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Can Relativity Explain Faster Than Light Particles?
gbrumfiel writes "Two weeks ago, researchers claimed particles called neutrinos were travelling faster-than-light and violating the laws of special relativity. But now it looks as though general relativity might be behind the experiment's unusual result. An independent analysis claims that the original experiment, known as OPERA, failed to take into account differences in earth's gravitational field between the neutrino source and the OPERA detector. As Nature News reports, gravity can distort time according to Einstein's theory, and the effect could explain why neutrinos appear to arrive 60 nanoseconds ahead of schedule. The OPERA team is now reviewing the new analysis."
Except with all the math half-way worked out.
Now it is c+1?
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It's not just a good idea, it's the law.
c++
Nice try.
Sincerely,
Einstein
They are reviewing their own paper to make their methods clear. FTFA:
"Dario Autiero of the Institute of Nuclear Physics in Lyons (IPNL), France, and physics coordinator for OPERA, counters that Contaldi's challenge is a result of a misunderstanding of how the clocks were synchronized. He says the group will be revising its paper to try to make its method clearer."
Meaning: Contaldi didn't understand how OPERA did it, and thought they had commited a somewhat stupid mistake. OPERA says they didn't make that error, and that they'll rewrite that part of the paper to make this clear. In other words, this is not news at all.
NO ONE considered the time distortion of gravity? I mean, sure, it's the first time that the time distortion due to gravity has ever been significant in any practical application, but it's still a fundamen... wait, it's not the first time? You're saying that there's an 18-year-old system that relies on this principle to work properly? How many people use this obscure system? Every single person in the civilized world? You'd think that at least one of these researchers would have heard about it, then.
Mod parent up +5 informative - and thread over.
"The agriculture ministry is not in charge of Gundam" - Japanese ministry official.
This news is disappointing, but expected. I don't mean that I expected someone to give this particular explanation, just that I expected someone to provide an explanation that did not require the neutrinos to travel faster than the speed of light.
The truth is that all men having power ought to be mistrusted. James Madison
The researchers made no such claim! In fact they explicitly said they disbelieved they saw faster than light particles, and that they thought their data was faulty somewhere. But what they DID do is ask for other scientists to check their data and find their data, and if possible recreate the experiment to help track down where the error was.
THIS IS CORRECT SCIENTIFIC PROCEDURE!
They actually answered the clock questions on the first video conference feed the day after the press release.
"Beware, you who seek first and final principles, for you are trampling the garden of an angry God and he awaits you just beyond the last theorem."
-Sister Miriam Godwinson
Sorry, everything reminds me of a SMAX quote after i've been playing. :)
Explanation to this phenomena is simple. Neutrinos travelled through tiny wormhole and that caused them to arrive faster. I won Nobel Prize!
Faster than light is still possible, but now it's due to gravitational effects instead of innate property of neutrinos. It makes finding the Higgs boson more important than ever.
Don't jumble words and think you know what's going on.
Let me guess - you're in management?
Faster! Faster! Faster would be better!
Are they using some other measurement of "speed" that isn't distance / time? It seems that slowing time down and going the same "speed" has the same net effect as going faster than the speed of light.
60 nanoseconds seems to be an incredibly large discrepancy to be explained by local gravitational differences.
I'm impressed that you worked it out half-way ..
Hey don't blame me, IANAB
If it turns out that time dilation due to gravity is the reason, then the error must be in the ETRF2000 or it was applied incorrectly in this case (Neutrinos moving from A to B). Considering that hundreds of people work on this project it seems unlikely to me that such an error slipped through. They even took into account the very small distance change induced by the L'Aquila earthquake.
xkcd reference
Even if it is just a matter of clarifying the paper, it's still peer review in action. When OPERA responds, Contaldi will have the opportunity to review their clarifications. Maybe he'll respond again and point out that OPERA is still in the wrong. Or maybe he'll be satisfied and move on. This is how science is done. How is that not news?
Oh, it's news all right. Just not end-of-the-world-as-we-know-it news. As pointed out in TFA, it's awfully hard to critique the experiment unless you're there seeing exactly what has been done. While I don't find it surprising that a few printed (or electronic) pages cannot describe hundreds of tons of equipment and countless hours of work it does speak to the complexity of modern science.
