A personal scientific low point.

When I started my PhD research, I was fairly enthusiastic about the future, but I soon got disillusioned. Before my supervisor went on summer holidays, he gave me a choice of two projects. Neither were any good, and when the Head of Department saw me, he suggested (probably to keep me quiet) that I find my own project. Accordingly, I elected to enter a major controversy, namely were the wave functions of a cyclopropane ring localized (i.e., each chemical bond could be described by wave interference between a given pair of atoms, but there was no further wave interference) or were they delocalized, (i.e. the wave function representing a pair of electrons spread over more than one pair of atoms) and in particular, did they delocalize into substituents? Now, without getting too technical, I knew my supervisor had done quite a bit of work on something called the Hammett equation, which measures the effect or substituents on reactive sites, and in which, certain substituents that had different values when such delocalization was involved. If I could make the right sort of compounds, this equation would actually solve a problem.

This was not to be a fortunate project. First, my reserve synthetic method took 13 steps to get to the desired product, and while no organic synthesis gives a yield much better than 95%, one of these struggled to get over 35%, and another was not as good as desirable, which meant that I had to start with a lot of material. I did explore some shorter routes. One involved a reaction that was published in a Letter by someone who would go on to win a Nobel prize. The very key requirement to get the reaction to work was omitted in the Letter. I got a second reaction to work, but I had to order special chemicals. They turned up after I had submitted my thesis. They travelled via Hong Kong, where they got put aside and forgotten. After discovering that my supervisor was not going to provide any useful advice on chemical synthesis, he went on sabbatical, and I was on my own. After a lot of travail, I did what I had set out to do, but an unexpected problem arose. The standard compounds worked well and I got the required straight line set with minimum deviation, but for the key compound at one extreme of the line, the substituent at one end reacted quickly with the other end in the amine form. No clear result.

My supervisor made a cameo appearance before heading back to North America, where he was looking for a better paying job, and he made a suggestion, which involved reacting carboxylic acids that I already had in toluene. These had already been reported in water and aqueous alcohol, but the slope of the line was too shallow to be conclusive. What the toluene did was to greatly amplify the effect. The results were clear: there was no delocalization.

The next problem was the controversy was settling down, and the general consensus that there was such delocalization. This was based on one main observational fact, namely adjacent positive charge was stabilized, and there were many papers stating that it must on theoretical grounds. The theory used was exactly the same type of programs that “proved” the existence of polywater. Now the interesting thing was that soon everybody admitted there was no polywater, but the theory was “obviously” right in this case. Of course I still had to explain the stabilization of positive charge, and I found a way, namely strain involved mechanical polarization.

So, where did this get me? Largely, nowhere. My supervisor did not want to stick his head above the parapet, so he never published the work on the acids that was my key finding. I published a sequence of papers based on the polarization hypothesis, but in my first one I made an error: I left out what I thought was too obvious to waste the time of the scientific community, and in any case, I badly needed the space to keep within page limits. Being brief is NOT always a virtue.

The big gain was that while both explanations explained why positive charge was stabilized, (and my theory got the energy of stabilization of the gas phase carbenium ion right, at least as measured by another PhD student in America) the two theories differed on adjacent negative charge. The theory involving quantum delocalization required it to be stabilized too, while mine required it to be destabilized. As it happens, negative charge adjacent to a cyclopropane ring is so unstable it is almost impossible to make it, but that may not be convincing. However, there is one UV transition where the excited state has more negative charge adjacent to the cyclopropane ring, and my calculations gave the exact spectral shift, to within 1 nm. The delocalization theory cannot even get the direction of the shift right. That was published.

So, what did I learn from this? First, my supervisor did not have the nerve to go against the flow. (Neither, seemingly, did the supervisor of the student who measured the energy of the carbenium ion, and all I could do was to rely on the published thesis.) My spectral shifts were dismissed by one reviewer as “not important” and they were subsequently ignored. Something that falsifies the standard theory is unimportant? I later met a chemist who rose to the top of the academic tree, and he had started with a paper that falsified the standard theory, but when it too was ignored, he moved on. I asked him about this, and he seemed a little embarrassed as he said it was far better to ignore that and get a reputation doing something more in accord with a standard paradigm.

