Ruminations on multiverses; Another view (Introduction)

by David Turell , Saturday, October 29, 2016, 06:41 (2729 days ago) @ David Turell

The LHC has found the Higgs, but is size is too small for the expectations in the standard model. It is considered 'unnatural' which means it doesn't really fit. All the values of particles are unexplained. They just are. As a result any opening to new physics which might support the idea of a multiverse does not exist:

http://www.forbes.com/sites/startswithabang/2016/10/25/no-the-lhc-hasnt-shown-that-we-l...

If you believe Scientific American then “New Physics Complications Lend Support to Multiverse Hypothesis.” From Vox you can learn that “If the LHC can’t find answers to questions like ‘why is the Higgs so light?’ scientists might grow to accept a more out-of-the-box idea: the multiverse.” And according to Business Insider, “If supersymmetry is wrong, [it would] lend more credence to other theories, like the idea that we live in a multiverse.”

The multiverse – a conjectured endless collection of universes – was once the realm of science fiction, but now it’s science. Physicists have conjectured that the laws of nature in each of the universes would be slightly different, and the possibilities are limitless. In some universes electrons would be much heavier than they are in ours, or atoms would decay faster, or gravity would be much stronger. Really anything could happen.

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Many of the other universes, however, would not contain living beings, because not every combination of natural possibilities for the laws of physics allows for sufficiently complex structures to form. A universe that expands too fast, for example, or that recollapses too quickly, would contain merely a well-mixed soup of elementary particles which, for all we know, wouldn’t write essays.
So some physicists think that their models for the early universe demonstrate there wouldn’t be only one universe but infinitely many. Ok then, you might say, weird enough, but what does this have to do with the LHC?

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The standard model contains many parameters for which they have no deeper explanation, and they are hoping that there exists an underlying – more fundamental – theory from which the parameters can be calculated.

A parameter that irks theoretical physicists particularly is the mass of the recently discovered Higgs-boson. It comes out to be about 125 GeV. That value is somewhat more than 100 times the mass of a proton and, on its own, sounds pretty unremarkable. But the Higgs-boson is a special particle in that it’s the only known (fundamental) scalar, which means it has spin zero. As a consequence of this, the mass of the Higgs-boson acquires correction terms from quantum fluctuations, and these correction terms are very large – larger than the observed value by almost 15 orders of magnitude.

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You need two constants that are equal for the first 15 digits and then differ in the 16th. If you’d pick two random numbers this would be extremely unlikely. It seems hand-selected and hence in need of explanation.

For this reason, physicists say that the small mass of the Higgs-boson is “not natural.”

The Higgs mass is the only parameter in the standard model which is not natural. Physicists understood this long before the Higgs itself was discovered, and for this reason many of them believed that the LHC would also find evidence for new physics besides the Higgs. The new physics, so they thought, was necessary to explain the smallness of the Higgs mass and thereby make it natural.

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The way things went, however, the LHC found the Higgs but no evidence for anything new besides that. No supersymmetry, no extra-dimensions, no black holes, no fourth generation, nothing. This means that the Higgs-mass just sits there, boldly unnatural.

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Since theoretical physicists haven’t found an explanation for the smallness of the Higgs-mass, they now try to accept that there simply may be no explanation. And if there is no explanation, so the argument goes, then no single value is special, and this must mean that all possible mass values have the same right to existence. In this case there should be a universe for any possible value of the Higgs mass. And for any possible value of every other particle’s mass. In other words, there should be a multiverse which contains universes for all possible combinations of parameters.

So, in a nutshell, the argument is that since theoretical physicists can’t explain the mass of the Higgs, any parameter can take on any possible value and we live in a multiverse.

It’s an interesting argument but it’s logically inconsistent. It relies on an expectation about what we mean by a “random number” or its probability distribution, respectively. There are infinitely many such distributions. The requirement that the numbers in the standard model should obey a certain distribution is merely a hypothesis that turned out to be incompatible with observation.

That, really, is all we can conclude from the data: physicists had a hypothesis for what is “natural.” It turned out to be wrong.
This doesn’t mean there is no multiverse. There might or might not be one. It just means the LHC results don’t tell us anything about it.

Comment: No proof, only conjecture. conjured up to deny fine tuning suggests God.