How Earth Cools

As you may have seen at the end of my last post, I received an objection to the existence of a greenhouse effect on the grounds that it violated the thermodynamics of heat transfer, and if you read what it says it is essentially focused on heat conduction. The reason I am bothering with this post is that it is an opportunity to consider how theories and explanations should be formed. We start by noting that mathematics does not determine what happens; it calculates what happens provided the background premises are correct.

The objection mentioned convection as a complicating feature. Actually, the transfer of heat in the lower atmosphere is largely dependent on the evaporation and condensation of water, and wind transferring the heat from one place to another, and it is these, and ocean currents, that are the problems for the ice caps. Further, as I shall show, heat conduction cannot be relevant to the major cooling of the upper atmosphere. But first, let me show you how complicated heat conduction is. The correct equation for one-dimensional heat conduction is represented by a partial differential equation of the Laplace type, (which I would quote if I knew how to get such an equation into this limited htm formatting) and the simplest form only works as written when the medium is homogenous. Since the atmosphere thins out with height, this clearly needs modification, and for those who know anything about partial differential equations, they become a nightmare once the system becomes anything but absolutely simple. Such equations also apply to convection and evaporative transfer, once corrected for the nightmare of non-homogeneity and motion in three dimensions. Good luck with that!

This form of heat transfer is irrelevant to the so-called greenhouse effect. To show why, I start by considering what heat is, and that is random kinetic energy. The molecules are bouncing around, colliding with each other, and the collisions are elastic, which means energy is conserved, as is momentum. Most of the collisions are glancing, and that means from momentum conservation that we get a range of velocities distributed about an “average”. Heat is transferred because fast moving molecules collide with slower ones, and speed them up. The objection noted heat does not flow from cold to hot spontaneously. That is true because momentum is conserved in collisions. A molecule does not speed up when hit by a slower molecule. That is why that equation has heat going only in one way.

Now, suppose with this mechanism, we get to the top of the atmosphere. What happens then? No more heat can be transferred because there are no molecules to collide with in space. If heat pours in, and nothing goes out, eventually we become infinitely hot. Obviously that does not happen, and the reason becomes obvious when we ask how the heat gets in in the first place. The heat from the sun comes from the effects of solar radiation. Something like 1.36 kW/m^2 comes in on a surface in space at right angles to the line from the sun, but the average is much less on the surface of earth as the angle is at best normal only at noon, and if the sun is overhead. About a quarter of that is directly reflected to space, and that may increase if the cloud cover increases. The important point here is that light is not heat. When it is absorbed, it will direct an electronic transition, but that energy will eventually decay into heat. Initially, however, the material goes to an excited state, but its temperature remains constant, because the energy has not been randomised. Now we see that if energy comes in as radiation, it follows to get an equilibrium, equivalent energy must go out, and as radiation, not heat, because that is the only way it can get out in a vacuum.

The ground continuously sends radiation (mainly infrared) upwards and the intensity is proportional to the fourth power of the temperature. The average temperature is thus determined through radiant energy in equals radiant out. The radiance for a given material, which is described as a grey body radiator, is also dependent on its nature. The radiation occurs because any change of dipole moment leads to electromagnetic radiation, but the dipoles must change between quantised energy states. What that means is they come from motion that can be described in one way or another as a wave, and the waves change to longer wavelengths when they radiate. The reason the waves representing ground states switch to shorter wavelengths is that the heat energy from collisions can excite them, similar in a way to when you pluck a guitar string. Thus the body cools by heat exciting some vibratory states, which collapse by radiation leaving them. (This is similar to the guitar string losing energy by emitting sound, except that the guitar string emits continuous decaying sound; the quantised state lets it go all at once as one photon.)