You wonder how much that is published isn't repeatable or understandable. Dropping rocks off off buildings and counting seconds with a stopwatch just doesn't cut it anymore. I read somewhere (can't quickly find it) that one of the drug companies (Bayer, IIRC) felt that over half of the experiments from the literature that they tried to repeat to consider the possibility of pharmaceutical development from the discovery, failed outright or gave much different results than published.
It's frustrating I suppose. We all know most research is wrong / useless - the hard part is teasing out which is or isn't.
Faster! Faster! Faster would be better!
But then when in stronger gravity you'll have to slow it down again. It's not just the clocks speeding up and slowing down. The gravity from stars and other massive astronomical objects wouldn't bend light if gravity didn't affect its speed too. The same principle that makes a refracting medium bend light can be used to explain how light bends in a vacuum in the presence of strong gravity.
In other words, c isn't a constant in all cases depending on the frame of reference. At least for now that's my opinion, and there has been an oversight.
I guess the problem would be like having a speedometer that allows you to change the definition of an hour, so you can claim to be going 10MPH when by everybody else's measure you'd be going 100MPH. That's the thing about time dilation. In one frame of reference c is constant, but it's not so in all frames of reference. Relativity is still very much in effect, but needs the definition modified to allow for recursion.
In other words, it's very possible to go faster than light. (It's definitely possible to be faster than light that has fallen into a black hole.) But you'll never be able to measure it's speed changing in a direct manner. It's the time dilation effect which doesn't allow it. (The apparent mass problem also has to do with energy density per unit time. When the unit time isn't exactly fixed - a second isn't necessarily a second - adjustments made for that might allow some seemingly paradoxical things to be done in this universe.)
Contrary to what many news-sites keep repeating, it is well known that traveling faster than speed of light does not contradict special relativity. It is well known that tachyons are consistent with SR. SR only entails that a particle is either always slower than the speed of light, or is always faster than the speed of light, but can't cross that boundary from either side. The real issue is that these particles are neutrinos which are supposed to be able to travel with less than speed of light as well.
Attitudes make the difference between Space and Time: we want to MAX our temporal, and MIN our spatial extension.
Bummed SMAC/X no longer runs on my Mac after Lion update. Am dusting off an old Mac Mini to set up as game machine now. Wish someone would write a new SMAC/X style game. Other than time killers on phone, don't do any computer gaming anymore.
I drank what? -- Socrates
*golf clap*
I drank what? -- Socrates
Or stayed at the Holiday Inn Express last night.
It's not news for one of two reasons, because one of two things is true:
Contaldi has poor reading skills. 'Peer review' is of low value from people who can't understand straightforward explanations that were understood by others.
or:
Science is proceeding as normal, and the outcome is still unknown .
Wake me when science reaches a conclusion, every minor typography fix on this paper is not newsworthy.
"Who is the Journal of Quantum Physics going to believe?" --Stephen Hawking
I'm certainly not disputing the legitimacy of science, but in this current age of misinformation, people need to realize that science is a discipline in constant flux. Nature and the Universe tend to stay constant, following their own laws--it's Man's perceptions and understanding that are continually changing. As we learn more and more, we tune our theories, hypotheses, and laws to better understand nature's hidden mysteries.
That the observation of a sub-atomic particle appears to confound or violate established scientific law really only means that it science has yet another mystery of nature that it does not yet fully understand. Maybe the methodology is flawed. Maybe the law is flawed. But that it happens at all should certainly not surprise any scientist--it should motivate to gain a better understanding.
Sure, and that paper obviously tries to get a better understanding by adding a theoretically known effect to the calculation which they think the experimentalists have neglected in their analysis, and found that it indeed seems to give subluminal speed.
Note that there is another paper today on archive which also tries to explain the result in current theory, but using relativistic quantum theory instead of general relativity. I don't know whether one, the other, both or none are correct. But people will check this, and if at least one of the papers is right, then no new theory is needed. You may wish for a new theory to be needed, and for the superluminal speed to be real, but science is not about wishes, science is about facts.
The Tao of math: The numbers you can count are not the real numbers.
