Ebook Discount

From May 25 – June 1, Athene’s Prophecy will be discounted to 99c/99p on Amazon. Alien help is required to save humanity in the 24^th century, but thanks to relativity, the expedition to get it has to start in the first century. A young Roman, Gaius Claudius Scaevola, is selected, and Pallas Athene gives him a prophecy, which comprises instructions what he has to do before, unknown to him, he will be abducted by an alien specimen collector. The first thing he must do is to prove the Earth goes around the Sun with what was known and was available in the first century.

To the best of my knowledge, this is the only book that shows how a scientific theory is formed. Can you do it? Try your luck

Meanwhile, Scaevola is in Egypt for the anti-Jewish riots, then to Syria as Tribunis laticlavius in the Fulminata, then he has the problem of stopping a rebellion when Caligulae orders a statue of himself in the temple of Jerusalem. You will get a different picture of Caligulae than what you normally see, supported by a transcription of a report of the critical meeting regarding the statue by Philo of Alexandria. (Fortunately, copyright has expired.). First of a series. http://www.amazon.com/dp/B00GYL4HGW

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Cosmic Catastrophes

Astronomers have found a record explosion (Monthly Notices of the Royal Astronomical Society, Volume 522, Issue 3, July 2023, Pages 3992-4002, https://doi.org/10.1093/mnras/stad1000) . The total energy output was stated to be 1.5 x 10^53 ergs. (People still use ergs??) An erg is 10^-7 of a Joule, so the explosion generated 1.5 x 10^46 Joules. These numbers are sort of mind-boggling. Try thinking of tonnes of TNT. The equivalent would be about 3.4 x 10^36 tonnes, or well over 10^28 of the largest hydrogen bombs ever exploded. That is 10 with 28 zeros after it. Of course we can hardly see it. It is about eight billion light years away, which is probably just as well. It is more than ten time brighter than any supernova ever recorded and so far has been going for three years. The “fireball” is about 100 times the size of the solar system and that mass is two trillion times brighter than the sun. If you want to impress your friends, the explosion is known as AT2021lwx. Astronomers have charming names for things.

So what could have caused it? One option would be a tidal disruption event. This is essentially when a star is tidally disrupted by the black hole and the black hole disrupts the star, leading to star matter pouring into the black hole. Oddly enough, this depends on a tidal radius, which in turn depends on the density of the star, so that for a given stellar mass and radius there is a corresponding upper black hole mass for which this cannot occur. Larger is not better for this. For this to be the cause of this event, the star would have to be almost fifteen times the mass of the sun, which is somewhat unlikely because such a massive star only lives for about 15 million years. It is hard to see how such a massive star could be born there, because the black hole would consume the gas first, and it  is hard to see how it could move there, so that is probably not the cause.

A better alternative is thought to be a vast cloud of gas, probably thousands of times more massive than the sun, falling into a black hole. The energy is simply gravitational potential energy being converted to heat as the gas falls towards the black hole and it estimated the temperature reached about 13,000 degrees C. The gas and dust was believed to be in a disk circulating the black hole, and something must have dislodged it and made it start to fall into the black hole. However, so far nothing has been modelled.

So, at the end of the day, we don’t know what it is.

On a much much smaller scale astronomers have noticed a optical outburst named ZTF SLRN-2020 (Nature, 617: 38 – 39) that lasted roughly ten days, and then slowly decayed over six months. The start of the burst coincided with infrared emission that lasted long after the optical emission had decayed. The optical radiation was featureless continuous emission at the red end, as well as lines corresponding to molecular absorption.

The first thought was this was a classical nova. This appears to happen when a white dwarf accretes hydrogen from a close companion star. A white dwarf is effectively a dead star, and is what is left over after nuclear fusion has stopped. They have the mass of the sun and the size of Earth, so they are dense. Hydrogen landing on it will trigger nuclear fusion. However, if this were the cause we would expect to see spectral lined from elements entrained in the gas and we don’t.