Such changes are reversible; if the wave has collapsed to a longer wavelength when energy is radiated away, then if a photon of the same frequency is returned, that excites the state. That slows cooling because the next photon emitted from the ground did not need heat to excite it, and hence that same heat remains. The reason there is back radiation is that certain frequencies of infrared radiation leaving the ground get absorbed by molecules in the atmosphere when their molecular vibrational or rotational excited states have a different electric moment from the ground state. Carbon dioxide has two such vibrational states that absorb mildly, and one that does not. Water is a much stronger absorber, and methane has more states available to it. Agriculture offers N2O, which is bad because it is harder to remove than carbon dioxide, and the worst are chlorocarbons and fluorocarbons, because the vibrations have stronger dipole moment changes. Each of these different materials has vibrations at different frequencies, which make them even more problematical as radiation at more frequencies are slowed in their escape to space. The excited states decay and emit photons in random directions, hence only about half of that continues on it way to space, the rest returning to the ground. Of that that goes upwards, it will be absorbed by more molecules, and the same will happen, and of course some coming back from up there with be absorbed at a lower level and half of that will go back up. In detail, there is some rather difficult calculus, but the effect could be described as a field of oscillators.

So the take-away message is the physics are well understood, the effect of the greenhouse gases is it slows the cooling process, so the ground stays warmer than it would if they were not there. Now the good thing about a theory is that it should predict things. Here we can make a prediction. In winter, in the absence of wind, the night should be warmer if there is cloud cover, because water is a strong greenhouse material. Go outside one evening and see.

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That Was 2017, That Was

With 2017 coming to a close, I can’t resist the urge to look back and see what happened from my point of view. I had plenty of time to contemplate because the first seven months were largely spent getting over various surgery. I had thought the recovery periods would be good for creativity. With nothing else to do, I could write and advance some of my theoretical work, but it did not work but like that. What I found was that painkillers also seemed to kill originality. However, I did manage one e-novel through the year (The Manganese Dilemma), which is about hacking, Russians and espionage. That was obviously initially inspired by the claims of Russian hacking in the Trump election, but I left that alone. It was clearly better to invent my own scenario than to go down that turgid path. Even though that is designed essentially as just a thriller, I did manage to insert a little scientific thinking into the background, and hopefully the interested potential reader will guess that from the “manganese” in the title.

On the space front, I am sort of pleased to report that there was nothing that contradicted my theory of planetary formation found in the literature, but of course that may be because there is a certain plasticity in it. The information on Pluto, apart from the images and the signs of geological action, were well in accord with what I had written, but that is not exactly a triumph because apart from those images, there was surprisingly little new information. Some of which might have previously been considered “probable” was confirmed, and details added, but that was all. The number of planets around TRAPPIST 1 was a little surprising, and there is limited evidence that some of them are indeed rocky. The theory I expounded would not predict that many, however the theory depended on temperatures, and for simplicity and generality, it considered the star as a point. That will work for system like ours, where the gravitational heating is the major source of heat during primary stellar accretion, and radiation for the star is most likely to be scattered by the intervening gas. Thus closer to our star than Mercury, much of the material, and even silicates, had reached temperatures where it formed a gas. That would not happen around a red dwarf because the gravitational heating necessary to do that is very near the surface of the star (because there is so much less falling more slowly into a far smaller gravitational field) so now the heat from the star becomes more relevant. My guess is the outer rocky planets here are made the same way our asteroids were, but with lower orbital velocities and slower infall, there was more time for them to grow, which is why they are bigger. The inner ones may even have formed closer to the star, and then moved out due to tidal interactions.

The more interesting question for me is, do any of these rocky planets in the habitable zone have an atmosphere? If so, what are the gases? I am reasonably certain I am not the only one waiting to get clues on this.

On another personal level, as some might know, I have published an ebook (Guidance Waves) that offers an alternative interpretation of quantum mechanics that, like de Broglie and Bohm, assumes there is a wave, but there are two major differences, one of which is that the wave transmits energy (which is what all other waves do). The wave still reflects probability, because energy density is proportional to mass density, but it is not the cause. The advantage of this is that for the stationary state, such as in molecules, that the wave transmits energy means the bond properties of molecules should be able to be represented as stationary waves, and this greatly simplifies the calculations. The good news is, I have made what I consider good progress on expanding the concept to more complicated molecules than outlined in Guidance Waves and I expect to archive this sometime next year.

