I have now begun putting some of my music compositions on my website, and currently there are five short pieces and my third piano sonata available for listening, or, if you play piano, a link to where scores can be purchased. If nothing else, they are different, and for skilled pianists there is the opportunity to give a world premier performance of something. The computer-generated sound is not without problems. For some reason, while it does well with accel., it hopelessly overdoes rit and ral. In the first movement of the sonata, it badly underdoes the sforzandos, and it ignores repeats, which is not necessarily bad. However, it gives some idea how I amuse myself. Listen at
Where did the rocky planets get their atmospheres from? This question is not trivial. Planets accrete by some mechanism whereby dust particles form larger objects and sooner or later these form planets. However, when they are small, they are either in a vacuum, or earlier they are in the gas that is falling into the sun and which will make the sun. If they are in a vacuum there is no gas to accrete. If they are in the gas streaming into the star they will absorb some gas more or less in proportion to what is in the gas stream, with some preference of heavier gas per unit concentration. However, that preference will not mean much because the concentration of hydrogen is so high it will swamp out most of the rest. When the rocky planet gets big enough, it will form an atmosphere from the accretion disk gas, so these two mechanisms predict either no atmosphere (accretion after the disk gas is gone) or gas that is predominantly hydrogen and helium.
When the sun ejected its accretion disk, it continued to send out a flux of high-energy UV radiation. What is expected to happen then is this would boil the hydrogen atmosphere into space, and this hydrodynamic outflow would take most of the other gases with it. None of the rocky planets in our solar system has enough gravity to hold hot hydrogen and helium for long. So any gas accreted so far is either underground or lost to space. The rocky planets start without an atmosphere, except maybe residual heavy gas that was not blown away by the strong UV. The only gases that are likely to have been so held are krypton and xenon, and they have an excess of heavy isotopes that indicate they may be such residues.
The next possibility is the gases were trapped underground and emitted volcanically after the extreme UV from the sun had stopped. Now the hydrogen and helium could leak away to space slowly and leave everything else behind. But we know that our atmosphere is not a remnant of gas from the accretion disk held by gravity or absorption because if it were, neon is about as common as nitrogen in those gases, and they would be absorbed at about the same rate and both would be held equally by gravity. If our atmosphere was delivered that way, it should contain at least 0.6 bar of neon, which is many orders of magnitude greater than what we see. Neon is a very rare gas on Earth.
Attempts to answer this question have mixed results, and tend to divide scientists into camps, wherein they defend their positions vigorously. One school of thought has the gases were forced into a magma ocean that arises from the heat of the collisions of entities about the size of Mars. I disagree with this. Should this have happened, the time taken to get the collisions going (originally estimated as 100 million years, subsequently reduced to about 30 million years with some unspecified correction to the calculations to accommodate the planet being here when the Moon-forming collision occurred) the gas would have long gone. And if the calculations were so wrong and it did happen, we are back to the neon problem.
The usual way out of this is to argue the gases came from carbonaceous chondrites, which are supposedly bits knocked off asteroids from the outer part of the asteroid belt. Such chondrites sometimes have quite reasonable amounts of water in them, as well as solids containing carbon and nitrogen. The idea is that these hit the earth, get hot, and the water oxidises the carbonaceous material to liberate carbon dioxide and nitrogen gas. Ten years ago I published the first edition of my ebook “Planetary Formation and Biogenesis”, which contained evidence that this could not be the source of the gases. The reasons were numerous and some of them complex, but one simple reason is the three rocky planets all have different proportions of the different elements. How can this happen if they came from a common source?
