The Fermi Paradox and Are We Alone in the Universe?

The Fermi paradox is something like this. The Universe is enormous, and there are an astronomical number of planets. Accordingly, the potential for intelligent life somewhere should be enormous, but we find no evidence of anything. The Seti program has been searching for decades and has found nothing. So where are these aliens?

What is fascinating about this is an argument from Daniel Whitmire, who teaches mathematics at the University of Arkansas and has published a paper in the International Journal of Astrobiology (doi:10.1017/S1473550417000271 ). In it, he concludes that technological societies rapidly exterminate themselves. So, how does he come to this conclusion. The argument is fascinating relating to the power of mathematics, and particularly statistics, to show or mislead.

He first resorts to a statistical concept called the Principle of Mediocrity, which states that, in the absence of any evidence to the contrary, any observation should be regarded as typical. If so, we observe our own presence. If we assume we are typical, and we have been technological for 100 years (he defines being technological as using electricity, but you can change this) then it follows that our being average means that after a further 200 years we are no longer technological. We can extend this to about 500 years on the basis that in terms of age a Bell curve is skewed (you cannot have negative age). To be non-technological we have to exterminate ourselves, therefore he concludes that technological societies exterminate themselves rather quickly. We may scoff at that, but then again, watching the antics over North Korea can we be sure?

He makes a further conclusion: since we are the first on our planet, other civilizations should also be the first. I really don’t follow this because he has also calculated that there could be up to 23 opportunities for further species to develop technologies once we are gone, so surely that follows elsewhere. It seems to me to be a rather mediocre use of this principle of mediocrity.

Now, at this point, I shall diverge and consider the German tank problem, because this shows what you can do with statistics. The allies wanted to know the production rate of German tanks, and they got this from a simple formula, and from taking down the serial numbers of captured or destroyed tanks. The formula is

N = m + m/n – 1

Where N is the number you are seeking, m is the highest sampled serial number and n is the sample size (the number of tanks). Apparently this was highly successful, and their estimations were far superior to intelligence gathering, which always seriously overestimated.

That leaves the question of whether that success means anything for the current problem. The first thing we note is the Germans conveniently numbered their tanks, and in sequence, the sample size was a tolerable fraction of the required answer (it was about 5%), and finally it was known that the Germans were making tanks and sending them to the front as regularly as they could manage. There were no causative aspects that would modify the results. With Whitmire’s analysis, there is a very bad aspect of the reasoning: this question of whether we are alone is raised as soon as we have some capability to answer it. Thus we ask it within fifty years of having reasonable electronics; for all we know they may still be asking it a million years in the future, so the age of technological society, which is used to base the lifetime reasoning, is put into the equation as soon as it is asked. That means it is not a random sample, but causative sample. Then on top of that, we have a sample of one, which is not exactly a good statistical sample. Of course if there were more samples than one, the question would answer itself and there would be no need for statistics. In this case, statistics are only used when they should not be used.

So what do I make of that? For me, there is a lack of logic. By definition, to publish original work, you have to be the first to do it. So, any statistical conclusion from asking the question is ridiculous because by definition it is not a random sample; it is the first. It is like trying to estimate German tank production from a sample of 1 and when that tank had the serial number 1. So, is there anything we can take from this?

In my opinion, the first thing we could argue from this Principle of Mediocrity is that the odds of finding aliens are strongest on earth-sized planets around G type stars about this far from the star, simply because we know it is at least possible. Further, we can argue the star should be at least about 4.5 billion years old, to give evolution time to generate such technological life. We are reasonably sure it could not have happened much earlier on Earth. One of my science fiction novels is based on the concept that Cretaceous raptors could have managed it, given time, but that still only buys a few tens of millions of years, and we don’t know how long they would have taken, had they been able. They had to evolve considerably larger brains, and who knows how long that would take? Possibly almost as long as mammals took.

Since there are older stars out there, why haven’t we found evidence? That question should be rephrased into, how would we? The Seti program assumes that aliens would try to send us messages, but why would they? Unless they were directed, to send meaningful signals over such huge distances would require immense energy expenditures. And why would they direct signals here? They could have tried 2,000 years ago, persisted for a few hundred years, and given us up. Alternatively, it is cheaper to listen. As I noted in a different novel, the concept falls down on economic grounds because everyone is listening and nobody is sending. And, of course, for strategic reasons, why tell more powerful aliens where you live? For me, the so-called Fermi paradox is no paradox at all; if there are aliens out there, they will be following their own logical best interests, and they don’t include us. Another thing it tells me is this is evidence you can indeed “prove” anything with statistics, if nobody is thinking.