Apart from that, my view of the world scene has not got more optimistic. The US seems determined to try to tear itself apart, at least politically. ISIS has had severe defeats, which is good, but the political futures of the mid-east still remains unclear, and there is still plenty of room for that part of the world to fracture itself again. As far as global warming goes, the politicians have set ambitious goals for 2050, but have done nothing significant up to the end of 2017. A thirty-year target is silly, because it leaves the politicians with twenty years to do nothing, and then it would be too late anyway.

So this will be my last post for 2017, and because this is approaching the holiday season in New Zealand, I shall have a small holiday, and resume half-way through January. In the meantime, I wish all my readers a very Merry Christmas, and a prosperous and healthy 2018.

Ross 128b a Habitable Planet?

Recently the news has been full of excitement that there may be a habitable planet around the red dwarf Ross 128. What we know about the star is that it has a mass of about 0.168 that of the sun, it has a surface temperature of about 3200 degrees K, it is about 9.4 billion years old (about twice as old as the sun) and consequently it is very short of heavy elements, because there had not been enough supernovae that long ago. The planet is about 1.38 the mass of Earth, and it is about 0.05 times as far from its star as Earth is. It also orbits its star every 9.9 days, so Christmas and birthdays would be a continual problem. Because it is so close to the star it gets almost 40% more irradiation than Earth does, so it is classified as being in the inner part of the so-called habitable zone. However, the “light” is mainly at the red end of the spectrum, and in the infrared. Even more bizarrely, in May this year the radio telescope at Arecibo appeared to pick up a radio signal from the star. Aliens? Er, not so fast. Everybody now seems to believe that the signal came from a geostationary satellite. Apparently here is yet another source of electromagnetic pollution. So could it have life?

The first question is, what sort of a planet is it? A lot of commentators have said that since it is about the size of Earth it will be a rocky planet. I don’t think so. In my ebook “Planetary Formation and Biogenesis” I argued that the composition of a planet depends on the temperature at which the object formed, because various things only stick together in a narrow temperature range, but there are many such zones, each giving planets of different composition. I gave a formula that very roughly argues at what distance from the star a given type of body starts forming, and if that is applied here, the planet would be a Saturn core. However, the formula was very approximate and made a number of assumptions, such as the gas all started at a uniform low temperature, and the loss of temperature as it migrated inwards was the same for every star. That is known to be wrong, but equally, we don’t know what causes the known variations, and once the star is formed, there is no way of knowing what happened so that was something that had to be ignored. What I did was to take the average of observed temperature distributions.

Another problem was that I modelled the centre of the accretion as a point. The size of the star is probably not that important for a G type star like the sun, but it will be very important for a red dwarf where everything happens so close to it. The forming star gives off radiation well before the thermonuclear reactions start through the heat of matter falling into it, and that radiation may move the snow point out. I discounted that largely because at the key time there would be a lot of dust between the planet and the star that would screen out most of the central heat, hence any effect from the star would be small. That is more questionable for a red dwarf. On the other hand, in the recently discovered TRAPPIST system, we have an estimate of the masses of the bodies, and a measurement of their size, and they have to have either a good water/ice content or they are very porous. So the planet could be a Jupiter core.

However, I think it is most unlikely to be a rocky planet because even apart from my mechanism, the rocky planets need silicates and iron to form (and other heavier elements) and Ross 128 is a very heavy metal deficient star, and it formed from a small gas cloud. It is hard to see how there would be enough material to form such a large planet from rocks. However, carbon, oxygen and nitrogen are the easiest elements to form, and are by far the most common elements other than hydrogen and helium. So in my theory, the most likely nature of Ross 128b is a very much larger and warmer version of Titan. It would be a water world because the ice would have melted. However, the planet is probably tidally locked, which means one side would be a large ocean and the other an ice world. What then should happen is that the water should evaporate, form clouds, go around the other side and snow out. That should lead to the planet eventually becoming metastable, and there might be climate crises there as the planet flips around.