Now, a paper has appeared (Péron and Mukhopadhyay, Science 377: 320 – 324) that states that the krypton gas in the Chassigny meteorite, shows Mars accreted chondritic volatiles before nebular gases. I have a logic problem with this: the nebula gases were there before Mars even started forming. There was never any time that there was a Mars and the nebular gases had yet to arrive. They then found the krypton and xenon had isotope ratios that fell on a line between cosmogenic and what they assigned as trapped Martian mantle gases. There is a certain danger in this because the rock would have been exposed to cosmic rays, which lead to spallation and isotope alteration. Interestingly, the xenon data contradicts a previous report by Ott in 1948 (Geochim Cosmochim Acta 52: 1937 – 1948), who found the xenon was solar in nature. It may be that these differences can be simply explained because these are taken from a meteorite and only very small amounts of the meteorite are allowed to be taken. The samples may not be representative. Interestingly Péron and Mukhopadhyay consider the meteorite to have come from the Martian interior, based on the observation by Ott that the sample had been heated to a high temperature and was presumably of volcanic nature. The problem I see with that is that Ott came to the same conclusion for a number of other meteorites that have quite different isotope ratios. It is usually wrong to draw major conclusions from an outlier result. Anyway, based on the argument that Ott thought this meteorite was igneous, this latest paper concludes that its rare gases came from the interior of Mars, and hence show the volatiles did not come from carbonaceous chondrites.
In my opinion, the conclusion is valid, but not for the right reasons. What annoys me is the example that a previous researcher thought the sample might have been volcanic rock is assume to have come from deep in the interior now, while the previous results that do not fit the proposition are put to one side. I think that small differences from two tiny samples show you should not draw conclusions. I know there are funding pressures on scientists to publish papers, but surely everything in their work and previous work they quote should be self-consistent or reasons be found for discrepancies.
From July 21 – 28, my thriller, The Manganese Dilemma, will be discounted to 99c/99p on Amazon.
The Russians did it; everyone is convinced of that. But just exactly what did they do? The curvaceous Svetlana has brought to the West evidence of new super stealth technology. Some believe there is nothing there since their surveillance technology cannot show any evidence of it, but then it is “super stealth” so just maybe . . . Charles Burrowes, a master hacker, is asked to work with Svetlana and validate the technology. Can Burrowes provide what the CIA needs before Russian counterintelligence or a local criminal conspiracy blow the whole operation out of the water? The lives of many CIA agents in Russia will depend on how successful he is. A thriller based on espionage, counter espionage, and old-fashioned crime.
The settlement of Mars is a popular science fiction staple. I have written some “Mars novels” myself. One criticism of settling Mars is that the planet does not have magnetic field to deflect radiation, so what is the situation? In my ebook “Red Gold” I suggested a magnetic field be generated by a superconductor placed between Mars and the sun, specifically at the first Lagrange point so it would be there continuously. That would divert charged particles in the solar wind. However, suppose you do not do that, what are the options. An account has been written on May 27, 2022 and is at arXiv:2205.13786.
There are two sources of radiation. The first is from the sun and consist mainly of protons, helium nuclei (5 – 8%) and heavier nuclei (~1%). These arrive with energies ranging from some keV to hundreds of MeV. Very occasionally they go to even higher energies, and their intensity varies with the solar cycle. The other source are the cosmic rays. These are accelerated by supernova shocks and interstellar magnetic fields, and appear to come evenly from all directions. They have similar composition to the solar radiation, but they arrive with far higher energies, their average being in the GeV range, and of particular hazard are the high-charge ions, thus there may be particles up to iron that are stripped of their electrons and are travelling through space near the speed of light. It is this high energy and high charge that makes them so dangerous.
The first defence Mars offers is bulk. A person standing on the Martian surface, particularly in a crater, receives less than half what they would receive in space, and that applies to cosmic rays. None of these have energy anywhere nearly enough to go through a planet. The atmosphere, while thin, offers some protection, and will remove protons with less than 150 MeV energy, and possibly more if in a deep enough crater (which is partly why in “Red Gold” I had my settlement near the bottom of Hellas Planitia, the deepest part of Mars.) Accordingly, the major chronic hazard is cosmic radiation, but a sudden strike by a major solar event is also lethal.
