Breaking the Speed of Light


It’s been a tenet of the standard model of physics for over a century. The speed of light is a unwavering and unbreakable barrier, at least by any form of matter and energy we know of. Nothing in our Universe can travel faster than 299,792 km/s (186,282 miles per second), not even – as the term implies – light itself. It’s the universal constant, the “c” in Einstein’s E = mc2, a cosmic speed limit that can’t be broken.

That is, until now.

An international team of scientists at the Gran Sasso research facility outside of Rome announced today that they have clocked neutrinos traveling faster than the speed of light. The neutrinos, subatomic particles with very little mass, were contained within beams emitted from CERN 730 km (500 miles) away in Switzerland. Over a period of three years, 15,000 neutrino beams were fired from CERN at special detectors located deep underground at Gran Sasso. Where light would have made the trip in 2.4 thousandths of a second, the neutrinos made it there 60 nanoseconds faster – that’s 60 billionths of a second – a tiny difference to us but a huge difference to particle physicists!

The implications of such a discovery are staggering, as it would effectively undermine Einstein’s theory of relativity and force a rewrite of the Standard Model of physics.

The OPERA Neutrino Detector. Credit: LGNS.

“We are shocked,” said project spokesman and University of Bern physicist Antonio Ereditato.

“We have high confidence in our results. We have checked and rechecked for anything that could have distorted our measurements but we found nothing. We now want colleagues to check them independently.”

Neutrinos are created naturally from the decay of radioactive materials and from reactions that occur inside stars. Neutrinos are constantly zipping through space and can pass through solid material easily with little discernible effect… as you’ve been reading this billions of neutrinos have already passed through you!

The experiment, called OPERA (Oscillation Project with Emulsion-tRacking Apparatus) is located in Italy’s Gran Sasso facility 1,400 meters (4,593 feet) underground and uses a complex array of electronics and photographic plates to detect the particle beams. Its subterranean location helps prevent experiment contamination from other sources of radiation, such as cosmic rays. Over 750 scientists from 22 countries around the world work there.

Ereditato is confident in the results as they have been consistently measured in over 16,000 events over the past two years. Still, other experiments are being planned elsewhere in an attempt to confirm these remarkable findings. If they are confirmed, we may be looking at a literal breakdown of the modern rules of physics as we know them!

“We have high confidence in our results,” said Ereditato. “We have checked and rechecked for anything that could have distorted our measurements but we found nothing. We now want colleagues to check them independently.”

A preprint of the OPERA results will be posted on the physics website

Read more on the Nature article here and on

UPDATE: The OPERA team paper can be found here.



114 Replies to “Breaking the Speed of Light”

  1. There is a fact wrong. The neutrinos didn’t make it in 60ns, they made it in 60ns _less than_ 2.4ms. This also tripped me the first time I read it elsewhere, where the wording is less than clear.

    1. So I see the headline on MSN and go through the process:

      1) Roll eyes and groan.
      2) Think “Let’s see the real story that spawned another sensational, misleading headline.”
      3) Go to Universetoday.

      Step # 4 in the process is rare, last used around the Dark Energy confirmation time.

      4) Continue perusing UT each day until it becomes clear how our understanding of Relativity has been incrementally enhanced and deepened by the data.

  2. I could do the math but there are some here who really enjoy that sort of thing and I won’t take that from you. How fast are these guys going? I see new propulsion systems and warp drives even! Maybe we could build a ship of neutrinos! This is the sort of article for which I come to UT!

    1. If these results are accurate – and I have doubts about that, due to the fact that no peer review whatsoever has been done (“science via press release” is intended to garner more funding, and serious researchers don’t do it) – then the neutrinos were traveling a very, very tiny fraction of a percent faster than the speed of light.

  3. Okay, I couldn’t wait. That’s 40,000 times the speed of light! Not what ANYONE would call a “tiny difference”. 300,000 km/s is fast but 12 billion km/s is definitely faster. Need some corroberation here. Anyone have any pet theories on how this might be accomplished? What could even push something to that speed? Does that mean neutrinos can’t have baryonic mass? Or is it one of those old standby’s…neutrinos never cross the speed threshold because they are tachyonic, never slower than the speed of light?

    1. Nope – as Evan said, the article wording is wrong. They appear to be arriving in 60 nanoseconds less than 2.4 milliseconds so, if the results are confirmed, are travelling very slightly faster (0.0025%) than light.
      Interesting, nonetheless! What would be nice would be a 500 mile long perfectly evacuated tube between the ‘transmitter’ and ‘receiver’, with light photons being sent in parallel with the neutrinos to confirm than nothing else is affecting the timing. Easier said than done! :o)

      1. If i turn on a flishlight moving at 200.000m/s wouldnt the beam of light go 200.000m/s faster than one emited at 0m/s, that being 500.000m/s?

      2. Nope. Anyone measuring the speed of the beam would still see it as 300,000 km/s, and no matter how fast they might or not be travelling. c is c.