Another possibility was a so-called red nova, which is caused by two stars merging. The nature of the light is quite similar, except the power output was far too small. Further, the star’s radius did not change appreciably. After some very detailed observing, they found the source was a sun-like star and the power output was consistent with the other object that did the merging being a giant planet. So it appears the star has swallowed a planet.

How would it do that? If planets get too large for the distance between them, gravity drives them into elliptical orbits with exchanged energy, i.e. one goes closer to the star and one goes further. If the exchange of angular momentum leads to the inner one having a very high eccentricity, its perigee can have a close enough approach to the star that frictional interactions cause the orbit to decay. Once that starts there is no escape for the planet.

Genius and Alleged Stupidity

This week’s post takes material from reviews of a book, specifically “The  Limits of Genius: the Surprising Stupidity of the World’s Greatest Minds” by Katie Spalding. This was highlighted by Physics World,  and no, I haven’t read the book, not the least because it is not available until May 25. So you can take this as a recommendation, or with a grain of salt, however you please. The information is second hand (and for you, third hand!): it starts with Katie Spalding and she had sources of whatever accuracy, then the reviewer had to interpret it correctly, and of course I have to interpret the reviewer’s comments. So beware. Getting the book might help because apparently the sources are well referenced. Anyway, here are some examples, plus some extra comments from me.

Mathematics is supposed to be the most logical of studies. Ada Lovelace was a mathematical prodigy and wrote the first computer program, in 1840. She was also addicted to gambling. Now you would think a brilliant mathematician would know how to win, or would know to avoid what was always loaded against her. But Lovelace apparently lost the family jewels, and when her mother-in-law bought them back, she lost them again. One could argue the mother-in-law was a little deficient in common sense; giving money to a compulsive gambler is not a sensible act.

Of course, losing is not always a sign of stupidity or incompetence in a mathematician. There is the story of John von Neumann, who was an extremely brilliant mathematician and who, with Oskar Morgenstern, founded game theory, an important mathematical approach to economics and decision-making. Apparently his students kept pestering him with challenges to play poker, and von Neumann kept refusing, until eventually he gave in. He played, and within 30 minutes he had lost all the money on him, and he left the game. Some of the students were somewhat derisive of his ability until one pointed out, “He really did not want to play poker with us.” He lost the money to stop the pestering.

René Descartes gets a mention for going to Amsterdam in his youth to smoke weed and get away from his father. Whether you call that stupid is up to you; sometimes in some families relationships are unbearable. However, and I don’t quite get this one, he is accused of becoming a fanatical supporter of a weird religious sect that did not actually exist. If there were a number of people sucking him in, surely it existed. Existence for a sect has a fairly low bar; all you need is a few people to call themselves whatever, and it exists.

Tycho Brahe was an incredibly clever astronomer, and despite having no telescope, eventually constructed the first “modern” star chart and catalogued a thousand stars. He was an assiduous worker, but apparently was also very argumentative. In his younger days he kept getting drunk, and sometimes ended up in duels. In one such duel he had his nose cut off at the bridge. Not exactly clever.

Whether this is stupid is a matter of opinion. James Glaisher nearly killed himself by taking multiple hot air balloon flight so high that he passed out. Nevertheless he recorded enough data that he could figure out details of the Earth’s atmosphere that revolutionized the nascent field of meteorology. Einstein enters as being stupid for loving sailing and not being able to swim. I could be accused similarly. For 25 years I spent my spring holiday (I am self-employed) catching whitebait (a local delicacy) on a small island. At the end I would have to paddle back across the tidal flow in a small boat with waders on. Swimming was not an option. But then again, sometimes you back yourself to do the obvious safely.

Some of what we would call “stupid” were really due to ignorance. Thus Marie Curie carried around radioactive materials in her pockets, which led to horrible skin lesions and her early death. Sigmund Freud used and prescribed liberal amounts of cocaine, but at that time the addictive nature of cocaine was not recognized. These are more ignorant than stupid.

