New experiment neither proves nor refutes FTL neutrinos

By Phil Plait | November 21, 2011 7:00 am

On Friday, a news story came out that a second experiment seems to support the results of an earlier experiment which showed neutrinos might be moving faster than light. I commented about this on Google+ at the time, but I want to post about it here as well. Let me be clear: this new result does not confirm FTL neutrinos! What it did was essentially eliminate one possible source of error. A big one still remains.

Let me recap: In September, a team of scientists at CERN working with the OPERA detector in Italy found that beams of neutrinos — subatomic particles that can travel straight through matter — seemed to get from the source in Geneva to the target in Italy 60 nanoseconds faster than a beam of light would make the trip. If true, it means they were moving faster than light (what scifi geeks like me call FTL) which, according to all the physics we understand, is impossible.

There was a lot of criticism of the experiment, as was expected and as it should be! It fell into two broad categories: a problem with the way they created the neutrinos, and a problem with timing.

The neutrinos were created at the accelerator at CERN as bursts containing gazillions of the particles. They move at essentially the speed of light, which is very fast. In fact, while the duration of the burst of neutrinos was very short in human terms, it was still long enough to blur out the results significantly. It’s like standing by the side of the road and trying to figure out when a cluster of cars passes you; do you measure the front of the cluster, the middle, or the tail end? In the case of the neutrinos, they didn’t know which neutrino was which; they measured all of them in the burst and used a statistical method to get an average travel time for each burst.

This is what a second experiment tried to answer. Using a different method the second time around, they were able to significantly tighten up the burst of neutrinos, reducing the error in the measurement by quite a bit. What they found were results consistent with the first experiment: the neutrinos traveled the 743 km trek 60 nanoseconds faster than light.

Holy cow! Does this prove the result?

No. Don’t forget the second source of error: timing. Most people, including me, think that the way they timed the experiment may be the source of the problem. This second experiment used the same timing techniques as the first! So if that’s the source of the error, this doesn’t really change anything.

And either way, we’re left where we were before: with a weird result that cannot really be confirmed or refuted without an independent experiment done by another group. That’s how science works.

I’ll note that another team of scientists has said the FTL results must be wrong due to energy arguments; that may be correct, but I still want to see a wholly separate experiment done. It’s much like nuking the aliens from orbit: it’s the only way to be sure.

 


Related posts:

Faster-than-light travel discovered? Slow down, folks
Followup: FTL neutrinos explained? Not so fast, folks.
Wall Street Journal: neutrinos show climate change isn’t real
Followup on the WSJ climate denial OpEd

 

CATEGORIZED UNDER: Cool stuff, Science, Skepticism, Top Post
MORE ABOUT: CERN, FTL, neutrinos, OPERA

Comments (62)

  1. Blargh

    IMO, the only way to be sure is to fire the neutrinos through two (preferably identical) detectors and measure the travel time between them – that way, the generation time uncertainty is eliminated, and any problems with the detectors’ timing should cancel out.
    Of course, that’s… unlikely… to happen. Neutrino detectors don’t come cheap.

  2. Tara Li

    Who knows? Maybe they will discover that the timing is right? They said they’ve covered most all of the objections raised – I would expect that includes the timing. Pretty much everyone *wants* it to be timing, but nobody’s actually been able to say “This is the mistake”.

  3. “In September, a team of scientists at CERN found that beams of neutrinos — subatomic particles that can travel straight through matter — seemed to get from the source in Geneva to the target in Italy 60 nanoseconds faster than a beam of light would make the trip.”

    In case of interest, it’s not scientists at CERN who measure the neutrinos arriving in Italy. OPERA is not a CERN experiment. CERN only sends the beams; the measurements are done by scientists at the Gran Sasso Lab (INFN). There are no CERN staff on the OPERA experiment.

  4. CraterJoe

    I think I don’t know about the subject to say what could be the cause. I’m with everyone else on doubting the speed limit was broken; cool if some new less world shaking dicovery was the result of it.