What is nothing?

Shakespeare had it right – there has been much ado about nothing, at least in the scientific world. In some of my previous posts I have advocated the use of the scientific method on more general topics, such as politics. That method involves the rigorous evaluation of evidence, of making propositions in accord with that evidence, and most importantly, rejecting those that are clearly false. It may appear that for ordinary people, that might be too hard, but at least that method would be followed by scientists, right? Er, not necessarily. In 1962 Thomas Kuhn published a work, “The structure of scientific revolutions” and in it he argued that science itself has a very high level of conservatism. It is extremely difficult to change a current paradigm. If evidence is found that would do so, it is more likely to be secreted away in the bottom drawer, included in a scientific paper in a place where it is most likely to be ignored, or, if it is published, ignored anyway, and put in the bottom drawer of the mind. The problem seems to be, there is a roadblock towards thinking that something not in accord with expectations might be significant. With that in mind, what is nothing?

An obvious answer to the title question is that a vacuum is nothing. It is what is left when all the “somethings” are removed. But is there “nothing” anywhere? The ancient Greek philosophers argued about the void, and the issue was “settled” by Aristotle, who argued in his Physica that there could not be a void, because if there were, anything that moved in it would suffer no resistance, and hence would continue moving indefinitely. With such excellent thinking, he then, for some reason, refused to accept that the planets were moving essentially indefinitely, so they could be moving through a void, and if they were moving, they had to be moving around the sun. Success was at hand, especially if he realized that feathers did not fall as fast as stones because of wind resistance, but for some reason, having made such a spectacular start, he fell by the wayside, sticking to his long held prejudices. That raises the question, are such prejudices still around?

The usual concept of “nothing” is a vacuum, but what is a vacuum? Some figures from Wikipedia may help. A standard cubic centimetre of atmosphere has 2.5 x 10^19 molecules in it. That’s plenty. For those not used to “big figures”, 10^19 means the number where you write down 10 and follow it with 19 zeros, or you multiply 10 by itself nineteen times. Our vacuum cleaner gets the concentration of molecules down to 10^19, that is, the air pressure is two and a half times less in the cleaner. The Moon “atmosphere” has 4 x 10^5 molecules per cubic centimetre, so the Moon is not exactly in vacuum. Interplanetary space has 11 molecules per cubic centimetre, interstellar space has 1 molecule per cubic centimetre, and the best vacuum, intergalactic space, needs a million cubic centimetres to find one molecule.

The top of the Earth’s atmosphere, the thermosphere goes from 10^14 to 10^7. That is a little suspect at the top because you would expect it to gradually go down to that of interplanetary space. The reason there is a boundary is not because there is a sharp boundary, but rather it is the point where gas pressure is more or less matched by solar radiation pressure and that from solar winds, so it is difficult to make firm statements about further distances. Nevertheless, we know there is atmosphere out to a few hundred kilometres because there is a small drag on satellites.

So, intergalactic space is most certainly almost devoid of matter, but not quite. However, even without that, we are still not quite there with “nothing”. If nothing else, we know there are streams of photons going through it, probably a lot of cosmic rays (which are very rapidly moving atomic nuclei, usually stripped of some of their electrons, and accelerated by some extreme cosmic event) and possibly dark matter and dark energy. No doubt you have heard of dark matter and dark energy, but you have no idea what it is. Well, join the club. Nobody knows what either of them are, and it is just possible neither actually exist. This is not the place to go into that, so I just note that our nothing is not only difficult to find, but there may be mysterious stuff spoiling even what little there is.