So, could there be life? If it were a planet with a Saturn core composition, it should have many of the necessary chemicals from which life could start, although because of the water/ice live would be limited to aquatic life. Also, because of the age of the planet, it may well have been and gone. However, leaving that aside, the question is, could life form there? There is one restriction (Ranjan, Wordsworth and Sasselov, 2017. arXiv:1705.02350v2) and that is if life requires photochemistry to get started, then the intensity of the high energy photons required to get many photochemical processes started can be two to four orders of magnitude less than what occurred on Earth. At that point, it depends on how fast everything that follows happens, and how fast the reactions that degrade them happen. The authors of that paper suggest that the UV intensity is just too low to get life started. Since we do not know exactly how life started yet, that assessment might be premature, nevertheless it is a cautionary point.

Asteroids

If you have been to more than the occasional science fiction movie, you will know that a staple is to have the trusty hero being pursued, but escaping by weaving in and out of an asteroid field. Looks like good cinema, they make it exciting, but it is not very realistic. If asteroids were that common, according to computer simulations their mutual gravity would bring them together to form a planet, and very quickly. In most cases, if you were standing on an asteroid, you would be hard pressed to see another one, other than maybe as a point like the other stars. One of the first things about the asteroid belt is it is mainly empty. If we combined all the mass of the asteroids we would get roughly 4% of the mass of the Moon. Why is that? The standard theory of planetary formation cannot really answer that, so they say there were a lot there, but Jupiter’s gravity drove them out, at the same time overlooking the fact their own theory says they should form a planet through their self-gravity if there were that amny of them. If that were true, why did it leave some? It is not as if Jupiter has disappeared. In my “Planetary formation and Biogenesis”, my answer is that while the major rocky planets formed by “stone” dust being cemented together by one other agent, the asteroid belt, being colder, could only manage dust being cemented together with two other agents, and getting all three components in the same place at the same time was more difficult.

There is a further reason why I do not believe Jupiter removed most of the asteroids. The distribution currently has gaps, called the Kirkwood gaps, where there are very few asteroids, and these occur at orbital resonances with Jupiter. Such a resonance is when the target body would orbit at some specific ratio to Jupiter’s orbital period, so frequently the perturbations are the same because in a given frame of reference, they occur in the same place. Thus the first such gap occurs at 2.06 A.U. from the sun, where any asteroid would go around the sun exactly four times while Jupiter went around once. That is called a 4:1 resonance, and the main gaps occur at 3:1, 5:2, 7:3 and 2:1 resonances. Now the fact that Jupiter can clear out these narrow zones but leave all the rest more or less unchanged strongly suggests to me there were never a huge population of asteroids and we are seeing a small residue.

The next odd thing about asteroids is that while there are not very many of them, they change their characteristics as they get further from the star (with some exceptions to be mentioned soon.) The asteroids closest to the sun are basically made of silicates, that is, they are essentially giant rocks. There appear to be small compositional variations as they get further from the star, then there is a significant difference. How can we tell? Well, we can observe their brightness, and in some cases we can correlate what we see with meteorites, which we can analyse. So, further out, they get significantly duller, and fragments that we call carbonaceous chondrites land on Earth. These contain a small amount of water, and organic compounds that include a variety of amino acids, purines and pyrimidines. This has led some to speculate that our life depended on these landing on Earth in large amounts when Earth was very young. In my ebook “Planetary Formation and Biogenesis”, I disagree. The reasons are that to get enough, a huge number of such asteroids would have to impact the Earth because they are still basically rock, BUT at the same time, hardly any of the silicate based asteroids would have to arrive, because if they did, the isotopes of certain elements on Earth would have to be different. Such isotope evidence also rules these out as a source of water, as does certain ratios such as carbon to chlorine. What these asteroid fragments do show, however, is that amino acids and other similar building blocks of life are reasonably easily formed. If they can form on a lump of rock in a vacuum, why cannot they form on Earth?

