it was standard practise , I'm ashamed to admit it, for ships to dump their rubbish over the side, once 12 miles off shore. I think the theory was the oceans are vast , so no impact , but there was so many ships these days, that it does impact. That practise was banned, waste disposal units somewhere on board ships these days. Big skip on deck if its a research ship. We bring the rubbish back and its delt with on land. I think the othe rdanger is tha tthe gyres trap the plastic for maybe 5 to 10 years , slowly they spin off . We're seing an increase in plastics around British waters , the Arctic and Antarctic and othe r parts of the planet. Whether it has an effect, the jury is out on that. One theory was it was just like roughage , although not nice it goes through biosystems , having done no harm. There is growing evidence that those plastic particles are magnets for harmfull organic components but also in their own rights can mimic things like oestrogen and cause hermaphrodite behaviour in shellfish. You can argue it can be as bad as climate change, a lot of climate change we could deal with but plastics in the ocean, we are stuck with. What would you say was the principal sources of the plastic , sewage, containers washed off ship decks? A whole variety of things . In 1992 a container load of plastic toys was washed off a ship off Japan. 40,000 plastic ducks , turtles etc were washed into the sea. People tracked these around, to the south Pacific. There was a theory they washed across the Arctic throuhg the Berring Strait and into the Atlantic. Problem is we get phone calls from #people who've found plastic ducks , but there are duck races arounfd the world and some make a bid for freedom and found on a beach somewhere. So problem identifying the right ducks. Some gets washed over . A lot is from badly managed landfill. It does work its way into watercourses , breaking down and finding its way into the ocean. We are getting better because we are recycling . One of the advantages of plastic being so expensive these days , its actually profitable to recycle plastic. So not just recycling for fun ,but hard economic reason now. As long as that continues. At least it tends to be stamped on the plastic , identifier of plastic type PPE or whatever and can be identified electrostatically and separated out, these days? With all these things it does show we can make a difference. With climate change there seems to be a lot of feeling, well, we can't do much about it, we may as well give up, or it costs too much. You can make differences. We banned lead from petrol 30 years ago or so. The fuel companies said at the time that engines would break down, refinaries saying they could not produce petrol without lead. To my knowledge it didn't affect petrol prices at the time and from personal experience my cars have run more reliably than 30 years ago. Again with plastic. If we legislate more and you do need that legislation usually. These areas of plastic debris, could they be collected up? No. It can be collected when on a beach, that works well. But in hte open ocean. Its not as though its a big island of plastic. I've a student a tthe moment trying to measure the levels of plastic around the UK. Looking at how much ends up in sediment and how much in hte water column. She's banging her head against a wall. Its requiring very long tows to get any plastic in there at all . We've gone through a lot of sediment work to find plastic . Its out there, its not piled high , except when it lands up on a beach, where you can see it clearly. When at sea you will often see it drifting past . If you went to pick up the gyres of it then you'd be creating so much CO2 in htat process, you can be doing more damage than leaving it. Muffin Island was it ...? We often talk of the Gulf Stream, keeping the UK mild , but its an extension of the Gulf Stream , The North Atlantic Drift, goes passed Britain, goes past Norway. Thats why Norway does not get iced in but Sweden does. Svalbard , the Spitzbergen Current , this motorway of flow that goes up to the Arctic. Muffin Island sits in this motorway. The plastic there wasa UN of plastic bags, from USA,UK, Canada , Norway, Sweden , France Germany . We identified the lot. ... smaller particles.? They get ground down on a beach, the wave and tide action. In the water , the wave action , the effect of the sun a tthe surface. No UV light below the surface but at the surface UV degradation. All these things do have an effect. But when they are large bits of plastic they cause less of a problemn than when its in microscopic form. One photograph, one bad press, could persuade a multinational to say come on guys lets clear this mess up? Some of these organisations do . I guess it does tend to fall on local conservation volunteers. Particularly in the USA, school kids on the beaches collecting plastic. Some companies help by paying per weight of plastic collected from beaches as a reward to such charities. There are