Physics of interest

I wonder how many readers are actually interested in my posts pointing towards odd physics papers that I usually don't fully understand myself.  Who knows, but here's some examples of recent physics stories I liked for their novelty:

*  Great title here: Can the Higgs Boson Save Us From the Menace of the Boltzmann Brains?

I can't be the only person who thinks of the Futurama episodes with giant floating brains whenever I hear "Boltzmann Brains", can I?

In any event, the paper notes that one of the simplest present explanations for the universe carries with it a serious "Boltzmann Brain" issue, and asks whether there is a way around it.   The answer seems to be:  maybe.   Here's co-author Sean Carroll giving an easier to read explanation of the paper.   I should have read that first.

*  The Economist, of all places, notes a paper that argues that dark energy, causing an acceleration in the expansion of the universe, does not exist at all.  Instead, the universe is just getting heavier:

In Dr Wetterich’s picture of the cosmos the redshift others attribute to expansion is, rather, the result of the universe putting on weight. If atoms weighed less in the past, he reasons, the light they emitted then would, in keeping with the laws of quantum mechanics, have been less energetic than the light they emit now. Since less energetic light has a longer wavelength, astronomers looking at it today would perceive it to be redshifted.

At first blush this sounds nuts. The idea that mass is constant is drilled into every budding high-school physicist. Abandoning it would hurt. But in exchange, Dr Wetterich’s proposal deals neatly with a big niggle in the Big Bang theory, namely coping with the point of infinite density at the beginning, called a singularity, which orthodox theories cannot explain.

Dr Wetterich’s model does not—yet—explain the shifts in the shapes of galactic clusters that the Dark Energy Camera, SuMIRe and ACTPol are seeking to clarify. But perhaps, one day, it could. Dr Wetterich is a well-respected physicist and his maths are not obviously wrong. Moreover, his theory does allow for a short period of rapid expansion, known as inflation, whose traces have already been seen in the CMB. Dr Wetterich, however, thinks this inflation did not happen just after the beginning of the universe (the consensus view), for he believes the universe had no beginning. Instead, a small static universe which had always existed turned into a large static one that always will exist—getting heavier and heavier as it does so. There was thus no singularity.

Probably, this theory is wrong. As Cliff Burgess of Perimeter Institute, a Canadian theoretical-physics centre, puts it, “The dark energy business very easily degenerates into something like a crowd of people who are each claiming to be Napoleon while asserting that all the other pretenders are clearly nutty.”

 I like to think that God has given us a direct clue to this, by ensuring that from middle age, a mass increase takes place in nearly all human bodies for no obvious reason.   So goes the universe too, possibly.

*   Someone from CERN complains that the LHC has not come up with any significant surprises for the Standard Model of physics, which is very annoying for physicists.  Here's the abstract:

The first three years of the LHC experiments at CERN have ended with "the nightmare scenario": all tests, confirm the Standard Model of Particles so well that theorists must search for new physics without any experimental guidance. The supersymmetric theories, a privileged candidate for new physics are nearly excluded. As a potential escape from the crisis, we propose thinking about a series of astonishing relations suggesting fundamental interconnections between the quantum world and the large scale Universe. It seems reasonable that, for instance, the equation relating a quark-antiquark pair with the fundamental physical constants and cosmological parameters must be a sign of new physics. One of the intriguing possibilities is interpreting our relations as a signature of the quantum vacuum containing the virtual gravitational dipoles.

 As with many papers on arXiv, you should read the introduction, which paints a comprehensible summary of the problem before venturing into scores of equations and terminology which are hard to follow.

*  Someone (I have no idea who)  from Hungary seems to think he has found a way that you can get Einstein's results without Einstein-ian physics.  The paper has a charming title:  A simple minded question: Do we live in the four-dimensional spacetime? and starts in a very modest fashion: 

The author of the present paper is not sure that the following ideas are worth for publication or they are more similar to a somewhat lunatic conception.

 I don't really follow the argument at all, but have only looked at the paper quickly.  Still, if this is ground breaking new physics, you read it here first.

*  If you are interested in the "fine tuning of the universe" issue, Catalyst on the ABC had a pretty good 30 minute summary last week, which features some short interviews from some of the big names in physics.   There are the more extended interviews with them here, I think, although I haven't watched them yet.

I saw from the show that Paul Davies, who moved from Adelaide University to Arizonia State University (he seems to showing greater affinity for "dry and remote" as he ages) finds a sort of backwards causation causation appealing, although I don't really understand the mechanism he thinks might work.  As Frank Tipler's similar idea, that the future God causes the past, seems to have sunk under the experimental finding of the mass of the Higgs boson, I should look up what Davies is saying on the topic.