However, to totally spoil our concept of nothing, we need to see quantum field theory. This is something of a mathematical nightmare, nevertheless conceptually it postulates that the Universe is full of fields, and particles are excitations of these fields. Now, a field at its most basic level is merely something to which you can attach a value at various coordinates. Thus a gravitational field is an expression such that if you know where you are and if you know what else is around you, you also know the force you will feel from it. However, in quantum field theory, there are a number of additional fields, thus there is a field for electrons, and actual electrons are excitations of such fields. While at this point the concept may seem harmless, if overly complicated, there is a problem. To explain how force fields behave, there needs to be force carriers. If we take the electric field as an example, the force carriers are sometimes called virtual photons, and these “carry” the force so that the required action occurs. If you have such force carriers, the Uncertainty Principle requires the vacuum to have an associated zero point energy. Thus a quantum system cannot be at rest, but must always be in motion and that includes any possible discrete units within the field. Again, according to Wikipedia, Richard Feynman and John Wheeler calculated there was enough zero point energy inside a light bulb to boil off all the water in the oceans. Of course, such energy cannot be used; to use energy you have to transfer it from a higher level to a lower level, when you get access to the difference. Zero point energy is at the lowest possible level.

But there is a catch. Recall Einstein’s E/c^2 = m? That means according to Einstein, all this zero point energy has the equivalent of inertial mass in terms of its effects on gravity. If so, then the gravity from all the zero point energy in vacuum can be calculated, and we can predict whether the Universe is expanding or contracting. The answer is, if quantum field theory is correct, the Universe should have collapsed long ago. The difference between prediction and observation is merely about 10^120, that is, ten multiplied by itself 120 times, and is the worst discrepancy between prediction and observation known to science. Even worse, some have argued the prediction was not right, and if it had been done “properly” they justified manipulating the error down to 10^40. That is still a terrible error, but to me, what is worse, what is supposed to be the most accurate theory ever is suddenly capable of turning up answers that differ by 10^80, which is roughly the same as the number of atoms in the known Universe.

Some might say, surely this indicates there is something wrong with the theory, and start looking elsewhere. Seemingly not. Quantum field theory is still regarded as the supreme theory, and such a disagreement is simply placed in the bottom shelf of the minds. After all, the mathematics are so elegant, or difficult, depending on your point of view. Can’t let observed facts get in the road of elegant mathematics!

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.

The Rivers of Mars: How and Why?

My first self-published ebook was about how to form a theory. The origin of this has an interesting history: Elsevier asked me to write a book, and while I know what they thought they were going to get, I sent back a proposal that I thought they could never accept, largely to get them off my back. They accepted it, at that stage, so I had to write. The problem for me was, it took somewhat longer than I expected; the problem for them was the time taken, the length, and then, horrors, they found out I was not an academic with lots of students forced to buy the book. The book was orphaned, but I was so far on I thought I might as well self publish it. The advocated methodology is that of Aristotle, and oddly enough, most of his scientific bloopers arose because he ignored his own instructions! So, let me show what I made of it on one of my projects: how did Mars ever have flowing rivers? Why I chose that is a story best left for a later post.

The first step is to state clearly what you know. In this case, Mars has some quite long what seem like riverbeds, and they start sometimes from the coldest parts of Mars. The longest goes from highlands 60 degrees south and stops somewhere near the equator, and these can only reasonably be explained by fluid flow. Almost certainly water is the only fluid there in sufficient volume, so it had to be at least part of the flow. However, water freezes at 0 degrees Centigrade, the average temperature on Mars now is about minus 60 degrees C, and when the rivers were flowing the sun had only about 2/3 its current heat output.

The next step is to ask questions. To start, how did water flow, starting from high altitude high latitude sites, where the temperatures would be well below that of the rest of the planet? Could we dissolve something in the water to lower the freezing point? Dissolving salts in the water depresses the freezing point, but even the aggressive calcium chloride will not buy you more than forty degrees, so that is not adequate by itself. There are worse problems with this explanation: where did these salts come from, and how could salts get into snow on the southern highlands?

The standard explanation is that there must have been a greenhouse effect, and many have argued for a very significant carbon dioxide atmosphere. There are three problems with this explanation. The first is, it won’t work. Anything less than ten atmospheres pressure is inadequate, and at three atmospheres, the carbon dioxide liquefies. You cannot get sufficient pressure. The second is, the winters on Mars are very long, and carbon dioxide would snow out on the poles, thus reducing the pressure, and because of the albedo of the snow, not all of it would revolatalize, so as the years progressed, the planet would quickly become what it is like now. The third problem is, if there were that much carbon dioxide, where did it go? From isotope fractionation, it appears that about half of the original material that stayed in the atmosphere has been lost to space. Some more could well be frozen out on the poles. However, if there were enough to sustain liquid water for extended periods of time, there should be a lot of carbonates, and there are not. Now it is true we do not know how much could be buried, so maybe that argument is a bit on the weak side. On the other hand, there is plenty of other evidence that the atmosphere of Mars was always thin, although not as thin as now, as there had to be enough to keep water liquid. A number of estimates put it in the 100 millibar range. Further, if it lasted for periods of a few hundred thousand years it could not have been carbon dioxide, at least not initially as otherwise most would have snowed out. Of course it could have been continuously replenished by volcanic action, but if so, there must be very large deposits of carbon dioxide at the poles and that does not appear to be the case. So by asking such simple questions, we have made progress.