different ways of doing it. ...? The million dollar question there is , is it the company or is it you. If you drop the plastic bag in the first place. We all use plastic bags and we've seen people getting angry in Tesco if they run out of bags. The companies are responding to public demand. You can argue that the supermarkets are responsible partly bu t not wholley. Its like climate change, we blame cars , we blame oil companies but we're the ones buying cars and using them. Its down to us where that useage goes, its up to us the plastic and what we do with it after use. I suspect we are in a room of peoiple that recycle everything but I suspect look at an average cross-section of the population , its not as prevalent as that. From what you say , the oceans are a major factor in the working of a planet. Wnen the sea gets iced over a tthe poles .... ? When the ice starts to form , it happens quickly because you're reflecting energy back. The othe rthing about when ice forms , sea ice formation is very different to ice forming on a pond. A complex relationship. Ice on a pond , the freezing point of water is 0. The freezing point of the ocean is abouit -1.9. The maximum density of fresh water is at 4 deg. So as a pond cools 6,to 5, to 4 you get convection . Once the whole pond gets to 4 deg, and stops convecting, then the thin layer at the top gets stuck, cools quickly and get ice forming. In the ocean the maximum density is at about -2.8 deg, below the freezing point, so it keeps convecting. Even though the outside temp may be -20 deg, the sea does not freeze becaus eof continuous convection. So why do oceans freeze. They either freeze very quickly , the entire depth or there is fresh water component, stuck at the surface, so maintained at the surface and a few metres of ice forming. In places like Greenland it can be a bit different. We were on a Schooner in a fjiord there, 10om deep, no fresh water there. The temp of the fiord was -1.9. All the students had read in the books that the theory is, that ships get stuck in ice in fast freezing. We suggested to the skipper we should get out of here, quickly, but the skipper was saying ,no you worry too much, I've never seen that happpen before. We persuaded him to move along the fiord . Then rapidly behind us the whole fiord turned into what looked like a slush-puppy. There was also a weird Dr Who type sound crossing the whole fiord, as it froze over. The skipper then put on full throttle to get out of there. Looking back , the entirte fjiord had frozen over, taking about 15 minutes, going from water to solid ice. When ice forms, it depends on where the ice is. Where ice is solid to the sea bed there is not much chance of plant growth. But you do get algae growing within the ice. With an ice sheet say 2m thick then there is lots of life beneath the ice and algae in the ice as well. Is there any evidence that human polution affects phytoplankton? The biggest problem is not stopping the growth but causing too much growth. Put too much nutrient in the water, we get eutrification, the plankton thrives. The wrong type of plankton mover in , you get cyanobacteria and that can reduce the oxygen levels. You get blooms, strips oxygen from the water column, kills the fish and creates a toxic environment. The irony is we don't kill the plankton but encourage the wrong type. Some plankton can perspire and expire and when they get to a thick enough level, they are cutting off their own light . Some of them without enough light , will respire. I have seen it in Southampton Water but not for a few years, certainly 20 years ago we used to regularly get what was called a red tide. It was very obvious, usually July, when lots of nutrients are getting into the water, lots of sunlight. Grow too much and thats when the ? take over. Not recent occurance may be because we've increased environmental awareness in Soton Water. I would not recommend swimming there, but the water quality has improved in recent years. Has the discovery of 1000 or so exoplanets affected our understanding processes on Earth? I'm not sure. On the one hand there is almost be definition , the statement that there ar ebillions of star systems out there so there will be billions even trillions of planets. So perhaps a few million light years away there is probably a cafe scientifique talking about the possibility of a water-covered planet out there. The argument is there should be lots of these things . But its not jus tthe distance of the planet from its star , but what is on it, water, an atmospher, is it big enough, does it have tectonic plates so no solar wind stripping of the atmsphere and stripping off life as well. Its more a question of how far does life get before something disatrous happens. There is a strong probability that you can get some sort of life but amoeba and inteligent life is a big difference. I suppose it has given us a better understanding of how systems work. Unfortunately your not getting detailed pictures of