I'm a mathematician, not a physicist. In special relativity the Lorentz transformation has a singularity at the speed of light. Its perfectly defined below and faster than the speed of light. Richard Feynman suggested that unless the math prohibits it, it will be found in nature. Of course, if we see a particle hitting another before it was emitted, we'd likely interpret it as the target "pulled" the particle from the emitter. This explains the alternate view of physics -- all matter emits dark, and light bulbs and stars suck the dark in. Mathematically it makes just as much sense as emitting massless photons. Who's going to buy the idea of a massless particle that goes the speed of light? Its crazy talk.
This is just a reminder that like economics, scientific method is really a confidence game. Its all a matter of whether you believe the rules stated so far are consistent.
They didn't have to raise the speed of light; they just raised it a semitone.
That's right. The universal constant for the speed of light is c#.
Welcome to the Panopticon. Used to be a prison, now it's your home.
But if a particle lacks mass - is it still limited by the speed of light?
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
In reality, it's traveling at exactly the speed of light.
Don't neutrinos have mass? Can particles with mass be accelerated to light speed? Without reading the article or the paper and not having taken even a college physics class, I would have expected that a neutrino should have been traveling at near light speed rather than "exactly the speed of light".
They could never duplicate this experiment in West Virginia because relativity is hard to define there.
"That's the way to do it" - Punch
But the neutrinos would follow the curved space, just like light would. The curved line in warped space-time IS the shortest distance.
Perhaps what they're saying is that the computed distance isn't taking the warp into effect, basically treating space-time as flat in the presence of the Earth. This would cause the distance to be underestimated, making the velocity of the neutrinos appear higher?
I thought they said they took gravitational factors into account, though.
If a particle has mass, its velocity will be less than C. If a particle has no mass, its velocity will equal C.
I personally chalk it up to the measurement between the emitter and the detector.
Yes I know they say they are very confident within a margin of error and that amount they are observing is within that margin of error so it must be right??
Personally I aint gonna start changing C based upon their confidence that their variation is within the margin of error that they say is within the margin of error of the distance between the gun and the target since everything else in GR & SR has been demonstrated correct thus far.
Hey KID! Yeah you, get the fuck off my lawn!
failed to take into account differences in earth's gravitational field
Even if they didn't account for it, so what?
The Schwarzschild solution for Time dilation has a C squared in the divisor.
Unless I'm doing the math wrong, It wouldn't even amount to 1 nanosecond, much less 60.
Physics allows for a clown to be in my basement, but that doesn't mean there IS a clown in my basement. Because some interpretations of general relativity allow for the possibility of faster-than-light particles does not, any any sense, mean that they exist. Right now, that is purely speculation with no evidence.
(Well, no evidence until OPERA.)
Perhaps they have a mass that varies based on electrical charge! We could call it 'the mass effect'.
Perhaps all this is just a ARG for Mass Effect 3.
If corporations are people, aren't stockholders guilty of slavery?
huh??
The speed of light is constant across all frames of reference. Frames of reference that are moving relative to each other will perceive light generated by the other frame of reference as having a different "clock" (i.e., frequency), but the speed of the red/blue shifted light will be the same in both frames of reference. The speed of light itself does vary across mediums (say, water vs glass vs air vs vacuum), but that doesn't come into play here. Also, they weren't measuring, directly, the speed of the neutrinos. They were comparing the time of the neutrinos' arrival at different sites and they found a difference that was unexpected. However, that measurement depends very much on the clocks being in sync, and this is what TFA is discussing.
The bending of light in a refractive medium is completely unrelated to the bending in a gravitational field, and your conclusion that the latter involves the speed of the light being altered is false.
"let us assume that the TTD was stationary at the LNGS site for 4 days while the appara-tus for clock comparison was set up. Using the value of V/c2 quoted above this would result in a total shift of t 30 ns."
Let us assume a scenario which fits our desired outcome has actually occured without any supporting evidence since our own figures fall far short of a cogent explanation for the discrepancy.
Let us further overlook the fact PTB was mearly used to independantly *VERIFY* the nanosecond level clock synchronization calibrated by METAS of the time links between the two stations.
From the OPERA paper:
"The difference between the time base of the CERN and OPERA PolaRx2e receivers was
measured to be (2.3 ± 0.9) ns"
Ooops...