Some lesser accusations were also made. Thus Lord Byron once took a bear to University. Stupid, but a show-off. Tesla is accused of “falling in love with a pigeon”. Here, “falling in love” is somewhat ambiguous. Thus I could be accused of loving Horatio, my pet cat, but hardly in the sense of a woman. Da Vinci is accused of being stupid for ruining a career through procrastination. Now, don’t you know someone who never gets things done on time? Certainly that is a character flaw, but hardly a sign of stupidity. Perhaps the most interesting accusation is against Thomas Edison, who was accused of trying to construct a phone to talk with ghosts. He failed, but is it really stupid to try something that nobody thinks will work. If it does, you will do remarkably well, and when it did not, Edison was at least honest.

So, to summarise, we have what appears to be an interesting book. If you want to know more, you know what to do. (Disclaimer: I have absolutely no financial interest in this publication.)

IPCC Conclusion: We Are Cooked!

Recall the saying, “There are lies, damned lies, and statistics”. I would add a further term at the end – ” There are lies, damned lies, statistics, and models.” What sparked this bout of negativity? Well, last week I went to a talk from one of the NZ representative of the International Panel on Climate Change. The talk was headed, “Where are we, and how do we get out of this?” The entire talk was devoted to where we are, and it was fairly grim, and the second part, how do we get out of this, was blank. Maybe there is no way out. Anyway, let me try to recall what was said. If there are errors here from the IPCC, assume they are due to my faulty memory.

The first thing to note is the goal back in the 1990s was to limit greenhouse emissions so as to keep the increase in temperature to 1.5 degrees C above pre-industrial levels. One could question that as a goal because pre-industrial was the so-called “Little Ice Age”, and arguably that is not a good reference point. Be that as it may, the governments of the world agreed to work on limiting emissions. First there was the Rio agreement in 1992, then the Paris agreement, which is supposedly legally binding on 196 parties, and the aim was to “pursue efforts” to limit the temperature raise to 1.5 degrees.

So how are we doing? It is one of the less successful agreements, in my view. The object was to limit and reduce emissions of CO2; what has actually happened is we have doubled the rate of emissions, and much of that since the “legally binding 2016 agreement”. The original target was not to hit the 1.5 degree rise before the end of the century. If we extrapolate current trends, we strike it in this decade. Oops!

So what are the effects? Currently, the odd good thing, but mainly the outcomes are bad to awful. What is somewhat unexpected is the effects differ by hemisphere, possibly because the Southern Hemisphere has most of the ocean, and ocean has an albedo about a third of that of land, so it absorbs so much more heat. The greatest increase in local temperature has come from that Arctic; it is heating rapidly. Funnily enough, the Antarctic is not following, and there are even spots where it is cooling. The heating of the Arctic does little for sea level rise because the ice was always floating, but the Greenland Ice Sheet is shedding water at a rate of 270 billion t/a, which contributes to the rising sea levels. Antarctica is losing ice at a rate of about 150 billion t/a, mainly due to warmer water undercutting the ice and melting from below. The end position is unclear; climate models suggest the two large Antarctic ice sheets should collapse, but there are some claims that the ice sheets are growing. Recall my comment on models?

The  other problem is weather. The winds are part of a gigantic heat engine, and the winds strengthen as the temperature difference increases. Accordingly, the rapid heating of the Arctic will moderate the temperature difference in the Northern hemisphere. Although that is not a free pass because hurricanes and typhoons are generated by seawater evaporating, so they will get stronger as the planet heats. The other problem for the Northern hemisphere is quieter wind systems lead to longer and more severe droughts. For the Southern Hemisphere, as we are  finding out, the wind systems become stronger and we have “atmospheric rivers” pouring large amounts of water from the tropics over us. But one interesting fact is that precipitation seems to be increasing over Antarctica. That may save us somewhat from being too inundated by sea-level rise.

