23 September 2011

Neutrinos Travelling Faster Than Light??

Posted by Dan Satterfield

The OPERA neutrino detector in Italy uses photographic film embedded in lead bricks to detect neutrinos.

Adrian Cho has a story on Science NOW about the scientists at OPERA in Italy asking for some help. OPERA is studying neutrinos released from CERN and they keep coming up with a result that shows the neutrinos are traveling faster than light! Cho rightly points out that this would be the greatest discovery in physics for a half century, but I think it would rank higher than that. This is pick me up off the floor and find me a trash bin to stuff the standard model into kind of stuff!

When I visited the South Pole I signed one of the neutrino detectors at Ice Cube, so I’m always fascinated by any news in the field. Imagine a particle so small and wispy, that it could travel through a slab of lead one light year thick and likely bump into nothing! There are billions passing from the sun through you right now and it doesn’t matter if it’s dark where you are, they go right through the Earth and you! Neutrinos come in 3 types and one of the biggest discoveries of the last few years is that they oscillate between these different flavors as they fly along at near light speeds. This is what OPERA is investigating, but their neutrinos seem to be arriving early!

It takes 2.43 milliseconds for the neutrinos to travel the 730 km from CERN but they are apparently arriving 60 nanoseconds ahead of schedule.  The folks at OPERA are trying to find out where they are making their error but have not been able to do so. They are now formally asking for help from the rest of the physics community and they will certainly get it. You do not have to be an expert in particle physics to learn the fundamentals and appreciate the gravity (pun not intended) of the questions being asked these days.

Optical detector for ice cube about to be lowered beneath the ice at the S. Pole.

Carl Sagan’s wise words are obviously the guiding principle here “Extraordinary claims require extraordinary proofs.” It’s far more likely that there are measurement errors here and the neutrinos are not traveling faster than light and furthermore, the researchers at OPERA know this. If particles travel faster than light, then all kinds of spooky things happen including travel backwards in time, and my developing a taste for the music of Lady Gaga.  Both are profoundly serious consequences.

Phil Plait at Bad Astronomy has just posted some wise words on this as well and the BBC has an exc. story on it. Think of it this way, you get a result that is either a mistake or 100 years of physics is all wrong. Which is more likely?? Unless you’re writing books aimed at those who refuse to accept the scientific evidence for evolution or climate change, you lean toward the mistake side of things!

Let’s step back away from the thorny bushes of day-to-day history and try to look at the trees a bit. As we enter the autumn of 2011, the LHC folks have looked in most of the likely places for the Higgs Boson and still not found it, while the mystery of dark matter and dark energy is deepening (neutrinos seem to be ruled out as the missing matter that holds the galaxies together). Do you get the feeling that we just might be on edge of a whole new understanding of our universe? I asked astrophysicist Neil de Grasse Tyson last year about not finding the Higgs and instead of a worried or puzzled look, his eyes lit up!

I think I understand why…