A Spanner in the Cosmological Works

One of the basic assumptions in Einstein’s relativity is that the laws of physics are constant throughout the Universe. One of those laws is gravity, and an odd thing about gravity is that matter always attracts other matter, so why doesn’t everything simply collapse and fall to one gigantic mass? Einstein “explained” that with a “cosmological constant” which was really an ad hoc term put there to stop that happening. Then in 1927 Georges Lemaȋtre, a Belgian priest proposed that the Universe started off as a tiny incredibly condensed state that expanded, and is still expanding –  the so-called “Big Bang”. Hubble then found that on a sufficiently large scale, everything is moving away from the rest, and it was possible to extrapolate back in time to see when it all started. This was not universally agreed until the cosmic microwave background, which is required by this theory, was detected, and detected more or less in the required form. All was well, until eventually, three “problems” were perceived to arise: the “Horizon problem”, the “Flatness problem”, and the “Magnetic monopole problem”.

The Horizon problem is that on a sufficiently large scale, everything looks the same. The problem is, things are moving away from each other at such great distances, so how did they come into thermal equilibrium when there was no contact between them? I must confess I do not understand this. If the initial mass is a ball of uniform but incredibly dense energy, then if it is uniform, and if the expansion is uniform, everything that happens follows common rate equations, so to get the large-scale uniformity, all you need is the uniform expansion of the energy and a common clock. If particle A wants to decay, surely it does not have to get permission from the other side of the Universe. The flatness problem is that the Universe seems to behave as if it followed Euclidean geometry. In the cosmological models, this requires a certain specific particle density. The problem is, out of all the densities, why is it more or less exactly right? Is this reasoning circular, bearing in mind the models were constructed to give what we see? The cosmic microwave background is a strong indication that Euclidean geometry is correct, but maybe there are other models that might give this result with less difficulties. Finally, the magnetic monopole problem is we cannot find magnetic monopoles. In this context, so far all electromagnetism is in accord with Maxwell’s electromagnetic theory and its equations exclude magnetic monopoles. Maybe we can’t find them because the enthusiasts who argue they should be there are wrong.

Anyway, around 1980, Alan Guth introduced a theory called inflation that would “solve” these problems. In this, within 10^-36 seconds after the big bang (that is 1 second of time divided by10 multiplied by itself 36 times) the Universe made a crazy expansion from almost no volume to something approaching what we see now by 10^-32 seconds after the big bang, then everything slowed down and we get what we have now – a tolerably slowly expanding Universe but with quantum fluctuations that led to the galaxies, etc that we see today. This theory “does away” with these problems. Mind you, not everyone agrees. The mathematician Roger Penrose has pointed out that this inflation requires extremely specific initial conditions, so not only has this moved the problem, but it made it worse. Further, getting a flat universe with these mathematics is extremely improbable. Oops.

So, to the spanner. Scientists from UNSW Sydney reported that measurements on light from a quasar 13 billion light years away found that the fine structure constant was, er, not exactly constant. The fine structure constant α is

α=e2/2εoch

The terms are e the elementary electric charge, εo is the permittivity of free space, c is the sped of light, and h is Planck’s constant, or the quantum of action. If you don’t understand the details, don’t worry. The key point is α is a number (a shade over 137) and is a ratio of the most important constants in electromagnetic theory. If that is not constant, it means all of fundamental physics is not constant.  No only that, but in one direction, the strength of the electric force appeared to increase, but in the opposite direction, decrease. Not only that but a team in the US made observations about Xrays from distant galaxies, and found directionality as well, and even more interesting, their directional axis was essentially the same as the Australian findings. That appears to mean the Universe is dipolar, which means the basic assumption underpinning relativity is not exactly correct, while all those mathematical gymnastics to explain some difficult “problems” such as the horizon problem are irrelevant because they have concluded how something occurred that actually didn’t. Given that enthusiasts do not give up easily I expect soon there will be a deluge of papers explaining why it had tp be dipolar.