There are two types of shielding. The first is active, the use of magnetic or plasma shields, but currently these are theoretical, such as my suggested L1 superconducting magnetic field generator. The second is passive, which is to place matter between the person and the source. At present we are reliant on passive measures. The better materials for stopping such charged particles are those with a high number density of atoms with many electrons per unit mass, which ends up meaning elements of low atomic number. Materials rich in hydrogen such as water or polyethylene perform well, although nothing practical can totally eliminate cosmic radiation.
For settlers on Mars, interactions with the atmosphere lead to neutrons and gamma rays being dominant. Terrain offers protection, thus being adjacent to a cliff will halve the exposure compared with open terrain. The water in regolith will greatly attenuate neutrons with less kinetic energy than 10 MeV. Liquid hydrogen is probably the best, but its extremely low temperature probably makes it impractical. Organic plastics work well; aluminium, which is used in spacecraft, is somewhat less satisfactory, but οn Μars the regolith is probably optimal, because it is already there and hence is cheap. On the other hand, it has to be bound by something, otherwise the wind will blow it away. The article suggests making bricks from regolith. The simplest protection is to live in caves. However, there may be a shortage of caves. People talk about lava tubes, but much of the volcanism on Mars has been around very large volcanoes, or older ones that erupted more in a pyroclastic fashion. They will be short on caves, while settlers are more likely to head for craters, which are not the obvious place to find caves, although rapidly exiting steam might leave one. One place where there might be caves is the Margaritifer Chaos, where there are signs of massive water outflows from a very small source.
However, living underground does not help plant growth, and the idea of having huge caverns with lights would require a huge investment in lights. It should be easy to make glass that will be opaque to UV radiation and will offer tolerable radiation protection. Silicate uses light atoms and should compare favourably with aluminium. Further, the danger of cosmic rays is largely long-term health; plants for food are not long-lived. One of the main problems for people settling on Mars is the cost and mass of what they have to take with them. Making bricks from regolith is great because regolith is there. The cost of lifting stuff up from Earth and taking it to Mars is huge, so as much as possible has to be made there. That is why lights for the underground growing of food would be very expensive. But the making of any habitat or plant growing area on the surface requires sealing to prevent gas pressure escaping. In my “Red Gold” I suggest one of the very first things that has to be learned is how to make a cement from Martian materials. The ability to make concrete is the first requirement to make the footers of “glass-houses” to grow plants, and cement is necessary to put bricks together. There is an awful lot of detail that has to be addressed because once settlers get there, if they haven’t got something, they cannot go to the corner store and get it.
A little over fifty years ago, the Systems Dynamics group at MIT produced a 200-page book called The Limits to Growth. Their message was, continued economic and population growth would deplete Earth’s resources and lead to global economic collapse by 2070. At the time, this was considered heresy. The journal Nature was scathing (See vol 236, pp 47 – 49, 1972). How could the foundations of industrial civilization, such as coal mining, steel-making, oil production, crop spraying, cause lasting damage? It was accepted that such industries caused pollution, but such effects were considered to be only temporary. At the time computer modelling was looked down upon. This is understandable; at the time computers were quite primitive compared with now, and big computers were only available to the major organizations. I recall four years before that someone doing a chemical bond calculation and coming back from the computer with what looked like a couple of kg of printout. His problem was that his program only produced two answers, depending on what he changed in the code. The answers were zero or infinity. As I remarked, the truth would be somewhere in between.
It is unlikely that any other computer model has made a bigger impact. There are still debates, but it is now clear that our activities have made irreversible environmental effects. As I have also noted in a previous post, there is also significant resource depletion. The elements have not gone anywhere, but that does not help if they are so diluted with other material that we cannot use them. Of course, it is arguable we could with unlimited energy, but we do not have that. The sun effectively produces unlimited energy, but it is too far away; here all it delivers is approximately 1360 W/m^2 at the top of the atmosphere, which is reduced to somewhere between 1000 – 1150 W/m^2 on a surface at right angles to the radiation at the surface. These numbers have to be divided by three for a 24-hr day, assuming no clouds.
