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Science

Faster-Than-Light Particle Results To Be Re-Tested 412

Posted by samzenpus
from the check-your-work dept.
surewouldoutlaw writes "After the astonishing news from CERN that the OPERA experiment had detected neutrinos traveling faster than light speed, challenging Einstein's theory of special relativity, there has been some skepticism over the results. Now Fermilab, near Chicago, has announced it will attempt to replicate the experimental results within four to six months."
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Faster-Than-Light Particle Results To Be Re-Tested

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  • If you didn't see this coming, then you don't understand science...

  • by Anonymous Coward on Monday September 26, 2011 @09:26AM (#37515322)
    The barkeep says 'We don't serve faster-than-light particles in here'. A neutrino walks into a bar.
  • Standard practice (Score:3, Informative)

    by dnewt (2457806) on Monday September 26, 2011 @09:28AM (#37515334)
    Confirmation of the results of an experiment by an independent party is standard practice in the scientific community. Without it, the findings wouldn't even be considered completely valid! Nothing to see here...
  • Damn straight (Score:5, Informative)

    by mbone (558574) on Monday September 26, 2011 @09:30AM (#37515342)

    They already did the experiment, and actually found similar results [arxiv.org] but did not claim any significance. Of course they are going to repeat this, once they finish kicking themselves.

    • Re:Damn straight (Score:5, Informative)

      by LeDopore (898286) on Monday September 26, 2011 @09:35AM (#37515404) Homepage Journal

      From TFA: “We should have a result in 4-6 months as the data is already taken. We just have to measure some of our delays more carefully,” - Jenny Thomas.

      MINOS was already repeating their measurements, but CERN got the jump on them. It's anyone's guess too whether there was a back channel of information from OPERA to MINOS that might have tipped them off and encouraged them to start taking data early. With so many people involved, you almost have to assume that preliminary findings migrate across the Atlantic pretty quickly.

      • Re:Damn straight (Score:5, Interesting)

        by mbone (558574) on Monday September 26, 2011 @09:51AM (#37515602)

        Yes, I would agree. 184 coauthors can keep a secret, if 183 are dead.

        Note that there is already a theoretical paper out on these results [arxiv.org], so it has been percolating around a little. Note also that this paper says

        The MINOS collaboration reported a measurement of the muonic neutrino velocities that hints to super-luminal propagation, very recently confirmed at 6 [sigma] by OPERA.

        Do I smell a priority fight coming ?

        • by lennier (44736)

          184 coauthors can keep a secret, if 183 are dead.

          And there's the plot of Final Destination 6: Einstein's Revenge.

    • by LordLimecat (1103839) on Monday September 26, 2011 @10:22AM (#37516020)

      Of course, once they realized that some fool of an intern ordered a Denon AKDL1 link cable [amazon.com] (see first review)-- which of course unleashes all sorts of problematic physics-- everything became clear.

      Once they replaced it with a link cable from best buy, the results were as expected.

  • Good (Score:5, Insightful)

    by Ironhandx (1762146) on Monday September 26, 2011 @09:31AM (#37515368)

    The process is working.

    The scientists at CERN asked for peer review and checking of their methodology. This announcement means that at least on paper the method was near-perfect for Fermilab to be committing resources in the near future to prove/disprove it.

    • Professor Brian Cox explains [bbc.co.uk]
      Hope this works for non-UK IPs; It's interesting.

      • by pacinpm (631330)

        Hope this works for non-UK IPs;

        It doesn't. At least not for Poland. I hate regionalization of content.

    • by Extremus (1043274)

      People at OPERA project are having an exemplar scientific conduct. It is amazing how they actively refused to elaborate any theories on their findings, restating their job as unbiased experimental physicists. This is pure scientific method.

