Speed-of-light results under scrutiny at Cern

Opera detector Enormous underground detectors are needed to catch neutrinos, that are so elusive as to be dubbed "ghost particles"

Related Stories

A meeting at Cern, the world's largest physics lab, has addressed results that suggest subatomic particles have gone faster than the speed of light.

The team has published its work so other scientists can determine if the approach contains any mistakes.

If it does not, one of the pillars of modern science may come tumbling down.

Antonio Ereditato added "words of caution" to his Cern presentation because of the "potentially great impact on physics" of the result.

The speed of light is widely held to be the Universe's ultimate speed limit, and much of modern physics - as laid out in part by Albert Einstein in his theory of special relativity - depends on the idea that nothing can exceed it.

Start Quote

We want to be helped by the community in understanding our crazy result - because it is crazy”

End Quote Antonio Ereditato Opera collaboration

Thousands of experiments have been undertaken to measure it ever more precisely, and no result has ever spotted a particle breaking the limit.

"We tried to find all possible explanations for this," the report's author Antonio Ereditato of the Opera collaboration told BBC News on Thursday evening.

"We wanted to find a mistake - trivial mistakes, more complicated mistakes, or nasty effects - and we didn't.

"When you don't find anything, then you say 'well, now I'm forced to go out and ask the community to scrutinise this'."

Friday's meeting was designed to begin this process, with hopes that other scientists will find inconsistencies in the measurements and, hopefully, repeat the experiment elsewhere.

"Despite the large [statistical] significance of this measurement that you have seen and the stability of the analysis, since it has a potentially great impact on physics, this motivates the continuation of our studies in order to find still-unknown systematic effects," Dr Ereditato told the meeting.

"We look forward to independent measurement from other experiments."

Graphic of the Opera experiment

Neutrinos come in a number of types, and have recently been seen to switch spontaneously from one type to another.

The Cern team prepares a beam of just one type, muon neutrinos, and sends them through the Earth to an underground laboratory at Gran Sasso in Italy to see how many show up as a different type, tau neutrinos.

In the course of doing the experiments, the researchers noticed that the particles showed up 60 billionths of a second earlier than they would have done if they had travelled at the speed of light.

This is a tiny fractional change - just 20 parts in a million - but one that occurs consistently.

The team measured the travel times of neutrino bunches some 16,000 times, and have reached a level of statistical significance that in scientific circles would count as a formal discovery.

But the group understands that what are known as "systematic errors" could easily make an erroneous result look like a breaking of the ultimate speed limit.

That has motivated them to publish their measurements.

"My dream would be that another, independent experiment finds the same thing - then I would be relieved," Dr Ereditato told BBC News.

But for now, he explained, "we are not claiming things, we want just to be helped by the community in understanding our crazy result - because it is crazy".


More on This Story

Related Stories

The BBC is not responsible for the content of external Internet sites


This entry is now closed for comments

Jump to comments pagination
  • rate this

    Comment number 65.

    physics, physics...you beautiful thing.

  • rate this

    Comment number 64.

    I really hope this is true. It will remind us that we don't know everything and when we say something is true, there is still some room for further revision or clarification. Kudos to these scientists for publishing this information and asking the wider scientific community to check their results.

  • rate this

    Comment number 63.

    We will need to think about wrewriting E=MC2, as C represents the speed of light, the max according to Einstein. If C is not the max, then E could concievably be greater, and our understanding of this and mass flawed. But Einstein was only a man and discovered what was there for him to discover. But who or what put it there? And as a man, aclever man, maybe is logic was flawed too

  • rate this

    Comment number 62.

    Where's my towel when I need it?

  • rate this

    Comment number 61.

    All explanations are simple: How 'bout the Corilolis effect where the target is moving toward the launch due to earth rotation?? hmmmm?

  • rate this

    Comment number 60.

    Mysticism ...400,000 years ...did not destroy the planet

    Science :.....200 years ....... might destroy the planet

    The game is not over yet, but there is a clear leader !

