The Anthropic Principle (Again)

Apparently Ed Witten has abandoned all rational thought about the fundamentals of the Universe and embraced a version of gasp! the Anthropic Principle. At least that's how Peter Woit sees it.

The Anthropic Principle is an answer to the question why are the fundamental laws of physics, and the values of electron mass, charge and the other fundamental constants, so nicely tuned to make it possible for human life to appear?.

The Anthropic Principle says, very crudely, that if they weren't, we wouldn't be here. To stop that being a tautology, it is taken to mean that the values of the physical constants are not compulsory. There are many values the fundamental constants could take, and most of them lead to a Universe that would be hostile to human life. We might be able to show more, which is that a Universe that started off with one or more fundamental constants that were very different would somehow never really get started: it might never cool down enough to become transparent, or it might fly apart because the force of gravity was too weak... there are all sorts of reasons. This would show is that if the Universe was stable at all, it would have to be life-friendly.

The Non-Anthropists want the Laws of Physics to be such that only Universes fit for human life can and must form. and only those Universes.

There are seventeen or so fundamental parameters in the Standard Model, and none can be derived from any of the others. The Non-Anthropists are claiming there is a set of as yet unknown Laws of Nature / Fields / Particles, without any arbitrary numerical parameters, that in turn determine the fundamental parameters of the Standard Model. After decades of work by some of the smartest people ever to walk the planet, we are nowhere near such a theory.

Suppose we did find such a set of fundamental-constant-determining laws. Would this answer the Non-Anthropists' question?

It might. But some ten-year-old would perk up and ask: why those laws? Why not others? .

The infinite regress of ten-year old's questions.

So there has to be a point at which we say "ENOUGH" about explanation, even in physics. I can safely say that any phenomenon that requires 10,000 engineers, a 13 TeV, 27-km accelerator, plus hundreds of hours of statistical analysis to find, will not be used by any medical equipment manufacturer. Or anyone else. For all practical purposes, the Dirac equation and its associated particles are "ENOUGH".

This is really the Non-Anthropists's problem. They want mo' research: to abandon smashing ever-higher energy beams of hadrons and finding no "new physics" year after year would be some kind of abandonment of the Human Project. Like not subsidising contemporary composers whose music is read more than it is performed. (Apparently actually performing one's work is passe. The Kool Kids pass around their latest compositions as MIDI files by e-mail.)

Hope springs eternal in the Non-Anthropists' breast. Next year someone may discover the Missing Laws / Fields / Particles.

I'm not saying they aren't there to be found. I don't know.

I am saying that, if we did find them, it would not help us reduce our carbon emissions, or whatever Liberal causes Non-Anthropists espouse. It would not cure cancer, or create a universal vaccine.

I guess I'm saying we know ENOUGH fundamental physics to work on all the other problems we need to solve.