WRONG! All this excitement is based on the claim by a bunch of very thorough experimentalists
that neutrinos (more about them later) have been found by them to be tad bit FASTER than
even light in vacuum!
If that is true, that would make a big revolution in physics, or would it? This is what is occupying
many minds as I write this(my first) blog. If the claim is true, does it mean that Einstein is
necessarily wrong? Or, does it still let Einstein off the hook but show that something else that all the scientists had taken for granted, is more subtle than one imagined? (Einstein sighs in the
background "Subtle is the Lord").
First, let me explain the claim. The full scientific details are available in the article:
http://arxiv.org/abs/1109.4897
It is by an experimental collaboration called the OPERA (The Phantom of the opera strikes
again?). The list of authors almost fills up the title page, something very common in high energy
physics experimental collaborations these days.
A piece of irony here! G. Brunetti, whose PhD thesis is all about the techniques used in this exit,
is currently at The Albert Einstein Center For Fundamental Physics at the University of
Berne (anyone still remember Berne's connection to Einstein?).
They send a beam of neutrinos from the European Center for Nuclear Research, CERN, now
famous for the LHC expt, to the Gran Sasso neutrino detector some 730 kms. They claim
to know this distance to the accuracy of 20 cms! They find that the neutrinos take 60.3 nanoseconds faster than what light in vacuum would take to cover the same distance.
It is not a one shot affair, they have roughly 16000 sample events.
First reaction is bound to be one of skepticism, not unreasonably so. Let me also record here the misgivings that hit you first:
Clearly it takes two clocks, one at CERN and another at Gran Sasso to agree, synchronized is
the technical word, to much better than 60 nanoseconds to make the result meaningful. Ordinary
GPS synchronized clocks won't do. They used Cesium atomic clocks to achieve a synchronization
error of only 2.3 ns with an additional error of 0.9 ns. So this is much smaller than the measured time difference, and this error is quoted.
You need to know the distance too, very accurately, and as said before they claim to know this
with only an error of 20 cms! Now can one really reach this level, given earth's crust has various motions, and to make matters worse there was a pretty strong earth quake in the vicinity in 2009! Yes, they claim they can, and the article gives all the relevant details.
Those who know something about neutrinos will wonder about this! Neutrinos are produced in this exit from high energy protons. These protons first give rise to Pions and these Pions decay to neutrinos. Now the bothersome detail is protons produce pions randomly, and the pions decay to neutrinos also randomly ! So no one can tell for sure when the neutrinos are born! Then how can you be so sure has to how long they took to reach their destination?
The beauty of this experiment is it does not matter ! The pions and protons are so energetic that they all are traveling incredibly close to the velocity of light, assuming Einstein is right, that the precise details of when the neutrinos are born is totally irrelevant !
What are the possible Consequences?
If the expts are found to be correct, this could well be the 9/11 of modern physics! The arxiv
article no also begins with 1109! But physicists are not going to give up that easily, and they
should not.
One consequence could be that Einstein was wrong about his special theory. Then all hell will
indeed break loose as everything that we believe in, be it the Standard Model, String Theory, whatever, depends one way or the other on this pillar. That would present the greatest opportunity ever to young people wanting to do theoretical physics!
On the other hand there could be other explanations, letting Einstein off the hook! For example,
extra dimensions could explain this. Imagine if instead of having to travel along the surface of
the earth, we could directly travel (hyper travel, already discovered in scores of Sci-fi books!). But
this will have a hard time explaining why neutrinos from supernovae don't travel faster than light, unless the Romans knew the secret of building a tunnel in hyperspace!
The other, more likely to me, is the possibility that we have been careless in treating time properly! This expt is based on the so called Time of Flight method, which treats
time very much as in classical physics whereas neutrinos and the way they move could be involving many subtle aspects of time in quantum mechanics.
So its best to wait and watch, not be simply cynical about this expt but analyze it thoroughly,
even repeat it many times.
I bet that Einstein himself would have thoroughly enjoyed that exercise, as for him, the quest for truth was far more important than establishing any orthodoxy !
Send me your comments and let us all try to give uncle Albert a helping hand, though he hardly
needs it!!!