      • Re:Good (Score:4, Informative)

        by Artraze (600366) on Monday September 26, 2011 @10:10AM (#37515828)

        I somewhat disagree. Their results met the criteria of scientific discovery and they (well, I certainly hope!) reviewed their process for any error. So even though they literally, by scientific standard, discovered FTL particles, they explicitly state that they don't actually think they did because it disagrees with existing theories. This is *biased* experimental physics.
        Yes, relativity has a good track record, and they likely missed something. OTOH, neutrinos are still a pretty new research topic and maybe relativity doesn't cover all the universe has to offer. I do think that these results should be retested, verified, and studied as much as possible. But I'm also seriously disappointed that an ostensibly legitimate discovery has to be presented as 'we screwed up but we don't know why so look at these' in order to avoid raeg from close minded scientists.

        • Re:Good (Score:5, Interesting)

          by Electricity Likes Me (1098643) on Monday September 26, 2011 @10:24AM (#37516048)

          You say that because you're probably not intimately familiar with just *how* well established General Relativity is.

          It's a theory which has survived decades of absurdly rigorous testing. Being cautious in how you present it is absolutely the correct approach - and far more responsible then how say, the debacle over cold fusion [wikipedia.org] was handled.

          These are not trivial measurements to make, nor is there any obvious explanatory theory that they confirm. They also aren't a gross excess - well bounded, but a very small difference which is on the same timescale as the delays in the processing speeds of the individual components of the apparatus. It's only us sci-fi nerds who fully expect (want) FTL to be possible and Relativity broken somehow.

          • Re:Good (Score:4, Informative)

            by Baloroth (2370816) on Monday September 26, 2011 @11:09AM (#37516534)

            And yet General Relativity isn't even as well established a theory as Newtonian mechanics was (which had a century of observational evidence backing it up), or for that matter geocentric theory, which had millennia of observations backing it up (every scientists before and during Galileo's time believe the Earth was stationary, except for a very very tiny handful. It was actually the scientists, not religion, that rejected Galileo's theory when he first presented it.)

            Both of them were overturned by more careful observations, in ways and of things we couldn't or hadn't observed before. We already know General Relativity has issues (specifically, with quantum mechanics), and while its predictions fit well with our observations so far, it hasn't actually been proven definitively. It is entirely possible that it is very accurate, but not precisely true. In fact, judging from the history of scientific theory, that is by far the most likely possibility.

            New science is nearly always happens when scientists find something they don't expect. These observations may be an error, or they may be the beginning of the discovery of an entirely new theory that explains General Relativity even better, just as Relativity explained Newtonian physics better.

            • Your metric for establishedness of a theory is flawed because it fails to take into account the rise in population (and even greater rise in scientific output per capita). GR could be considered to be more established than Newtonian physics, because, even though it's been the main paradigm for a shorter time, in this time it was recognised (and not disproven) by a larger number of people.

          • by Artraze (600366)

            I'm quite familiar with how well tested GR is. I'm, not, however, aware of any of those tests involving neutrinos. Besides, we already know we don't know how GR relates to quantum mechanics. Maybe this is just an example of that on a macroscopic scale. The point being is that GR is extremely robust in those areas where it's been heavily verified, but that robustness doesn't automatically translate into robustness in other areas. Before we had high energies / high precision Newtonian mechanics were also

        • by 0123456 (636235)

          So even though they literally, by scientific standard, discovered FTL particles, they explicitly state that they don't actually think they did because it disagrees with existing theories. This is *biased* experimental physics.

          If relativity is broken, much of modern physics falls apart. Not only that, but we have measured neutrino velocity before to within one part in a few million and they weren't FTL.

          So given that, any sensible scientist will say 'here are our results, surely there's something wrong but we can't find it', and I think we can be almost certain that there is indeed something wrong in the measurements. We'll know sooner or later.

  • by wfstanle (1188751) on Monday September 26, 2011 @09:39AM (#37515452)

    I did have a college physics covering relativity but it was a long time ago. Correct me if I am wrong, but Einsteins Special Relativity theory doesn't prohibit speeds faster than light. It just prohibits speeds EQUAL to the speed of light. If so, It would be problematic to accelerate past the speed pf light or to decelerate to slower than the speed of light.

