Martian Fluvial Flows, Placid and Catastrophic

Image

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.

 

 

 

 

 

Advertisements

Book Discount

From April 18 – 25, Athene’s Prophecy will be discounted to 99c on Amazon in the US and 99p in the UK. Science fiction with some science you can try your hand at. Have you got what it takes to actually develop a theory? The story is based around Gaius Claudius Scaevola, given the cognomen by Tiberius, who is asked by Pallas Athene to do three things, before he will be transported to another planet. The scientific problem is to prove the Earth goes around the Sun with what was known and was available in the first century. Can you do it? Try your luck. I suspect you will fail, and to stop cheating, the answer is in the following ebook. Meanwhile, the story.  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

The M 87 Black Hole

By now, unless you have been living under a flat rock somewhere, you have probably seen an image of a black hole. This image seems to be in just about as many media outlets as possible, so you know what the black hole and its environs look like, right? Not necessarily. But, you say, you have seen a photograph. Well, actually, no you haven’t. That system is so far away that to get the necessary resolution you need to gather light over a very wide array, so the image was obtained from a very large number of radio telescopes and the image was reconstructed by a sequence of mathematical processes. Nevertheless, the black sphere and the ring will represent fairly accurately part of what is there.

No radiation can escape from a black hole so the black bit in the middle is fair, however the image as presented gives no idea of its size. Its radius is about 19 billion km, which is a little under five times the distance from the sun to Pluto. This is really a monster. Ever wondered what happens to photons that are emitted at right angles to the gravitational field? Well, at 28 billion km or thereabouts they go into orbit around the black hole and would do that for an infinite time unless they get absorbed by dust falling in. The bright stuff you see is outside the rotating photons, and is travelling clockwise at about half light speed.

The light is obviously not orange and the signals were received as radio waves, but when emitted they would be extremely high energy photons. We see them as radio waves because they have lost that much energy climbing out of the black hole’s gravitational field. One way of looking at this is to think of light as a wave. The more energy the light has, the greater the frequency of wave crests passing by. As the energy lowers due to gravity lowering the energy of the light, the wave gets “stretched” and the number of crests passing by lowers. At the edge of the black hole the wave is so stretched it takes an infinite amount of time for a second crest to appear, which means no light can escape. Just outside the event horizon the gravity is not quite strong enough to stop it, but a gamma ray wave might take 100,000 of our years for the next crest to pass when it gets to us. The wave is moving but it is so red-shifted we could not see it. Further away from the event horizon the light is a little less stretched, so we see it as radio waves, which is what we were looking at in this image, even if it still started as gamma rays or Xrays.

It has amused me to see the hagiolatry bestowed upon Einstein regarding this image. One quote: “Albert Einstein’s towering genius is on display yet again.” As a comment, I am NOT trying to run down Einstein, but let us be consistent here. You may note Newton also predicted a mass at which light could not escape. In Newtonian mechanics the energy of the light would be given by E =mc^2/2, while the gravitational potential energy would be GMm/R. This permits us to calculate a radius where light cannot escape as R = 2GM/c^2, which happens to be exactly the same as the Schwarzchild radius from General Relativity.

Then we see statements such as “General relativity describes gravity as a consequence of the warping of space-time.” Yes, but that implies something that should not be there. General Relativity is a geometric theory, and describes the dynamics of particles in geometric terms. The phrase “as a consequence of” should be replaced with “in terms of”. The use of “consequence” implies cause, and this leads to statements involving cosmic fabric being bent, and you get images of something like a trampoline sheet, which is at best misleading. Here is another quote that annoys me: “Massive objects create a sort of dent or well in the cosmic fabric, which passing bodies fall into because they’re following curved contours (not as a result of some mysterious force at a distance, which had been the prevailing view before Einstein came along)”. No! Both theories are done a great disservice. Einstein gave a geometric description of how bodies move, but there is no physical cause, and it has the same problem, only deeper, than the Newtonian description had, because you must then ask, how does one piece of space-time know exactly how much to distort? Meanwhile, Newton gave a description of the dynamics of particles essentially in terms of calculus. Whereas Einstein describes effects in terms of a number of tensors, which most people do not understand, Newton invented the term “force”.