The asteroid belt also has the odd weird asteroid. The first is Ceres, the largest. What is weird about it is that it is half water. The rest are essentially dry or only very slightly wet. How did that happen, and more to the point, why did it not happen more frequently? The second is Vesta, the second largest. Vesta is rocky, although it almost certainly had water at some stage because there is evidence of quartz. It has also differentiated, and while the outer parts have olivine, deeper down we get members of the pyroxene class of rocks, and deeper down still there appears to be a nickel/iron core. Now there is evidence that there may be another one or two similar asteroids, but by and large it is totally different from anything else in the asteroid belt. So how did that get there?

I rather suspect that they started somewhere else and were moved there. What would move them is if they formed and came close to a planet, and instead of colliding with it, they were flung into a highly elliptical orbit, and then would circularise themselves where they ended up. Why would they do that? In the case of Vesta, at some stage it suffered a major collision because there is a crater near the south pole that is 25 km deep, and it is from this we know about the layered nature of the asteroid. Such a collision may have resulted in it remaining in orbit roughly near its present position, and the orbit would be circularised due to the gravity of Jupiter. Under this scenario, Vesta would have formed somewhere near Earth to get the iron core. Ceres, on the other hand, probably formed closer to Jupiter.

In my previous post, I wrote that I believed the planets and other bodies grew by Monarchic growth, but that does not mean there were no other bodies growing in a region. Monarchic growth means the major object grows by accreting things at least a hundred times smaller, but of course significant growth can occur for other objects. The most obvious place to grow would be at a Lagrange point of the biggest object and the sun. That is a position where the planet’s gravitational field and the sun’s cancel, and the body is in stable or metastable orbit there. Once it gets to a certain size, however, it is dislodged, and that is what I think was the source of the Moon, its generating body probably starting at L4, the position at the same distance from the sun as Earth, but sixty degrees in front of it. There are other metastable positions, and these may have also formed around Venus or Mercury, and these would also be unstable due to different rocky planets. The reason I think this is that for Vesta to have an iron core, it had to pick up bodies with a lot of iron, and such bodies would form in the hotter part of the disk while the star was accreting. This is also the reason why Earth has an iron core and Mars has a negligible one. However, as I understand it, the isotopes from rocks on Vesta are not equivalent to those of Earth, so it may well have started life nearer to Venus or Mercury. So far we have no samples to analyse that we know came from either of these two planets, and I am not expecting any such samples anytime soon.

A Giant Planet Around a Dwarf Star

The news here, at least, has made much of the discovery of NGTS-1b, described as a giant planet orbiting a dwarf star. It is supposed to be the biggest planet ever found around such a small star, and it is supposed to be inexplicable how such a big planet could form. One key point that presumably everyone will agree with is, a small star forms because there is less gas and dust in the cloud that will form the star than in the cloud that forms a big star. Accordingly there is less total material to form a planet. Missing from that statement is the fact that in all systems the amount of mass in the planets is trivial compared to the mass of the star. Accordingly, there is nothing at all obscure about an unexpectedly big planet if the planet was just a bit more efficient at taking material that would otherwise go into the star.

So, a quick reality check: the star is supposed to be about 60% the size of the sun, and the planet is about 80% the mass of Jupiter, but has a somewhat larger radius. Planets up to twenty times the size of Jupiter are known around stars that are not more than about three times the size of our sun, so perhaps there is more being made of this “big planet” than is reasonable.

Now, why is it inexplicable how such a large planet could form around a small star, at least in standard theory? The mechanism of formation of planets in the standard theory is that first gas pours in, forms the star, and leaves a residual disk (the planetary accretion disk), in which gas is essentially no longer moving towards the star. That is not true; the star continues to accrete, but several orders or magnitude more slowly. The argument then is that this planetary accretion disk has to contain all the material needed to form the planets, and they have to form fast enough to get as big as they end up before the star ejects all dust and gas, which can take somewhere up to 10 million years (10 My), with a mean of about 3 My. There is some evidence that some disks last at least 30 My. Now the dust collides, sticks (although why or how is always left out in the standard theory) and forms planetesimals, which are bodies of asteroid size. These collide and form bigger bodies, and so on. This is called oligarchic growth. The problem is, as the bodies get larger, the distance between them increases and collision probability falls away, not helped by the fact that the smaller the star, the slower the orbiting bodies move, the less turbulent it will be, so the rate of collisions slows dramatically. For perspective purposes, collisions in the asteroid belt are very rare, and when they occur, they usually lead to the bodies getting smaller, not bigger. There are a modest number of such families of detritus asteroids.