    • Special relativity prohibits faster than light travel unless you don't care about causality.

      Given that it's hard to do science at all without causality that's going to be a hard sell. So the alternative is to throw out (tweak) special relativity.

      Maxwell's equations imply special relativity imply nothing can travel faster than light.

      There's a lot of very established physics that is going to need rethinking if this result is real.

      Tim.

  • Six if they don't. ;)
  • by LeDopore (898286) on Monday September 26, 2011 @09:44AM (#37515506) Homepage Journal

    OPERA has just found that either neutrinos travel 0.03% faster than photons we've measured, or their equipment has an unknown systematic error. Assuming there's no equipment error, I would find it more palatable to assume that light around Earth travels a bit below c and that neutrinos travel closer to c. What we think of as vacuum could really be a medium with refractive index 1.0003, perhaps due to a uniform background of weakly-interacting particles (maybe even dark matter) that affect photons but not neutrinos.

    I have a physics undergrad degree; if there's someone here with better qualifications, would you care to weigh in on the idea that c could be 0.03% faster than the speed of light we measure on Earth?

    • by rwa2 (4391) *

      My only regret is that the only people who might actually want to invest in 0.03% faster neutrino communication technology are HF traders, so they can shave another 60ns or so advantage from their competitors :-/

      But who knows, maybe the galaxy is filled with neutrino-based communications we haven't been tuned into, and someday SETI will pick up their messages of "sell! sell!"

      • I'd be surprised if they weren't designing a neutrino-based network already. Either neutrinos move faster than light or neutrino detectors have less lag than fiber-optic NICs. It's a win-win.

        • by Artraze (600366)

          Meh... All jokes aside, if neutrino communications could be managed (in particular, efficient and highly directional emitters/detectors) would be worth a lot more regardless of this experiment.
          First, light only travels about 66% c in fiber, and said fiber needs to wrap around the circumference of the Earth. So not only would neutrinos travel faster than light in a fiber (as they go pretty close to c for sure), but they could also just so straight there through the Earth. You'd probably be looking at rough

          • So not only would neutrinos travel faster than light in a fiber (as they go pretty close to c for sure), but they could also just so straight there through the Earth

            I was thinking about this but if I understand correctly, neutrinos are "filtered out" as they pass through greater amounts of solid material, so to ensure a signal would go through a great deal of solid material (like the whole planet) it would take a great deal of energy on the emitter side.

            I have little more than high-school physics knowledge so I don't know if the amount of energy required alone would make it impractical. But I do know that instruments used to detect neutrinos from the sun are placed und

    • by Artraze (600366) on Monday September 26, 2011 @09:56AM (#37515666)

      It's an interesting idea, but quite unlikely... Remember that the speed of light is (supposedly!) an absolute, somewhat like absolute zero, and thing tend to approach it asymptotically. One can therefore tend to see where exactly the asymptote lies, and we'd quite likely notice the difference. For example, particles in the LHC travel at c - 0.0000009% and have the corresponding properties as predicted by relativity. If they were, in fact, traveling at c - 0.03% our calculations should be / are off by over 3 orders of magnitude (gamma 7500 vs 4).

      In short, that much error in c would pretty much wreck relativity anyways.

      With the caveat that I don't really have better qualifications than you :).

    • by evanbd (210358)
      If that were the case, we should be able to accelerate particles to faster than light speeds. There's nothing that prevents a particle from traveling above c in a material with an index of refraction > 1; see Cherenkov radiation [wikimedia.org].
    • Plausible, but will be really interesting if the neutrinos can travel faster than light. Why? Imagine the possibilities. And I could put another possibility: What if the photon have mass (really small, but not zero) and this mass is slightly larger than that of a neutrino? This would cause the neutrino to be faster than the photon.
    • by vlm (69642) on Monday September 26, 2011 @10:05AM (#37515772)

      What we think of as vacuum could really be a medium with refractive index 1.0003

      Ahh, the old subatomic ether thing. Look up michelson-morley interferometer experiment that lead to all that relativity stuff... At 300 ppm, that effect, if it existed, would prevent most interesting interferometer technology from existing. No FFT-IR spectroscopy, most inertial navigation systems would be too drifty to use, astrophysicists would not be able to do the interferometer thing using multiple scopes...