Now you will often see the argument that light is bent around the sun and that “proves” General Relativity is correct. Actually, Newtonian physics predicted  the same effect, but general Relativity bends it twice as much as predicted by Newtonian physics, so yes, in that sense General relativity is correct if the bend is correctly found to be twice that of Newton. You will then see statements along the lines this proves the bent path is “due to the warping of spacetime”. That is, of course, nonsense. The reason is that in Einstein’s relativity E = mc^2, which is twice that of the Newtonian energy, as you can see from the above. The reason for the difference appears to be the cosmic speed limit of light speed, which Newton may or may not have considered, but had no reason to go further. Why do I say Newton might have considered it? Because as a postulate, the fundamental nature of the speed of light goes all the way back to Empedocles. Of course, he did not make much of it.

Finally, I saw one statement that “the circular nature of the black hole again confirms the correctness of Einstein’s theory of General Relativity. Actually, Aristotle provided one of the first recorded reasons why gravity leads to a sphere. Newton would certainly have predicted a basic sphere, and of course the algorithm used to make the image would not have led to any other result unless there were something really dramatically non spherical. The above is not intended to downplay Einstein, but I am not a fan of the hagiolatry that accompanies him either.

Asteroid (101955) Bennu

The results of the OSIRIS-REx probe have now started to be made public, and while this probe was launched to answer questions about carbonaceous asteroids, and while some information has been obtained that is most certainly interesting, what it has mainly done, in my opinion, is to raise more questions. As is often the case with scientific experiments and observations.

Bennu is a carbonaceous asteroid with a semimajor axis of about 1.26 AU, where 1 AU is the Earth-Sun distance. Its eccentricity is 0.2, which means it is Earth-crossing and could collide with Earth. According to Wikipedia, it has a 1 in 2700 chance of impacting Earth between 2175 – 2199. I guess I shall never know, but it would be a threat. It has a diameter of approximately 500 meters, and a mass of somewhere in the vicinity of 7 x 10^10 kg, which means an impact would be extremely damaging near where it struck, but it would not be an extinction event. (The Chicxulub impactor would have been between five to seven orders of magnitude bigger.) So, what do we know about it?

It is described as a rubble pile, although what that means varies in terms of who says it. It is generally not considered to be an original accretion, and it is usually assumed to have formed inside a much larger planetoid which provided heat and pressure to form more complex minerals. Exactly why they are so sure of this is a puzzle to me, because we do not know what the minerals are, and how they are bound into the asteroid. Carbonaceous asteroids usually are found in the outer asteroid belt, and the assumption is this was dislodged inwards as a result of the collision that formed it. Standard theory assumes there were such collisions, but it also assumes such collisions led to planetary formation, and the rather awkward fact that there are no planets in the asteroid belt tends to be overlooked. These collisions are doing a lot of work, first making protoplanets then planets, and second, smashing up protoplanets to make asteroids, with no explanation why two different results arise other than “we need two different results”. Note that the collision velocities in the asteroid belt would be much milder than for the rocky planets, so smashing is more likely the closer to the star. Its relevance to planetary formation may be low since it did not form a planet, and there are no planets that have compositions that could realistically be considered to have come from such a chemical composition.

It is often said that Earth was bombarded with carbonaceous chondrites early on, and that is where the reduced carbon and nitrogen came from to sustain life, as well as the amino acids and nucleobases used to create life. Additionally, it is asserted that the iron and a number of other metals that dissolve in iron that we have on the surface must have come from asteroids, the reason being that in the early formation of Earth, the whole was a mass of boiling silicates in which such metals would dissolve in iron and go to the core. That we have them means something else must have brought them later. This shows one of the major faults of science, in my opinion. Rather than take the observation as a reason to go back and question whether the boiling silicates might be wrong, they introduce a further variable. Unfortunately, this “late veneer”  is misleading because the advocates have refused to accept that we have fragments of asteroids as meteorites. Their isotopes show they could only have contributed the right amount of metals, etc, if they were emulsified in all of Earth’s silicates. But wait. Why would these be emulsified and not go to the core while the original metals were not emulsified and did go to the core?

These asteroids are also believed by many to be the origin of life. They have very small amounts of amino acids and nucleobases, but they have a much wider range of amino acids than are used by our life. If they were the source, why did we not use them? Even more convincing, the nitrogen in the meteorite fragments has more 15N than Earth’s nitrogen. Ours is of solar composition; the asteroids apparently processed it. There is no way to reduce the level of heavy isotopes so these asteroids cannot be the source.