The further out the lower the concentration of matter, simply because there is a lot more space. A Jupiter-sized body has to grow fast because it has to get big enough for its gravity to hold hydrogen, and then actually hold it, before the disk gases disappear. Even accreting gas is not as simple as it might sound, because as the gas falls down the planetary gravitational field, it gets hot, and that leads to some gas boiling off back to space. To get going quickly, it needs more material, and hence a Jupiter type body is argued (correctly, in my opinion) to form above the snow line of water ice. (For the purposes of discussion, I shall call material higher up the gravitational potential “above”, in which case “below” is closer to the star.) It is also held that the snow line is not particularly dependent on stellar mass, in which case various planetary systems should scale similarly. With less material around the red dwarf, and as much space to put it in, everything will go a lot slower and the gas will be eliminated before a planet is big enough to handle it. Accordingly, it seems that according to standard theory, this planet should not form, let alone be 0.036 A.U. from the star.

The distance from the star is simply explained in any theory: it started somewhere else and moved there. The temperature at that distance is about 520 degrees C, and with solar wind it would be impossible for a small core to accrete that much gas. (The planet has a density of less than 1, so like Saturn it would float if put in a big enough tub of water.) How would it move? The simplest way would be if we imagined a Jupiter and a Saturn formed close enough together, when they could play gravitational billiards, whereby one moves close to the star and the other is ejected from the system. There are other plausible ways.

That leaves the question of how the planet forms in the first place. To get so big, it has to form fast, and there is evidence to support such rapid growth. The planet LkCa 15b is around a star that is slightly smaller than the sun, it is three times further out than Jupiter, and it is five times bigger than Jupiter. I believe this makes our sun special – the accretion disk must have been ejected maybe as quickly as 1 My. Simulations indicate that oligarchic growth should not have led to any such oligarchic growth that far out. My explanation (given in my ebook “Planetary Formation and Biogenesis”) is that the growth was actually monarchic. This is a mechanism once postulated by Weidenschilling, in 2004 (Weidenschilling, S., 2004. Formation of the cores of the outer planets. Space Science Rev. 116: 53-56.) In this mechanism, provided other bodies do not grow at a sufficient rate to modify significantly the feed density, a single body will grow proportionately to its cross-sectional area by taking all dust that is in its feed zone, which is augmented by gravitation. The second key way to get a bigger planet is to have the planetary accretion disk last longer. The third is, in my theory, the initial accretion is chemical, and the Jupiter core forms like a snowball, by water ice compression fusing. Further, I argue it will start even while the star is accreting. That only occurs tolerably close to the melting point, so it is temperature dependent. The temperatures are reached very much closer to the star for a dwarf. Finally, the planet forming around a dwarf has one final growth advantage: because the star has a lower gravity, the gas will be drifting towards the star more slowly, so the growing planet, while having a less dense feed, also receives a higher fraction of the feed.

So, in my opinion, apart from the fact the planet is so lose to the star, so far there is nothing surprising about it at all, and the mechanisms for getting it close to the star are there, and there are plenty of other “star-burning” planets that have been found.

Why has the monarchic growth concept not taken hold? In my opinion, this is a question of fashion. The oligarchic growth mechanism has several advantages for the preparation of scientific papers. You can postulate all sorts of initial conditions and run computer simulations, then report those that make any sense as well as those that don’t (so others don’t waste time.) Monarchic growth leaves no real room for scientific papers.

Gravitational Waves and Gold

One of the more interesting things to be announced recently was the detection of gravitational waves that were generated by the collision of two neutron stars. What was really interesting to me was that the event was also seen by telescopes, so we know what actually caused the gravitational waves. Originally it was thought that gravitational waves would be generated by colliding black holes, but I found that to be disturbing because I thought the frequency of detection should be rather low. The reason is that I thought black holes themselves would be rather rare. As far as we can tell most galaxies contain one in their centre, but the evidence for more is rather sparse. True, they are not easy to see, but if they come into contact with gas, which is present within galaxies, the gas falling into them will give out distinct Xray signals and further, they would perturb the paths of close stars, which means, while we cannot see the black hole, if they were common, there should be some signs.