thes eexoplanets, you're reliant on how certain types of e-m radiation is refracted or reflected rather than seeing the actual planets themselves. Have we nailed down when and how Mars lost its water and atmosphere? I don't know ,the short answer to that one. There is evidence there was water and there was an atmosphere. One of the problems is that Mars is quite small , there has to be enough gravity to keep water and any atmosphere. We don't know if it disappeared catastrophically or gradually? No . There was a recent paper looking at where the moon has come from. The arguments are something hit the Earth that became the moon or 2 similar rocks around the Sun collided and formed the Earth and moon. A lot is supposition. .... covered in ice and some sort of activity going on. Titan is very similar to Earth in a number of ways ... what are the chances? Possible. It depends what you mean by life. For us to be here has taken about 2 billion years of evolution. In that time its been a relatively stable planet. We've had major events , like wiping out the dinasaurs, we've been ice covered and ice free. There are possibilities of some sort of life on these planets. The organic chemistry is there to do that. A colleague of mine looks at the oceanography of these planets. What would the liquid flows be like, different gravities, different spin rates. There is an entire science of looking at processes on other planets, not necessarily water, such as methane oceans, any iquid. They obey the same physical laws obeyed on this planet, just different constants. ... evolutionary tree for this to occur... plankton.. ? The bacteria on the sea bed ... , they rely on sulphides from the vents so you get extensive marine growth in the volcanic vent areas. That is important for the micronutrients, for bacteria to grow, but also energy for warmth. You get brine shrimps that live on the edge, go too far from hte vent , cold , 2 deg C, and no food source. But 1 foot nearer the vent and the water is 400 deg C. Go too close and they will burn from the IR but seawater blocks the IR so they live in that foot of space. A fine line between thriving and being shrimp cocktail. Are they related to the stuff on the surface, yes. You can argue that a lot of life started in the ocean and went back to the ocean over millions of years. How closely related, I don't know. Do we know what sort of life is at the mantle, the water there? One of the reasons that plate tectonics works is that you need water to lubricate the plates. So oceanic plates going under continental plates, the water lubricates under very high pressure. Without it you get the Mars situation, if the water disappears then any plate system disappears as well. A vicious circle, the plates sieze up , the convection to the core disappears. Where does the salt of seawater come from? Every year there is an award for the most stupid statement by celebrities on science topics. One I had to deal with was an American celebrity and the statement she made was the oceans were salty because of whale sperm. To make that amount of salt, very salty whales. A BBC producer I had dealings with was convinced that the salt of the sea came from just one process, from the volcanic vents. The salt of the ocean is basically everything, everything that dissolves in seawater. You can take seawater, not just NaCl but potassium chloride, gold platinum etc, anything that exists, is in seawater. Very low levels, I would not recommend extracting gold from seawater. You'd have to drain the Solent and Southampton Water to get enouhg gold for 1 ring. Its there because water is a universal solute. Although it does not seem effective at getting paint off your hands, it does dissolve most things. More general solvent than say white spirit. It means that over time with water flowing over land , water flowing mines and aquifers its picking up minerals. I think in the early days NaCl came from hydrochloric acid and sodium minerals in the rocks. You do loose salt as well as gain it, it does settle out to the seabed as well. Is the salinity of the ocean increasing, probably but only a small amount over a million years, not something we could measure. A combination of volcanic activity, from the core, and the fact water flows in a lot of places and a lot of minerals around. If you get away from land , take samples from north and south Atlantic , Pacific, Indian and Southern oceans , the salinity will vary but look at the chemical constituents of those waters and they will be pretty much identical. The amount of sodium, chlorine, iron , calcium, magnesium , sulphates, then the same proportion of those chemicals , anywhere in any ocean. Thats because the process is so slow , over millions of years its all pretty well mixed up. Perhaps not over a hundred years, but over a million years, its homogeneous, a big blender.

Monday 11 May, Dr Diego Altamirano, Southampton University: Tic, Tac, Tic, Tac: predicting explosions on Neutron star surface.