The next question is, how did the gases and water get to Mars? This is a rather convoluted question, but the simple answer is, the river flows lasted for only a few hundred thousand years and they started about 1.5 billion years after Mars formed. They also corresponded to significant periods of volcanic eruptions, so the most likely answer for the gases is they came from volcanic eruptions. Most of the water would have too, however it is possible that there were ice deposits near the surface following accretion. The next question is, how did the gases get below the surface of Mars to be erupted?

If we think about them being adsorbed during accretion, then, with the exception of water and ammonia, because the heats of adsorption are very similar for various gases, they would be adsorbed approximately proportional to their concentrations in the disk gases. That would mean, predominantly hydrogen and helium, although these would have been subsequently lost to space. However, neon would also be a very common gas, and to a lesser degree argon, but both neon and argon (apart from argon 40, which is a decay product of potassium 40) are very rare on Mars, so that was not the mechanism.

A commonly quoted mechanism is the volatiles arrived on the rocky planets through comets. That is not valid, at least for Earth, the reason being that the deuterium levels on comets are too high. Another suggestion is they arrived on carbonaceous chondrites. That too does not ring true, first because there would have had to be a huge number more of them, but not silicaceous asteroids, and second, the isotopes of some other elements rule that out. As far as Mars goes, there is the additional point that since it had no plate tectonics, and it had a rocky surface approximately three million years after formation, there is no mechanism to get the gases below the surface.

The only way they could get there is to be accreted as solids. Water would bind chemically to silicates; carbon would probably be accreted as carbides, or as carbon; nitrogen would be accreted as nitrides. The gases are then formed by the reaction of water with the carbides or nitrides, so the amount of gas available depends on how many of these solids were formed, and how much water was accreted. The lower levels of these gases on Mars is due to the fact that the material in the Mars feeding zone never got as hot as around Earth during stellar accretion. The higher temperature in the Venusian accretion zone is why it also has about three times the nitrogen as Earth: nitrides were easier to form at higher temperatures. Water binding to silicates happened after the disk cooled, but before the dust accreted to planets, and Mars has less water because the better aluminosilicates never phase separated because the temperatures earlier were never hot enough. Venus got less water because the disk never got as cool as around Earth and the silicates could not absorb so much.

When water reacts with nitrides and carbides it makes ammonia and methane, and these are most stable under high pressure, which is easily obtained in the interior of planets. If so, this hypothesis predicts that the initial atmosphere would comprise ammonia and methane. This is usually considered to be wrong because ammonia in the atmosphere is quickly decomposed by UV radiation, however, the ammonia will not stay in the atmosphere. Ammonia is rapidly absorbed by water, and even snow, and it will liquefy ice even at minus 80 degrees C. That gets it out of the atmosphere quickly and now there is a simple mechanism why water would flow, and also why it would later stop flowing near the equator and form ice deposits: as it got warmer, the ammonia would evaporate off. The atmosphere would start as methane, but would gradually be oxidised to carbon dioxide, which is why the atmosphere had such a short life. The carbon dioxide would react with ammonia, and eventually the ammonium carbonate would be converted to urea and the water would stop flowing. Thus in this theory under the soil of Mars, provided it has not reacted further, there is just the fertilizer settlers would need.

Star and Planetary Formation: Where and When?

Two posts ago, as a result of questions, I promised to write a post outlining the concept of planetary accretion, based on the current evidence. Before starting that, I should explain something about the terms used. When I say something is observed, I do not mean necessarily with direct eyesight. The large telescopes record the light signals electronically, similarly to how a digital camera works. An observation in physics means that a signal is received that can be interpreted in one only certain way, assuming the laws of physics hold. Thus in the famous two-slit experiment, if you fire one electron through the slits, you get one point impact, which is of too low an energy for the human eye to see. Photomultipliers, however, can record this as a pixel. We have to assume that the “observer” uses laws of physics competently.