Now, what does a rubble pile conjure up in your mind? I originally considered it to be, well, a pile of rubble, loosely adhering, but Bennu cannot be that. First, consider the escape velocity, which is more than 20 cm/sec in the polar regions but reduces down to 10 cm/sec at the equator, due to the centrifugal force of its rotation. That is not much, and anything loose would be lost in any impact. Yet the surface is littered with boulders, three more than 40 m long. Any significant shock would seemingly dislodge such boulders, especially smaller ones, but there they are, some half buried. There are also impact craters, some up to 150 meters in diameter. Whatever hit it to create that and excavate a hole 150 m in diameter must have delivered a shock wave that should impart more than 10 cm s−1 to a loosely lying boulder, although there is one possible exception, which is when the whole structure was sufficiently flexible to give without fragmenting and absorb the energy by converting it to heat while adding to the kinetic energy of the whole.

Which brings us back to the rubble pile. Bennu’s relative density is 1.19, so if placed in water it would not float, but it would not sink very quickly either. For comparison, it is less than half that of granite and about a third of many basalts. CI asteroidal material has a bulk density of 1.57, while CM asteroidal material has a bulk density of 2.2.  Accordingly, it is concluded that Bennu has a lot of voids in it, which is where the concept of the rubble pile comes to bear. On the other hand, there is considerable stiffness, so something is restricting movement.

So what do we not know about this asteroid? First, we have only a modest idea of what it is made of, although a sample return might be possible. It may well be made entirely of large boulders plus the obvious voids put together with something sticking the boulders together, but what is the something? If made of boulders, what are the boulders made of? It never got hot enough out there to melt silicates, so whatever they are must b held together by some agent, but what? How resilient is that something, and how many times can it be used before it fails? This is important in case we decide it would be desirable to alter its orbit to avoid a collision with Earth. What holds the boulders together? This is important if we want to know how planets form, and whether such an asteroid will be useful in any way. (If, for example, we were to build a giant space station, the nitrogen, organic material and water in such an asteroid would be invaluable.) More to do to unravel this mystery.

Some Shortcomings of Science

In a previous post, in reference to the blog repost, I stated I would show some of the short-comings of science, so here goes.

One of the obvious failings is that people seem happy to ignore what should convince them. The first sign I saw of this type of problem was in my very early years as a scientist. Sir Richard Doll produced a report that convincingly (at least to me) linked smoking to cancer. Out came a number of papers rubbishing this, largely from people employed by the tobacco industry. Here we have a clear conflict, and while it is ethically correct to show that some hypothesis is wrong, it should be based on sound logic. Now I believe that there are usually a very few results, and maybe as few as one specific result, that makes the conclusion unassailable. In this case, chemists isolated the constituents of cigarette smoke and found over 200 suspected carcinogens, and trials with some of these on lab rats were conclusive: as an example one dab of pure 3,4-benzopyrene gave an almost 100% probability of inducing a tumour. Now that is a far greater concentration than any person will get smoking, and people are not rats, nevertheless this showed me that on any reasonable assessment, smoking is a bad idea. (It was also a bad idea for a young organic chemist: who needs an ignition source a few centimeters in front of the face when handling volatile solvents?) Yet fifty years or so later, people continue to smoke. It seems to be a Faustian attitude: the cancer will come decades later, or for some lucky ones, not at all, so ignore the warning.

A similar situation is occurring now with climate change. The critical piece of information for me is that during the 1990s and early 2000s (the period of the study) it was shown there is a net power input to the oceans of 0.64 W/m2. If there is a continuing net energy input to the oceans, they must be warming. Actually, the Tasman has been clearly warming, and the evidence from other oceans supports that. So the planet is heating. Yet there are a small number of “deniers” who put their head in the sand and refuse to acknowledge this, as if by doing so, the problem goes away. Scientists seem unable to make people fact up to the fact that the problem must be dealt with now but the price is not paid until much later. As an example, in 2014 US Senate majority leader Mitch McConnell said: “I am not a scientist. I’m interested in protecting Kentucky’s economy.” He forgot to add, now.