The obvious problem for people is economic growth. Some people assume that economic growth can continue if we adopt technology much faster, particularly employing more renewable energy. Others argue we have to abandon the idea of growth. Was living as per we did in, say, 2016 that bad? One problem is that politicians need votes, and to get them they want to raise GDP. Thus if there is a choice of what to do, politicians will go for that which produces the most jobs. Excessive spending on the military increases jobs; corresponding spending on healthcare does not, but which is the more useful?
One analysis (Rockström et al. 2009, Nature 461: 472 – 475) argued there were boundaries. If we stayed within these the planet would adjust and correct our behaviour, but as we approached those boundaries (i.e. too much of something is being emitted) the planet may respond in a non-linear and often in an abrupt way. Most of these thresholds depend on one, or sometimes more, variables. They suggest ten such processes have such boundaries, three of which, biodiversity loss, climate change, the nitrogen cycle, are already exceeded, while a fourth, the phosphorus cycle is close to the breaking point and a fifth, ocean acidification is troublesome. Two more, chemical pollution and atmospheric aerosol loading were not quantified. Three, fresh water use, land use, and ozone depletion are considered to be under control.
The last time the poles were essentially ice-free the CO2 levels were approximately 450 ppm. As can be seen from my last post, exceeding that seems inevitable without drastic action. For biodiversity, extinctions are currently about 100 – 1000 times greater than natural. Biodiversity is very important to maintain the resilience of the system. The production of nitrogen fertilizer and the cultivation of legumes convert around 120 million t/a of nitrogen, which is more than the combined efforts of all Earth’s terrestrial processes. This ends up as pollution, it erodes resilience of some of the plant life, and it sends nitrous oxide into the atmosphere, and this makes a major contribution to greenhouse forcing. Excess nitrogen fertiliser leads to turbid waterways, lakes, etc, and sometimes pronounced algal blooms. About 20 Mt of phosphorus is mined each year, and about half of this finds its way into oceans. This is around eight times the natural erosion rate. When critical levels of phosphate enter the oceans, large scale anoxic events occur, which can lead to mass extinctions of marine life. The authors conclude that as long as we do not exceed the thresholds, we can pursue long-term economic and social development. Our problem is, we are crossing some.
There is an interesting review on climate change (Matthews & Wynes, 2022, Science 376: 1404 – 1409). One point that comes up early is how did this sneak up on us? If you look at the graph on global temperatures, you will see that the summers in the 1940s were unusually hot, and the winters in the 1960 – 1980 period were unusually cool, with the net result that people living between 1940 – 1985 could be excused for thinking in terms of extremes instead of averages that the climate was fairly stable. As you will recall, at 1990 there was a major conference on climate change, and by 1992 goals were set to reduce emissions. It is just after this that temperatures have really started rising. In other words, once we “promised” to do something about it, we didn’t. At 1960 the CO2 levels in the atmosphere were about 320 ppm; by 1990 the CO2 levels were about 365 ppm, and at 2022 they are about 420 ppm. The levels of CO2 emissions have accelerated following the treaty in which much of the world undertook to reduce them. Therein lies out first problem. We are not reducing emissions; we are increasing them, even though we promised to do the opposite. (There was a small reduction in 2019-2020 as a result of the Covid lockdowns, but that has passed.) In short, our political promises are also based on hot air.
The current warming rate is approximately a quarter of a degree Centigrade per decade, which means that since we are now about 1.25 degrees warmer than the set 1850 baseline, we shall hit the 1.5 degrees warming somewhere just after 2030. Since that was the 1990 target not to be exceeded, failure seems inevitable. According to the models, to hold the temperature to 1.5 degrees C above our baseline we must not emit more than 360 Gt (billion tonne) of CO2. The IPCC considers we shall emit somewhere between 400 -650 Gt of CO2 before we get carbon neutral (and that assumes all governments actually follow up on their stated plans.) What we see is that current national targets are simply inadequate, always assuming they are kept. Unfortunately, there is a second problem: there are other greenhouse gases and some are persistent. The agricultural sector emits nitrous oxide, while industry emits a range of materials like sulphur hexafluoride, which may not be there in great quantity but it is reputedly 22,800 times more effective at trapping infrared radiation than CO2, and it stays in the atmosphere for approximately 3,200 years. These minor components cannot be ignored, and annual production is estimated at about 10,000 t/a. It is mainly used in electrical equipment, from whence it leaks.
