Don’t tear up your physics books just yet

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Rationalbrain is finally back in Oz, having done six weeks of skeptical inquiry in Europe. Oh, and I had a damn fine time, too.

To those few readers left after my recent jibe at iPad users, let me urge you not to be concerned at the recent news report, describing an experiment in which some sub-atomic particles known as neutrinos were allegedly detected exceeding the speed of light.

In case you think this is no big deal, if verified, this would be a HUGE deal. It would mean that one of our fundamental physical laws, that nothing can exceed the speed of light, would be violated, resulting in all sorts of mayhem. Apart from anything else it would mean that effects could precede causes, which would be a real nuisance.

In due course it would result in the possibility of us being able to travel in time, meaning, amongst other things, one fewer themes for sci-fi writers to use. Just think of it: Dr Who and half the Star Trek episodes and films ever made would be so yesterday.

But seriously, this whole faster-than-light result is an excellent example of the way science works, or at least, should work, and it demonstrates the importance of transparency in research. In particular, it shows how science is self-correcting.

In this case, some researchers obtained experimental results that particles could travel faster than light, which had the potential to overturn our well-established understanding of the physical world. They did this by measuring the transit time of these particles as they travel from one point on the Earth to another, over around 730 km.

On rechecking their results, they then published the experiments, inviting the science world to challenge the findings – as if to say: “hey guys, here’s some amazing findings, we can’t find any errors in our experiment, can you?” One of the team involved said:

“My dream would be that another, independent experiment finds the same thing – then I would be relieved. But for now we are not claiming things, we want just to be helped by the community in understanding our crazy result – because it is crazy”.

Sure enough after a s**tload of chatter over the interwebs on the subject, the mystery seems to have been solved, and the excess speed accounted for. In short, the timing was actually done using GPS satellites. The team made the error of assuming that the clocks were effectively on the ground, rather than aboard satellites way overhead. If the clock is overhead, then there’s all sorts of relativistic effects to account for. According to Einstein’s theory of relativity, when observers are in different ‘frames of reference’, then their perceptions of time and distance are different. In this case, the satellites and the experimental setup are definitely in different frames. Once the calculations were done, the experimental error was accurately identified. Yay.

The great irony here is that this result originally had the potential to overturn Einstein’s general theory of relativity – but in the end, it was the theory that explained the discrepancy, hence the experiment simply provided another confirmation of the theory. Here’s a nice summary of the story.

So, the moral of the story, to once again paraphrase Carl Sagan, is that extraordinary claims require extraordinary evidence.

If only the purveyors of bogus remedies, who claim that their remedy operates ‘outside the laws of physics’, would subject their claims to as much scrutiny.

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