Ebook discount

From May 27 – June 3, Ranh, the fifth in a series  but written largely as a stand-alone, will be discounted to 99c/99p on Amazon. The Scaevola series is linked through one character (Scaevola) following a quest. Ranh is the name given to a planet fictionally orbiting Epsilon Eridani, a star that is only 900 My old, and hence has not had time to develop life beyond the anaerobic bacteria level. However, 67 million years ago, some alien transported Cretaceous life from Earth and it has evolved to a space faring civilization. Because life was clearly “created”, since there are no fossils older than 67 My, the civilization is a theocracy. Some human has sent a message back in time, and this has been interpreted by a Cardinal that received it as a divine order to clear the planet of ultimate creation, (Earth) of those pesky mammals. A small delegation has arrived from Earth to negotiate a peace treaty. But how can negotiations persuade the deeply religious to ignore a divine order? A tale of plotting, conspiracy, religious fervour, murder, treachery, honour, diplomacy, and tail-ball.

After Lockdown, Now What?

A number of countries are emerging from lockdown and New Zealand is in the select group in which there are very few new cases, and indeed we have days in which no new cases are recorded. Now comes the damage. The Economist ran an article that summarized what happened in China following the release of lockdown. Rides on public transport are down by a third, restaurants have 40% fewer clients, and hotel stays are a third of normal. Bankruptcies may be up to 20%. People are still wary, either of the virus or their wallet.

It is one thing to open shops, but another thing to get people to go to them and buy stuff. If the disease is still around, while some will take the risk, many others will not, although on this front, in NZ shops initially had huge days. It is not totally bad for those shops that can last the distance because for many things provided people have the money, they will still buy the same amount, other than, perhaps luxury consumables. However, the question then is, will they still have money? Different countries will have different problems here. Apparently in Europe a fifth of the labor force are in special schemes where the state pays their wages, but that presumably, cannot go on indefinitely. In NZ, after a week following lockdown, the jury is still out. People are working, but are they becoming wary?

In New Zealand, the State offered wage assistance to companies that had their income reduced by 30% due to the lockdown, which was a lot, but a number of companies, including the airlines, shed a lot of staff because it was obvious they were not going to operate at anywhere near their previous level. Airlines create a rather unusual situation: pilots rightly earn a lot of money, so would they be prepared to share work with another pilot, each at half-pay? The company keeps pilots on its books for when things improve, and most importantly for the pilots, they keep their minimum required flying hours up to date. That approach won’t work for low-paid workers. But then airlines may not have much work anyway. Here, there has to be social distancing. The passengers may at last get reasonable leg room (Yay!) but either ticket prices increase sharply or the airline realizes there is no point in losing money with half-full planes through social distancing.  The simplest way to raise ticket prices is to cut out the “specials”, so designed to fill aircraft. If the expensive ones with a small markup still sell, the airline may remain viable. So what should the pilots do? The question then comes down to predicting the future.

Herein lies the problem: most people will have choices, and those who more correctly accommodate themselves to whatever happens prosper. Those who make unfortunate choices, or worse, bad choices, will suffer. Governments also have choices, and they tend to be influenced by the next election, which in our case is this year. Propping up zombie companies is bad for the economy, but mass unemployment is bad for votes. What will happen? The pandemic will uncover some scabs in our society. Here, half of our deaths came from badly run rest homes. My guess is the biggest economic price will be paid by the poor, or the small business owner who is joining the poor. Furthermore, governments may still not be able to stem the downturn. In New Zealand, the Government announced a big spend-up in infrastructure, and shortly afterwards the biggest construction and civil engineering company shed 10% of its staff.

What happens to globalization? What most people do not realize is how interconnected the world economy is. As an example, Boeing assembles aircraft, but the parts come from a wide-ranging source. For a Rolls Royce motor, it too will depend on parts from a wide range of sources. If any of these sources break down because of the pandemic, there will be a problem. Equally, with a great reduction in international flights, maybe Boeing will stop buying when it can’t sell. Widespread unemployment could cascade out. Meanwhile, selected industries will clamour to their governments for bail-outs. There will be a cry for protectionism, without realizing how much “local” industry depends on elsewhere.The odd thing is, we now have a rather unique chance to shape the future. Can we do it sensibly? And what, really, is sensible? And how do you prevent the spoils, such as they are, going to the already super rich?

What to do with Waste Plastics

One of the great environmental problems of our time is waste plastics, and there are apparently huge volumes floating around in the oceans of the world. These would generally get there by people throwing them away, so in principle this problem is solved if we can stop that irresponsible attitude. I can already hear the, “Good luck with that,” response. Serious fines for offenders would help, as would more frequent proper rubbish disposal bins. But this raises the question, what should we do with waste plastics?