      The other problem is we've verified E=mc2 and time dilation to much better than 300 ppm both of which depend on c.

      Also, its expensive, and a bit beyond my basement, but your average RF engineer can build stuff to better than 300 ppm on first principles.

      Then you start offending the chemists. I have to think about it a bit, but wouldn't this screw up quite a bit of chemistry (and physics) related to ferromagnetic materials? And the NMR scanners wouldn't work right, or at least how they work would depend on the phase of the moon, from memory 300 ppm is a pretty huge shift.

      Who would notice a change in c is an interesting thought experiment.

    • by tgd (2822)

      I've seen that mentioned a few times ... but if light travels less than C, then light would have to have a slight mass, which would mean the speed of a photon would vary by the energy it has.

      It doesn't.

    • by radtea (464814)

      OPERA has just found that either neutrinos travel 0.03% faster than photons we've measured, or their equipment has an unknown systematic error.

      Or they screwed up the data analysis, which is my bet: http://www.tjradcliffe.com/?p=543 [tjradcliffe.com]

    • by Kristian T. (3958)

      Only an undergrad myself - but I was thinking the same thing. The implications of FTL would enable the creation of thought experiments breaking most known laws of physics (at least as we know them).

      On the other hand, light travelling slightly slower than what maybe aught to be called the "causality propagation limit" would only challenge our knowledge about the nature of the vacuum - which is already up for debate. Light already travels slower than c in all substances other than vacuum, and Einstein certain

    • Surely with an undergraduate degree you did the derivation of the wave equation in free space from Maxwell's equations?

      The only part you might have missed (I'm sure you'll have been told it but might not have realized the significance) is that Maxwell's equations are independent of the inertial frame that you pick. And therefore light propagates at c in all inertial frames.

      Special relativity is what falls out if you assume that Maxwell's equations are correct.

      There's all sorts of experiments that have been

    • by jovius (974690)

      If that was the case there would be noticeable effects in satellite communications - think about time, location etc. The effect would have been observed by now.

    • Hasn't the value of c been verified to within a very tight tolerance, many times, by a great many people, and with much rigor? If we now found c to be different, you'd have to explain a mountain of evidence, ie how did everyone come up with the same number every single time, even though they were doing it in slightly different ways, in different places, and importantly in different frames of reference? Surely the systematic error would have shown up somewhere?

      Various considerations such as the fact that emp

    • A GPS clock is accurate to within 14ns. Your proposed variation from c would throw it off more than that.

      The value of c has been well established over the past century through experimental measurement. That said, I'm not sure how many of those experiments have been done through solid rock. Could the mass in the rock be tunneling the neutrinos somehow?

      Oh, no, the Italian lady could be technically right.

    • by Kjella (173770)

      Well, from what I gather they've not sent photons in a vacuum along the neutrinos, they've simply calculated the distance and found the neutrinos arrive faster than they theoretically should. So the first step would be to double check the distance, atomic clocks and sensor delays, if those are off then the discrepancy would disappear in a puff of smoke.

      Like someone pointed out in an earlier article, if neutrinos generally traveled 0.03% faster than light then we'd see delays in years on supernova bursts but

    • by Fzz (153115)
      The evidence from supernova 1987A [wikipedia.org] seems to contradict this. Neutrinos from the supernova would have arrived years before the light if c were 0.03% faster than we measure on Earth. Instead they arrived a few hours earlier, which is to be expected, as light from the initial explosion took some time to emerge from the exploding star whereas the neutrinos did not.
  • Random question:

    What kind of technology and materials would we need to get the giant Fermilab etc. down from square kilometres down to square metres or even inches? Would cheap fusion energy, or room-temperature super-conductors, or limitless supplies of carbon nanotubes/diamond/graphene help reach that particular goal?