Graphics and videos used in this talk on his site
I hope you will leave this talk with an order of magnitude understanding of the energetics or how powerful they are, how big they arre. Millions of years of evolutions of stars lives. Stars are formed in a cloud of gas. There are 2 possibilities basically. If the cloud was big enough it can form a small star, like the sun or form a large star. For me that is 10 times the solar mass or 100 times the sun mass. Depending on the original mass , is what will happen to it at the end. Today I will concentrate on the big mass ones, lets say 10or 15 solar masses . Basically a star is a ball of gas, difficult to imagine, its not solid. Very condensed gas and its falling in on itself, the only thiong stopping it , not to fall into a very small point is that the temperature at the centre of the star are so high that there is fusion of say hydrogen to heavier elements. When there is fusion you produce energy and the enrgy is trying to go out , this supports the star. In the whole evolution of a star, there is always a fight between gravity that is trying to push gas down and energy that is coming from the nucleus of the star . So a star starting with a core of hydrogen , converting to helium and very hot . At a certain point you run out of hydrogen , so no more energy trying to go out and the star has to reach another equilibrium. This is when you go to another star form , maybe a super-giant. Its bigger because its nucleus cannot collapse for the hydrogen to helium and higher elements. But to obtain equilibrium the outer layers of the star have to move outwards. This continues until you hav ea supernova . That stage is when you reach a core of iron and then it doesn't work any more . After the supernova explosion , which i will challenge the use of that term. Then depending on the original mass of the star , if 10 to 15 solar masses you will end up with a neutron star or if 20 to 50 solar masses then you will finish with a black hole. I will concentrate on the former. We visualize it as a ball that is very compact, having what we interpret as magnetic fields. What are these balls, the neutron stars. Its intuitive that you have an explosion , because you start with something compact obviously a sphere and suddenly you have gas going out forming a large structure, supernova remnants. Is it an explosion or an implosion? Video of controlled demolition of a building. They don't put one big bomb to make it explode they distribute charges at the base of the building in such a way that when that support structure goes, everything falls, its an implosion. But there is a lot of debris going out. You might see that and think that most of the building is flying away, but that is not the case its just dust . If you weighed the dust produced compared to the amount of concrete , that remains, it is insignificant. The same happens in the supernova , start with a massive star, it implodes on itself because it ran out of the energy tyhat was holding it up , collapses, creates something very compact in the centre and some of it will fly away. You see a lot of light coming out but not material, just energy. You see the light and dust interaction with the external environment. But remember its an implosion. So how much matter is compressed when you create a neutron star . You have the atom, the proton , the electrons and neutrons , the electrons being relatively far from the nucleus . Start compressing and compresing and at some point you are pussing the electrons very close to the protons to the point that the positive charge proton and negative charge electron , so close that they become a neutron, and no charge. If this was our solar system and all in scale , Earth is nothing compared to the Sun. How much do you have to compress the Earth to make it into a neutron star, assuming you were able to compress it. To half a sugar cube you have a black hole. More or less the size of a football stadium. Now consider the Sun , how much to compress to make it a neutron star, to a sphere of about 30km, so Southampton out but short of Winchester. How dense is dense. Assuming you were super superman, and went to a neutron star and picked up a spoonful of neutron material , , and bring it to Earth. How much would a spoon of neutrons weigh.? A hundred million tons. 2,000 million people into a spoon. Even super superman could not land on a neutron star because gravity is so strong that as you get too close it would just smash you to the surface, be pulverised to dust. So its extreme. Everything in our universe rotates. How fast does a neutron star rotate? In RPM. A ceiling fan about 250rpm. A car wheel at 100mph , about 1400 rpm. A washing machine in spin about 2000 rpm. A kitchen blender goes 10,000 to 30,000 rpm . You know when you put things in a blender everything is turned to dust and would fly away. Here we ahave a neutron star that is attracting you, pushing you down and rotating very fast, about 700 times a second about 42,000 rpm. A ball the size of Southampton and surroundings, super dense , rotating at that speed. Thats very extreme. Q: Why do they rotate. You've seen an ice skater , spinning slowly with arms extended and simply bringing their arms in , they speed up in rotation. Anything that rotates has angular momentum , a physical parameter. You don't loose angular momentum, it is conserved. Conservation of angular momentum. Express the matter of a spinning object away from the centre you spin slowly, bring the mass near the centre , the