Experiments and logic

At the moment the OPERA faster than light (FTL) result is far too uncertain to be trusted, and needs replication, but, in an article just published in New Scientist [1] (see below) R. Garisto argues that: "models which explain [the FTL] by breaking relativity are ruled out". He says he knows this because a recent paper by Cohen and Glashow [2] proposed that a neutrino going faster than light "may lose energy rapidly by bremsstrahlung", and the OPERA neutrinos did not, so they cannot have travelled FTL. Surely there is an error in logic here, since Garisto is effectively saying: you cannot violate standard physics unless you do it using standard physics.

Travelling faster than light violates standard physics in about the biggest way possible, and it is wrong to reject theories that explain experimental results (as Garisto says he has) by saying that they violate standard physics. Such an attitude would doom fundamental physics to an endless sterility. In physics, experiment (even if later shown to be flawed) must come first. If the OPERA result is supported experimentally, then standard physics is going to have to mumble sheepish apologies, and new physics will be needed. My point here is not that I think the OPERA result is necessarily correct, but rather that, in cases like this, objective logic should be applied, rather than a blind faith in standard physics.

[1] http://www.newscientist.com/article/dn21515-lights-speed-limit-is-safe-for-now.html
[2] http://prl.aps.org/abstract/PRL/v107/i18/e181803

Underlying randomness

One of the courses I teach is climatology, and I try to emphasise both the observations and the maths and theory. In climatology there are a lot of simple balances. For example (to simplify): in the north Atlantic the wind pushes the water up into a wide bump centred on the Azores and the ocean currents flow clockwise around this bump producing Coriolis forces inwards that balance the pressure-gradient forces outwards. This produces a simple circular pattern (in geostrophic balance). I think this illustrates an interesting point: systems, like the ocean, jiggle around randomly, until one day, by chance, they find a balance, and it is the nature of balances, once set up, to remain, since they are stable. By the time we get around to observing it, and for most of the time, this simple balance is what we see. I guess this also applies to the rest of physics and is behind the simplicity and predictability of what we see in the world, but the crazy underlying randomness is always there, ready to return.

Wide binaries

There has been a great observational study done recently by Hernandez et al. (see: http://arxiv.org/abs/1105.1873). They have looked at wide binary stars and found that when they are separated by 7000AU or more, so that their accelerations decrease below 2*10^-10 m/s^2, then their behaviour becomes non-Newtonian, in that their orbital speeds are so large that the centrifugal (inertial) forces separating them should be greater than the gravitational pull inwards from the mass that we can see, so they should zoom off to infinity. A similar behaviour is seen in galaxy rotation curves, which deviate from Newtonian behaviour below this same acceleration. For these simple binary systems, it is hard to see how dark matter (DM) could kick in at a particular acceleration, and Newton and MoND both predict only about 1/10th of the orbital speeds seen. This provides a experimentum crucis, and so I have recently been testing MiHsC on these data: because of their low acceleration, MiHsC predicts a decrease in the stars’ inertial masses so they manage to orbit each other at the faster speed without inertia separating them. The orbital speed predicted by MiHsC is still only 1/2 of that seen, but this is much better than the 1/10th from Newtonian dynamics and MoND. I have just today submitted an abstract on this to the UK’s National Astronomy Meeting (NAM 2012).