  5. Matt

    i read a blog somewhere that made me laugh so hard, he explained the results as ” the neutrinos got to the receiving station 60 nanoseconds before they were even fired” the fundamental misunderstanding of lightspeed i think is the problem but it just made me laugh… thought i would share.

  6. Ah yes, Ian (#3) you’re correct. I fixed it, and thanks.

    Interesting, actually: that’s not a typo, since it’s not a misspelling, and it’s not a Freudian Slip. I was thinking CERN so that’s what I typed, even though I knew they were with OPERA. Is there a name for that kind of mental typo?

  7. Trebuchet

    This is what’s cool about science: Experimental results contradict accepted theory, and the experimenters invite the world to help to help them figure out what may have gone wrong. And if nothing did, accepted theory gets replaced (eventually) by something new.

    Meanwhile, creationists are saying “Science was wrong about something, therefore evolution is wrong.” Same world, different universe.

  8. Pete Jackson

    @5 Phil: This is just a case of faster than light travel reversing causality!

  9. Eric Shumard

    @Blargh(#1): The MINOS collaboration is repeating their neutrino velocity measurement which should be done in a few months. They employ two neutrino detectors, one near the beam source and another 734 km downstream and use the timing difference between the two detectors. The earlier MINOS measurement is consistent with the OPERA result but had much larger stated uncertainty than OPERA.

  10. The neutrinos probably nipped into the tardis for a moment…

    But yeah, there’s an error still to be discovered. Relativity is too well established by experiment & observation to fall easily.

  11. Reverend J

    What are your thoughts on the asymmetry they potentially found with the HLCb experiment?

    http://www.msnbc.msn.com/id/45347624/ns/technology_and_science-science/#.Tsp70fL3IRU

  12. Beer Case

    Is it possible to measure photons travelling between Geneva and Gran Sasso, Italy? From what I understand they need to know the exact distance, and from there calculate the time photons would need, if they COULD travel in a straight line down to Gran Sasso? A radiosignal, being made up of photons, would suffice. But thanks to the curvature of the earth, photons either can’t travel very far at all, or have to travel following a curved path?

    My point being, the neutrino-experiment lacks a control group!

  13. Michael Swanson

    C’mon, Phil. It’s not like going faster than light is hard: you make a spaceship (or a measly neutrino if you’re poor or lazy) go the speed of light…and then you just go a little bit faster!

    Pfft. “Scientists.”

  14. Well, it is good that they changed only one “variable” in the experiment. Now that can be taken out of consideration.

    I was thinking there may be a very simple explanation for all of this. Have you been to Switzerland? Have you been to Italy? Most people I know prefer the food and the atmosphere in Italy over Switzerland. Perhaps the Neutrinos were simply in a hurry?

  15. chris j.

    Matt @5:
    under general relativity, aren’t “traveled faster than light” and “arrived before it was sent” equivalent statements?

  16. Tara Li

    @11 Richard – I don’t see where superluminal neutrinos break relativity. The only real problem you get is that you get imaginary numbers – but those pop up all the time in quantum math. Causality may get in trouble, but eh – I’ve never quite understood the attitude of physicists that something doesn’t happen until you see it happen. For three planets in an equilateral triangle, when planet A blows up, both B and C will see it happen at the same time, and know that the other planet saw it at the same time, and will get the same figure for when it happened when they account for light travel delay.

    After all, Dirac came up with a nice result that didn’t make sense at the time – and most physicists wanted to just toss it out as a non-physical solution. Oh, well – they did end up finding those positrons, after all.