Much later (I had a living to earn) I had the time to make a review. I found over 60 different types of experiment that falsified the standard theory that was now in textbooks. That could not get published. There are few review journals that deal with chemistry, and one rejected the proposal on the grounds the matter was settled. (No interest in finding out why that might be wrong.) For another, it exceeded their page limit. For another, not enough diagrams and too many equations. For others, they did not publish logic analyses. So there is what I have discovered about modern science: in practice it may not live up to its ideals.


Scientific low points: (2)

The second major low point from recent times is polywater. The history of polywater is brief and not particularly distinguished. Nikolai Fedyakin condensed water in, or repeatedly forced water through, quartz capillaries, and found that tiny traces of such water could be obtained that had an elevated boiling point, a depressed freezing point, and a viscosity approaching that of a syrup. Boris Deryagin improved production techniques (although he never produced more than very small amounts) and determined a freezing point of – 40 oC, a boiling point of » 150 oC, and a density of 1.1-1.2. Deryagin decided there were only two possible reasons for this anomalous behaviour: (a) the water had dissolved quartz, (b) the water had polymerized. Everybody “knew” water did not dissolve quartz, therefore it must have polymerized. From the vibrational spectrum of polywater, two new bands were observed at 1600 and 1400 cm-1. From force constant considerations this was explained in terms of each OH bond being of approximately 2/3 bond order. The spectrum was consistent with the water occurring in hexagonal planar units, and if so, the stabilization per water molecule was calculated to be in the order of 250-420 kJ/mol. For the benefit of the non-chemist, this is a massive change in energy, and it meant the water molecules were joined together with a strength comparable to the carbon – carbon bonds in diamonds. The fact that it had a reported boiling point of » 150 oC should have warned them that this had to be wrong, but when a bandwagon starts rolling, everyone wants to jump aboard without stopping to think. An NMR spectrum of polywater gave a broad, low intensity signal approximately 300 Hz from the main proton signal, which meant that either a new species had formed, or there was a significant impurity present. (This would have been a good time to check for impurities.) The first calculation employing “reliable” methodology involved ab initio SCF LCAO methodology, and water polymers were found to be stabilized by polymer size. The cyclic tetramer was stabilized by 177 kJ/mol, the cyclic pentamer by 244 kJ/mol, and the hexamer by 301.5 kJ/mol. One of the authors of this paper was John Pople, who went on to get a Nobel prize, although not for this little effort.

All of this drew incredible attention. It was even predicted that an escape of polywater into the environment could catalytically convert the Earth’s oceans into polywater, thus extinguishing life, and that this had happened on Venus. We had to be careful! Much funding was devoted to polywater, even from the US navy, who apparently saw significant defence applications. (One can only imagine the trapping of enemy submarines in a polymeric syrup, prior to extinguishing all life on Earth!)

It took a while for this to fall over. Pity one poor PhD candidate who had to prepare polywater, and all he could prepare was solutions of silica. His supervisor told him to try harder. Then, suddenly, polywater died. Someone notice the infrared spectrum quoted above bore a striking resemblance to that of sweat. Oops.

However if the experimentalists did not shine, theory was extraordinarily dim. First, the same methods in different hands produced a very wide range of results with no explanation of why the results differed, although of course none of them concluded there was no polywater. If there were no differences in the implied physics between methods that gave such differing results, then the calculation method was not physical. If there were differences in the physics, then these should have been clearly explained. One problem was, as with only too many calculations in chemical theory, the inherent physical relationships are never defined in the papers. It was almost amusing to see, when it was clear there was no polywater, a paper was published in which ab initio LCAO SCF calculations with Slater-type orbitals provide evidence against previous calculations supporting polywater. The planar symmetrical structure was found to be not stable. A tetrahedral structure made by four water molecules results in instability because of excessive deformation of bond angles. What does that mean, apart from face-covering for the methodology? If you cannot have roing structures when the bond angles are tetrahedral, sugar is therefore an impossible molecule. While there are health issues with sugar, impossibility of its existence is not in debate.

One problem with the theory was that molecular orbital theory was used to verify large delocalization of electron motion over the polymers. The problem is, MO theory assumes it in the first place. Verifying what you assume is one of the big naughties pointed out by Aristotle, and you would thing that after 2,400 years, something might have stuck. Part of the problem was that nobody could question any of these computations because nobody had any idea of what the assumed inputs and code were. We might also note that the more extreme of these claims tended to end up in what many would claim to be the most reputable of journals.