      3. That is what is so contra intuitive in physics. Logically it would be like that but experiments shows that this universe does follow a different logic than the human logic.

        And reality always wins over what humans think.

      4. 0.0025% faster is stated as statistically significant. All measurements are being accepted as perfect. The transmission equipment is claimed to be precise. Instead, there are probable errors that likely will be confirmed when technology improves in the near future, as it always does. Should the results stand, then the speed of light may be taken as the maximum speed of photons only, where the wave/particle duality may result in a “drag” that is not understood. “Zero” mass neutrinos may actually be ever so slightly faster than light, or not. Time will tell.

      5. Bob: I hope you and I have the time left in our lives to see the tell. My bet is that the equipment is insufficient to the task at hand but the results have stirred an even more fascinating dialogue in this column. Do keep those observations coming. They are fascinating in themselves. Now someone tell me about the math underlying the period of inflationary expansion in our universe; a subject as challenging as these speed of light commentaries. I may not have the gray matter to comprehend the discussion since I am mostly all ears!

      6. In the beginning there was only energy compressed into a single dimension. Space was “created” at the “time” of the Big Bang when two and then three physical dimensions were born. Space is not constrained by any speed limit as it is not physical, hence objects could be interpreted as having moved faster than light after the Big Bang when in fact it was space that expanded rapidly.. Since space expands in all directions the oldest observable radiation takes longer to arrive than expected as appears to slow down, or red shift, as space expands further. Perhaps the increasing expansion of space was brought about by additional, yet undetectable other than by gravitational pull, birth of additional physical dimensions.

      7. Assuming neutrinos do follow the standard model and travel at a fixed speed as established does it necessarily follow that neutrinos travel through dark matter at that same speed and yet dark matter to my humble knowledge has no known material description yet is postulated to exist. Is dark matter as postulated to exist in pristine form or could it also exist in unique combinations with matter as we describe it.

  4. Is it strange that the media is aware of this before peer review? Is that a red flag, or has this been externally vetted in some way?

    That’s the question I have… but if it comes up roses the, well, today is a pretty amazing day in the history of science, right?

  5. I agree with @O’Connor. This statement is incorrect. The statement should read the neutrionos arrived 60 nanoseconds earlier than expected, not 40,000 times faster.

    Where light would have made the trip in 2.4 thousandths of a second, the neutrinos made it in 60 nanoseconds – that’s 60 billionths of a second

  6. Errr…There’s also a mistake in the third sentence, should read 186,282 mps, not mph. just a typo I’m sure. I’m surprised you didn’t catch it IVAN, however I know that you disregard non- metric forms of measurement.

  7. I’m going to go out on a limb and say these results will not be reproduced by other researchers and the claims eventually retracted.

    1. this.

      they even might not be able to figure it out, and other researchers looking at their data might not be able to figure it out, but until it gets reproduced somewhere else, it doesn’t change anything; it’s just a mysterious systematic error.


      dang, that is one hell of a run on sentence.

    2. That’s entirely possible- the issue is simply that they couldn’t find anything that was distorting their research. Now, if it’s repeatable under similar conditions, then we have an interesting discovery.

  8. Speed of light mistakenly indicated as per hour rather than per second: understandable oversight. Time of point-to-point travel of neutrinos in this experiment erroneously reported as 60 nanoseconds TOTAL rather than sixty nanoseconds FASTER than 2.4 milliseconds: completely misleading.

    1. Ditto , if you read the Nature article , it is clear that he neutrinos are just 60 nanoseconds faster.
      Also I thought something : May be neutrinos actually move at the right speed of light ! ; It is light which is a laggard ! There is something on earth we don’t take into account and it slow the light. This mysterious thing permeate the void even the best we can make. And slow the light , like air or water do.

      1. The speed of light is the speed of light in the void. The speed of light in the air is slightly different and the speed of light in the water is way smaller. Thus your theory is most likely incorrect.

      2. I am out of the office until 26/09/2011.

        Je suis en congé , et répondrai à votre message à mon retour.

        Note: This is an automated response to your message “[universetoday] Re: Breaking the Speed of Light” sent on 24/9/2011 9:29:44.

        This is the only notification you will receive while this person is away.

    2. You’re completely right, while the speed of light conversion into miles was a complete typo, the 60-nanosecond speed was a confusion on my part while reading the releases. Both have been corrected.

      1. Thank you, and I’m glad you understood I wasn’t being critical. Besides, I’m glad you brought that item to our attention in the first place; quite fascinating…and mysterious!

  9. I think the researchers are doing the responsible thing here. They’ve got a result that cannot be right, but they can’t figure out where the error is coming from. So they’ve opened the floor to other scientists to see if THEY can find the bug.

    If all the other researchers can’t find the error, and subsequent experiments get similar results, only THEN do you begin to entertain the possibility that this result is actually real. It almost certainly is not.

    1. The results absolutely CAN be right, it would simply indicate the standard model is insufficient to describe our universe- something that we already know given that it cannot explain gravity.

