Monday, October 10, 2011

From 0 to the speed of light in a nanosecond

So we learned recently that some neutrinos at CERN seem to have travelled faster than the speed of light and that's a bit alarming. We may have to rewrite Einstein's theories and so on.

Some things, in theory, can travel faster, but they cannot carry information, which the neutrinos in question certainly do.

A few explanations come readily to mind and the researchers who reported the results do favour one of them: that there is a systemic reason for the apparent speed of the particles. Note that it is not an explanation to say that they may be different particles, because that is equally impossible.

One problem in quantum physics that remains without a decent explanation is quantum entanglement. Basically, pairs of particles are "entangled" so that each has a quality that is a polar opposite to the other's. It's easiest to understand by saying that if one is spinning clockwise, the other must be spinning anticlockwise. (This is close enough to the truth for our purposes.) What you need to recognise here is that until measured, we cannot say which way each is spinning. It's possible to separate the particles and then measure the polarity of one. This immediately fixes the polarity of the other. It's as though one particle lets the other know what its state is.

My understanding is that string theory explains this by suggesting that the particles are connected in a way that is not apparent to us because there are many more physical dimensions than we can perceive. As far as I know, the belief is that there is a sense in which everything is in the same place at the same time.

Which is kind of cool.

Does it explain the neutrinos? Probably not. They probably just fucked up the measurements.

Could Einstein have been wrong? Well, on a macro scale, he's been shown to be right to a very precise degree. But at very small scales, it's proved to be very difficult to make quantum physics and relativity play nicely together. Scientists have worked for decades now on trying to unify the two theories. It's possible that one is "wrong". I say "wrong" because it may be that "incomplete" is the better word.

Personally, I doubt our current cosmology is even close to correct, and I have strong doubts that string theory really does describe reality. IDK enough maths to get to the truth of it, but as I've noted in previous posts, it must not be forgotten that mathematicians and physicists build models that they hope will coincide with reality, not descriptions of reality itself.