"More importantly, we have only considered the path taken by the TTD along a surface trajectory. The path taken by the neutrinos is some 3 kms below the surface at its midpoint along the trajectory connecting CERN and LNGS. At this level of accuracy the surface time mea-sured by all clocks involved will differ from the proper time along the true trajectory and this further compli-cates the interpretation of the OPERA results."
The difference between totally switching off the earths effect on spacetime as the neutrino beam moves 730km results in being able to cover .5mm more distance over the same time. The effect is not worth thinking about yet they deem it necessary to include it anyway. Their own figures come up short.
The problem here is that tachyons, if they exist, move faster with lower energy, and approach the speed of light at high energies.
IIRC the neutrinos from the experiment were at much higher energies than those observed from a supernova explosion
in the 80's i think, where the photons and neutrinos arrived about simultaneous.
The vacuum in the universe isn't actually a perfect vacuum, and thus it has a small refractive index,
meaning the the speed of light in the universe is a bit slower than in perfect vacuum, so those
neutrinos can travlel faster than light and could be used to tell us in advance when a supernova explosion occured,
so we can point our telescopes in that direction.
E = mc^2 refers to rest energy, it is the amount of energy you get if you convert an unmoving mass directly into energy. Photons, having no mass, have no rest energy by definition. 0 * c * c = 0. E / 0 is undefined, not infinite. Literally the only line of your reply without a significant error is the first one. E=mc^2 has nothing to do with the assertion that massless particles must travel at c, that comes from other parts of special relativity.
Actually, the theory of special relativity has no problem with particles going faster than light. The problem lies with accelerating particles from slower than light in vacuum to faster than light in vacuum. Or, for that matter, with slowing down from faster to slower than c.
Would it be possible to have neutrino generators and detectors at both sites and test the speed in both directions? That would probably mean testing the speed between CERN and Fermilab. That way, if there was an error in clock synchronisation, it would show up because the neutrinos would take longer in one direction than the other.
If C# is now the speed of light- does that mean that Java exceeds the speed of light?
"That's the way to do it" - Punch
I think you're being too harsh. Clarity is important. Misunderstandings get people on the wrong way. I think it's much better to add a clarification than to complain about people misreading the work.
Don't neutrinos have mass? Can particles with mass be accelerated to light speed? Without reading the article or the paper and not having taken even a college physics class, I would have expected that a neutrino should have been traveling at near light speed rather than "exactly the speed of light".
We have very strong evidence that at least two of the three neutrinos must have mass due to neutrino oscillation (used to be at least one of three, until we saw the other type of oscillation iirc), and from this we hypothesize that all the neutrinos have mass.
That mass, though, is extremely small (don't recall the experimental upper bound, but it's orders of magnitude smaller than electrons), so they would be traveling very close to c.
The enemies of Democracy are
"Dario Autiero of the Institute of Nuclear Physics in Lyons (IPNL), France, and physics coordinator for OPERA, counters that Contaldi's challenge is a result of a misunderstanding of how the clocks were synchronized. He says the group will be revising its paper to try to make its method clearer."
The heck with that! What I want to know is: How can a company that gives away a free browser possessing only a minuscule market share afford to employ a physics coordinator?
#DeleteChrome
No, no... That would be called "Flash".
Browsing at +1 - no ACs, I ignore their posts. So refreshing!
Distort time by 60 nanoseconds over such a (relatively) short distance? That's a huge distortion. Something else is likely involved in the explanation than gravity.
I swear they give me mod points to shut me up.
"And when we find Him, Sister Godwinson, you'll be right and we'll be satisfied." -Me
Please consider this account deleted, I just can't be bothered with the spam anymore.
Use the full equation:
E = (mc) + (pc).
If p=0 (p is the momentum; so if you're at rest, p=0), E=mc.
If m=0 (the case for photons, for example), E=pc.
If neither p nor m are zero, E = sqrt(E0^2 + (pc)^2), where E0=mc^2 is the rest energy.
That's not the problem with this, though. The problem here is the supernova explosion in Andromeda, where neutrinos and photons arrived here at about the same time. (I forget the exact difference.) If their speeds were any different, then over that distance they shouldn't have arrived at anywhere near the same time. This makes almost all explanations of the time difference detected that don't involve experimental error to be very dubious.