The problem of ignoring what you do not like is general and pervasive, as I quickly learned while doing my PhD. My PhD was somewhat unusual in that I chose the topic and designed the project. No need for details here, but I knew the department, and my supervisor, had spent a lot of effort establishing constants for something called the Hammett equation. There was a great debate going on whether the cyclopropane ring could delocalise electronic charge in the same way as a double bond, only mre weakly. This equation would actually address that question. The very limited use of it by others at the start of my project was inconclusive, for reasons we need not go into here. Anyway, by the time I finished, my results showed quite conclusively that it did not, but the general consensus, based essentially on the observation that positive electric charge was strongly stabilised by it, and on molecular orbital theory (which assumes it initially, so was hardly conclusive on this question) was that it did. My supervisor made one really good suggestion as to what to do when I ran into trouble, and this was the part that showed the effect the most. But when it became clear that everyone else was agreeing the opposite and he had moved to a new position, he refused to publish that part.

This was an example of what I believe is the biggest failing. The observation everyone clung to was unexpected and needed a new explanation, and what they came up with most certainly gave the right answer for that specific case. However, many times there is more than one possible explanation, and I came up with an alternative based on classical electric field theory, that also predicted positive charge would be stabilized, and by how much, but it also predicted negative charge would be destabilized. The delocalization concept required bothto be stabilised. So there was a means of distinguishing them, and there was a very small amount of clear evidence that negative charge was destabilised. Why a small amount of evidence. Well, most attempts at making such compounds failed outright, which is in accord with the compounds being unstable but it is not definitive.

So what happened? A review came out that “convincingly showed” the answer was yes. The convincing part was that it cited a deluge of “me too” work on the stabilization of positive charge. It ignored my work, and as I later found out when I wrote a review, it ignored over 60 different types of evidence that showed results that contradicted the “yes” answer. My review was not published because it appears chemistry journals do not publish logic analyses. I could not be bothered rewriting, although the draft document is on the web if anyone is interested.

The point this shows is that once a paradigm is embedded, even if on shaky grounds, it is very hard to dislodge, in accord with what Thomas Kuhn noted in “The structure of scientific revolutions”. One of the points Kuhn noted was if the paradigm had evidence, scientists would rush to write papers confirming the paradigm by doing minor variations on what worked. That happened above: they were not interested in testing the hypothesis; they were interested in getting easy papers published to advance their careers. Kuhn also noted that observations that contradict the paradigm are ignored as long as they can be. Maybe over 60 different types of observations that contradict, or falsify, the paradigm is a record? I don’t know, but I suspect the chemical community will not be interested in finding out.

Global warming and rain.

One day when I was a boy in Hokitika (West Coast, South Island, New Zealand) it was raining when I went to school and it got worse, so I had to walk home through water lying everywhere. The water was up to my ankles everywhere, and deeper in lower lying areas. This did not come from the river, but merely from the rain falling, and in nine hours, from memory there was nine inches of rain (a little under 23 cm). This was regarded as exceptional rain then, a once in a hundred year flood.

Now we have global warming so what do we expect? You hear lots of talk about drought, and yes in some parts of the world there will be drought, but in others there will be more rain. The reason is, if the oceans get warmer more water should go into the air. By itself that may not matter too much if the air gets warmer as well, but problems arise if such warm air meets cooler air. This is the sort of thing that causes rain, but now there is more water in the air.

What happens next depends on exactly how the cause behaved. The obvious thing is the rain falls, but when the humidity collapses into rain drops, its going from the gas phase to liquid releases a lot of energy. If there is enough cold air, it might just heat it, especially if the cold came from mountains forcing the air upwards relatively slowly so that it cools and rains on one side of the mountains. That is what happens around Hokitika. Now the hot air blows a strong warm wind over the land to the east, the so-called föhn wind. If the energy cannot be dissipated that way, then stronger circular winds are generated. The tropical cyclones are examples. There was one recently in Madagascar recently that did extreme damage.

So, how will global warming affect these? The short answer is, there will be a variety of ways. Stronger cyclones, more frequent cyclones (because milder systems that get stronger enter the classification) but the more obvious one is more rain because more water has been evaporated. Which gets me back to Hokitika. They have just had a weather system pass over that lasted about a day and a half of continuous rain, and dumped 800 mm of rain in that period (about 31 ½ inches). That is as much as some places get in a year. A little way inland, in the same period they got 1,082 mm, and that is almost 43 inches.

There has been a variety of flooding around the place. A number of houses were inundated because the storm-water drains could not cope and one woman died. Apparently she was driving; she did not like the speed of the water flowing down the road, so she got out. If when driving you see rapidly flowing water of unknown depth ahead, stop and sit it out, or turn back to higher ground. Do not enter. If you are correct in your fear that a car cannot maintain its grip on the road, you walking would be in a worse position. The force of rapidly flowing water will sweep you off your feet, and if it is deep, you are lighter and therefore have less grip. Your grip depends on your weight.