  • Comment number 59.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 58.

    You have got to love science. I hope the checked results get well reported. I love the "journey" reporting. So much more interesting than sport, recession or war.

  • rate this

    Comment number 57.

    @Virgil Cottongim "100 years from now we will be cave men...."
    The right words, but in the way you think. Mankind is so arrogant that not only do we think we have sussed out the universe, turn evolution theory into fact, but also engineer massive financial ponzi schemes and frauds that will crash our economy and yes it will put us all back in caves a 100 years from now, or sooner.

  • rate this

    Comment number 56.

    Why does the speed of light appear in the equation e = mc squared? It is because the equation requires a term which is the fastest possible speed of information. If light speed is not the fastest possible speed of information then that equation would be wrong, but it has been experimentally shown to be true.

  • rate this

    Comment number 55.

    These are good scientists, accumulating evidence ruling out errors, checking results and when then want other scientists to repeat the experiments before making any claim.

    This is all what peer review is about, its quite funny how some people commenters think peer review is bad.

  • rate this

    Comment number 54.

    I suspect a nice big bug in their computer programs or a flaw in their maths will be found some time in the next couple of weeks.

    How can the world's media pick uncomfirmed results from a scientic paper without posting a link to the original document so the amateur scientists can read it and draw their own conclusions?

    What happened to don't publish until after a peer review?

  • rate this

    Comment number 53.

    if E does not =mc squared
    then E could = mc cubed

  • rate this

    Comment number 52.

    Our determination of the speed of light may not necessarily be correct. Perhaps the speed of these neutrinos is the new more accurate measurement.

  • rate this

    Comment number 51.

    I blame EU regulations! Or is it 'God' playing around? , Maybe the Particles are evolving, as predicted by Darwin.
    Lets have some more stupid ideas from out there.
    Or we could accept that as untrained readers the story is of interest but we do not have the knowledge to make valued comments.
    (or is it the Klingons?)

  • rate this

    Comment number 50.

    I see a comment from Laurel (# 15) To clear that up, E=mc2 terms, E is energy. To arive at that m is mass and c is the speed of light. First you multiply the m by the speed of light, then square that, which gives you the E... (Not 2X2 =4..., lol) Anyway, my thoughts, why cannot we exceed the speed of light? Nothing is fixed in this universe.. 100 years from now we will be cave men....

  • rate this

    Comment number 49.

    I just had the funniest thought.

    Tower of Babel - Part 2

  • rate this

    Comment number 48.

    32. Nissim
    You're missing the point. At the moment e=mc^2 because that is a theory which explains most things and has not been disproved. You cannot cite it as proof the experiment has failed when the point is showing that it might be wrong! If it proves that particles can move faster than c, it comes down to a finding a new theory that fits the results, which may or may not contain e=mc^2.

  • rate this

    Comment number 47.

    @32 Nissim
    You can't conclude there is a mistake in the experiment by your arguments. Quantum entanglement, for example, follows from the laws of Quantum Mechanics and may allow for information to travel faster than light. Einstein did not believed in this and he formulated the EPR paradox (see Wikipedia); later, experiments by John S. Bell confirmed the predictions of quantum entanglement.

  • rate this

    Comment number 46.

    Finally a particle moving at warp speed? How do we create a neutrino-powered warp drive? Beam me up Scotty!


Page 56 of 59


More Science & Environment stories



  • How ebola spread graphicPatient zero

    Tracking first Ebola victim and how virus spread

  • A young Chinese girl looks at an image of BarbieBarbie's battle

    Can the doll make it in China at the second attempt?

  • Prosperi in the 1994 MdSLost in the desert

    How I drank bat blood and urine to survive in the Sahara

  • Afghan interpetersBlacklisted

    The Afghan interpreters left by the US to the mercy of the Taliban

  • Flooded homesNo respite

    Many hit by last winter's floods are struggling to pay soaring insurance bills

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.