For the first regular non-podcast-announcement post in awhile*, I just came across this Wired.com article: “ It’s Official: Neutrinos Can’t Beat Speed of Light.” While I doubt this will get much play in most main media outlets, I’m sure it will be talked quite a lot about on science blogs and podcasts. Instead of talking about the results (beyond summarizing them), I’m going to talk about the process here and how, in my opinion, the scientists involved did NOT do the wrong thing.
Pons and Fleischmann and Science by Press Release
Pons’ and Fleischmann’s names will forever live in infamy for doing science by press release. In 1989, they held a press conference where they claimed they had succeeded in cold fusion (fusion at temperatures below millions of degrees).
They were wrong. Every single experiment after them that tried to duplicate their work failed. Disgraced but indignant, both moved to France and took £12 million of Toyota’s money with no results after 10 years. Fleischmann now lives in England and Pons gave up US citizenship and is still living in France.
Both are still championed by the “alternative energy” community for having succeeded in cold fusion but being held back and put down by The Powers that Be (as in alternative medicine, as in, not real).
CERN’s Announcement of Faster-than-Light Neutrinos
Part of Einstein’s momentous work in the early 1920s was to propose that nothing can travel faster than light. Every experiment ever done since then has eventually shown that this is correct, as far as we can tell.
In 1987, a supernova happened in a neighboring dwarf galaxy (as seen from Earth). The neutrino burst arrived a few hours before the visible light counter-part, exactly in line with theory (that neutrinos travel slower than light, but they are unimpeded by the atmosphere of the dying star which is why the light was delayed).
In 2011, scientists at CERN announced the results of numerous runs of the same experiment that showed that neutrinos somehow seemed to travel faster than light. The difference in timing was 60 nanoseconds (a nanosecond is 0.000000001 seconds). But, their results were consistent over the course of 15,000 repetitions.
They had checked everything they could think of and debated the results within the team. Finally, they released a paper and held a press conference about the paper wherein they stated (paraphrased): “These are our results. We know this violates established physics, but we have tried everything we can think of to figure out where we might have made a mistake. Please help us and critique our work!”
If their results were real, and neutrinos do travel faster than light by the amount they measured, then the neutrinos from the 1987 supernova should have arrived at Earth years before the visible light counterpart. Not hours.
With the decline of dedicated science reporters, science reporting in most media outlets has declined in quality over the past decade. Significantly. Media in general took the sexy headlines of “Einstein Was Wrong” and “Light Speed Limit Broken” and other such things.
What they didn’t report was that this is part of the scientific process. Work needs to be vetted and repeated before it is accepted.
A few months ago (March 2012), it was announced that a possible source of systematic error was found: A loose cable. (Systematic error/uncertainty is something that will always give you the same relative offset in an experiment. This is in contrast to random error where you get literally random sources of error that crop up.)
Because of the very precise timing required in this experiment, a loose cable may seem innocuous, but it was enough to account for the difference.
In the time since March, the experiment has been redone many times and, today (June 8, 2012), CERN research directory Sergio Bertolucci presented results at a conference that shows the neutrinos travel at just under the speed of light.
Pseudoscience Already Grabbed It
Unfortunately, just as pseudoscientists hawking their latest perpetual motion devices still point to Pons and Fleischmann as having succeeded in creating cold fusion, already in the past few months several have latched onto the idea of FTL neutrinos to bolster their own line of beliefs.
I have heard from numerous, different people on some forums I monitor as well as the “venerable” Coast to Coast AM show saying things such as, “ESP exists because CERN scientists have shown that things can travel faster than light!” Or, “UFOs are aliens from other planets and we already know that they can get here faster than light because CERN scientists have shown that things can travel faster than light!”
Do I expect them to retract their claims now that the science has been corrected by the same people who made the claim to begin with? Of course not. But hopefully I’m wrong.
These scientists did not do science by press release, they vetted their work within the team and performed over 15,000 experiments. Even when presenting their work, they still didn’t believe their results and they were calling on the rest of the physics community for help. That was not the route taken by Pons and Fleischmann.
I think that this shows well how science is generally supposed to work when you have an extraordinary claim (Alex Tsakiris …):
- Established physics theory borne out from hundreds or thousands of experiments.
- A single new experiment suggests it’s wrong.
- Experimenters repeat their experiment many times, and search for sources of error that would explain the anomalous result.
- Not finding it, they publish a peer-reviewed paper about the work and ask the broader community for help.
- Many people come in and try to figure out where the latest experiment may have gone wrong.
- Course A: If they find the mistake, they retract the initial claims and the established physics is shown to still hold.
- Coarse 1: If they don’t find the mistake, then an independent experiment must be set up that is designed to measure the same phenomenon and run. If it verifies the new results, then the established theory must be modified. If it doesn’t, then the original experiment remains an interesting anomaly to be explained but does not affect the established theory.
And that’s what happened here.
*Sorry folks, I know that I’ve been lax lately, I have no excuse other than work and other things that have taken priority. This blog is unfortunately not my tip-top priority. And the last three weeks have seen three astronomical events that have generated about 100GB of images I’m trying to finish processing (annular eclipse, lunar eclipse, Venus transit). And I’m behind on work in my day job.