There were two major fall-outs from this. Anything that could be vaguely related to polywater was avoided. This has almost certainly done much to retard examination of close ordering on surfaces, or on very thin sections, which, of course, are of extreme importance to biochemistry. There is no doubt whatsoever that reproducible effects were produced in small capillaries. Water at normal temperatures and pressures does not dissolve quartz (try boiling a lump of quartz in water for however long) so why did it do so in small capillaries? The second was that suddenly journals became far more conservative. The referees now felt it was their God-given duty to ensure that another polywater did not see the light of day. This is not to say that the referee does not have a role, but it should not be to decide arbitrarily what is true and what is false, particularly on no better grounds than, “I don’t think this is right”. A new theory may not be true, but it may still add something.

Perhaps the most unfortunate fallout was to the career of Deryagin. Here was a scientist who was more capable than many of his detractors, but who made an unfortunate mistake. The price he paid in the eyes of his detractors seems out of all proportion to the failing. His detractors may well point out that they never made such a mistake. That might be true, but what did they make? Meanwhile, Pople, whose mistake was far worse, went on to win a Nobel Prize for developing molecular orbital theory and developing a cult following about it. Then there is the question, why avoid studying water in monolayers or bilayers? If it can dissolve quartz, it has some very weird properties, and understanding these monolayers and bilayers is surely critical if we want to understand enzymes and many biochemical and medical problems. In my opinion, the real failures here come from the crowd, who merely want to be comfortable. Understanding takes effort, and effort is often uncomfortable.

Scientific low points: (1)

A question that should be asked more often is, do scientists make mistakes? Of course they do. The good news, however, is that when it comes to measuring something, they tend to be meticulous, and published measurements are usually correct, or, if they matter, they are soon found out if they are wrong. There are a number of papers, of course, where the findings are complicated and not very important, and these could well go for a long time, be wrong, and nobody would know. The point is also, nobody would care.

On the other hand, are the interpretations of experimental work correct? History is littered with examples of where the interpretations that were popular at the time are now considered a little laughable. Once upon a time, and it really was a long time ago, I did a post doctoral fellowship at The University, Southampton, and towards the end of the year I was informed that I was required to write a light-hearted or amusing article for a journal that would come out next year. (I may have had one put over me in this respect because I did not see the other post docs doing much.) Anyway, I elected to comply, and wrote an article called Famous Fatuous Failures.

As it happened, this article hardly became famous, but it was something of a fatuous failure. The problem was, I finished writing it a little before I left the country, and an editor got hold of it. In those days you wrote with pen on paper, unless you owned a typewriter, but when you are travelling from country to country, you tend to travel light, and a typewriter is not light. Anyway, the editor decided my spelling of a two French scientists’ names (Berthollet and Berthelot) was terrible and it was “obviously” one scientist. The net result was there was a section where there was a bitter argument, with one of them arguing with himself. But leaving that aside, I had found that science was continually “correcting” itself, but not always correctly.

An example that many will have heard of is phlogiston. This was a weightless substance that metals and carbon gave off to air, and in one version, such phlogisticated air was attracted to and stuck to metals to form a calx. This theory got rubbished by Lavoisier, who showed that the so-called calxes were combinations of the metal with oxygen, which was part of the air. A great advance? That is debatable. The main contribution of Lavoisier was he invented the analytical balance, and he decided this was so accurate there would be nothing that was “weightless”. There was no weight for phlogiston therefore it did not exist. If you think of this, if you replace the word “phlogiston” with “electron” you have an essential description of the chemical ionic bond, and how do you weigh an electron? Of course there were other versions of the phlogiston theory, but getting rid of that version may we’ll have held chemistry back for quite some time.

Have we improved? I should add that many of my cited failures were in not recognizing, or even worse, not accepting truth when shown. There are numerous examples where past scientists almost got there, but then somehow found a reason to get it wrong. Does that happen now? Since 1970, apart from cosmic inflation, as far as I can tell there have been no substantially new theoretical advances, although of course there have been many extensions of previous work. However, that may merely mean that some new truths have been uncovered, but nobody believes them so we know nothing of them. However, there have been two serious bloopers.