So where does this leave us? Well, the IPCC has modelled a huge number of possible futures, but my feeling is, almost all of them will not happen. We know the situation is getting bad, but what is being done to fix things? Not a lot. And it is not that good plans are not being implemented. If this talk was indicative, we have NO GOOD PLANS. Does that mean we cannot do anything? No it does not. But as General Wesley Clark said there are two sorts of plans: those that won’t work and those that might work. You have to take one that might work and make it work, And herein lies some problems. We don’t know for sure what will work, although some seem highly probable, but we also have no mechanism to make them work. Recall what I said about the rate of emissions doubling when everyone was supposed to be reducing them? We have governments carrying out emissions trading schemes, as if that would solve the problem, but it is just raising costs; the rate of emissions is increasing. There might be a legally binding treaty, but if everyone is violating it, what good is that? There is no method to get governments to impose plans that might work, and politicians, usually, could not tell whether a plan could work, although they may well predict, correctly, if left to them it would not work. This is a highly technical problem that has to be understood to solve it. Politicians simply do not have the technical background.

Liar Liar!

Do you think you can detect liars? If so, according to a Nature article (https://doi.org/10.1038/s41562-023-01556-2 ) you are most probably mistaken. A meta-analytic test involving 24,483 people who had to attempt to pick truth/lie, found truth/lie discrimination no better than 4% better than random guessing. Not exactly a stunning achievement. You will read about cues such as liars avoid eye contact, and basically they do not. Liars have heard about that! Worse, truthful people do it as well. If you rely on behavioural cues, you find that there is a 96% overlap of these behavioural variables between truth-tellers and liars.

A current approach is to combine many cues, and the article reports that airport security personnel were trained to handle 92 cues. One problem is most of such a large number will be weak cues, but more significantly, who can do a rapid analysis of 98 variables in their head? Back to guessing, except those involved will have a very fancy name for the procedure that leads to guessing.

The problem is we need to end up with a binary judgement. This happens in many cases. A jury must decide on guilt or innocence, in a job interview someone must hire or reject. The action is discrete; twenty-seven ifs and buts have to be rejected, and your decision should be better than the toss of a coin. So how are such decisions reached? The usual way of dealing with too much information is to ignore most of it. The approach is to select a very few cues. If we want to do that for lie detection, we need to know the best possible cues.

In some experimental tests, when subjects could use any cue they liked, the accuracy was about 50%, which is what they would get from random guessing. However, when the same subjects were asked to make their decision based on richness of detail, success rose to about 66%, in other words two/thirds were  correct. A second cue was whether the statement could in principle be verified; accuracy then rose the about 70%, but note that no verification actually took place. The key was, could it be verified? This was not actually done because in the tests decisions had to be made more or less on the spot, but it would be possible to ask what would be seen if someone went to inspect the situation to verify it or not.

An experiment was  done where participants were asked to determine on a single cue (detailedness) or use multiple cues (detailedness, affect, unexpected complications, admissions of lack of memory). The success rate with a single cue  was 59%, while with multiple cues, 54%. More information in the decision-making process led to worse decisions. Of course, you might well think this difference is not very great, and worse there may have been something in the material that biased the results, so just maybe the conclusion is only marginally significant. Another point might be that some of the additional cues were not very relevant. A memory lapse might be an excuse for not having tho0ught up the lie fully, but it can also be genuine. Who recalls all the fine details of having seen something but there was no reason at the time to think it was particularly important?

There is another problem with this sort of study, which was acknowledged by the authors. Subjects were instructed to lie or tell the truth. This may have led to deliberate “false cues”, and even if it did not, there is nothing at stake for the liar. Knowing there is a serious price to pay if caught out, liars may be more prepared to embellish their lies, and give additional details. Second, the success of this approach  was demonstrated only where statements were about episodic memory and truth-tellers were both willing and able to provide specific details. In real situations, there may not be many details remembered when telling the truth, while a liar may produce more.

So, to summarize, those TV shows where there is someone who can pick a lie with infallible accuracy are, well, telling the audience porkies.

How to Beat the Potential Lithium Shortage?