  17. David Brown

    “… the way they timed the experiment may be the source of the problem.” Does dark matter alter GPS timing? Is the currently accepted theory of dark matter (DM) fatally flawed? Is there some new physics in gravitational theory that changes time by increasing the predicted gravitational slowing of time? Why might a GPS timing calibration problem explain the OPERA anomaly? My thinking is: GPS timing is CONSISTENTLY wrong by an extremely small fraction if and only if Fernandez-Rañada’s idea about anomalous gravitational acceleration of clocks happens to be correct if and only if the -1/2 in the standard form of Einstein’s field equations should be replaced by -1/2 + dark-matter-compensation-constant if and only if dark-matter-compensation-constant is approximately sqrt((60±10)/4) * 10^-5.
    http://en.wikipedia.org/wiki/Pioneer_anomaly
    http://arxiv.org/abs/gr-qc/0410084 “The Pioneer anomaly as acceleration of the clocks”
    The MOND paradigm posits a departure from standard Newtonian dynamics, and from General Relativity, in the limit of small accelerations. — Mordehai Milgrom, “DM or MD?”
    http://arxiv.org/pdf/1101.5122v1 “MD or DM? Modified dynamics at low accelerations versus dark matter” by M. Milgrom, 2010, Proceedings of Science
    According to Kroupa, the 2009 paper “Universality of galactic surface densities within one dark halo scale-length” shows that “the surface density of luminous (normal) matter within the putative (mathematically formal) dark-matter halo scale radius is invariant among galaxies. This result demonstrates a physical coupling between baryons and dark matter particles which is not contained in the CCM, and would only be fixed within the dark-matter hypothesis if a fifth (dark) force is invented. However, the baryon surface density is automatically contained in the alternative-gravity theory (most notably Mordehai Milgrom’s MOND).”
    http://www.astro.uni-bonn.de/~pavel/kroupa_cosmology.html Pavel Kroupa: Dark Matter, Cosmology and Progress
    http://arxiv.org/pdf/0909.5203v1 “Universality of galactic surface densities within one dark halo scale-length” by Gentile, Famaey, Zhao, & Salucci, 2009
    Is there overwhelming evidence that general relativity theory is not entirely correct? Is Milgrom’s MOND essential for understanding GPS timing? Is the OPERA neutrino anomaly an experimental blunder or a paradigm changer?

  18. Kkozoriz

    Even if they had nuked the site from orbit and were sure that they’d gotten all the aliens, the mother creature was still on the ship. They may have been sure but they were also wrong. Just saying…

  19. alfaniner

    @14 It’s not like going faster than light is hard: you make a spaceship (or a measly neutrino if you’re poor or lazy) go the speed of light…and then you just go a little bit faster!

    It would be cool if they called it the Tufnel Drive.

  20. jason

    Correct me if I am wrong on this, and it is possible, but if they confirm the neutrinos were FTL then would it not indicate that relativity is incomplete rather than wrong? Similar to how Newton works very well at certain scales but isn’t adequate at relativistic speeds or in the example of Mercury’s orbit.
    Instead of throwing relativity out the window as incorrect, it applies just fine within certain range and then we need additional theory to account for the discrepancy.

  21. Matthew Bentley

    I’m with Chuck Yeager on this one, who said regarding the sound barrier, “I don’t believe the damn thing exists!” There is no light barrier, and there’s nothing magical about the speed of light. It’s just that observations require photons, so of course nothing “appears” to travel faster than light! But here are a few numbers that I’ve crunched: MINOS found that neutrinos travel 6600 to 24,000 m/s FTL, the original CERN experiment found something similar: neutrinos travel 6150 to 8060 m/s FTL, and the latest “bunched beam test” found they travel about 7630 m/s FTL. Three experiments, all of which essentially agree. Then we have SN1987A, which emitted photons and neutrinos traveling within 0.6 m/s of the speed of light, but these were observed only, not clocked! There is a difference, because neutrinos and light arriving on Earth from the LMC 168,000 LY away might very well have traveled at a variable speed of light rather than 299792458 m/s all the way! Likewise for subterranean neutrinos, which evidently broke the speed of “c” but not necessarily the possibly (variable) speed of light.

