Thursday, September 18, 2008

Will it be a disaster for physics if the Higgs boson is the ONLY thing the Large Hadron Collider finds?

Physicist Stephen Barr, author of Student's Guide to Natural Science, thinks so. At First Things's On the Square, he writes,
Some people say that the LHC will discover something called the Higgs particle. It almost surely will, but if that is all it discovers, it will be a huge disappointment and in fact a disaster for physics. It is (almost) certain that the Higgs particle is there. That in itself is no big deal.
But here's the big deal:
What people really are hoping to see at the LHC is evidence of these new kinds of matter predicted by supersymmetry. Until recently, most theorists probably thought that the chances were much greater than 50 percent that the supersymmetry solution of the Higgs problem is correct, and that evidence for it would be seen at the LHC. Some doubts are creeping in, however.

First of all, theories based on the supersymmetry idea are not without serious difficulties. But what has made the doubts increase in many physicist’s minds recently (including many top physicists) is the possibility that the Higgs puzzle may be explained anthropically rather than by supersymmetry. If we live in a multiverse, it is possible that, in different places in the multiverse, the Higgs field has different strengths. In most places it might have its natural strength. But in rare places it may happen to have the much smaller value that it has where we are. And—it can be argued convincingly—only in those rare places can there be life. We see a strangely small value of the Higgs field, because we are living in a highly atypical part of the multiverse, namely a part where the Higgs field has a value that allows life to exist.

By "multiverse", I gather that Barr does not mean "many universes" but rather that in our universe, conditions may be very different in one region than in another.

Most scientists have assumed that the universe is much the same everywhere, but that is an assumption, not a finding.

If indeed, the conditions in our region might be specialized to allow life, I suppose that would be another instance of fine tuning of the universe for life.

See also: From the "missing the point" diaries: Anthropic topic? Or anthropic flopic?