The accretion of a star almost certainly starts with the collapse of a cloud of gas. What starts that is unknown, but it is probably some sort of shock wave, such as a cloud of debris from a nearby supernova. Another cause appears to be the collision of galaxies, since we can see the remains of such collisions that are accompanied by a large number of new stars forming. The gas then collapses and forms an accretion disk, and these have been observed many times. The gas has a centre of mass, and this acts as the centre of a gravitational field, and as such, the gas tries to circulate at an orbital velocity, which is where the rate of falling into the star is countered by the material moving sideways, at a rate that takes it away from the star so that the distance from the centre remains the same. If they do this, angular momentum is also conserved, which is a fundamental requirement of physics. (Conservation of angular momentum is why the ice skater spins slowly with arms outstretched; when she tucks her arms in, she spins faster.

The closer to the centre, the strnger gravity requires faster orbital velocity. Thus a stream of gas is moving faster than the stream just further from the centre, and slower than the stream just closer. That leads to turbulence and friction. Friction slows the gas, meaning it starts to fall starwards, while the friction converts kinetic energy to heat. Thus gas drifts towards the centre, getting hotter and hotter, where it forms a star. This has been observed many times, and the rate of stellar accretion is such that a star takes about a million years to form. When it has finished growing, there remains a dust-filled gas cloud of much lower gas density around it that is circulating in roughly orbital velocities. Gas still falls into the star, but the rate of gas falling into the star is at least a thousand times less than during primary stellar accretion. This stage lasts between 1 to 30 million years, at which point the star sends out extreme solar winds, which blow the gas and dust away.

However, the new star cannot spin fast enough to conserve angular momentum. The usual explanation is that gas is thrown out from near the centre, and there is evidence in favour of this in that comets appear to have small grains of silicates that could only be formed in very hot regions. The stellar outburst noted above will also take away some of the star’s angular momentum. However, in our system, the bulk of the angular momentum actually resides in the planets, while the bulk of the mass is in the star. It would seem that somehow, some angular momentum must have been transferred from the gas to the planets.

Planets are usually considered to form by what is called oligarchic growth, which occurs after primary stellar accretion. This involves the dust aggregating into lumps that stick together by some undisclosed mechanism, to make first, stone-sized objects, then these collide to form larger masses, until eventually you get planetesimals (asteroid-sized objects) that are spread throughout the solar system. These then collide to form larger bodies, and so on, at each stage collisions getting bigger until eventually Mars-sized bodies collide to form planets. If the planet gets big enough, it then starts accreting gas from the disk, and provided the heat can be taken away, if left long enough you get a gas giant.

In my opinion, there are a number of things wrong with this. The first is, the angular momentum of the planets should correspond roughly to the angular momentum of the dust, which had velocity of the gas around it, but there is at least a hundred thousand times more gas than dust, so why did the planets end up with so much more angular momentum than the star? Then there is timing. Calculations indicate that to get the core of Jupiter, it would take something approaching 10 million years, and that assumes a fairly generous amount of solids, bearing in mind the solid to gas ratio. At that point, it probably accretes gas very quickly. Get twice as far away from the star, and collisions are much slower. Now obviously this depends on how many planetesimals there are, but on any reasonable estimate, something like Neptune should not have formed. Within current theory, this is answered by having Neptune and Uranus being formed somewhere near Saturn, and then moved out. To do that, while conserving angular momentum, they had to throw similar masses back towards the star. I suppose it is possible, but where are the signs of the residues? Further, if every planet is made from the same material, the same sort of planet should have the same composition, but they don’t. The Neptune is about the same size as Uranus, but it is about 70% denser. Of the rocky planets, Earth alone has massive granitic/feldsic continents.

Stronger evidence comes from the star called LkCa 15 that apparently has a gas giant forming that is already about five times bigger than Jupiter and about three times further away. The star is only 3 million years old. There is no time for that to have formed by this current theory, particularly since any solid body forming during the primary stellar accretion is supposed to be swept into the star very quickly.