Probably the most frustrating situation has been for tourists south of the Franz Josef glacier, where they are stranded. To the south, the road is apparently cut off around Haast, and to the north of the Fox Glacier, the Waiho bridge was washed out by a river carrying down quite large boulders. A little earlier there were sightseers walking on the bridge, but fortunately they all got off before the bridge went. To give some idea of the water, here are links to two videos of the bridge going: https://www.youtube.com/watch?v=ldCjVqfkKFk   and  https://www.youtube.com/watch?v=wPf49aaomYI The first one also gives a brief example of the New Zealand accent, and the vernacular. Note the bridge was a Bailey bridge and is in principle not expected to be permanent.

Once something like this happens, the blame game starts. One argument was that the river has a history of flooding and of eroding out the land and changing course, so why build a more permanent bridge? Another was the crossing is situated on a major fault and apparently the land is not good for foundations. I suspect that since it is in a very low population area, money is also a relevant issue. Where I live, there are a number of bridges across the Hutt river, and it runs along a major fault line, but being in a major metropolitan area, bridges are built. However, another more pertinent accusation came from a local who had complained a few days before that someone excavating the riverbed a little upstream had created a channel that would direct the heaviest rocks in a flood in the direction of the first supports to give way. Oops! No doubt more will follow.

When I wrote that (yesterday), the weather system was still to the south of here but working its way north. Yesterday we had wind gusts of up to 120 k/h, and while the system was working its way north, apart from some heavy rain last night, it had run out of steam. Today it is quite warm, sunny, no problem.

So is this a sign of climate change? A single incident is not, however I note that the “one in a hundred year rain event” in my youth has happened again now, and apparently in the 1980s. This time it has dumped almost four times the amount of water, and the Tasman Sea is about two Centigrade degrees above average this summer. You form your own opinion.

Processing Minerals in Space

I have seen some recent items on the web that state that asteroids are full of minerals and fortunes await. My warning is, look deeper. The reason is, most asteroids have impact craters, and from basic physics but some rather difficult calculations you can show these were formed from very energetic collisions. That the asteroid did not fly to bits indicates it is a solid with considerable mechanical strength. That implies the original dust either melted to form a solid, or a significant chemical reaction took place. For those who have read my “Planetary Formation and Biogenesis” you will know why they melted, assuming I am right. So what has that got to do with things? Quite simply, leaving aside metals like gold, the metal oxides in molten silica form the olivine or pyroxene families, or aluminosilicates. That is they form rocks. To give an example of the issue, I recently read a paper where various chondrites were analysed, and the method of analysis recorded the elements separately. The authors were making much of the fact that the chondrites contained 19% iron. Yikes! But wait. Fayalite contains almost 55% iron by weight, but it is useless as an ore. The olivine and pyroxene structures have tetrahedral silicon oxides (the pyroxene as a strand polymer) where the other valence of the oxygen is bound to a divalent cation, mostly magnesium because magnesium is the most common divalent element in the supernova dust. What these authors had done was to analyse rock.

If you read my previous post you will see that I have uncovered yet another problem with science: the authors were very specialized but they went outside their sphere of competency, quite accidentally. They cited numbers because so much in science depends on numbers. But it is also imperative to know what the numbers mean.

On Earth, most of the metals we obtain come from ores, which have formed through various forms of geochemical processing. Thus to get iron, we usually process haematite, which is an iron oxide, but the iron almost certainly started as an average piece of basalt that got weathered. It is most unlikely that good deposits of haematite will be found on asteroids, although it is possible on Mars where small amounts have been found. If Mars is to be settled, processing rocks will be mandatory for survival but the problems are different from those of asteroids. For this post, I wish to restrict myself to discussing asteroids as a source of metals. Let us suppose an asteroid is collected and brought to a processing site, the question is, what next?

The first problem is size-reduction, i.e.breaking it down to more manageable pieces. How do you do that? If you hit it with something, you immediately separate, following Newton’s third law. If you want to see the difficulties, stand on a small raft and try to keep on hitting something. Ah, you say, anchor yourself. How? You have to put something like a piton into solid rock, and how do you do that without some sort of impact? Of course it can be done, but it is not easy. Now you start smashing it. What happens next is bits of asteroid fly off into space. Can you collect all of the pieces? If not, you are a menace because the asteroid’s velocity v, which will be in the vicinity of 30 km/s if near Earth, has to be added to whatever is given to the fragments. Worse, they take on the asteroid’s eccentricity ε(how much difference there is between closest and farthest distance from the sun) and whatever eccentricity has been added by the fragmentation. This is important because the relative velocity of impact assuming the target is on a circular orbit is proportional to εv. Getting hit by a rock at these sort of velocities is no joke.

