Monday, September 26, 2011

Relativity and how we do science: Some first thoughts.

Last Friday, I heard the tail end of a news item indicating that scientists had observed particles travelling faster than light.  This refutes Einstein’s theory of special relativity, and is not the first time that one or other piece of scientific work has come out punching holes in this classic reformulation of how the universe works.  The last time I read such claims it was Al Kelly, who published something in an Irish engineering journal, and the time before that I think it was someone who had two box shaped areas deep underground in Greenland where it was predicted to fail for about three milliseconds twice a year.
As someone claiming to be a scientist, we are used to such things, and treat them with the same sense of intelligent enquiry with which we approach a stage magician. We look carefully and try to work out what the trick is.
This is part of our natural defences. Our belief in science builds in filters which allow to concentrate on the significant changes which move theory forward and filer out all the noise of magnets purifying water, anti gravity and alien visitations.
Later that morning I heard that it was scientist from CERN, and that they had seen something like 15,000 such particles.
This moves it from being a silly season story to something that needs more attention.  I now started chasing up more information, read the preprint and noted that the author list seemed to have around 100 scientists, who are operating within their field, and all of whom have a lot to lose if they have got this wrong. (Scientists are classily good at getting things wrong once they get away from their speciality, Pons and Fleischmann and Pauling on mega doses of vitamin C being examples of this.) I go back and chase up what I know of superluminal activity. Cherenkoff radiation happens when particles exceed the speed of light in a medium, Loci i.e. non material things such as the point where a rotating light beam hits a wall if far enough away from it, or the scan point of the electron beam hitting an oscilloscope screen can travel faster than the speed of light too. And there is a whole theory of faster than light particles, Tachyons, which come out of second solution set to the equations, and which can be imagined as slowing down as you add energy to them.
I’m not going to comment on the truth or otherwise of the claims. My physics is not sharp enough to punch holes in the paper as presented. What interests me is how I evaluate the claims.  My initial reaction was a time worn and healthy scientific scepticism.
When the evidence was re presented with a powerful ad hominum argument (CERN) I then go to evaluate the argument on its internal consistency by examining the paper, and look to my network of knowledge to see where this new piece of evidence fits in.
This is, I think, how most of us do science.

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