By now, lithium is probably recognized as a useful material and is considered to be critical for dealing with climate change. A recent  paper in Nature (vol 616, 245) discussed some of the issues. In 2018, demand for lithium was about 55,000 t/a, by 2025 it is expected to reach 150,000 – 190,000 t/a, and by 2100 it could reach 700,000 t/a. The IEA predicts that by 2030, only about half of what is required could be delivered. The production of lithium is currently complicated. Ores are roasted at 1100 degrees C, then baked in acid at 250 degrees C to leach out acid solubles. Apparently about a half a dozen chemical reactions are carried out to get rid of impurities, and the solution is evaporated to make lithium carbonate. To make a tonne of lithium salt, you need 60 MWh of electricity and 70 cubic meters of water, while the overall process, including mining, emits up to 35 t of CO2. Worse, most of the lithium occurs in basically dry areas, such as in Western Australia. The waste includes elements such as arsenic, thallium, chromium uranium and thorium. Finally, by 2030 there will be roughly 8 million t of sodium sulphate as a byproduct. This arises th4rough the lithium carbonate being made bey taking lithium sulphate and sodium carbonate. Lithium carbonate is only soluble in water at about 1% at 20 degrees C.

The need for an improved extraction process is obvious, but just because the need is obvious does not mean it will be easy. One method proposed is to find a sorbent that you pass the solutions through and only the lithium is absorbed. Ther e appears to be only one problem with this proposal: as yet we do not have such a sorbent. Is one possible? I would guess yes, but it may take some time to develop, and of course you want to be able to get the lithium out of the sorbent and reuse it. What are the prospects? It is possible to make substances like zeolites with specifically sized channels and have functional groups in them that will absorb the desired product. My guess is the zeolites are unsatisfactory because their absorbing properties come for cationic charge, which would presumably repel lithium, but there is plenty of scope to have the concept played out with something more suitable. So I would give that option a firm “maybe”.

The next suggestion is electrolysis. My concern is that the impurities noted above would coat the electrodes, while the lithium would stay in solution. It may well be somewhat more concentrated around the anode, but they will not deposit. Basically, what is being done is to electrolyse water, and coat some electrodes. Unless there is some undisclosed trick, I give this a fairly firm “dubious”.

The Nature paper suggests that one way to use the otherwise waste sodium sulphate (which is very water soluble) would be to convert it back to sodium hydroxide and sulphuric acid. No route was suggested, and while this is possible, my guess is it would be extremely expensive. Of course, the solution would have a certain amount of lithium carbonate as well.

The digging up of rocks could be avoided by passing water into the mineral bed, similar in concept to fracking. That, to me, would almost certainly work, although at what cost remains to be seen. There would still need to be  good purification techniques.

Another alternative noted in the paper is not to bother purifying the lithium, but to use disordered rock salts, which are more abundant than cobalt or nickel. At this point the article seems to overlook why cobalt is used in the first place: it can form a trivalent cation as well as a divalent one. When the lithium changes oxidation state at the anode, something has to do the opposite at the cathode, AND it has to do so without a volume change. If it fails and has a volume change, the cathode will fracture after so much charging and the battery dies. The article notes these disordered rock salts require high voltage charging, at which point they become unstable. Not desirable. There are so many things that we do not know how to get around for this to work I consider it extremely doubtful.

Recycling sort of works. The batteries are shredded ( and hopefully do not catch fire because  a lithium fire is almost impossible to put out), then the lot is heated to recover the metals as an alloy, while the lithium is in a slag. It is then treated like an ore. That needs a better process.

So, where does this end up? In my opinion the most likely outcome will be a different type of battery. A sodium ion battery will have unlimited sodium, but since it has yet to work we do not know what else it requires. My bet goes back to the chemistry I suggested in my first Mars novel: an aluminium chlorine battery, although prior to charging it merely contains aluminium chloride. Neither of those elements are in short supply.

