Tuesday, November 3, 2015

Gimme Predictions!

A question physicists always ask when someone pitches a new theory to them is, “What are some testable predictions of your theory?” If a theory doesn’t make testable predictions, they reject it immediately, unless it’s one of their own pet theories, such as string theory or the multiverse, both of which don’t make any predictions at all but are strongly supported anyway. Go figure. Anyhow, what are some predictions of the spacetime model featured in this blog?

In a sense, one could say that the model “predicts” all the phenomenology of the standard models of particle physics and cosmology, since everything is there in the model. A specific prediction confirmed in 2012 is the mass of the Higgs boson. The Higgs field is not a particle field, but it does fluctuate around its vacuum expectation value, and these fluctuations are seen as Higgs bosons. The model’s prediction is that the Higgs boson mass will be around 120 GeV, actually a little higher because this value is based on an approximation that lowers the result. The LHC experiments have recently confirmed that the Higgs boson mass is approximately 125 GeV. I’m happy with this agreement within 4%. 

A prediction of the model still to be confirmed (or not) is the composition of the dark matter around galaxies. In the inflaton spacetime model, dark matter is a remnant of inflation. The conversion of inflaton energy to particles at the end of inflation is less than 100% efficient. The energy that remains is dark matter.

There are other phenomena in the model that can be considered predictions because I didn’t put them into the model, but instead discovered them there. Two good examples concern neutrinos. In the model’s discrete spacetime, neutrinos behave very peculiarly. They oscillate between a velocity slightly above the speed of light and one slightly below it. When traveling faster than the speed of light they are righthanded and have imaginary mass. When traveling slower than c, they are lefthanded and have real mass. I was trying to think of a way to fix this peculiarity when I realized that in the tachyonic phase, a neutrino could not be turned into an electron by an SU(2) rotation. Therefore, lefthanded electrons would have neutrino partners but righthanded electrons would not. As far as anybody could tell, there would be no righthanded neutrinos. That is just what is observed! So the model predicted that nature is chiral without anyone’s even looking for it! Later, when neutrino oscillations were confirmed experimentally, I went looking for a way to incorporate them into the model. To my surprise, I found that the requirements for neutrino oscillations—neutrino mass differences and different mass and flavor eigenstates—were already there in the model. I think it is a mark of a good model when it tells you things you weren’t even looking for.

The model allows you to calculate the mass of the electron very simply, something that even the standard model doesn’t do. That’s a prediction that’s already confirmed. In principle, you can also calculate the value of the cosmological constant, but I haven’t done it because it seems to require a supercomputer and a programming wizard, both of which are beyond me. However, a rough estimate can be obtained rather easily, and I have done that here.

There are other interesting predictions about the structure of hadrons and the second- and third-generation leptons. Electrons are resonances of points. Hadrons are resonances of superpositions of points. Points are, after all, quantum states, so a superposition of several of them is another point, quantum mechanically. Thus, hadrons are point particles! Muons and tau particles are superpositions, too, and therefore composite particles. These predictions need to be confirmed, and I confess I’m not sure at this point how to do that, although there’s no reason to think it can’t be done..

In short, the model makes lots of correct predictions, including some that no other model makes, and there’s lots of work for the future.