However, suppose you collect all the rock, you have two choices: you can process the rock as is, or you can try to refine it. If you adopt the latter idea, how do you do it? On Earth, such processing arises through millions of years of action with fluids, or through superheated fluids passing through high temperature rock. That does not sound attractive. Now some asteroids are argued to have iron cores so the geochemical processing has been done for you. Of course you still have to work your way through the rock, and then you have to size reduce the iron, which again raises the question, how? There is also a little less good news awaiting you: iron cores are almost certainly not pure iron. The most likely composition is iron with iron silicide, iron phosphide, iron carbide and a lot of iron sulphide. There will also be some nickel, together with corresponding compounds, and (at last joy?) certain high value metals that dissolve in iron. So what do you do with this mess?

Then, supposing you separate out a pure chemical compound, how do you get the metal out? The energy input required can be very large. Currently, there is a lot of effort being put into removing CO2from the atmosphere. The reason we do not pull it apart and dump the carbon is that all the energy liberated from burning it has to be replaced, i.e.a little under 400 kJ/mol. and that is such a lot of energy. Consider that as a reference unit. It takes roughly two such units to get iron from iron oxide, although you do get two iron atoms. It takes about five units to break forsterite into two magnesium atoms and one silicon. It takes ten such units to break down kaolinite to get two aluminium atoms and two silicon atoms. Breaking down rock is very energy intensive.

People say, electrolysis. The problem with electrolysis is the material has to dissolve in some sort of solvent and then be separated into ions. Thus when making aluminium, bauxite, an aluminium oxide is used. Clays, which are aluminosilicates such as kaolinite or montmorillinite, are not used, despite being much cheaper and more easily obtained. In asteroids any aluminium will almost certainly be in far more complicated aluminosilicates. Then there is the problem of finding a solvent for electrolysis. For the least active metals, such as copper, water is fine, but that will not work for the more active ones, such as aluminium. Titanium would be even more difficult to make, as it is made from the reduction of titanium tetrachloride with magnesium. You have to make all the starting materials!

On Earth, many oxides are reduced to metal by heating with carbon (usually very pure coal) and allow the carbon to take the oxygen and disappear as a gas. The problem with that, in space, is there is no readily available source of suitable carbon. Carbonaceous chondrites have quite complicated molecules. The ancients used charcoal, and while this is NOT pure carbon, it is satisfactory because the only other element there in volume tends to be oxygen. (Most charcoal is about 35% oxygen.) The iron in meteors could certainly be useful, but for some other valuable elements, such as platinum, while it may be there as the element, it will probably be scattered through the matrix and be very dilute.

Undoubtedly there will be ways to isolate such elements, but such methods will probably be somewhat different from what we use. In some of my novels I have had fusion power tear the molecules to atoms, ionise them, and separate out the elements in a similar way to how a mass spectrometer works, that is they are accelerated and then bent with powerful electromagnetic fields. The “bend” in the subsequent trajectory depends on the mass of the ions, so each isotope is separated. Yes, that is fiction, but whatever is used would probably seem like fiction now. Care should be taken with any investment!

Repost from Sabine Hossenfelder’s blog “Backreaction”

Two posts this week. The first is more for scientists, but I think it mentions points that people reading about science should recognise as possibly there. Sabine has been somewhat critical of some of modern science, and I feel she has a point. I shall do a post of my own on this topic soon, but it might be of interest to read the post following this to see what sort of things can go wrong.
Both bottom-up and top-down measures are necessary to improve the current situation. This is an interdisciplinary problem whose solution requires input from the sociology of science, philosophy, psychology, and – most importantly – the practicing scientists themselves. Details differ by research area. One size does not fit all. Here is what you can do to help.