The first was “cold fusion”. Martin Fleischmann, a world-leading electrochemist, and Stanley Pons decided that if deuterium was electrolyzed under appropriate conditions you could get nuclear fusion. They did a range of experiments with palladium electrodes, which would strongly adsorb the deuterium, and sometimes they got unexplained but significant temperature rises. Thus they claimed they got nuclear fusion at room temperature. They also claimed to get helium and neutrons. The problem with this experiment was that they themselves admitted that whatever it was only worked occasionally; at other times, the only heat generated corresponded to the electrical power input. Worse, even when it worked, it would be for only so long, and that electrode would never do it again, which is perhaps a sign that there was some sort of impurity in their palladium that gave the heat from some additional chemical reaction.

What happened next was nobody could repeat their results. The problem then was that being unable to repeat a result when it is erratic at best may mean very little, other than, perhaps, better electrodes did not have the impurity. Also, the heat they got raised the temperature of their solutions from thirty to fifty degrees Centigrade. That would mean that at best, very few actual nuclei fused. Eventually, it was decided that while something might have happened, it was not nuclear fusion because nobody could get the required neutrons. That in turn is not entirely logical. The problem is that fusion should not occur because there was no obvious way to overcome the Coulomb repulsion between nuclei, and it required palladium to do “something magic”. If in fact palladium could do that, it follows that the repulsion energy is not overcome by impact force. If there were some other way to overcome the repulsive force, there is no reason why the nuclei would not form 4He, because that is far more stable than 3He, and if so, there would be no neutrons. Of course I do not believe palladium would overcome that electrical repulsion, so there would be no fusion possible.

Interestingly, the chemists who did this experiment and believed it would work protected themselves with a safety shield of Perspex. The physicists decided it had no show, but they protected themselves with massive lead shielding. They knew what neutrons were. All in all, a rather sad ending to the career of a genuinely skillful electrochemist.

More to follow.

A Further Example of Theory Development.

In the previous post I discussed some of what is required to form a theory, and I proposed a theory at odds with everyone else as to how the Martian rivers flowed. One advantage of that theory is that provided the conditions hold, it at least explains what it set out to do. However, the real test of a theory is that it then either predicts something, or at least explains something else it was not designed to do.

Currently there is no real theory that explains Martian river flow if you accept the standard assumption that the initial atmosphere was full of carbon dioxide. To explore possible explanations, the obvious next step is to discard that assumption. The concept is that whenever forming theories, you should look at the premises and ask, if not, what?

The reason everyone thinks that the original gases were mainly carbon dioxide appears to be because volcanoes on Earth largely give off carbon dioxide. There can be two reasons for that. The first is that most volcanoes actually reprocess subducted material, which includes carbonates such as lime. The few that do not may be as they are because the crust has used up its ability to turn CO2 into hydrocarbons. That reaction depends on Fe (II) also converting to Fe (III), and it can only do that once. Further, there are many silicates with Fe (II) that cannot do it because the structure is too tightly bound, and the water and CO2 cannot get at the iron atoms. Then, if that did not happen, would methane be detected? Any methane present mixed with the red hot lava would burn on contact with air. Samples are never taken that close to the origin. (As an aside, hydrocarbon have been found, especially where the eruptions are under water.)

Also, on the early planet, iron dust will have accreted, as will other reducing agents, but the point of such agents is, they can also only be used once. What happens now will be very different from what happened then. Finally, according to my theory, the materials were already reduced. In this context we know that there are samples of meteorites that have serious reduced matter, such as phosphides, nitrides and carbides (both of which I argue should have been present), and even silicides.

There is also a practical point. We have one sample of Earth’s sea/ocean from over three billion years ago. There were quite high levels of ammonia in it. Interestingly, when that was found, the information ended up as an aside in a scientific paper. Because it was inexplicable to the authors, it appears they said the least they could.

Now if this seems too much, bear with me, because I am shortly going to get to the point of this. But first, a little chemistry, where I look at the mechanism of making these reduced gases. For simplicity, consider the single bond between a metal M and, say, a nitrogen atom N in a nitride. Call that M – N. Now, let it be attacked by water. (The diagram I tried to include refused to cooperate. Sorry) Anyway, the water attacks the metal and because the number of bonds around the metal stays the same, a hydrogen atom has to get attached to N, thus we get M-OH  + NH. Do this three times and we have ammonia, and three hydroxide groups on a metal ion. Eventually, two hydroxides will convert to one oxide and one molecule of water will be regenerated. The hydroxides do not have to be on the same metal to form water.