Ebook Discount

From April 20 – 27, Dreams Defiled, the second in a series (the first was discounted last month) will be discounted to 99c/99p on Amazon. The expedition made contact with aliens, but the message was clear: you are not ready for contact. Some of the party will work to improve Earth’s behaviour, but one has had his ambition destroyed, and he is forbidden to tell anyone what he saw. His ambition now is to be important, by using any foul means required. A study of how a normal person can be degraded to a monster, and for others, how good intentions fall apart when faced with the inevitable protests. A tale of murder, politics and Mars.

The Tyrannosaur Smile

My previous post complained about cherry-picking data to support a conclusion. There is an obvious alternative problem: what happens when there is a paucity of data. There are two alternatives: give up and wait for more, or try to draw conclusions from what is available. The study of dinosaurs is a good example. We know they existed because we have some skeletons and we also have numerous miscellaneous bones. We can put reasonable flesh on those bones because we know they had to walk, so there had to be sufficient muscle power to move them, and we know they had to eat, so they had to catch food. So we can extrapolate from what we know. The problem is that in doing that we can start to make mistakes.

If you recall the movie Jurassic Park, the dinosaurs were all grey and they had scaly skins. The assumption was they had evolved from animals that definitely had scaly skins, and there was no reason to believe otherwise. Another point was that some of them were quite gigantic. Things like fur and feathers evolved from scales, and they did so to keep the animal warm. For the huge dinosaurs, keeping warm may not have been a problem; keeping cool might have been because Jurassic temperatures were about ten degrees hotter than now. Cretaceous temperatures were also warm, and there were forests near the poles. Antarctica had no appreciable snow, although it still had the long night in winter and the long day in summer. Accordingly, the assumption was they still had scaly skins. When I was young, the general feeling was they were lizards, albeit strange ones, and did not generate and control their internal temperature, but rather took what was going. If it got cold, they tended to simply slow down.

That picture changed, but not in time, it seems, for the movie. The first thing that changed was it turned out that therapods, at least, grew exceptionally quickly. This could be deduced from bone density and the way the bones were laid down. That tended to indicate that they were high heat generators, and suggested that therapods at least had to maintain an internal temperature. It also suggested that they had to eat much more than if they were more like lizards, if only to meet the growth rates.

Now, the question was, has the conclusion gone wrong? Suppose the bone structure has been misinterpreted? The way science works is that when you reach such a conclusion, you ask, if that conclusion is correct, what else is implied? The obvious one is that if therapods were warm-blooded, they would need to eat more to provide the energy, so to maintain an equilibrium there had to be far more prey than predators. Predators like lions need approximately 100 prey per lion. If there are significantly less for any length of time, the prey all get eaten and hence exterminated, which kills off the lions. So what was the ratio of predator to prey for the dinosaurs? It turns out the ratio strongly favours warm blooded dinosaurs, butthere is a catch. The ratio amongst fossils might reflect what is easiest to fossilize. Perhaps prey was killed around water holes where fossilization was more likely if the residue was buried in mud. However, some confirmation was eventually found; some fossilized predators from China were found with feather remains. They evolved feathers to keep warm, and probably coloured them for display as birds do.

That leads to more detailed questions. One, as raised in Nature (vol 616, p19) asks whether tyrannosaurs had lips. The nearest living relatives to the therapods are crocodiles and alligators, and as you might know, crocodiles have no lips. Accordingly, the movies like Jurassic Park have very toothy carnivores. That might seem desirable to keep the audience attention, but is it correct? The evidence now seems to say no; that is wrong. No lips have been found, but why does an animal close its mouth? In this, we note that iguanas and Komodo dragons have lips. The teeth are not visible unless the animal opens its mouth. So being a lizard does not mean no lips.

What we have to do is answer, why does a Komodo dragon have lips and a crocodile does not? We ask, what do lips do that leads to their evolution? The answer lies in the teeth. Enamel on teeth needs to stay hydrated otherwise it is prone to cracking. Lips are needed to keep the teeth moist, from the saliva. Crocodiles have very thick enamel and they live in water, so hydrating them is less of a problem. But the therapods actually had teeth with rather thin enamel, which suggests they had lips and a closed mouth to keep the teeth wet. Exactly what the lips looked like, though cannot be answered unless we find a fossil with them preserved.

