Who’s there? … Knock Knock. Rosie Walton finds out what all the neutrino fuss is about.

In October 2011, the Neutrino community at OPERA self-published a controversial paper on the physics pre-print server, the arXiv. OPERA is an experiment with an established and well respected team of particle physicists. The arXiv is an open access, free repository for academic work hosted by Cornell University. The neutrino paper is controversial because it is one of the first publications to gain international press attention without appearance in a commercially-run journal. The paper is also arguably the first widely discussed paper featuring results from the Large Hadron Collider collaboration at CERN. If that wasn’t enough, it also has the potential to change our understanding of the universe because it challenges an established assertion of Einstein’s Relativity: that nothing can travel faster than the speed of light.

Faster than light neutrinos?

But let’s pause for a minute and take a deep breath. Is this result really as controversial as it has been made out in the popular press? Or might it be the dissemination of science which is actually changing – as opposed to one of the cornerstones of modern physics?

Rewind to the summer of the previous year, and representatives from the same neutrino community were paddling their feet in the Greek sea, dining on a beach and relaxing in the June sun at Neutrino 2010 – the annual neutrino physics conference. Do not be fooled -the neutrino community is not one that takes regular breaks, and this is just as well, because we are dealing with one of the most elusive and difficult to study particles.

The fact we are at a junction in history where human beings would even consider it possible to measure the speed of a particle like the neutrino is really quite astonishing. To summarise why – the Neutrino (1) is so small it is completely invisible to even our most powerful microscopes, (2) travels millions of meters per second and (3) can ‘walk through walls’ and hence whizzes untraced through any detection equipment you might have set up to catch it. What OPERA have achieved in measuring the speed of the Neutrino then, is fantastically significant in its own right. But this is not the speed we expected.

When I was stood on that beach near Athens for ‘Neutrino 2010’ in my capacity at the time as editor of the New Journal of Physics – discussing with OPERA physicists the merits of open-access publishing – the last thing I would have expected was a six-sigma significance faster-than-light measurement. But somehow if it was going to come from somewhere, it would be the Neutrino community. When I ask how one tiny particle has drawn such a large number of physicists to study it – the answer sits simply as: it’s an incredibly rich area of research because it’s associated with all the major problems in particle physics, and there are still lots of viable experiments left to do.

Since the result, there has of course been an enormous number of popular science accounts appearing on the blogosphere. My personal favourite is by a trusted acquaintance of mine, Professor Sean Carroll -who writes the following about the faster than light neutrino result in his blog post for Cosmic Variance:

There are two things you need to know about this result (1) it is enormously interesting if it is right and (2) it’s probably not right

In these two, beautifully composed statements Sean captures what must be the most infuriating universal truth about the entire process of scientific discovery – it is incredibly difficult to make any new contribution to knowledge, but it is fantastically interesting and useful if you do.

So is it ‘right’?

Crucially, the arXiv paper as it stands is an experimental paper concerned purely with the measurement of the neutrino’s speed. The paper contains the line:

‘We deliberately do not attempt any theoretical or phenomenological interpretation of the results’

Let me assure you of this: no one in the OPERA collaboration is sat at home thinking ‘Einstein is wrong, and time travel is possible’. They are running around talking to other physicists, making plans for future collaborations and plans for improvements to future measurements. They are doing this because they know this work is a long way off having substantial enough experimental evidence for any meaningful conceptual insights about the nature of space, matter and time to be drawn.

This used to be discussed behind subscription-only journals

The trouble is, we have gone ‘open access’ on everything, and for the neutrino community, this has meant letting the public in to see what is going on at a time when everything is up in the air. The truth is, all of this conjecture and argument about interpretations and measurements used to be done behind closed doors. It used to be done within subscription-only journals and at expensive conferences. Today we are seeing it published in an open-access journal without any formal peer-review, being ‘live-blogged’ from the CERN EP seminar, debated via Twitter and openly on websites and television. The result has been digested for a number of different audiences, by a number of different communities.

Physics has ‘gone live’ so to speak. It’s not the faster-than-light measurement in itself which is controversial; it is the having to present it to the entire world while it’s still very much a ‘work-in-progress’ that feels difficult. Realistically though, is this not inevitable within the climate of openness and transparency we are aspiring to? And moreover, isn’t it a good thing that perhaps for the first time in history so far, the public have begun to get a feel for the infuriating situation research scientists find themselves in everyday when they get out of bed?

‘Today I might make a break-though in modern science, but I will probably just take a very tiny (almost insignificant) step in the right direction’

The future of scientific discovery to me looks bright, open, and dynamically connected to popular science: let the neutrinos speed on. If they still happen to be faster than light after a few more years of measurements, then give me a call and let’s have a chat about Einstein, Lorentz invariance and time travel.

Featured image credit: CERN (neutrino beams)