Now, the important thing is, only one hydrogen gets transferred per water molecule attack. Now suppose we have one hydrogen atom and one deuterium atom. Now, the one that is preferentially transferred is the one that it is easier to transfer, in which case the deuterium will preferentially stay on the oxygen because the ease of transfer depends on the bond strength. While the strength of a chemical bond starts out depending only on the electromagnetic forces, which will be the same for hydrogen and deuterium, that strength is reduced by the zero point vibrational energy, which is required by quantum mechanics. There is something called the Uncertainty Principle that says that two objects at the quantum level cannot be an exact distance from each other, because then they would have exact position, and exact momentum (zero). Accordingly, the bonds have to vibrate, and the energy of the vibration happens to depend on the mass of the atoms. The bond to hydrogen vibrates the fastest, so less energy is subtracted for deuterium. That means that deuterium is more likely to remain on the regenerated water molecule. This is an example of the chemical isotope effect.

There are other ways of enriching deuterium from water. The one usually considered for planetary bodies is that as water vapour rises, solar winds will blow off some water or UV radiation will break a oxygen – hydrogen bond, and knock the hydroden atom to space. Since deuterium is heavier, it is slightly less likely to get to the top. The problem with this is that the evidence does not back up the solar wind concept (it does happen, but not enough) and if the UV splitting of water is the reason, then there should be an excess of oxygen on the planet. That could work for Earth, but Earth has the least deuterium enrichment of the rocky planets. If it were the way Venus got its huge deuterium enhancement, there had to be a huge ocean initially, and if that is used to explain why there is so much deuterium, then where is the oxygen?

Suppose the deuterium levels in a planet’s hydrogen supply is primarily due to the chemical isotope effect, what would you expect? If the model of atmospheric formation noted in the previous post is correct, the enrichment would depend on the gas to water ratio. The planet with the lowest ratio, i.e. minimal gas/water would have the least enrichment, and vice versa. Earth has the least enrichment. The planet with the highest ratio, i.e. the least water to make gas, would have the greatest enrichment, and here we see that Venus has a huge deuterium enrichment, and very little water (that little is bound up in sulphuric acid in the atmosphere). It is quite comforting when a theory predicts something that was not intended. If this is correct, Venus never had much water on the surface because what it accreted in this hotter zone was used to make the greater atmosphere.

Where to settle on Mars?

A few weeks ago I wrote an introductory post on Martian settlement issues (https://wordpress.com/post/ianmillerblog.wordpress.com/716 ). I am now going to ask, where should such a settlement be? Obviously, this is a matter of opinion, but there are some facts to consider. The first is seasons. The northern hemisphere spring and summer is about 75 Martian days longer than the autumn and winter (and opposite for the southern hemisphere. This is a consequence of the elliptical orbit, but it also means that the longer seasons mean the planet is further from the sun (which is why it is going slower) and because of the axial tilt that generates the seasons as well as the elliptical orbit, most likely places can get up to 40% less sunlight in winter than in summer. Add to that that by being so much further from the sun, Mars never gets more than about half the Earth’s solar energy. So the southern hemisphere has a shorter but warmer pair of seasons, and a longer colder other pair. Temperatures in summer can get up to 20 degrees C in the day and in winter, fall to minus 120 degrees C during the night. No plant can survive that, so besides providing air, heat is also required.

There is a reasonably easy way to get around the heat problem. Assuming you have a nearby power plant, and as I shall show in other posts, if a settlement is to be viable, it will have a heavy demand for high quality energy, then there will inevitably be waste heat. Space mirrors can also supplement the heat and light. Heating the planet is not on (you would need mirrors of area greater than the Martian cross-sectional area) but heating a settlement is plausible.

The location could be decided on the basis of nearness to raw materials, but that leaves open the question of which ones? The obvious one is metal ores, but here we do not know where they are, of even if they are. Again this can be left for another post.