Cows and Climate Change

There is no doubt the climate is changing. When I as a child, tornados happened in Kansas. Now they happen here with some sort of regularity, and we have had a sequence of ex-tropical cyclones and cyclones over summer. Things have to be done, but they have to be constructive. One problem is the issue can only be understood in terms of science and the level of scientific understanding with decision makers is abysmal. It is like asking the blind to sort out dangerous chemicals by reading the labels. Consider the issues of cows. Cows burp methane. Methane is a greenhouse gas. Therefore we need to eliminate cows. Pass the oatmilk.

A recent paper in Nature Geoscience (R. J. Allen, https://doi.org/10.1038/s41561-023-01144-z, 2023) appears to throw proverbial spanners in works relating to methane. Data suggests that since pre-industrial times, methane levels have risen from approximately 0,75 ppm to 1.8 ppm. I am sceptical of the first figure; how did they measure it then, and more interestingly, why did they measure it then? I dislike calculated figures because the calculations tend to be loaded with the bias of whoever does the calculations. If an assumption is required, it becomes a loaded one. However, if we accept those figures, models tell us this leads to an effective radiation forcing of just under half a watt per square meter. Thus methane is a serious problem, at least according to a disparate bunch that includes vegans, those who accuse dairy milk of causing cancer, and a group who protest just about everything. The problem is that ruminants, including cows, emit methane, so the argument goes that banning cows would go a long way to solving the problem.

However, methane has a relatively short lifetime in our atmosphere (about a decade), when it undergoes a sequence of oxidative changes that eventually lead to carbon dioxide and since all the carbon came from plant material, and hence the atmosphere, it is not clear to me that banning dairying would make much difference. The vegans probably also ignore the fact that more methane appears to come from rice paddies. I am not suggesting that we do nothing about the methane. Anything that reduces a greenhouse gas is useful.

However, the point of this paper is that methane is not as bad as current models suggest. Models that only focus on the longer wavelength greenhouse effects overestimate the effect of methane by about 30%. This is because methane absorbs short wavelength UV in the upper atmosphere, and causes photochemistry to make compounds that absorb further longer wave-length electromagnetic radiation. This cools the surface because the high energy photons convert their energy to heat when they reach the surface of the  planet. There is less heat if they don’t get there.

An even larger effect (approximately 60% offset) arises if we include enhanced cooling due to cloud rapid adjustments. We get increased lower altitude clouds, which enhance the reflection of short wavelength light, and we get decreased high level clouds, which enhances outgoing longer wavelength radiation. This does not mean methane is good; it remains a greenhouse gas, but what it means is that everything is far more complicated than most models accept. Also, it cannot hurt to reduce emissions. However, equally, the extremes promoted by the extreme protestors are simply not valid.

A second proposal (Schmitz et al.  Nature Climate Change https://doi.org/10.1038/s41558-023-01631-6 2023) may seem a little odd. The objective is to enhance carbon capture  and storage in plants, soils and sediments. They do this by protecting and restoring wild animals, and restoring their ecosystem. The argument is such an ecosystem contains more carbon than farmland, or worse, wasteland, or in one case, waste space. The way this works is that a diversity of animal species with medium to large bodies assist seed dispersal and germination of large-seeded trees with carbon-dense wood, herbivory that reduces  plant competition and increases soil nutrient supply and enhances soil carbon storage. In terms of increases of CO2 reduction, in Mt/year, wildebeests on the savannah will provide 4.4, the musk ox 30, the grey wolf 260, and the champions, fish, 5,500. By simply protecting species currently there we can secrete 5.8 Gt of CO2 / annum. By restoring species we can go further, again in Mt/a, the African elephant, 13, bison 595, and the total comes to 6.4 Gt/a. (If you notice the numbers don’t quite add up, that is because I left out minor contributions.) Now surely pastoral cows also increase soil nutrient supply and enhance soil carbon storage. It also shows it is necessary to consider the whole system, and not cherry pick the facts that strengthen your case.