  22. Anchor
  23. Blargh

    @ Eric Shumard:
    Oh, cool! I learn something new every day. :)

    @ Beer Case:
    You’re correct in that the distance and flight time are all they need. But both sites are underground, 730 km apart, so sending photons in a straight line isn’t exactly feasible. :)
    Even if it was, the rock would affect the flight time (it’s the speed of light in a vacuum that’s constant), so it wouldn’t be very useful anyway.

    @Anchor: that’s the argument Phil mentions in the last paragraph.

  24. mike burkhart

    You can’t change the laws of physics Jim . O darn and I thought we would be going at warp speed in a few years to other stars and galaxys . Phil ,you just love to kill others dreams . On the brite side love the photo of the warp speed efect form Star Trek the Motion Picture.

  25. Anchor

    @Blargh: Sure. Just thought I’d underscore the fact that there is an experimental RESULT (NOT just an “argument”) from ICARUS (using the same beam) which the experimenters themselves characterize as a refutation of the OPERA claim of FTL neutrinos, is all.

  26. Matthew Bentley

    The reason the ICARUS experiment apparently “refutes” the CERN/Gran Sasso FTL results, is that the neutrinos are not superluminal at all, and therefore would not emit Cherenkov-like radiation. In other words, if the baseline could have been tunneled out and evacuated of air, a parallel photon beam would have arrived at the same time as the neutrino beam, but both would have exceeded the commonly accepted constant c. Faster-than-light and faster-than-c are not the same! This hypothesis explains the speed-of-light neutrinos (within 0.6 m/s) detected from Supernova 1987A while also explaining the so-called “FTL” (actually faster than c ) neutrinos clocked in the MINOS and both CERN/Gran Sasso experiments. The value of c has never been clocked anywhere except at the surface of planet Earth. The underground neutrinos exceeded the speed of c, but not light.

  27. @Jason: “Correct me if I am wrong on this, and it is possible, but if they confirm the neutrinos were FTL then would it not indicate that relativity is incomplete rather than wrong? Similar to how Newton works very well at certain scales but isn’t adequate at relativistic speeds or in the example of Mercury’s orbit.”

    You’re absolutely right, but it’s unclear just how it could work out that way. Relativity is not wrong, it may be ever so slightly tweaked, different from our current understanding in such a way that it is not easily detectable under normal relativistic conditions (it’s more than a bit funny to me to type the phrase ‘normal relativistic conditions’).

    The thing is that, while it would be somewhat easy to envision slight variances in the various relativistic effects, it is quite difficult to image c being effectively wrong as the ‘cosmic speed limit’.

    c pops out of Maxwell’s equations, and much of modern physics is based off creative ways of looking at the math in Maxwell’s equations. Those equations have been folded inside and out, tweaked, stretched and prodded in all the mathematical ways possible to come up with the last century’s physics (including the incredibly well-tested Special and General Relativity).

    The rub is that Maxwell’s equations and those derived from them simply break horribly for speeds faster than c.

    It’s hard to imagine a case where Maxwell’s equations and the last century of physics derived from them would be so wonderfully predictive about the world around us, and yet be so fundamentally wrong about c. It’s possible, but it’s just hard to imagine it to be so.

    And when met with an experiment that results in a speed of these neutrinos which is *so very close* to the *exact* calculated vale of c, but just over, then scientists become extremely suspicious that something more mundane is going on, that some other reason for the *ever so slight* variance from the exact calculated value.

    Smart money is on sub-light neutrinos, but everybody would dearly love to lose that bet!

    I wrote more about it here if interested:
    Point-Five Past Lightspeed | is this your homework?
    http://www.isthisyourhomework.com/point-five-past-lightspeed/

  28. Chris Turkel

    Man can we stop with this. Einstein never said nothing could faster than light. He nothing could ACCELERATE faster than light. Big difference. I hate when science reporters get this wrong.

  29. BadAikidoka

    Earth rotates and travels through space at a not insignificant speed. Do you think Italy could move sixty light-nanoseconds during the experiment?