Is there any way around this? In my opinion, yes. I shall put up my answer in a later post, although for those who cannot wait, it is there in my ebook, “Planetary Formation and Biogenesis”.

Martian Fluvial Flows, Placid and Catastrophic


Despite the fact that, apart localized dust surfaces in summer, the surface of Mars has had average temperatures that never exceeded about minus 50 degrees C over its lifetime, it also has had some quite unexpected fluid systems. One of the longest river systems starts in several places at approximately 60 degrees south in the highlands, nominally one of the coldest spots on Mars, and drains into Argyre, thence to the Holden and Ladon Valles, then stops and apparently dropped massive amounts of ice in the Margaritifer Valles, which are at considerably lower altitude and just north of the equator. Why does a river start at one of the coldest places on Mars, and freeze out at one of the warmest? There is evidence of ice having been in the fluid, which means the fluid must have been water. (Water is extremely unusual in that the solid, ice, floats in the liquid.) These fluid systems flowed, although not necessarily continuously, for a period of about 300 million years, then stopped entirely, although there are other regions where fluid flows probably occurred later. To the northeast of Hellas (the deepest impact crater on Mars) the Dao and Harmakhis Valles change from prominent and sharp channels to diminished and muted flows at –5.8 k altitude that resemble terrestrial marine channels beyond river mouths.

So, how did the water melt? For the Dao and Harmakhis, the Hadriaca Patera (volcano) was active at the time, so some volcanic heat was probably available, but that would not apply to the systems starting in the southern highlands.

After a prolonged period in which nothing much happened, there were catastrophic flows that continued for up to 2000 km forming channels up to 200 km wide, which would require flows of approximately 100,000,000 cubic meters/sec. For most of those flows, there is no obvious source of heat. Only ice could provide the volume, but how could so much ice melt with no significant heat source, be held without re-freezing, then be released suddenly and explosively? There is no sign of significant volcanic activity, although minor activity would not be seen. Where would the water come from? Many of the catastrophic flows start from the Margaritifer Chaos, so the source of the water could reasonably be the earlier river flows.

There was plenty of volcanic activity about four billion years ago. Water and gases would be thrown into the atmosphere, and the water would ice/snow out predominantly in the coldest regions. That gets water to the southern highlands, and to the highlands east of Hellas. There may also be geologic deposits of water. The key now is the atmosphere. What was it? Most people say it was carbon dioxide and water, because that is what modern volcanoes on Earth give off, but the mechanism I suggested in my “Planetary Formation and Biogenesis” was the gases originally would be reduced, that is mainly methane and ammonia. The methane would provide some sort of greenhouse effect, but ammonia on contact with ice at minus 80 degrees C or above, dissolves in the ice and makes an ammonia/water solution. This, I propose, was the fluid. As the fluid goes north, winds and warmer temperatures would drive off some of the ammonia so oddly enough, as the fluid gets warmer, ice starts to freeze. Ammonia in the air will go and melt more snow. (This is not all that happens, but it should happen.)  Eventually, the ammonia has gone, and the water sinks into the ground where it freezes out into a massive buried ice sheet.

If so, we can now see where the catastrophic flows come from. We have the ice deposits where required. We now require at least fumaroles to be generated underneath the ice. The Margaritifer Chaos is within plausible distance of major volcanism, and of tectonic activity (near the mouth of the Valles Marineris system). Now, let us suppose the gases emerge. Methane immediately forms clathrates with the ice (enters the ice structure and sits there), because of the pressure. The ammonia dissolves ice and forms a small puddle below. This keeps going over time, but as it does, the amount of water increases and the amount of ice decreases. Eventually, there comes a point where there is insufficient ice to hold the methane, and pressure builds up until the whole system ruptures and the mass of fluid pours out. With the pressure gone, the remaining ice clathrates start breaking up explosively. Erosion is caused not only by the fluid, but by exploding ice.

The point then is, is there any evidence for this? The answer is, so far, no. However, if this mechanism is correct, there is more to the story. The methane will be oxidised in the atmosphere to carbon dioxide by solar radiation and water. Ammonia and carbon dioxide will combine and form ammonium carbonate, then urea. So if this is true, we expect to find buried where there had been water, deposits of urea, or whatever it converted to over three billion years. (Very slow chemical reactions are essentially unknown – chemists do not have the patience to do experiments over millions of years, let alone billions!) There is one further possibility. Certain metal ions complex with ammonia to form ammines, which dissolve in water or ammonia fluid. These would sink underground, and if the metal ions were there, so might be the remains of the ammines now. So we have to go to Mars and dig.