      But yes, anything that could indicate a hole in a widely-accepted theory with as accurate predictive power as the Standard Model is an incredible result and deserves careful validation and humble treatment.

  10. This is a little off topic, but let me get this straight. We can send Neutrinos through solid earth at the speed or possibly faster than the speed of light and then detect them arriving at their target destination…?

    When can I can a wireless Neutrino internet connection?

    1. I’m guessing something like that won’t happen until the neutrino detectors and emitters get small enough to fit into a network card.

      1. It could take solid lead shielding several light years thick to prevent interference from random neutrino sources …. so your not going to like the miniaturization or the cost. Sowwy.

  11. This will burn off like the morning fog. The invariant mass is mc^2 = sqrt(E^2 – p^2), where this is negative for the tachyon. The neutrino mass would be imaginary valued. Now I do not know what it means to measure an imaginary valued quantity. The Regge poles m^2 = J^2 – n, n = 1 or 4 for open/closed strings, predicts an imaginary mass for a Tachyon with J = 0. These states are not physical and a constraint which removes them gives the elementary SO(24) SUGRA. The vacuum state for the tachyon is removed by standard QFT techniques. We might also think of them as being on a spacelike interval that recedes off to infinity instantly in the frame or gauge condition chosen.

    The speed of light is an invariant, where nothing can go faster than light because nothing can go slower than light. A distance in spacetime is

    d = (ct)^2 – x^2 – y^2 – z^2.

    Ignoring y and z and if something is moving along the x direction as x = vt then

    d = (c^2 – v^2)t^2.

    This leads to the curious observation that the faster something moves the shorter its spacetime distance is. There are two situations at either extreme. The first is that the object is at rest with us, and so d = ct. We and it are moving along a fourth dimension at the speed of light, even though we are at rest. The other is that c = v, which means that d = 0, or there is not spacetime distance. However, now this object is moving along the x direction at x = ct. It is not then hard to see that in effect everything is moving at the speed of light in their frame — not faster or slower, but c = universal speed of everything.


    1. Yes! So very fast moving mass could be seen as compressing space-time as its energy passes through at constant speed c, yes?

    2. OK I combed the net to see if I could understand how apparently scientists are able to “slow” light also using negative refractive index materials and whether this means somthing is going faster or slower than light?…

      Although the light is considered slowed in certain mediums, apparently this slowing only refers to the group velocity (of the wave-group w/in the EM field) and not the wavefront speed or main velocity of the light itself. To be honest it all makes my head hurt (but I enjoy trying to understand it and get a little more through osmosis each time I circle this message board;)

      Another possible instance of violation of speed c I could find was:

      (wikipedia reference on (Slow Light))
      It is thought that the Scharnhorst effect does allow signals to travel slightly faster than c, but the special conditions in which this effect can occur prevent one from using this effect to violate causality.
      Slow light is the propagation of an optical pulse or other modulation of an optical carrier at a very low group velocity. The term is usually only applied when the velocity is at least hundreds of times slower than the speed of light in a vacuum. –end quote

      Probably the best example I could find of something that violates the light “speed-barrier” / constant (c) in nature is (for readers – I know u are well aware):

      Quoting –
      Quantum teleportation is not the same as the teleportation most of us know from science fiction, where an object (or person) in one place is “beamed up” to another place where a perfect copy is replicated. In quantum teleportation two photons or ions (for example) are entangled in such a way that when the quantum state of one is changed the state of the other also changes, as if the two were still connected. This enables quantum information to be teleported if one of the photons/ions is sent some distance away. –end quote

      I guess by defintion teleporation involving quantum entanglement doesn’t involve sending physical objects or energy instantaeously (only conveying information through the quantum states of ions/photons) but it is starting to get close as “information” is one of the variables constrained by the speed of light as is matter/energy.

      Heres a quick thought experiment I dreampt up: Hypothetically if information were able to be transmitted vast distances instantaneously, perhaps a machine at the other end could use this information to replicate matter/energy based on this information – Then it could be said mass/energy travelled faster than light?? Perhaps my accounting is too creative???

      Curious 4 your insights LC.



      1. Quantum teleportation is a way quantum states may be nonlocally correlated at a distance. This process is not really a faster than light communication, and further the “Alice-Bob” teleportation requires that Alice communicate the orientation of her apparatus, which is the contextuality of the quantum outcome. Quantum mechanics is noncontextual with no local hidden variables. This requires Alice to communicate a classical signal to Bob with the orientation of her apparatus which selects the basis of states..

        The slow light or light trapping is an example of extreme indices of refraction. These systems are compared to black holes, and some model experiments are being worked to test certain theories. This does not change what I said about the speed of light being the universal speed.