The next question is air. Air pressure depends on altitude, and much of the exploration so far has been around the zero of altitude, where we get pressures of around 6 -8 millibar, depending on the season. In the southern hemisphere summer, the pole shrinks and vaporizes a lot of carbon dioxide, thus increasing atmospheric pressure. In my novel Red Gold I put the initial settlement at the bottom of Hellas Planitia. That is in the southern hemisphere, and is a giant impact crater, the bottom of which is about nine kilometres deep. That gives more atmospheric pressure, but at the cost of a cold winter. The important point of Hellas Planitia is that at the bottom of the impact crater the pressure, is high enough to be the only place on Mars for liquid water to exist, particularly in summer. The reason this was important, at least in my novel, is that unless you find water, you will probably have to pump it from the atmosphere and condense it. Also, while you are pumping up domes, you will want to get the dust out of the air. The dust is extremely fine. That means very fine filters, which easily clog; electrostatic dust precipitators, which may be too slow for many uses; or a form of water filtration. In Red Gold, I opted for a water-ring type pump. Of course here you need a certain amount of water to get started, and that will not be a small amount. The water will still evaporate fairly quickly, hence the need to have plenty of water, but the evaporite will go into the dome, so it is recoverable or usable. It could also be frozen out before going in; whatever else is in short supply on Mars, cold is not one of them, although with the low atmospheric pressure, the heat capacity of air is fairly low.

So strictly speaking, based on heat and air, both have to be heavily supplemented, it does not matter where you go. However, I think there is another good reason for selecting Hellas Planitia as the site. It is generally considered that water, or at least a fluid, flowed on Mars. The lower parts of Hellas have signs that there was water there once, and to the east two great channels, the Dao and the Harmarkis, seemingly emptied themselves into the Hellas basin. Water will flow downhill, so a lot of it would have resided in depressions, and either evaporated, or solidified, or both. So, there is a good chance that there is water there, or anything that got dissolved in the water. The higher air pressure will also help reduce sublimation by a little bit, so perhaps there will be more there than most places.

The next issue is, you wish to grow food and have plants make oxygen. Obviously you will need some fairly sophisticated equipment to get the oxygen from the plants to wherever you are going to live, assuming you don’t live with the plants, but the plants have to grow first. For that you need soil, water and fertilizer. The soil is the first problem. It is highly oxidised, and chlorides have been oxidised to perchlorates. That is fine for making a little oxygen, but it has to be treated or it will kill plants. Apparently it is something as good as bleaching powder. Again, you will have to take the treatment chemicals with you; forget something critical or do not bring enough, and you will be dead. Mars is not a forgiving place.

That leaves fertilizer. Most rock has some potassium and phosphate in it, and if these have been washed out, their residues will be where the water ended, so that should be no problem if you go to the right place. Nitrogen is slightly different. The atmosphere has very little nitrogen. On Earth, plants get their nitrogen from nitrates washed down in rain, from decayed biomass, and from farmers applying it. None of that works there immediately. Legumes can “fix” nitrogen from the air, but there isn’t much there to fix and partial pressure is important. You can, of course, pump it up and get rid of carbon dioxide. A lot of these issues were in the background of my ebook novel Red Gold, ad there, I proposed that Mars originally had somewhat more nitrogen, but it ended up underground. The reason is for another post, but the reason I had then ended up as being the start of my theory regarding planetary formation. However, the possibility of what was leached out or condensed out being at the bottom of the crater is why I think Hellas Planitia is as good a place as any to start a settlement.

Quick Commercial: Red Gold will be discounted to 99 c for six days starting the 13th. It is basically about fraud, late 1980s style, but much of the details of settling Mars are there.

The Grenfell Fire, and the Logic of Plastics in Cladding

For me, the most depressing recent news was the London fire, in which a high-rise of flats (apartments for Americans) somehow caught fire, and once it did, it spread like crazy. There is a lot of blame to share around for the death toll. Apparently people were told to stay in their flats, but that advice was given by firemen who were unaware that the building had no useful fire doors, or the other usual means of containing and retarding fires. After all, if the building is concrete, and there is no easy way to spread the fire, it should be able to be kept local. So what went wrong? We don’t know about why the interior of the building seemed to burn very nicely, but it seemed that the outside burned furiously. The outside had an aluminium cladding, apparently to make it look more attractive. The aluminium tiles were backed by polyethylene, which is essentially a solid hydrocarbon of structure similar to diesel, but a much larger molecular weight. That burns very well, and if you saw video of it, you would see great globs of fire falling off the building.