As a scientist:

  • Learn about social and cognitive biases: Become aware of what they are and under which circumstances they are likely to occur. Tell your colleagues.
  • Prevent social and cognitive biases: If you organize conferences, encourage speakers to not only list motivations but also shortcomings. Don’t forget to discuss “known problems.” Invite researchers from competing programs. If you review papers, make sure open questions are adequately mentioned and discussed. Flag marketing as scientifically inadequate. Don’t discount research just because it’s not presented excitingly enough or because few people work on it.
  • Beware the influence of media and social networks: What you read and what your friends talk about affects your interests. Be careful what you let into your head. If you consider a topic for future research, factor in that you might have been influenced by how often you have heard others speak about it positively.
  • Build a culture of criticism: Ignoring bad ideas doesn’t make them go away, they will still eat up funding. Read other researchers’ work and make your criticism publicly available. Don’t chide colleagues for criticizing others or think of them as unproductive or aggressive. Killing ideas is a necessary part of science. Think of it as community service.
  • Say no: If a policy affects your objectivity, for example because it makes continued funding dependent on the popularity of your research results, point out that it interferes with good scientific conduct and should be amended. If your university praises its productivity by paper counts and you feel that this promotes quantity over quality, say that you disapprove of such statements.

As a higher ed administrator, science policy maker, journal editor, representative of funding body:

  • Do your own thing: Don’t export decisions to others. Don’t judge scientists by how many grants they won or how popular their research is – these are judgements by others who themselves relied on others. Make up your own mind, carry responsibility. If you must use measures, create your own. Better still, ask scientists to come up with their own measures.
  • Use clear guidelines: If you have to rely on external reviewers, formulate recommendations for how to counteract biases to the extent possible. Reviewers should not base their judgment on the popularity of a research area or the person. If a reviewer’s continued funding depends on the well-being of a certain research area, they have a conflict of interest and should not review papers in their own area. That will be a problem because this conflict of interest is presently everywhere. See next 3 points to alleviate it.
  • Make commitments: You have to get over the idea that all science can be done by postdocs on 2-year fellowships. Tenure was institutionalized for a reason and that reason is still valid. If that means fewer people, then so be it. You can either produce loads of papers that nobody will care about 10 years from now, or you can be the seed of ideas that will still be talked about in 1000 years. Take your pick. Short-term funding means short-term thinking.
  • Encourage a change of field: Scientists have a natural tendency to stick to what they know already. If the promise of a research area declines, they need a way to get out, otherwise you’ll end up investing money into dying fields. Therefore, offer reeducation support, 1-2 year grants that allow scientists to learn the basics of a new field and to establish contacts. During that period they should not be expected to produce papers or give conference talks.
  • Hire full-time reviewers: Create safe positions for scientists specialized in providing objective reviews in certain fields. These reviewers should not themselves work in the field and have no personal incentive to take sides. Try to reach agreements with other institutions on the number of such positions.
  • Support the publication of criticism and negative results: Criticism of other people’s work or negative results are presently underappreciated. But these contributions are absolutely essential for the scientific method to work. Find ways to encourage the publication of such communication, for example by dedicated special issues.
  • Offer courses on social and cognitive biases: This should be mandatory for anybody who works in academic research. We are part of communities and we have to learn about the associated pitfalls. Sit together with people from the social sciences, psychology, and the philosophy of science, and come up with proposals for lectures on the topic.
  • Allow a division of labor by specialization in task: Nobody is good at everything, so don’t expect scientists to be. Some are good reviewers, some are good mentors, some are good leaders, and some are skilled at science communication. Allow them to shine in what they’re good at and make best use of it, but don’t require the person who spends their evenings in student Q&A to also bring in loads of grant money. Offer them specific titles, degrees, or honors.

As a science writer or member of the public, ask questions:

  • You’re used to asking about conflicts of interest due to funding from industry. But you should also ask about conflicts of interest due to short-term grants or employment. Does the scientists’ future funding depend on producing the results they just told you about?
  • Likewise, you should ask if the scientists’ chance of continuing their research depends on their work being popular among their colleagues. Does their present position offer adequate protection from peer pressure?
  • And finally, like you are used to scrutinize statistics you should also ask whether the scientists have taken means to address their cognitive biases. Have they provided a balanced account of pros and cons or have they just advertised their own research?

You will find that for almost all research in the foundations of physics the answer to at least one of these questions is no. This means you can’t trust these scientists’ conclusions. Sad but true.


Reprinted from Lost In Math by Sabine Hossenfelder. Copyright © 2018. Available from Basic Books, an imprint of Perseus Books, a division of PBG Publishing, LLC, a subsidiary of Hachette Book Group, Inc