      2. Here is a thought experiment I posted a year or two back for your amusement: A future military force is interested in protecting an important base from a laser attack, let’s call it the White House. They install a communications network around the area connected to light detectors serving as an early warning system. Let’s then say that a lossless anomalous dispersive medium is used (similar to that used in the Princeton experiment) within the cable network of the detection/warning system that is connected to a receiving station at the White House. A peak of a wave pulse (within the detection network) could be manipulated to arrive at the White House receiving station faster than a prospective laser beam sent to the White House through the air.
        There is no question that if such a transmission cable could be constructed that such a pulse could be sent faster than a laser beam. There is no question about whether or not the wave pulse could be detected as it was detected in this experiment. The question about whether or not this wave pulse constitutes a signal or not is merely a matter of semantics since the medium produces a smooth light pulse with a finite spectrum whereas traditional signals are defined as having an infinite spectrum. We know from experiments done by Gauthier that the pulse received cannot carry information within itself. That information does not propogate faster than c. But what if the pulse itself is the information? A computer at the White House could detect that a pulse is being received from the (hard-wired) laser attack detector system and can then have a number of nanoseconds to activate a counter-measure to an airborne laser attack before it arrives.
        The only argument that I think could be used against this is that the detector would likely have to do some computations to confirm the light pulse is an attack before sending a pulse. That would likely delay the arrival of the pulse until after the laser beam struck. Also a few nanosends might not be enough time to activate an effective defense.

      1. It is very educative and invites you to dig deeper into the material instead of staying in the philosophical only layer.
        A lot of philosophical gets exposed as quackery very fast the moment you go into the maths part.

        e.g. Did you notice that he wrote the 4ths dimension (time) as ct? And not t?
        ct = lightspeed x times = distance.

      2. LC is UT’s most prolific science commentator. He digs under the surface and presents the mathematical arguments and mechanics that underpin our understanding.

        Overtime, LC’s comments become less difficult to understand if one takes the effort to look up the terms and principles he often refers too.

        Of course, sometimes he throws out a curve ball and presents in-depth information on theoretical work (often areas he is working on). These occasional posts still break me out in a moderate sweat.

      1. The equation is a form of Pythagoras’ theorem; c^2 = a^2 + b^2 for a right triangle. In general it is a distance formula in any space with an orthonormal coordinate system. In spacetime there is a sign difference between the time part and the space part.


  12. I have to say some facts here are wrong because Eisenstein’s theory of relativity says that “if u travel at the speed of light u can travel through time”. So if the neutrino travels even faster it should disappear the moment it is shot and should travel through time

    1. Or it’s traveling backwards through time in the opposite direction you observed. Which would mean the neutrinos in the experiment were actually from a future experiment, and whoever conducted the first experiment probably stopped evolution from happening in some alternate timeline.

  13. What the hell? I’m seeing this in newspapers everywhere around the world. If confirmed, then yes – this would be an extraordinary finding. But extraordinary claims required extraordinary evidence, and I would have expected that at least 3 or four independent teams would have confirmed the result before we’d see hoo-haa in the press about it. Science-by-press-release is deplorable.

    The most disappointing thing about this is that when a systematic error is found in the measurements (which is most likely the case), there will be no public retraction by the news organisations. I’ll spend the next 20 years explaining to people how there was not in fact ‘some experiment that proved you can travel faster that the speed of light’, or that they have zero idea what they’re talking about when they claim ‘Einstein was wrong and they knew it all along’.


  14. There was a controversy regarding the neutrino emissions from SN 1987A as to why they arrived 3 hours before the visible light did. One explanation is that neutrinos travel faster than the speed of light and the other was postulated was simply that the visible light could not be seen until the shock wave from the collapsar reached the surface of the star whereas the neutrinos were not so inhibited. I am wondering if this result correlates in any way with the SN1987A data. How much faster would the neutrinos from this star in the megellantic cloud have to be going than light speed to arrive 3 hours earlier, and does that match the speed of these neutrinos? It is a simple math problem once you know the distance to that star which I do not.

    1. 3 hours in a travel time of around 168000 years looks to be a tinier ratio but that’s an interesting thought. I get a ratio of about 2.4×10-14 which I think is smaller than the difference being observed. That assumes all neutrinos play the same game though.

      1. Thanks, that’s the trouble with SIMPLE arithmetic! I have an error in the calculation for the possible difference in speed for the supernova neutrinos compared to photons and it is actually 2E-9. Still way too small compared to the experimenters ratio.

      2. Thanks, that’s the trouble with SIMPLE arithmetic! I have an error in the calculation for the possible difference in speed for the supernova neutrinos compared to photons and it is actually 2E-9. Still way too small compared to the experimenters ratio.

    2. If the measured neutrino velocity is correct, given the distances involved with SN1987A, the neutrinos should have gotten here years before photons, not hours. SN1987A is really good evidence that neutrinos are subluminal.

      1. Yes. On the Nature blog, theoretical physicist Ellis was referred to as having made similar comments. The FERMI MINOS paper mentions it too.