  30. Peter Eldergill

    “It’s like standing by the side of the road and trying to figure out when a cluster of cars passes you; do you measure the front of the cluster, the middle, or the tail end? ”

    Or, perhaps a better analogy would be the clump of bicycles (the Peleton I think) in the Tour de France. They give every cyclist in it the same finish time.

    Pete

  31. Eugene

    I’m curious: if neutrinos can pass through pretty much anything due to their negligible mass and speed, and you’re measuring your cluster from such a huge distance, how do you KNOW the neutrinos being measured in Italy are the same ones sent from Geneva? What’s keeping stray neutrinos from screwing things up?

  32. Peter Eldergill

    Partly because they repeated the experiment something like 2000 times and kept getting the same results I think

    Pete

  33. Grand Lunar

    Thanks for this info, Phil. The media isn’t much help in seperating noise from real data.

    I’d love to see independent verification to confirm or refute the latest results.

    I’d love to see whether we’ve taken a first step into a larger world, or just made one little mistake.

  34. TheVirginian

    I have to pick a nit here, but it’s a big one that I’ve seen elsewhere.
    The equation that says nothing can travel AT the speed of light, also says FTL travel is possible. FTL travel is NOT impossible. I had this in physics at VPI in the early 1970s, when I was trying to become an engineer. I was not engineer material, but made good grades in math and science and remember this physics equation in particular because it showed I had not understood the “light barrier” problem. Matter can travel slower or faster than light, it just cannot travel AT the speed of light, which is a problem if you’re trying to get from sublight to supralight. The whole tachyon issue is based upon the recognition that FTL travel is possible, and that there might exist a universe that exists only FTL!!!

  35. katwagner

    @6. Phil – an acute dumb fit.

  36. Javadi

    I hope following link be interesting for you.

    CERN Experiment and Violation of Newton’s Second Law in English

    http://www.gsjournal.net/Science-Journals/Research%20Papers/View/3747

    CERN Experiment and Violation of Newton’s Second Law in Persian

    http://www.gsjournal.net/Science-Journals/Essays/View/3693

  37. murtadha

    i’ve heard, the mistake is , they ‘re not counting special relativity effect on the timing. is that true?

  38. puppygod

    @Phil

    Interesting, actually: that’s not a typo, since it’s not a misspelling, and it’s not a Freudian Slip. I was thinking CERN so that’s what I typed, even though I knew they were with OPERA. Is there a name for that kind of mental typo?

    I believe the correct technical term is brainfart. At least that’s the one I use :)
    Seriously though, it’s just a kind of retroactive interference, I think.

    @BadAikidoka

    Earth rotates and travels through space at a not insignificant speed. Do you think Italy could move sixty light-nanoseconds during the experiment?

    Hmm, it shouldn’t matter at all – both sender and receiver ar travelling on the same planet. Though, it might be result of acceleration. AFAIK the Earth rotation is slowing down – does anybody know how fast exactly and what timescale we are talking about? My gut feeling is that it shouldn’t matter, but we are talking about really, really precise time measurements. Can somebody calculate it?

  39. Mephane

    Could it not be an error in the experiment, but about our assumptions of what the neutrinos went through? As we all (hopefully) know, not only speed, but also gravitation introduces time dilation. Could there be a large pocket of greatly less dense material than usual where the neutrinos went through, effectively coming through a zone of lower gravitation, and thus experiencing time passing a bit faster (or to be more precise, a bit less slow) than us? And if so, could such an anomaly detected on the surface by carefully mapping the value of G along the geodesic going right over the path the neutrinos went?

    Feel free to dismiss the idea if it is not viable at all. I can imagine that possible this could never have as large an effect as required to explain the 60ns, or that my own assumption of how *local* gravitation can also affect time dilation in relation to the overall gravitation of the planet.

  40. Messier Tidy Upper

    I’m wondering whether tachyon-neutrino interactions may have something to do with this?