system configuration is changed. The system depends on the total mass and the distribution of the mass. By pulling in smaller you rotate faster. You started witha star that was very big, it was rotating. Suddenly the mass goes to a small space , because of conservation, its rotation speeds up. We're not there on extreme things. Magnetic fields. If I refer to 10 Gauss in magnetic field you will probably not know what that means unless you're an engineer. A human brain , having a thought, is 10^-8 gauss. The Earth's magnetic field is .3 Gauss A magnet in a refrigerator is about 50 Gauss. A hospital magnetic resonance machine uses a lot of power because it produces 30,000 Gauss. So Gauss in terms of things you can visualise. The record of the highest magnetic field produced on Earth, in a lab , and was 100 Tesla which is about a million Gauss. Its called the non-destructive record, because stronger magnetic fields in labs have been produced but they exploded or everything broke. How much is the magnetic field of a neutron star? For the highest magnetic field neutron star. A million gauss is the record on Earth, a lot of zeros. This is the reason why we study them. Because they are places where everything is extreme. And the main idea of my research and similar researchers is to understand. Does the physics we know still work in this environment. When you have densities or magnetic fields totally impossible on Earth. These objects are extremely extreme and thats why we like to study them. Up to now I've described generic ones, I'll now describe the ones that I study. You can have neutron stars that are alone in space and you have to try and detect them. The ones I study are in a binary system. So you have a star like the sun and a neutron star and if they are close enough then the NS starts pulling gas out of the star. |So instead of a rounded star you end up with a pear shape . Gas dfalls but not directly becaus ehte gas has angular momentum . It has to spiral in . When close to the NS it experiences enotrmously strong magnetic fields which are dipole shaped and pulls the gas into the poles. That is why it produces a kind of lighthouse effect. The poles are brighter due to the magnetic effects on hte gas. One of the smallest systems we know of is a NS and a white dwarf , from the other branch of star evolution. 130,000 km, as the gas gets closer to the NS , because of friction it becomes hot and then hotter still, until millions of degrees and produces X-rays. So we use xray telescopes to study this . Xrays will not penetrate our atmosphere, good for us. So telescopes such as Chandra XMM-newton, and nustar , from different countries , up in space. One thing that happens on a NS. You have the sphere , gas falling on it which is pure hydrogen. The NS is spinning fast but the gravity is so strong that the gas cannot escape. It will spread around the NS very fast. So hydrogen accululating on the NS surface , a layer of pure hydrogen . Then another such layer and everything gets compressed. So the lower layer gets hotter and hotter , with higher and higher pressure it reaches a point where it fusion reacts hydrogen into higher elements. The same exact thing that happens inside our sun, at the nucleus , happens at the surface of a NS. We say thermonuclear Xray bursts. Suddenly somewhere on the NS surface starts burning and burns the whole surface. It takes 1 or a few seconds depending on the type of explosion to burn the whole NS surface. So a runaway over a sphere of 50km in radius that burns within a second. There is a lot of energetics there , pulling everything away. The 1980s was one of the first observations from Xray telescopes. A measurement of how much xrays we get . There is an average that comes from the disc. Sometimes there are spikes every few hours . Each spike is the NS surface burning. So a cycle, accumulate gas, burn it, accumulate, burn and so on. Another plot Xray brightness v time, the persistence emission as the disc becomes brighter , the bursts happen more often. That makes sense because the faster you put gas on it the quicker you reach the conditions to have an explosion. A more complex plot. A lot of information in one plot. Time and Xreay brightness on one axis , frequency and the colour is whether you detect a signal or not. Each time we detect a burst we detect a signal that is periodic of the same period. In this case 364Hz , we are seeing the NS rotating, the lighthouse effect. A NS with one part hotter , then brighter and lighthousing. You see the NS . The most important part of the talk is in the next slide. How energetic is each of these explosions in terms of H-bombs. Each one is about 100 15megaton Hbombs exploding simultaneosly over each postage stamp size part of the NS surface. So a big number. I think the 15Mton Hbomb was only detonated on 2 occassions. The first in 1954 the only one of that type exploded in US territory , it was a disaster . It was 1/3 of the most energetic bomb , exploded by the Russians. Every few hours millions of those H bombs exploding and the whole process starts again. Putting in other terms for each such explosion more energy is released than the full sun in a week or so. One more thing relating to these explosions. Something that may give us a hint to the physics happening on NS. All very impressive the energetics but its difficult to understand how things happen in detail. The big picture we have but the detail, the physics is still not clear. We've found something called marginally stable burning . Put in gas fast enough , you don't have time to accumulate. Stable burning is over in a moment. If you are a bit below, not fast enough then you have marginally stable burning. In our studies a famous plot , the disc an explosion and another explosion within half an hour then more explosions . There is a region of more peaks than elsewhere. It is an oscillation that goes up and down , starts fast and then slows down and disappears after the explosion. The NS becoming hotter , but not enough fuel to have a runaway so starts cooling down. But when cooling down gets more gas from the disc. So a cycle of seeing the NS getting hotter and colder, repeating until it cannot handle it any more and then it all burns up. It doesn't happen always but when it does then you can predict when that explosion is going to happen. Q: The hydrogen fusing to helium or beryllium or something? To carbon. My idea was to give you a peek at the extremes we are studying. I hope when you go home you will check out more about these systems. There is funky physics that occur close to thes e NS , more than 45 minutes talk worth. Q: what happens to the space-time around this thing ? A NS is on the limit of becoming a black hole. A black hole curves space-time. NS do it also but not as much. In the graphic of a black hole making the curve in the mesh, a NS does so but not as much as a black hole but more than a normal star. Q: What is happening there is the fuel for this NS is coming from a white dwarf and it is converting it into Xrays and photons. Consuming and converting it? Not all of it. When you burn something you always have ashes. The question is what an ash is . When you burn H to He, helium is hte ashes. Produce a lot of energy and are left with He. Then the next level is burn He into C , the ashes are C. You continue until you cannot do it any more and basically iron. When the white dwarf is exhausted and the NS has no mor e fuel? It stays htere and cools down, stating at the same mass. And rotating at the same speed but it loses energy. Because of the magnetic field it sends away electrons, so slowly losing energy. Then as losing energy , it is losing angular momentum, and slows down. And become bigger? Not bigger but slower. The loss of electrons is negligible to its size . You've found NS that have gone through this process and are going slow now? Yes And over 20 years can you measure how much slower it has got? Yes and no. You can measure how they get slower or faster. That is a very slow process. Over 20 years you measure instead of being 10 seconds rotating it is 9.999...8, a process that takes thousands of years. The stuff heavier than iron. Is that material ejected in the supernova explosion as it collapses down into a NS. Like a lizard shedding its skin and the skin is the heavier elements? There is a whole area of astronomy trying to understand how you produce heavier elements than iron. Because basically it all should stop at iron , for supernovas. When you have the implosion a lot of energy is going out and you have weird particles, neutrinos and the like. When that happens you have the interaction between those particles and normal compact gas and can create heavier elements. It happens at the explosion , not as a product of the life of a star. Is that the only route that can occur, in collapse to a NS? There are plenty of proposed ways. The question is which is the most efficient one to have affected the universe. This is probably the most efficient one. What is the physics that you study? I study how gas falls onto a NS and black holes and I'm trying to understand all of that process. The NS explosions are basically the same as occur inside the sun. We can produce some of these explosions on Earth. So we can compare and see if there is a difference. There is always a balance , study these things because you want to know but also some of these things can help in other areas of physics. eg the LHC in Switzerland. We have those sort of accelarators close to a NS. They are far away and its a mix of different things so difficult to pinpoint the wanted processes. In an ideal case I'd have a NS or a black hole and have one particle , say a peanut, and see how it goes down and hits the NS and how much energy released. Of course that is not possible as its too far. If you could do that you would see the whole motion of the peanut and compare with Einsteinian general relativity and what should happen. General relativity has been tested close to Earth and it works. Before him was Newton and can use his laws to predict the outcome of 2 cars colliding. Then Einstein came along and Newton is not enough. The idea is , is there anything else which lies above general relativity that explains all the physics. That would be an ultimate goal, to test that. GR predicts black holes with an event horizon but we have not tested that the event horizon exists. There isa black hole, something unseen in the centre and things happening around it, yes , but we want to test those predictions fully. So you've built computer models of the NS processes and what do you see? To do the simulations correctly you have to put in a lot of physics. Although computers are very fast, we're still unable to do it. For example , water going down a plughole. I'm sure everyone would be able to describe the process. Water swirls in , from left or right, no problem. Now do the same experiment with clear water but as its falling in , drop a bit of coffee on it or oil and try to describe that. Now you will have problems, it