The first answer is it is unlikely there is a single answer because there are such a variety of plastics. Some, like polyester or polyethylene, can be reasonably easily recycled for low specification uses, but the problem here is there is a limit to how many plastic buckets, etc, can be sold. Technically, quite a high level of recycling can be achieved. Quite a while ago, during the first oil crisis, a client asked me to devise a means of recycling mixed coloured polyethylene so I devised a process that recovered a powder that could be used to make almost anything that virgin polyethylene could make, except maybe clear: there was always a slight beige colour from residual dyes etc that could not be got out, at least in a one-cycle process. Polyethylene degrades – you will all have seen it go brittle from sunlight. This shortens the chains and oxidizes parts and I was proud of this process because it got rid of all the degradation and short-chain material.

A pilot plant was built, then the process was abandoned.  The reason was the oil prices tumbled, and there was no way the process could make money, particularly since big multinationals appeared to be dumping polyethylene into New Zealand. Some manufacturers loved this, and were able to export all sorts of plastic things, at least for a while. Part of the reason the process would have lost money, of course, was that despite getting the raw material rather cheaply, the yield at the end was lower because of the loss of the degradation products, but the killer was getting rid of the degradation products. They could be burnt for process heat, but that would need a specially designed burner, and there would still be the pigment remains to be disposed of. Good idea, but could not compete with the oil industry.

Another possible process is pyrolysis. This came to my attention when I recently saw a paper in the latest copy of “Energy and Fuels” put out by the American Chemical Society. Polyethylene gives a mix of oil, gas and carbonaceous solid, but you can get almost 80% in the form of oil that could be directly used as a diesel fuel after distillation. There appear to be a fraction that boils too high for the diesel range, and gets waxy, but those who have recalled a recent post by me will see that it would do well in the heavier marine heavy fuel oil. The resultant oil has a mix of linear alkanes and terminal alkenes, and the fragmentation is such that the double bond prefers the smaller fragment. There is also some miscellaneous stuff resulting from the oxidative degradation. Polypropylene, however, showed a lot more oxygen, with a range of alcohols, esters and also acids in addition to highly branched hydrocarbons, however, almost 20% was the single compound 2,4-dimethyl-1-heptene. It would manage with the light ends as petrol, and the heavier ends contributing to diesel. 

Polystyrene gave what corresponds more to a heavy oil, although 40% was actually styrene, which could be used to make more polystyrene. Importantly, the cetane rating for the oil from polyethylene was 73; for polypropylene, 61. Polystyrene oil was unsuitable for diesel, but if hydrogenated, the lower boiling cut would make a high octane petrol. The average pump diesel fuel has a cetane rating of about 50, and the higher the rating, the faster the engines can go, so pyrolysis of waste polyethylene and waste polypropylene will make an excellent diesel fuel, with the heavy ends going towards shipping.  However, the heavy ends of polystyrene would have to be dumped because they contain fluorinated material, presumably a consequence of additives, and you certainly do not want an exhaust stream rich in hydrogen fluoride. And here is the curse that plagues anything involving recycling: too many companies put in additives that will be impossible to remove, and which either prevent proper recycling or will have consequences that are at best highly unpleasant, while they offer no option for dealing with them.

How do we separate these plastics out? Fragment them, and stir in water. Polyethylene and polypropylene are the two plastics that float. Foam, of course, has to be omitted. So, will this end up being done? My guess is, not in the immediate future. In terms of economics, it cannot beat the entrenched oil industry, unless governments decide that cleaning up the environment is worth the effort.

Puffy Planets

It is possible now with exoplanets to determine their mass, e.g. by measuring a wobble in the star’s motion due to the pull of the planet, and if the planet transits the star, you can measure its size because the light you see from the star starts to dim when the planet starts to transit, and the last of the dimming is when the other side emerges. You get a secondary measurement when it stops dimming at the bottom of the light graph, and starts brightening. You know the speed at which it crosses because you have measured its “year”, or orbital period. If you know its size and you know its mass, you can work out its density, which gives clues as to what it is made of.