    Could some of the neutrinos convert to tachyons (hypothetical particles that always travel faster than light) or could some neutrinos have been converted from tachyons and would this perhaps explain the slightly superluminal result?

    Is that at all plausible?

    Why do I ask? Well many years ago I “invented” an starship with an FTL drive that worked by converting neutrinos to tachyons – or such was the technobabble anyhow! ;-)

  41. Robin

    I’ll get excited when other labs independently find similar results. I’m not going to get excited about a lab redoing their experiment in a slightly different fashion, with the same detectors and the only difference being shorter bursts of neutrinos.

    @Beer Case (#13): It’s not really possible to do this with photons. The thing that neutrinos have going for them is that they move through pretty much everything unimpeded. To replicate this with photons, you’d have to send them through a vacuum for that same distance.

  42. Nigel Depledge

    Beer Case (13) said:

    Is it possible to measure photons travelling between Geneva and Gran Sasso, Italy? From what I understand they need to know the exact distance, and from there calculate the time photons would need, if they COULD travel in a straight line down to Gran Sasso? A radiosignal, being made up of photons, would suffice. But thanks to the curvature of the earth, photons either can’t travel very far at all, or have to travel following a curved path?

    My point being, the neutrino-experiment lacks a control group!

    What we call the speed of light in a vacuum, c, is not merely a measured quantity. It is a prediction that falls out of Maxwell’s equations.

    And the experimenters determined the distance between the CERN source and the OPERA detector to within 20 m. They checked their calculations very thoroughly, and no-one is suggesting that the error was in the distance measurement.

    Thus, no “control” light beam is needed to race against the neutrinos.

  43. Nigel Depledge

    David Brown (18) said:

    Is the currently accepted theory of dark matter (DM) fatally flawed?

    Wait, what?

    We have a currently-accepted theory of dark matter?

  44. Well this hasn’t lasted long.

    Latest study – as reported via BBC world news piece linked to my name here – seemingly casts a fair bit of doubt on the FTL neutrinos thing.

    Dangnabbit! I was hoping – albeit not really expecting – the FTL result would stand. Sigh.

  45. Nigel Depledge

    Jason (21) said:

    Correct me if I am wrong on this, and it is possible, but if they confirm the neutrinos were FTL then would it not indicate that relativity is incomplete rather than wrong? Similar to how Newton works very well at certain scales but isn’t adequate at relativistic speeds or in the example of Mercury’s orbit.
    Instead of throwing relativity out the window as incorrect, it applies just fine within certain range and then we need additional theory to account for the discrepancy.

    Not necessarily.

    Some commentators are suggesting that this result could be the first hint that additional spatial dimensions exist (i.e. the neutrinos did not exceed light speed, they took a short-cut). If this is so, then SR remains intact and needs no modification.

  46. Scot

    First I would like to say, I hope the neutrinos are traveling faster than light, I personally would like to see something that allows our known perspective of physics to be shifted a bit. This could be our, “we are not what the sun revolves around”, or “we are not the center of the universe”, or “the earth is not flat after all..”
    Now without knowing all of the details of the test etc here are some things that come to my mind.
    When I see someone mention the speed of light they mention it (as in a vacuum) well last time I checked the center (nor the crust) of our earth is not presented as a vacuum, now unfortunately we are not able to measure the speed of light between the two locations (as far as I know) so to me maybe it is the title of the article that really needs to be examined. Here are some of my personal optional titles that may not cause as large of an up roar “New possibilities in fluctuations of the speed of light”, or “Speed of light accelerates traveling through planets”.
    Bottom line I see this as a scientific gauntlet that has been thrown down. “Here is what we have found, confirm our findings or prove us wrong..”
    One thing that is still very cool about this, we are able to shoot neutrinos through the earth and measure them on the other side.. Personally I think this is very cool and well a bit scary..

  47. Mike Saunders

    If their timing is off, its really bad news. Timing down to the picosecond should be easily achievable. I do it in my lab every day, with a lot less fancy equipment than CERN undoubtedly has.