There are some signs. The star Cygnus X-1 is apparently shedding material into some unseen companion, and giving off X-rays as well as light. A similar situation occurs for the star M33-X-7, which is in the galaxy Messier 33, which in turn is 2.7 million light years away. Now obviously there will be more that we cannot see because they are not tearing stars apart, but they are still rare. Obviously, collisions would be rarer still. With all the stars in the Universe, how often do we see a collision between stars? I am unaware of any in my life. Nevertheless, there have been estimates that there are about a billion moderately sized black holes (i.e. about 15- 20 times the size of our sun) in our galaxy. However, when we probe to see how they came up with this figure, it turned out that it arose because it was obvious that you needed them to be this common to get the frequency of the detection of gravitational waves. That reasoning is somewhat circular.

How would they collide? Like other stars within the galaxy, they would travel in orbit around a galactic centre, in which case the chances of meeting are rather low. And even if they did approach, why would they collide? The problem involves the conservation of angular momentum (the same sort of thing that the skater uses to slow down the spin by sticking her arms out). When one body approaches another, assuming they are not going to directly collide (in which case there is no angular momentum in their joint system) then they follow a hyperbolic orbit around each other and end up going away from each other in the reverse of however they approached. For one to capture the other, either the systems have to spin up to conserve angular momentum, or they have to throw something out and whichever they do, orbital decay requires a mechanism to get rid of a lot of energy. Further, they cannot spin up, which is an exchange of angular momentum, without tidal interactions forcing it. Now tidal interactions work by part of one body “flowing” in response the gravity of the other. The material does not have to move a lot, but it has to be able to move, and the black hole is so dense I don’t see it is very likely, although admittedly we know nothing about what goes on inside a black hole. We do know that nothing can escape from a black hole, so the mechanism of losing energy and angular momentum by ejecting something is out.

Now that such an event has been properly assigned to the collision of two neutron stars it makes me, at least, feel that everything is far more likely to be correct. Neutron stars are what is left over from a supernova, and it is easier to see neutron stars capture each other. First, neutron stars are made from very large stars, and while these are rarer than most other types of star, sometimes they come as double stars. That would make neutron stars close to each other, which is a start. Further, neutron stars are more likely to be deformable, and most certainly are more able to eject material into space. Neutron stars are really only held together by their intense gravity, and as they approach each other, the gravity tends to cancel, as the approaching object pulls against the pre-existing force. If the force needed to hold the neutrons becomes insufficient, the ejection of a significant amount of material is possible. After all, nuclei with a significant number more neutrons than protons are quite unstable, and each decaying neutron gives off over 1 MeV of energy. The neutron star is effectively a huge nucleus, but is held together by intense gravity rather than the strong force.

Apparently in this collision, a huge amount of material was ejected into space, and it is argued that this sort of event is what caused the formation of the metals heavier than iron, including gold and platinum. Such atoms then get mixed with the ejecta from supernovae and the hydrogen and helium from the start of the Universe, and here we are. It is a good story. However, I wonder if it is true that that is where all the gold etc. comes from? What bothers me about that explanation is that it is argued that atoms up to iron are made in stars and supernovae, but heavier ones are not because in the clouds of the ejecta, there isn’t time for the processes we know about. In my opinion, the intense pressures of the supernova that forms the neutron star would also form heavier elements. They don’t have to be made by adding protons and neutrons, after all, the synthetic elements we make, such as element number 118, are made by colliding big nuclei together. In this context, if you see a graph of the relative occurrence of the various elements, the curve is more or less smooth. Yes, there is a bit of a peak for elements around iron, but it then decays smoothly, and I would have expected that if some were made by a totally different procedure, then their relative concentrations would lie on different curves. I guess I shall never know. I can’t see anyone taking samples from the core of a supernova any time soon.

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.