Consider the following densities in g/cm cubed:  Earth 5.51, Mercury 5.43, Venus 5.24, Mars, 3.93, Neptune, 1.64, Uranus, 1.27, Jupiter, 1.33, Saturn, 0.69. What we get from that is that since rocks have densities between 2.5 – 3 for felsic rocks, and 3 – 4 for basalt, and iron has a density of about 7.8, Earth, Mercury and Venus all have significant iron cores, Mars will have only a small one at best, and the other planets have a lot of gas. However, they have to have cores. The usual theory of planetary formation is that the planet starts with a core, it grows, and when it gets big enough it starts to attract gas. The cores in the outer solar system will comprise ices and silicates, while in the rocky planet zone, because the accretion disk is hotter, the ice has vaporized so we are restricted to rocks. If a rocky planet gets big enough that its gravity can hold gas, it too can become a giant. That is the theory, anyway. Our assessment of Neptune is that while the core is icy, it will also have silicates, and it took it until about 10 earth masses before it started accreting gas rapidly. Uranus would be similar, but the reason it is less dense is, at least in my interpretation, because as the disk gets denser the closer to the star, once it started accreting gas it could do so faster than Neptune could. Accordingly, since they are the same size, Neptune had to grow more core, and in my opinion, that was due to the mechanism of core formation. However, that is not relevant here. As you can see, the lowest density is Saturn, because it is full of hydrogen and helium. Jupiter is denser because, in my opinion, it accreted gas faster and the heat boiled off a lot of hydrogen and helium, which is why it has about three times the amount of gases such as nitrogen compared with hydrogen as the sun, and, of course, the stronger gravity compresses gas better. (The sun was also much hotter, but it has far more gravity.)

There is another theory of planetary formation, where the gas disk becomes unstable and collapses. This may well occur, but it usually is considered to work a long way from the star. One reason is, unless the two instabilities occur at the same time, when you get a double star, if the planetary material is orbiting the star, the closer it is to the star the orbital speeds are different at different distances and the instability would shear. Planets have to be reasonably close to the star to get a transit recorded frequently enough.

Anyway, puffy planets. If we look at Kepler 87 c, it is a planet close to a star the size of the sun and towards the end of its life in the main sequence. It is about as far away as Venus and about 6.4 times Earth’s mass, so it is not expected to be able to hold big atmospheres, yet its density is 0.152 g/cm cubed. The planet HIP 41378 f is an even worse problem. It has a mass very similar to Uranus, the star is 1.15 the size of the sun, and the planet is about 1.37 times further from the star than Earth is from the sun. Interestingly, if it had a big enough satellite, that’s satellite would be in the habitable zone.  However, the planet is definitely weird: its density is approximately 0.09 g/cm cubed. That qualifies as a super-puff. There are a number of planets with densities less than 0.3 g/cm cubed, so for whatever reason, they are not freaks.

The question now is, how could a planet have such a low density? I suppose observational error cannot be entirely ruled out, but I think it should be. If there were just one, maybe we could be skeptical, but that many? The next possibility might be they are still accreting, but Kepler 87 c cannot be accommodated by that explanation because the star is so old. Further, if a giant is accreting gas, it gets very hot (we have seen these in newly forming planets) and these super-puffs are cold. Another guess might be that for some reason the atmosphere is extended far beyond what is expected. There are two reasons why this won’t be right. The first is gravity. If the planet is a giant, its gravity is strong enough to suck the gas in close. If there were more gas the planet would grab it. The second is light would get through and we would expect a spectral change during the eclipse, but we don’t see that.

So, what is the explanation? A recent proposal, and one that I think looks good, is that what we are seeing is a planet with rings, like Saturn. The rings have to be dense enough to block off quite a bit of the light passing through them, but what we are seeing is something similar to what Galileo thought Saturn was. If HIP 42378 f  had rings going out to 2.6 times the planetary radius, its density would be 1.23 g/cm cubed, very similar to Uranus. Now, if we go back to the habitable moon, maybe that is not so silly after all. Why do rings form? One possibility is that some gigantic collision caused a lot of fragments, and some of them came in within the Roche limit, and fragmented. The Saturnian system is consistent with this – a lot of small moons, including some at Lagrange points of larger ones, and one anomalously very large moon. And as an aside, an alien using these sort of measurements would conclude Saturn was an exceptional super-puff.