    • by janimal (172428)

      You would probably be looking at an inversely proportional need for power and cooling, since you will want to generate the same energies.

    • by vlm (69642)

      Random question:

      What kind of technology and materials would we need to get the giant Fermilab etc. down from square kilometres down to square metres or even inches? Would cheap fusion energy, or room-temperature super-conductors, or limitless supplies of carbon nanotubes/diamond/graphene help reach that particular goal?

      A limitless supply of gold would seem to be prerequisite.

      Seriously though the killer is cubed squared law problems. Dump a few megawatts into a few hundred square megameters of "stuff" and it scarcely gets above room temperature. Dump a few watts into a few square cm and you have whats known as a "soldering iron"... Of course with infinite money I suppose you could develop a semiconductor industry designed around a thousand degree operating temperature, with all new substrates and dopants and packaging..

    • Stronger magnets are always going to be advantageous for a particle accelerator, so yeah, room temperature superconductors (ones that have all the necessary properties to make good electromagnets) would be a major breakthrough. However, in terms of making an accelerator like the Tevatron or the LHC smaller, there are some physical economies of scale that make see-it-from-space rings more suitable than lab scale. Circular accelerators lose energy due to synchrotron radiation; these losses are inversely propo
  • I want a neutrinos modem so that my downloads are finished before I click on the links!

  • by danhaas (891773) on Monday September 26, 2011 @09:53AM (#37515632)

    The theory of Relativity still holds true, what this experiment (if it's accurate) changes is our idea of matter and causality: if neutrinos have imaginary mass, they are allowed to traver faster than light, as tachyons; and causality may have to be revised, from a onward moving arrow to a regular dimension, in which the future can influence the past.

  • by prograde (1425683) on Monday September 26, 2011 @09:59AM (#37515704)

    I can only assume that they've corrected for General Relativity. Everyone seems to be pointing to the obvious potential sources of error: knowing when the neutrinos are created, knowing when they arrive, knowing the distance that they've traveled.

    What about variations in the Earth's gravitational field between the two clocks? Or along the path that the neutrinos follow? You can't call the planet a point-source of gravity - the density of matter is quite lumpy.

    I haven't seen a back-of-the-envelope calculation for this...maybe it's orders of magnitudes impossible? Would it require a tiny black hole to throw the timing off by 60ns...or would a big uranium deposit be enough? I could probably do the Lorenz transforms for Special Relativity myself, but General is a bit beyond me!

    • Interestingly, someone was talking about the start of the "nitpicking" in connection with this experiment. I can't remember the article, or I'd link it, but they mentioned things like adjusting for the oblation of the Earth, tidal pull of the Moon, GPS location of the labs, and such things. Stuff that makes a pretty small difference to the measured distance in % terms, but I guess this needs to be super-accurate.

    • by mbone (558574)

      The back of the envelope for all of the General Relativity effects are too small by 3-4 orders of magnitude.

  • ...ago, of course.

  • A million internet points for the person who commercializes this in to a faster than light inter-planatary communication network and calls it subspace [memory-alpha.org].
  • I'm not even remotely qualified to comment on this, but I seem to remember light being affected by gravity and thus the mass around it, where as neutrinos are virtually unaffected by normal matter. What this says to me is the neutrinos are showing us what the actual speed limit of the universe is compared to what we think it should be as an observer sitting on a giant ball of gravity rich mass. Basically, in space, they go the same speed, which is why the neutrinos and photons from a distant stellar event

  • With the small but consistent error in the results, what I have not seen is how you know that this isn't a measurement that the distance did not change.
  • ...these results were calculated in ITALY.

    I don't know about you, but according to my experience, NOTHING runs on time there.

    Not even neutrinos.

    So the idea that they arrived early? hahaha, clearly a clock error.

10.0 times 0.1 is hardly ever 1.0.

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