None of this suggests that we do not have a problem with greenhouse gas emissions. What it does suggest is there may be a multitude of ways to solve the problem, and contributions can come from a variety of sources.

Lunar Water

Currently, if people go to the Moon, they will have to take everything they need with them. Shelter might be able to use some local materials, but almost everything else will have to come from Earth. Tools and manufactured items obviously have to be taken, but so must food, air and water. But what happens in the longer run? The expenses that will be run up like that will mean that the Moon will remain a useless lump of rock unless some alternatives are found.

A recent paper (He et al. Nature geoscience https://doi.org/10.1038/s41561-023-01159-6 ) claimed that the Changé-5 rover found water of about 1mg/g in glass beads formed by impacts. They then estimated that there were enough such glass beads across the lunar surface to get 2.7 x 10^14 kg of water. An interesting point was that the water had the D/H ratio approximately equal to solar hydrogen, and the authors proposed the water was imprinted into the beads by the solar wind. Looks like the problem is solved: the surface area of the Moon is 38 million square km, so one square kilometre will give you 7,000 t of water. If there is that much water in glass beads, and we would have at least 7 million t of such glass beads per square km, why did none of the Apollo samples bring back any of these glass beads? My guess is this is something of a gross overestimate. I have no doubt there are glass beads and they truly found water in them, but sorry, the estimate of how many there are must be wrong. The rover may have accidentally found a good deposit.

So that raises the question, is there water on the Moon? First, the information here is mixed. There is a dreadful bias to find what you expect. The original samples brought back from the Apollo missions had a water content, but the people who found it assumed it came from absorption when the samples were on Earth so they disregarded the water. Interestingly, the samples had a D/H ratio that was effectively solar, so the water could not have come from Earth. So the preconceived notion that the moon was anhydrous meant that the possibility of humans staying there for any length of time was not considered to be serious. Had it been found that there was water, maybe the Apollo program would not have been terminated and maybe the space station would not have been built as more effort would focus on the Moon. The history of space travel changed by “I know best”.

“Water” formed by solar winds is well established,  but it is formed as hydroxyl groups. With silicates, the outer surface does not properly complete its bonding, so hydrogen atoms can convert lone oxygen radicals to hydroxyls. The other half of the bond would be a radical that could react with water in the solar wind. That this probably happens is found by the “water” giving a reasonable spectroscopic signal in the evening, but is much weaker during the lunar morning. There are other samples that have  been shown to contain low levels of water. Apatites returned by Apollo had water up to 200 ppm, and some unusual volcanic glasses had water up to 46 ppm. Even more surprising is a claim that one sample of lunar soil contained nitrogen in low levels, and that nitrogen was not solar as it had enhanced levels of 15N.

So, there is water on the Moon. The TV program, “For All Humanity” had a lunar research settlement beside a crater where, deeper down the sun never penetrated. There was ice. Ridiculous? Not at all because NASA crashed a vehicle into such a region and found water of very approximately 5.6% by mass. Associated with the water was (as a % of the water) H₂S 16.5%, NH₃ 6%, SO₂ 3.2%, ethylene 3.1%, CO₂ 2.2%, methanol 1.6%, methane 0.7% (Colaprete et al. 2010 Science 330: 463-468). The water would be trapped as ice in regions where the sun does not strike, as these get extremely cold, rock being a very poor conductor of heat. It has been estimated that at latitudes greater than 80 degrees, water could be trapped in parts of craters that get no sunlight. Where did those minor materials come from? The assumption is that in this case the Moon was struck by some cometary material, and the temporary atmosphere was cold-trapped.

Water is indeed critical, but in some ways nitrogen is even more critical. Going in and out of a habitat is bound to lose air, and nitrogen is critical to dilute oxygen. It is also critical if you want to grow plants. Whether we would want to stay on the Moon for long is a matter of opinion, but at least now it may be more a possibility.