Settling Mars and High Energy Solar Particles

Recently, the US government announced that sending people to Mars was a long-term objective, and accordingly it is worth looking at some of the hazards. One that often gets airing is the fact that the sun sends out bursts of high-energy particles that are mainly protons, i.e. hydrogen atoms with their electrons stripped off. If these strike living matter, they tend to smash the molecules, as they have energy far greater than the energy of the chemical bond. These are of little hazard to us usually, though, because they are diverted by the earth’s magnetic field. It is this solar wind that is the primary cause of auroras. The solar wind particles knock electrons out of gas molecules, and the light is generated when electrons return. As you might guess, if these particles can knock out enough electrons from molecules to generate that light show, the particle flux would be quite undesirable for DNA, and a high cancer rate would be expected if some form of protection could not be provided.

The obvious method is to divert the particles, and electromagnetism provides a solution. When a charged particle is moving and it strikes a magnetic field, there is a force that causes the path of the charged particle to bend. The actual force is calculated through something called a vector cross product, but in simple terms the bending force increases with the velocity of the particle, the strength of the magnetic field, and the angle between the path and the magnetic field. The force is maximum when the path is at right angles to the magnetic field, and is actually zero when the particle motion is parallel to the field. The question then is, can we do anything about the solar particles with this?

The first option would be to generate a magnetic field in Mars. Unfortunately, that is not an option, because we have no idea how to generate a dynamo within the planet, nor do we know if it is actually possible. The usual explanation for the earth’s magnetic field is that it is generated through the earth’s rotation and the iron core. Obviously, there is more to it than that, but one thing we know is that the density of Mars is about 3.9 whereas Earth is about 5.5. Basalt, the most common mix of metal silicates, has a density ranging from 3 to 3.8, but of course density also increases with compression. This suggests that Mars does not have much of an iron core. As far as I am aware, it is also unclear whether the core of Mars is solid or liquid. Accordingly, it appears clear there is no reasonable hope of magnetizing Mars.

The alternative is to put an appropriate magnetic field on the line between Mars and the sun. To do that, we have to put a properly aligned strong magnetic field between Mars and the sun. The problem is, bodies orbiting the sun generally only have the same angular rotation about the sun as Mars if they are at the same distance from the sun as Mars, or on average if they are orbiting Mars, in which case they cannot be between, and if they are not between all the time, they are essentially useless.

However, for the general case where a medium sized body orbits a much larger one, such as a planet around a star, or the Moon around Earth, there are five points where a much smaller object can orbit in a fixed configuration with respect to the other two. These are known as Lagrange points, named after the French mathematician who found them, and the good news is that L1, the first such point, lies directly between the planet and the star. Thus on Mars, a satellite at L1 would always seem to “eclipse” the sun, although of course it would be too small to be noticed.

Accordingly, a solution to the problem of high-energy solar particles on settlers on Mars would be to put a strong enough magnetic field at the Mars sun L1 position, so as to bend the path of the solar particles away from Mars. What is interesting is that very recently Jim Green, NASA Planetary Science Division Director, made a proposal of putting such a magnetic shield at the Mars-Sun-L1 position. For a summary of Green’s proposal, see .

The NASA proposal was focused more on reducing the stripping of the atmosphere by the solar wind. If so, according to Green, such a shield could help Mars achieve half the atmospheric pressure of Earth in a matter of years, on the assumption that frozen CO2 would sublimate, thus starting the process of terraforming. I am not so sure of that, because stopping radiation hitting Mars should not lead to particularly rapid sublimation. It is true that stopping such charged particles would help in stopping gas being knocked off the outer atmosphere, but the evidence we have is that such stripping is a relatively minor effect.

The other point about this is that I made this suggestion in my ebook novel Red Gold, published in 2011, which is about the colonization of Mars. My idea there was to put a satellite at L1 with solar panels and superconducting magnets. If the magnet coils can be shielded from sunlight, even the high temperature superconductors we have now should be adequate, in which case no cooling might be required. Of course the novel is science fiction, but it is always good to see NASA validate one of your ideas, so I am rather pleased with myself.