## Friday, June 15, 2018

### Hooper: we need to contain, catch stars outside the Local Group

Many physicists are getting "broader" if not "distracted". Edward Witten wrote a nice 38-page-long introduction to information theory. The reason isn't quite clear but maybe he wants to be sure he's an expert in these matters – I had absolutely no doubts he was one – and the best way to learn is to teach.

Mistele, Price, and Hossenfelder use a neural network, quite a complex software, to find a shocking conclusion: if a paper or a physicist looked good so far, he or it will probably look pretty good in the following year, too. While Hossenfelder implicitly wants to frame this finding as some suspicious news about physics, the predictability is clearly a net positive. The fame of physicists and papers isn't changing by random criteria, at random moments, and fashions. Physics actually has some hard content that may be identified and whose value doesn't go away fast. Of course a good neural network may catch patterns that distinguish good papers from others. What's bad is that most people don't want to learn any of the things that even a neural network can do pretty well.

What is happening at the Fermilab? The U.S. facility no longer competed in the first discovery of the Higgs boson. In the recent decades, what were the top Fermilab theorists up to? One of them, Dan Hooper, gave us an amusing answer yesterday (a diagram of the project was embedded as a picture above):
Life Versus Dark Energy: How An Advanced Civilization Could Resist the Accelerating Expansion of the Universe
Looking for the basic laws of Nature and their beauty is no longer fashionable among most taxpayers. So the Fermilab is thinking about the urgent problems that face the mankind. The most urgent problem, Dan Hooper points out, is that due to the cosmological constant, all the stars outside our Local Group (of 54+ galaxies including ours) will accelerate outwards and cross our cosmic horizon and will therefore become forever inaccessible.

That's very bad because once we run out of fossil fuels and the thermonuclear energy in all the stars of the Local Group, and it will be around 100 billion years after Jesus Christ talked to a fig tree, we will need the energy from additional stars – but they will be gone.

So that's pretty bad. Fortunately, Dan Hooper has a solution, too.

Hooper urges us to build giant Dyson Spheres or similar structures around the stars that plan to escape from our visible patch. The energy collected by these Dyson Spheres should be used to accelerate the escaping stars towards us so that they don't escape, after all – or they escape much later than otherwise predicted.

Elon Musk is expected to collect funds from the investors (about one trigintillion is needed to start with) for his new company that will catch all the stars, once he reinvents and names this new infrastructure. Sources indicate that the new spheres to catch the stars outside the Local Group will be called Hooperlips and the company will be reunited with its Hyperloops siblings.

Hooper doesn't seem to mind that his great invention may be stolen. In fact, he is placing it to the public domain so that everyone – including wealthier, extraterrestrial civilizations that follow his papers on arXiv.org – will be able to build these spheres and catch the naughty stars into their Hooperlips. He actually predicts that these aliens will really love his paper and turn it into reality.

It's funny and I think it's just fine when very decent particle physicists think about these matters. There are some risks, however. A problem is that most of Hooper's expertise – his main comparative advantage – is arguably unused in these matters. His paper may be more visible because he's Hooper (and similar claims and proposals by Musk are more visible because he's Musk – well, Musk is much more famous than Hooper and the reason is called the money). But there exist no good reasons to think that he's a real "exceptional expert" in catching the naughty stars.

Lots of kids or engineers or otherwise ordinary people could have written similar papers – and they could ultimately be more clever than Hooper's. So my point is that there exist certain limits of everyone's expertise. He may be expected to be much better in things that are close enough to the field where he was trained or proven to be better than most. On the other hand, this comparative advantage fades away in sufficiently different questions.

On top of that, I think that the thinking about the ways to catch the stars outside the Local Group is way too optimistic. If other civilizations evolve similarly to ours, I am not too optimistic. In a few centuries, we're more likely to deal with Brawndo that kills the crops, rather than with the containment of the stars. If the IQ of the folks decreases by one point every 3 years, it will be some minus 33 billion in the year 100 billion AD. And the IQ equal to minus 33 billion makes one rather stupid, to put it gigamildly.

Dreams are easy but projects such as the containment of stars would also need some real work by a very big civilization - and the civilization would have to rise tremendously to start with. Given the clear slowdown of many kinds of the technological progress and the reversal of processes such as the Flynn effect, and given the strengthening of anti-industrial, anti-human, and Luddite movements that have some psychological problems with the GDP growth and progress, should we think that we're still going in the right direction? Can any civilization get much further than where we are today at all?

And even if the rough estimate is right and our civilization (or others) will grow enough to meaningfully occupy other celestial bodies, I simply don't believe that it will be obsessed with maximizing the reach in this way – with harnessing the energy from all stars that were once visible. At the end, people or similar creatures act in order to maximize their utility function or happiness, and that's something different than maximizing the total energy they extract from the stars. So Hooper's picture seems to assume some kind of naive, communist-style economy in which the prosperity was measured by millions of tons of coal or steel. Prosperity – and the dollars – aren't really equivalent to joules or tons of steel.

You know, the identification of the raw materials with the "wealth" is a Marxist illness. Similarly, the crackpot Marx's theory of value tries to quantify the value of products as the amount of suffering by a worker that came into the production. But while there might be correlations, these quantities aren't the same. Value is something that quantifies how much a person or people like something or want to own something, relatively to how much is available. Energy, coal, or steel are useful but they're not the ultimate goals of anybody. They are just tools to achieve other things that matter. And they may become less important if the industry switches to another commodity or becomes more energy-efficient.

So I am pretty sure that the energy of the stars and material in the Local Group will be just enough for every terrestrial or extraterrestrial "actual manager" in the following 100 billion years. ;-)