    3. It is not just that neutrinos arrived 3 hours faster; but it is the light that has been observed 3 hours late.

      1. Thanks to all for the responses. There is a small teaching point here with regards to random walk which is how it is possible for photons to be held back 3 hours when the star that went supernova obviously could not have been 3 light hours wide in diameter. Only when the shock wave from the implosion reached and obliterated the surface of the star could the photons produced from the event be seen. Since neutrinos do no interact with matter in the same way as photons they did not experience random walk and came straight at us. The three hour delay for the photons then is a function of both the diameter of the souce star before it imploded and the speed of propagation of the shock wave that spectacularly tore the remainder of the star apart.
        So it looks like the speed of light is upheld for neutrinos from this evidence that nature threw at us and we recieved in 1987. I am still curious enough to follow this to see what systematic methodological error or flaw led to this confounding result. Perhaps something useful and unexpected will come out of this with regards to how to calibrate the equipment properly or how to control the methods better to stamp out unexpected correlations that bias the results, but most likely instead of a great discovery this will turn out to be a great embarassment that will quickly be forgotten.
        In any event, a methodological error is far more likely than the alternative that somehow the different condtions of the OPERA experiment (versus a supernova) accelerated the neutrinos by an unknown mechanism. I would rule out the medium between the detector and OPERA as a source of acceleration from what we learned from the SN1987A event.

      2. I still am sceptical about neutrinos acting like tachyons. The SN1987A event might prove this concept wrong. I am now thinking if the effect of Earth’s rotation is included in their computations.

  15. “The invariant mass is mc^2 = sqrt(E^2 – p^2), where this is negative for the tachyon. The neutrino mass would be imaginary valued.” I recall a press report a few years back where a group measured the square of the neutrino rest mass and got a negative number with error bars below zero … I don’t remember ever seeing an explicit rebuttal or retraction (we never do, it seems), just Wikipedia now saying that the best estimates are positive.

    Given the lack of peer review and the stunningness of the result, I too think it smells like moldy cannoli, and I too expect this to not be reproduced and to fade quietly from view. But boy it’ll be stunning if reproduced elsewhere.

  16. Einstein’s theories of relativity do NOT say that nothing can travel faster than the speed of light. They say that nothing with non-zero rest mass can ever cross that barrier; although, zero rest-mass particles can do so. The real problem here is the relation between local and non-local events, e.g.: the dynamics of universal structure. Experimental tests of Bell’s inequality have shown that microscopic causality must be violated; i.e.: there must be faster-than-light travel. In any physical theory, we must assume that there is some kind of non-local structure – and this non-local structure itself violates causality – i.e.: it must assume faster-than-light connections exist in order for it to exist and to validate any physical laws.

  17. Einstein’s theories of relativity do NOT say that nothing can travel faster than the speed of light. They say that nothing with non-zero rest mass can ever cross that barrier; although, zero rest-mass particles can do so. The real problem here is the relation between local and non-local events, e.g.: the dynamics of universal structure. Experimental tests of Bell’s inequality have shown that microscopic causality must be violated; i.e.: there must be faster-than-light travel. In any physical theory, we must assume that there is some kind of non-local structure – and this non-local structure itself violates causality – i.e.: it must assume faster-than-light connections exist in order for it to exist and to validate any physical laws.

    1. Einstein’s theories of relativity do NOT say that nothing can travel faster than the speed of light.

      Yes, it does. Particles “on shell” get “off shell” by acquiring imaginary energy. These entities are computational devices of field theory, not real particles.

      Experimental tests of Bell’s inequality have shown that microscopic causality must be violated;

      Excuse me? The very idea behind the inequality and its test is that relativity is taken to be preserved. So causality is preserved too, naturally. All physical observations and theories to date are causal. To suggest otherwise is to not have done due diligence.

      The outcome of the tests is consistent with the prediction, and shows that there are no hidden variables. Hence relativity and quantum mechanics are compatible, and especially quantum systems shows entanglement.

  18. So, the most advanced particle physics lab in the world has got it wrong? And wasted two years worth of work and 16,000 “events” at who knows what cost, just to be told by every par-time wikiscientist (refrence the hacks on most sites these days, no disrespect to the real guys who kindly explain the hard stuff for me) with a computer and more supposed knowledge than The big E himself that its all wrong? Hmmmm…..still, science via press release has about as much weight as one of these ftl particles.

    1. No, no, we are just goofing off.

      But then maybe they were. As you say, it wasn’t exactly a cautious release of extraordinary support for an extraordinary claim.

  19. Should consider plate tectonics and continental drift that could influence the experiment. Experiment to be confirmed by other laboratories of physics

  20. I would think that perhaps these things are traveling at the correct limit and light is being slowed by gravity and interactions with other particles… my 2 cents.

  21. If this turns out to be confirmed, then it would be the most remarkable discovery since Einstein’s theory itself.

    However, I’m thinking that something mundane was missed, which caused an error. I kinda hope it is true, because I want a warp drive! 😉

  22. I’m not a scientist, so I have to ask – how do they know its not some random neutrinos from elsewhere they are detecting?