  48. Scott B

    “And either way, we’re left where we were before: with a weird result that cannot really be confirmed or refuted without an independent experiment done by another group. That’s how science works.”

    Unless it’s climate science. In which case we can just build models of our assumptions and treat it like an experiment. We can also take estimate of climate sensitivity from multiple people that range from almost zero to up to 10C and have a UN panel decide which number they like and treat that number as fact in future peer-reviewed papers.

  49. Jim P

    Special relativity deals with matter not being able to attain the speed of speed of light and photons (electromagnetic waves/particles) traveling at the speed of light. Neutrinos are neither so what is to say they have the same ‘speed’ restrictions as normal observable photons? Is the propagation of neutrinos through space (the curl equations for E and B) the same as that for regular electromagnetic photons? If not, then their time of flight may not have the same restrictions as for em photons.

  50. Ed Z

    Throughout the last century and this one, as experiments confirmed Einstein’s Special and General Theories of Reliativity, classical mechanics ( Newtonian mechanics) was not thrown out. It was still used. It was understood that classical mechanics couldn’t be applied accurately beyond a certain boundary: speeds close to that of light. If, in the end, it is verified that the neutrinos can exceed the speed of light in a vacuum, this doesn’t mean all of Relativity is thrown out. How about the failure to get protons and electrons to exceed the speed of light and all other experimental results confirming relativity? If the experiment turns out to be right, then maybe it would show that there is something special about neutrinos. I’m really interested in the outcome here because since the last century, tachyons have been considered to be a non-physical result. Bosonic String theory that predicted tachyons was considered to be a big problem that required modification so that the tachyons wouldn’t be predicted. So I started to wonder, if the experimental results here are confirmed then maybe…only maybe…neutrinos might have a tachyonic state part of the time.

  51. Nigel Depledge

    Scot (53) said:

    When I see someone mention the speed of light they mention it (as in a vacuum) well last time I checked the center (nor the crust) of our earth is not presented as a vacuum, now unfortunately we are not able to measure the speed of light between the two locations (as far as I know) so to me maybe it is the title of the article that really needs to be examined. Here are some of my personal optional titles that may not cause as large of an up roar “New possibilities in fluctuations of the speed of light”, or “Speed of light accelerates traveling through planets”.

    I’m not sure if this is relevant.

    They were not racing a beam of neutrinos against a beam of light. What we call the speed of light in a vacuum, c, falls out of Maxwell’s equations on the propagation of electromagnetic waves. Maxwell’s equations have been tested over and over and over again, and have been found to work.

    Without a constant speed at which EM waves travel through a vacuum, our theory of electromagnetism would not allow us to do all the amazing things we have done with it.

  52. Nigel Depledge

    Scot (53) said:

    One thing that is still very cool about this, we are able to shoot neutrinos through the earth and measure them on the other side.. Personally I think this is very cool and well a bit scary..

    I’m not sure why you’d find it scary. Neutrinos emitted by the sun pass through the Earth at the rate of billions every second. Neutrinos hardly ever interact with anything.

  53. Nigel Depledge

    Mike Saunders (54) said:

    If their timing is off, its really bad news. Timing down to the picosecond should be easily achievable. I do it in my lab every day, with a lot less fancy equipment than CERN undoubtedly has.

    IIUC, the issue may be around the synchronisation of the time between CERN and OPERA.

  54. Nigel Depledge

    @ Scott B (55) –
    That’s a dramatic claim.

    Are you intending to back it up wih some evidence, or just expect everyone to believe you?

  55. Taed

    This is touched on in other comments and probably by the experiment itself, but my first reaction is that the error could be due to not knowing the exact distance. 60 ns is only about 60 feet (20 m). Since apparently both sides of the experiment are underground, it seems that getting a good distance measurement would be difficult and prone to error. Someone commented that the distance was measured accurately, but I remain skeptical.

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