We don’t know exactly why the polyethylene was there. Some say heat insulation, others say to give the cladding rigidity. Much has also been made of the fact that for about $3 a tile more, the backing could have been fire resistant. I am not sure what that backing is as the maker’s website does not say, but would guess it is some sort of polyamide or polyurethane with non-flammable filler. These certainly do not catch fire as easily, but there is another catch with some of them: in a fire they do burn, and while not as well, they tend to give off some rather poisonous gases. There is another catch. According to the manufacturer, the fire resistant tiles passed ASTM E 84 tests, which are the standard tests for surface burning characteristics, but so did the polyethylene backed tiles. That sort of lab test does not represent a real fire.

This brought back memories of my past, when I got involved with two structural foams that could be suitable for building cladding. One was a glass foam, originally intended to be made from waste glass. This would make quite a good wall cladding without the aluminium, except possibly on the bottom floor because it does not have very good impact resistance. Thin glass shatters on impact, but it does not burn or corrode. You can also have a wide range of colours. The other is a plastic foam, for which you do not even need fillers to make it fire resistant.

The story of my involvement with that goes back to the late 1970s. In the late 1960s, New Zealand discovered a large offshore natural gas field, and the government took it upon itself to enter a “take or pay” agreement so the field would be developed. It was not clear what their idea was, but presumably electricity generation was one of them. However, when the first energy crisis struck, about 1972 from memory, there was a sort of panic, and after a lot of deliberation they decided to construct a synthetic fuels plant at Motunui, which was to use a process developed by Mobil. I was on a committee to advise on the science, and I advised this was a bad idea because they could not build it for anything like the costs presented to them. As it turned out, my projected cost was out by $200 million, but no site had been chosen, and my estimate was “plus site development”. (In the end, the site development would have been about $130 million, so I was rather pleased with myself.) However, at the committee, I was about 4.5 times greater than the figure they were comfortable with (and note the government was going to pay) so I was never asked to be on such committees again. However, when that process was chosen, I knew that there was one byproduct they would not know what to do with: 1,2,4,5-tetramethylbenzene. The reason: it is a solid, which is not good in petrol for cars. The good news from my point of view was that it could be oxidized to pyromellitic dianhydride, which would be a precursor to stepladder and even ladder polymers, and in particular to polyimide plastics. The bad news was that the top public servants did not want their synfuels project upstaged, and the politicians were unenthused, probably because they were totally out of their depth.

So to get rid of the road blocks, I needed a stunt. As it happened, the fire hazard with plastic foams was to be the subject of a half-hour nationwide TV program, and I was invited to comment as a scientist. I agreed, provided I could have a few minutes for a demonstration of fire resistant foams. That was agreed, so I made myself some polyimide foam. This was rigid, and not much use for furniture, but you can’t really do much development work with one day’s notice. So I turned up, and at the end of the program, which had the dangers of fires, and of the poisonous gases drilled into everyone, I had the cameras turned on me. I put a bit of home-made foam in the palm of my hand and directed a gas torch at it. It glowed a nice yellow-hot under the flames, and I just sat there. Eventually they got bored of watching this, and they turned off the torch, then made the comment, “It still stinks, though.” So, with a bit of acting here, I held the plastic up to my face and sniffed deeply, and made no expression. Since there was no fire, while the plastic was ablating slowly, once the torch was taken away there was no more reaction. Unfortunately, my wife forgot to record this so I can’t actually prove it.

The whole point of this, of course, is it is possible to make very fire resistant foams. Without the type of chemical plant I was proposing, such foams would be expensive, but the question then is, is preventing x number of deaths worth spending a few extra dollars (or in this case, pounds)? In my opinion, there is no real excuse. Yes, the foam I made was rigid, but as building insulation, so what? While science can provide answers to many problems, there is not much point in it if nobody in power takes any notice.

Chemicals over Syria

The news over the past week was dominated by a “chemical attack” in Syria, and the US response. However, there was then a flurry of various theories as to what had happened, the most usual one being that Assad was at it again, using sarin on his own population. So, what do we know, and what theories are consistent with what we know? In my scientific books, I have maintained that for any subset of facts, the smaller that subset the more likely there is that there will be at least one other theory consistent with the facts. What one then does is design experiments to s falsify some of them, so that eventually you end up with just one, and that is most likely to be correct. With human activities that is a little harder to do, and we have to relax somewhat the Royal Society’s motto Nullius in verba, which loosely translated means, take nobody’s word. With something like Syria, you cannot check everything rigorously, but you can look for self-consistency and reliability.