    1. They produce neutrinos in bunches, and can recognize the accelerator beam packet periodicity, rough travel time, and over all particle bunch spread by comparing to a local detector.

  23. OOPZZZ! …Nothing in our Universe can travel faster than 299,792 km/s (186,282 mph), not even…

  24. If nothing else, this story has created a regular ‘firestorm’ of controversy and a re-examination of accepted theory. That in itself makes this news release valuable, even if or when it is proven wrong!

  25. If neutrinos are traveling faster than the speed of light there’s a time dilation effect to consider. Therefore the ones you think passed through my body didn’t because I wasn’t there at the same time they were.

  26. Free of Einstein’s cage? I’ve always hoped so, but then there’s the problem of colliding with 10^6 Hydrogen atoms per cubic metre at > c, we’re going to need a shield. I love TL’s idea of failing to account for Earth’s curvature though, that would that be embarrassing. All in all I’m glad I was born when I was, everything seems to be turning up surprises right now. The advanced supernova neutrino burst is an interesting thought but if neutrinos can exceed c then why does it have to be by a fixed amount?

  27. And if the results prove to be accurate and some things actually can travel faster than the speed of light, so what? I always thought that is what science is all about, learning new things using the scientific method. Is it possible to learn new things without occasionally learning that previous learning was incorrect? I don’t think so. We ought to always keep our minds open.

  28. “We don’t allow FTL neutrinos here”, said the barman. A neutrino walks into a bar.

    [HT Miscience]

  29. Nice, what an interest in mere physics!

    So … has everybody caught where they goofed yet?*

    It is an easy one. According to the paper the distance measurement procedure is documented here, and they use the geodetic distance in the ETRF2000 (ITRF2000) system as given by some standard routine. The european GPS ITRF2000 system is used for geodesy, navigation, et cetera and is conveniently based on the geode.

    I get the difference between measuring distance along an Earth radius perfect sphere (roughly the geode) and measuring the distance of travel, for neutrinos the chord through the Earth, as 22 m over 730 km. A near light speed beam would appear to arrive ~ 60 ns early, give or take.

    Of course, they have had a whole team on this for 2 years, so it is unlikely they goofed. But it is at least possible.

    [Note added after publication: I reread the paper, and I don’t see the explicit conversion between the geodesic distance and the travel distance anywhere. Maybe they *did* goof.]

    Unfortunately the technical details of the system and the routine used to give distance from position is too much to check this quickly. But the difference is a curious coincidence with the discrepancy against well established relativity.

    * Extraordinary claims need extraordinary evidence. Other outstanding concerns are:

    1. This needs to be repeated.

    2. It is not a clear photon vs neutrino race. Physicist Ellis and others here noted that the time differential for the supernova SN 1987A was a few hours, but at the distance of ~ 200 000 ly it should have been years if the suggested hypothesis would be correct.

    3. Analogous to the experiments where light waves seemingly travels faster than photon speed in vacuum, they don’t measure travel times of individual neutrinos but averages over a signal envelope. That must be carefully measured to establish that particles (or information, for that matter) travels faster than relativity allows.

    Especially since the neutrino beam oscillates between different kinds of particles!

  30. No. The photons travel through space at the same speed. If you were traveling at nearly the speed of light the photons would slowly leave your flashlight. Space is not analog.

  31. I formulated the existence de speeds of some particles in the vacuum greater than c in my paper “VELOCIDADES MAYORES QUE LA VELOCIDAD DE LA LUZ” (“Speeds greater than the speed of the light”) published in 1969 in the newspaper “El Siglo” in Colombia. The present discovery on the speed of the neutrinos is the beginning of the show of the speeds superluminaries.

  32. I formulated my theory on the existence de speeds of some particles in the vacuum greater than c in my paper “Velocidades mayores que la velocidad de la luz” (“Speeds greater than the speed of the light”) published in 1969 in the newspaper “El Siglo” in Colombia. The present discovery on the speed of the neutrinos is the beginning of the show of the speeds superluminaries.

  33. If they are right, one day we may say: “If I were made of neutrinos…” instead of “If I could turn back time…”

  34. Of course, for example here is Phillip Gibbs, an “independent physicist” (i.e. most likely a general crackpot; at the very least a facilitator of such through his ViXra clone of Arxiv), who nevertheless makes some valuable comments:

    “The only physical idea that would correspond to a lack of energy dependence [seen in the CERN results] would be if the universe had two separate fixed speeds, one for neutrinos and one for photons. I don’t think such a theory could be made to work, and even if it did you would have to explain why the SN1987A neutrinos were not affected. I think the conclusion has to be that there is no new physical effect, just a systematic error that the collaboration needs to find.”

  35. If you listen to the media, and don’t have a science education, then you might think there was a serious chance that scientists have broken the speed of light barrier. Here’s my digested version of the recent FTL hoopla…

    * Einstein was wrong?