Current infrastructure, such as electricity generators, industrial plant, ships, aircraft and land transport vehicles all have predictable lifetimes and emissions. These exceed that required to pass the 1.5 degree C barrier already unless some other mitigation occurs. Thus, the power stations already built will emit 846 Gt CO2, which is over twice our allowance. People are not going to abandon their cars. Another very important form of inertia is socio-political. To achieve the target, most fossil fuel has to stay in the ground, but politicians keep encouraging the development of new extraction. The average voter is also unhappy to see major tax increases to fund things that will strongly and adversely affect his way of life.
One way out might be carbon capture. The idea of absorbing CO2 from the atmosphere and burying it may seem attractive, but how is it done, at what cost in terms of money and energy required to do it, and who pays for it? Planting trees is a more acceptable concept. In New Zealand there is quite a bit of land that was logged by the early settlers, but has turned out to be rather indifferent farm land. The problem with knowing whether this is a potential solution or not is that it is impossible to know how much of such land can be planted, given that a lot is privately owned. However, planting trees is realistically something that could help, even if it does not solve the problem.
The article seems to feel that the solution must include actions such as lifestyle changes (carless days, reduced speed limits, reduced travel, a reduction of meat eating). My feeling is this would be a very difficult sell in a democracy, and it is not exactly encouraging to persuade some to purchase electric vehicles then be told they cannot use them. The article cites the need for urgency, and ignores the fact that we have had thirty years where governments have essentially ignored the problem. Even worse, the general public will not be impressed to find they are required to do something that adversely affects their lifestyle, only to find that a number of other countries have no interest in subjecting their citizens to such restrictions. The problem is no country can stop this disaster from happening; we all have to participate. But that does not mean we all have to give up our lifestyles, just to ensure that politicians can get away with their inability to get things done. In my opinion, society has to make changes, but they do not have to give up a reasonable lifestyle. We merely need to use our heads for something better than holding up a hat. And to show that we probably won’t succeed, the US Supreme Court has made another 6:3 ruling that appears to inhibit the US Federal Government from forcing certain states to reduce emissions. We shall cook. Yes, this might be a constitutional technicality that Congress could clear up easily, but who expects the current Congress to do anything helpful for civilization?
Throughout July, my ebooks at Smashwords will be significantly discounted. The fictional ebooks, which are thrillers and, similar to Andy Weir, with real science in the background include:
Puppeteer: A technothriller where governance is breaking down due to government debt, and where a terrorist attack threatens to kill tens to hundreds of millions of people and destroy billions of dollar’s worth of infrastructure.
‘Bot War: A technothriller set about 8 years later, a more concerted series of terrorist attacks made by stolen drones lead to partial governance breaking down.
Troubles. Dystopian, set about 10 years later still, the world is emerging from anarchy, and there is a scramble to control the assets. Some are just plain greedy, some think corporate efficiency should rule, some think the individual should have the right to thrive, some think democracy should prevail as long as they can rig it, while the gun is the final arbiter.
Spoliation. A thriller set about asteroid mining, where some of the miners mysteriously disappear. Then someone tries tο weaponise a large asteroid. A story of greed, corruption and honour, combining science and visionary speculation that goes from the high frontier to outback Australia.
There is also the non-fictional “Biofuels”. This gives an overview of the issues involved in biofuels having an impact on climate change. Given that electric vehicles, over their lifetime probably have an environmental impact equivalent to or greater than the combustion motor, given that we might want to continue to fly, and given that the carbon from a combustion exhaust offers no increase in atmospheric carbon levels if it came from biofuel, you might be interested to see what potential this has. The author was involved in research on this intermittently (i.e. when there was a crisis and funding was available) for over thirty years. https://www.smashwords.com/books/view/454344