So what do we know? First, a number of people, including children, died in Khan Sheikhun some time on the morning of Tuesday 4th April. Some survivors were taken to hospitals elsewhere. According to US surveillance, one SU 22 took off from Shayrat air base and dropped objects on Khan Sheikhun. That is about all we know. What is most likely to be true? First, the symptoms of the survivors were argued to be consistent with their having experienced sarin, although one of the hospitals reported the symptoms were consistent with sarin, but the clothing showed signs of chlorine, which implies there were two gases present. Strictly speaking, sarin does not give unique symptoms, and a number of other organophosphorus compounds would also give these symptoms, although not so acutely. One such compound might be methylphosphonyl difluoride, the precursor to sarin.

There are also video clips of white helmets as first responders helping the victims. They had no protection. Sarin is a liquid, and it is absorbed thorough skin. Had this been sarin, we would expect those first responders to die. There is a further problem with white helmets; there are also statements on the web that the white helmets, operating only in al Qaeda controlled territory, give preference to militants, and have staged scenes on behalf of al Qaeda. That does not mean they did so here, but it also raises questions as to the reliability of their statements.

Whether there were one or two agents is also important, and this point is not entirely clear. Two agents is more consistent with a dump having been hit. More confusion comes from one report that the town was struck by one rocket. Further, the town is a stronghold of al Qaeda affiliates, who are not necessarily going to tell the truth. Apparently, UN inspectors are trying to piece together what really happened, and in principle, these uncertainties should be clarified. The US intelligence statement states that at least one of the items dropped from the SU 22 was a canister of sarin, but how would they know that? There are also clips showing a shed that has no bomb damage and hence what came in must have been a gas canister. However, there is no evidence anything came in. The makers of such clips refuse to show holes in the roof, and while there is a clip of what looks like an undamaged munition being tested, from the way it is laying, either it was irrelevant or it had been moved.

There are at least three theories circulating for what happened. The first is the most popular: Assad’s air force dropped bombs with chemical weapons. The second is the Russian version: Assad’s air force dropped bombs on a dump of chemical weapons, or material for chemical weapons. The third is that ISIS/al Qaeda did it deliberately to get US involvement. A fourth might be that ISIS/al Qaeda did it accidentally. At this point it is important to determine whether the delivery was by one rocket. If so, the Syrian air force is off the hook, although the Syrian army could have fired it.

One argument against Assad having done it is that it makes no sense for him to have done so. He is gradually winning the war, and President Trump has indicated the US did not want to get involved with Syria. He would know that the US would be really irritated if he did, so why would he? To do so would be just plain stupid, but unfortunately this argument has a flaw: there appears to be no shortage of stupidity in the world.

Another argument against it is he handed over his chemical weapons. The problem then is, how truthful is this? On the other hand, if he had complied, the likes of al Qaeda definitely did not. They, and ISIS, control so much of Syria it is almost certain they would have had control over some such dumps.

Very shortly after, the US navy fired 59 cruise missiles at Shayrat air base. The US says all fifty-nine reached their target; some reports indicate that only 23 struck it. What happened to the others? Here is an example of the fundamental problem: some people are asserting statements that are not true. However, we have not heard anything of where rogue ones struck, so either Assad missed a trick, or the US story is true. Assad also missed another trick here. The US in some reports claims there were chemical weapons at Shayrat. If so, why did they fire weapons that would liberate sarin when it would almost certainly go to the local residential area? They would be doing what Russia asserts Assad did. So what is the outcome?

For me, the most obvious one is we cannot trust any report on this matter so far. Too many politics are involved. On a lesser scale, President Trump showed that he was not going to wait for evidence from the UN inspectors. He was an action man. What did he achieve by doing this? Apparently he damaged at least six Syrian aircraft, although five of them, from the photographs, look not hopelessly damaged but they also look obsolete. Relations with Russia have taken a dive. For me, there are two consequences I fear. The first is, if ISIS has any chemical weapons, now is the time to use them on innocent civilians. That will bring the US in demolishing Assad’s forces. One of the more bizarre aspects of this incident is that the US has entered a civil war (always a bad idea) and is actively supporting both sides. The second is that President Trump has also threatened North Korea. Bombing Assad’s forces is superficially consequence-free (in the long term it is anything but) but bombing North Korea would reset the Korean war. I only hope some real thinking goes on soon.