    Not yet, he isn’t. Science is all connected. It would be difficult to break the speed of light limit and not break the theories that allow your GPS or your computer to work. Similar neutrinos from distant astronomical events arrive after the light. The paper cites the SN1987A supernova evidence.

    The paper’s authors are saying that the measured time of flight of the neutrinos is out by 60 nanoseconds: if this measurement were accurate then the neutrinos were going faster than light. They practically say that result is so insane, there has almost has to be something systematically wrong with the measurements. For completeness, we include the possibility of FTL particles, but we don’t really believe it ourselves.

    * The timing is out by 60 nanoseconds

    60 nanoseconds is 120 cycles of a 2 GHz clock, like the one you may have in your computer. It is 2 meters at the speed of light. This is not a tiny difference to a huge sum like the Pioneer anomaly.

    We can synchronize clocks to much better than this. We do not need to race light alongside the neutrinos. If we have a fibre optic link, we can send a pulse from CERN CNGS to OPERA, and back again. If you know the time for the round-trip, then half the time is the time taken to go one way, with maybe a tiny correction if one end is higher than the other, and the light is doing work against gravity.

    We can measure 700 Km to much better than 2 meters. There is a lovely graph showing the distance plotted against time, showing the shifts in 3D. The continental drift of 1 cm/year shows up clearly. You can see a sudden jump of 7 cm that coincided with the L’Aquila earthquake.

    * Is the result repeatable?

    The authors quote a six sigma limit on the result. The ‘sigma’ or standard deviation is a measure of how far away from the average value you are on a standard ‘bell’ cure graph. Six sigma means that the odds of this occurring naturally from the known random variables is 3.4 in a million.

    This shows that they have done about as much as is sensible to eliminate random error. However, if they are measuring from the wrong place, they will have exactly the same error every time. This is not a random error but a systematic error. I could get the same probabilities by averaging thousands of measurements with an inaccurate ruler, but that would not make me right.

    * Okay, Mister Wise-Ass, what is it then?

    Well, we don’t know. The OPERA detector is a big thing, and the CERN CNGS source is far from small. Remember that the Hubble telescope was originally assembled to an accuracy of 1/400th of a wavelength of light, tested, sent into space, and then found to be half an inch out. It would be easy to lose a meter or so trying to work out where exactly the detector plane lies within OPERA, or something like that.

    It may not be a spatial error: the timing is pretty complicated too. The detector does not instantaneously detect neutrinos, so you have to correct for all the delays in the system, and maybe one of those delays has been overdone.

    * So, how can we know what’s going on?

    The experimenters are doing the right thing. They looked for an obvious solution. They could not spot it, so they are opening the problem up for others to look at it. Sometimes, when you have worked on the same apparatus for years, a newcomer is able to spot something that you have missed.

    They have already repeated the experiment on the same apparatus a lot of times.
    It would be nice to reproduce this in a separate lab, but there isn’t really another facility quite like this just now. They aren’t cheap. If we really cannot sort this problem, we are going to have to build something.

    If we made another OPERA at half the distance, we would get a timing difference of 60 nanoseconds if there is a timing error, or 30 nanoseconds if the particles were really going faster than light. This would be expensive, but it might be practial to make another smaller detector much closer to CERN CNGS. If you are 30 times closer then you ought to get 30×30 or about a thousand times the signal. If we are 30 times closer and we still get the 60 nanoseconds timing error, then we know something is wrong.

    My guess is the mistake will be found, and we won’t have to build an extra detector. If we build an extra detector, the most likely result is still that we find a systematic error. If we build a second detector and the speed still comes out the same fraction faster than light, then we may start talking about faster than light particles with some small measure of belief that they may really exist.

    The truth is out there somewhere. It’s probably rather dull.

    1. FWIW, in 60 ns light travel ~ 18 m.

      It is also reasonable, since a 2 GHz chip would be a few millimeters long, so 120 clock cycles traveling the chip through transistor gates would be a factor 10 or more slower.

      If you get down to compare with 2 meters light travel, you have shrunk the chips and/or quickened the transistors *a lot*.

      1. Yep. Damn. I wrote that rather too fast, and under the influence of a BBC news mention of “evidence for faster than light particles”, and dropped a power of ten. Bah.

        18 meters is a big error for a survey, so this would tend to point towards a timing error. However, the paper has a lot of authors, and I expect they have thought along these lines before they posted.


  36. See full letter at:

    Dear Antonio Ereditato,

    I am taking you up on your appeal for scrutiny of the results from the OPERA experiment that you made public at a BBC News interview on September 22nd, 2011 ( :

    “we want just to be helped by the community in understanding our crazy result – because it is crazy”.

    When I heard your name on TV, in newspapers, etc. I was reminded of, and hopefully you will recall, the several dinners and gatherings over several years we shared at CERN 30 years ago with Luciano Ramello, Tiziano Camporesi, Mario Caria, Vittorio Remondino, etc. when I was working at CERN on the trigger of the Delphi experiment.