mixes, disipates or not. To analyse that situation fully you need a supercomputer , for molecule by molecule. Now for a NS with a gas disc of H , with friction and its really messy. We're getting there . For 4 months of computer processing the experts in this field managed to describe 1 second of activity in a NS disc. When you get to a very massive NS, just before becoming a black hole, is there a sudden transitiion? a borderline? There is another group of astronomers trying to understand that. From the observation , theoretical and simulation points of view. We call it neutrons , from pushing electrons and protons together to get a neutron. But we don't know the structure of a NS, we don't know what is inside. It has to be something like neutrons , fluids of neutrons moving. From the observational point of view need to identify which is the most massive NS. So if the say the heaviest NS is 2.5 solar masses, then you constrain your models to that, if say the models show a maximum of 1.8. So a lot of work in identifying the mass and radius of NSs. You can measure the radius in some cases. Nature plays games against us. For those that we can measure the mass, we cannot measre the radius and vice versa. If we can measure both then we get an equation of state, which describes how the different layers in a NS should be. Then add one more gram and it becomes a black hole. When that happens it should happen in a second. In my mind to get these phenominal magnetic fields, you need some sort of charge separation or polarisation , but be definition , neutrons are non-polarised , no charge. Where does a phenominal charge separation come from. Where is the magnetic field coming from? When we talk of NS we originally had a prediction that we would have stars made of neutrons, but its not as simple as that. Don't quote me on this as I'm not using the correct terminology. You have a surface and below it a sea of electrons moving around. That movement creates a current that then creates a magnetic field. A bit like the iron core of the earth. Its another area of research trying to understand how you can have such large magnetic fields. The NS I study are 10^8 Gauss. Others are studying magnatars which are 10^14 to 10^15 Gauss. The ones I study are kind of understood but not the magnatars yet. So you get these repeat explosions, how long does that process go on until all the fuel is expired? and what is the final result at the end? You have these super explosions but the NS doesn't even realise it. Like a volcano and the Earth. For the volcano its a lot of energy but to the Earth its insignificant. You would not notice the Earth has not changed its rotation period around the sun as a result of one volcano activity. A NS doesn't care. What does matter is how much gas you're putting onto the nS. There are systems where the disc is very stable, its putting in the same amount of gas all the time. We call it the bursting clock because you can predict every 2 hours you have 1 explosion, perfect. Its been like that for 20 years and can continue like that until all is sucked out of the companion. That could be thousands of millions of years depending on who is your companion. What happens then when the companion is exhausted? My understanding is then the companion star is finished , it is getting closer to the NS. So either the companion goes farther away and gas transfer ceases or if it gets too close then it would disappear. The processes on the NS would then stop also? Yes as no more fuel. If these explosions, these bursts, are directed in some sense is there any relation to gamma ray burst that as far as i know their cause is still unknown ? Gamma ray bursts are bursts in gamma , so even more energetic than Xrays. But one-off and very far off and so far we don't know what they are. One of the theories is 2 NS that merge to produce a gamma ray burst. How do you detect and measure these great magnetic fields at such a great distance? Magnetic fields are related to polarisation. Polarisation allows you to measure the magnetic field very accurately. However we don't have an Xray polarimeter so far. But for NS that are alone in space , no companion, so rotating and a magnetic field. You know the period today and measure 10 years from now, and calculate the slow down. Then there is a quite simple formula based on some assumptions , how much it has gone down, the original period, tells you the magnetic field. For the 10 ^15 super strong ones that is the way to measure it , because the stronger the magnetic field , the faster it will slow down. Does that mean the slowing moving NS are the older ones? Yes and no. This was only answered 2 years ago. Imagine you are an astronomer, looking for radio pulsars , how fast a NS is. Most are very slow and you have some fast ones. But the fast ones are old and the slow ones are new. In the 80s they proposed you have a slow NS but if its in a binary system , then you have the disc that spins up the NS , then absorbs the whole star and then starts slowing down. Its not the oldest that is the slower but you can have a really old one that is fast if you caught it exactly after ... depends on the surroundings. In physics generally and in astronomy its exchange of energy, angular momentum. Everything has to be conserved, it has to change from one side to the other. You can start with slow but if you change from one star to the other, angular momentum , you can end up very fast even if its old.

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