Friday, October 7, 2011

An Ugly Little Fact

 
The great tragedy of science—the slaying of a beautiful hypothesis by an ugly fact.

attributed to Thomas Henry Huxley (1825 - 1895)
A group of scientists from Italy and Switzerland have reported that neutrinos can travel a bit faster than the speed of light [Measurement of the neutrino velocity with the OPERA detector in the CNGS beam]. If true, it will change our understanding of general relativity.

So how do the knowledgeable scientists deal with this ugly little fact"? Are they ready to abandon general relativity? No, they aren't. The typical response is skepticism combined with a "wait and see" attitude while the result is confirmed. Chad Orzel of Uncertain Principles has a nice analysis of the experiment: Faster Than a Speeding Photon: "Measurement of the neutrino velocity with the OPERA detector in the CNGS beam". Chad concludes with,
So, if you had money to bet on it, bet that this result is wrong. But these guys aren't complete chumps, and if something is wrong with their experiment, it's something pretty subtle, because they've checked all the obvious problem areas carefully.
Victor Stenger expresses similar skepticism in an article published on Huff Post [No Cause to Dispute Einstein].
As someone who worked in neutrino physics for thirty years before retiring from research in 2000, I should be more excited than most by the report from CERN that neutrinos have been observed moving faster than light. And I am. The experiment looks very well done and the scientists involved are saying all the right things -- that their result is very preliminary and must be independently replicated before accepting it as scientific fact. If the observation is confirmed, it may be the most important discovery in science in the last 100 years.

However, a big fly in the ointment is the supernova in the Large Magellanic Cloud, which sits just outside our galaxy 168,000 light-years from Earth. It was first seen by the naked eye on February 24, 1987. Three hours before the visible light reached Earth, a handful of neutrinos were detected in three independent underground detectors. If the CERN result is correct, they should have arrived in 1982. So, if I were a wagering man, I would bet the effect will go away because of some systematic error no one has yet been able to think of.
These responses are typical. Instead of immediately rewriting the textbooks in light of a new discovery, scientists initially express skepticism of results that conflict with well-established models. They do this because history has convinced them that most of those discoveries will never be confirmed and the standard model remains intact. [See alos Sean Carroll: Can Neutrinos Kill Their Own Grandfathers?]

Thomas Huxley was wrong. That's not how science works.

Read more »

No comments:

Post a Comment