    Here is my scrutiny of the results of your experiment.

    I will first summarize what you stated – that you measured the time it took for a neutrino beam to travel a distance of 732 Km, and it took 60 nanoseconds less time than it would have taken a light beam to travel the same distance.

    After trying and failing to find any errors you stated:

    “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‘. ”

    The most logical step to have taken the first time you found this “crazy” result three years ago would have been to plan a specific low cost experiment that would clarify this discrepancy. Instead, you kept doing and redoing the same experiment for three years acquiring “travel times of neutrino bunches some 16,000 times”! Remember Albert Einstein’s definition of insanity: Doing the same thing over and over again and expecting different results.”

    You needed to clarify the discrepancy of a Time of Flight (TOF) measurement of 60 nanoseconds (equivalent to 60,000 picoseconds) over a total duration of 2.43 milliseconds.

    There exist thousands of articles describing apparatus (detectors and electronics) that can make accurate TOF measurement with a resolution as precise as 10 picoseconds (or even 6 picoseconds as presented some time ago at a workshop at Stanford Linear Accelerator –SLAC-).

    So this is what I would have done three years ago:

    Since the discrepancy you found is so big, you do not need the neutrino to travel 732 Km in order to see this discrepancy. Using simple proportions traveling just 3.2 Km distance should give you a difference of about 260 picoseconds which is 26 times greater than the 10 picoseconds resolution step of your measuring apparatus.

    Remember Galileo’s simple experiment of taking two stones of different weights and dropping them at the same instant from the leaning tower of Pisa and then verifying that they reached the ground at the same time.

    Now, send two beams in burst of bunches (these can be sent separately, but simultaneously and repetitively will facilitate viewing the minimum differences in real-time), one light and one neutrino in the underground 3.2 Km SLAC tunnel (or take two LHC experiment sites A and B at CERN of approximately 5 to 7 Km distance from each other, send neutrino bunches underground and send light bunches between 2 towers above ground from site A to site B); build two identical electronic channel circuits (or purchase off-the-shelf components) with a time resolution of 10 picoseconds (or 6 picoseconds) to measure the traveling time of the two beams; within the detector, use the same transducer (if possible) to convert light into electrical signals (e.g. Photek PMT240 or fast SiPM from Hamamatsu or STMicroelectronics); then SWAP THE TWO ELECTRONIC CHANNEL CIRCUITS and repeat the experiment on the two burst of bunches to make sure that the neutrino beam (as well as the light beam) has the same speed regardless of which electronic channel is used (otherwise the fault would lie in the measuring device). By synchronizing the start of the burst of bunches, at the arrival point you would be able to see in real time with a fast oscilloscope the minimum difference on travel time between the two beams (just like two cars racing).

    If the discrepancy (neutrino bunches arriving faster than the light bunches) still persists, then you should be confident of having done a diligent accurate experiment and others should be able to obtain the same results.

    The reason for measuring the speed of the light beam as well as the neutrino beam is not because it is necessary to measure one more time the speed of light which has been measured thousands of times, but the goal is to test the accuracy or your electronics (achieved by swapping electronic channel circuits), with the speed of light as your source of calibration or reference. Believe me, it was not trivial for me to design DUT (Device Under Test) boards at the Superconducting Super Collider in 1992 for the HP8200 half-million dollar test station of integrated circuits with a time resolution accuracy of 50 picoseconds at all pins of the device under test. I was certain that my design and circuit implementation were correct only by comparing signals.

    In scientific research it is necessary to master calculations that will predict specific results. It is necessary to master how to conduct an experiment, to master the knowledge of electronics, detectors, and all components that will be used in the experiment. It is necessary to know the expected results, reproducible by different instrumentation (swapping electronic channel circuits), and ultimately confirm or reject calculations. Only then is money not wasted, experiments can confirm calculations, and the door to progress is opened. Here it looks like nothing has been mastered because the discrepancy is not explained with calculations, it is not explained from the results of the experiment, and it is just called “crazy results.” Results from untested performance of the measuring instrumentation (achievable by swapping electronic channel circuits that measure two parameters), risks alarming many people, discredits scientific research and wastes a lot of newspaper ink and TV time.

    Have you calculated how much money you and your collaborators have spent these past three years on conducting inconclusive tests instead of comparing in a scientific way the speed of two beams?

    There would be no need to mention the word “crazy” after having conducted this scientific procedure.

    In research it is important to discuss, identify, and implement scientific procedures that allow the laws of nature to be understood. A dialogue is key to identifying the most cost effective scientific procedure that will yield the most accurate results.

    I hope this example of a scientific procedure to check if neutrino breaks the speed of light helps.

    Best regards,

    Dario Crosetto
    900 Hideaway Pl.
    DeSoto, TX, 75115 – USA

    Email: [email protected] or [email protected]

    Link to the BBC NEWS: “Speed-of-light results under scrutiny at Cern”

Comments are closed.