I mean, if neutrinos can cycle into a fourth variety (the "sterile neutrino") that goes faster than light for some reason ("taking a shortcut through the bulk?"), then why did the neutrinos from the supernova arrive at about the same time as the photons? This question can be adapted for any other explanation that I've thought of for neutrinos actually moving faster than light.
OTOH, I don't believe that changing the "fastest particle" to the neutrino instead of the photon would noticably affect relativity. It would just make the tests more difficult. c would then be tied to the speed of the neutrino rather than to that of the photon, and all the other arguments would remain sound. And the speed of the neutrino being so close to that of the photon would probably mean that all the confirming experiments still fell within experimental error. (Of course, there's also the factor that if you accelerate something using electromagnetic forces, you CAN'T get it to move faster than light. And neutrinos would be very poor candidates for something to accelerate something else with.)
I think we've pushed this "anyone can grow up to be president" thing too far.
This is a great article describing how difficult it is to control systematic errors with clocks in this kind of Time Of Flight experiment. An undergraduate level of understanding of relativity is all that's required and it makes you think. Also contains some snarkiness.
Well... at least we know that "Silver" light travels at the speed of C#.
"That's the way to do it" - Punch
But rather massive more Neutrinos.
What?
Regardless Relativity does not allow for particles to be accelerated to the speed of light because of the amount of energy needed.
However, and this is important, particles already traveling at the speed of light are allowed.
No, that's not true if you mean a mass-full particle. A particle with rest mass traveling at the speed of light is forbidden for the same reason accelerating it to the speed of light is forbidden -- that particle would have infinite energy. It takes infinite energy to accelerate a particle to the speed of light because at the speed of light it has infinite energy. If you somehow suppose it is already at the speed of light, then it would already have infinite energy.
Particles without mass, on the other hand, can only travel at the speed of light.
It's possible they discovered tachyons.
If they discovered the kind of tachyon that would allow them to transfer information -- and this experiment would count -- then they broke Special Relativity, possibly the principle of causality.
The enemies of Democracy are
About Physics.
I don't know about most, but you obviously didn't, judging on your comment. Disclosure: I not only did do basic physics, but am actually a physicist.
Yes.
Then you have to relearn your math. Anything divided by zero is undefined. Something going to zero in the denominator makes the term go to infinity if the numerator doesn't also go to zero (or does, but slower). But that's irrelevant anyway. The energy-momentum relation of a particle in special relativity is E^2 = (mc^2)^2 + (pc)^2. For a particle at rest (p=0), this gives the well-known E=mc^2. For photons, we have m=0, and E=pc (as it must be, or the laws of classical electrodynamics would be wrong). No division by zero in sight.
They indeed haven't measures particles with no mass, but not because of the "problems" you claimed, but because, as we know today, the neutrinos do have mass. This is known due to the neutrino oscillations which have been found, and which were the solution to the solar neutrino problem. There are no theoretical problems with massless neutrinos (at least from the theories we know today; maybe some future unified field theory will not allow massless neutrinos). Indeed, for most of the time neutrinos have been thought to be massless.
The Tao of math: The numbers you can count are not the real numbers.
challenges to research are actively encouraged in some aspects of science whereas they are unfortunately denounced in others. I am glad to see this team inviting others to find the faults if any, now to see this applied to more politically sensitive subjects would be nice
* Winners compare their achievements to their goals, losers compare theirs to that of others.
If a particle has mass, its velocity will be less than C. If a particle has no mass, its velocity will equal C.
REST mass... </pedantic>
WARNING! This girl exceeds the MAXIMUM SAFE standards established by the FDA for BRATTINESS
" In other words, c isn't a constant in all cases depending on the frame of reference. At least for now that's my opinion, and there has been an oversight."
Except that it is. Unless, of course, you can offer us an experiment where two different observers do in fact get a different value of c (that is, speed of light in vacuum). You can think loud all you want, but show me the experiment.
SR is based upon three assumptions or principles:
1. Causality (cause before effect)
2. Relativity (the laws of physics are the same for all reference frames, i.e. there is no 'privileged' reference)
3. Constancy of the speed of light (as was implied by Maxwell's equations)
Maintaining all three principles at once is how we end up at the rules of time dilation. Because of time dilation, if one could communicate between two inertial reference frames faster than light, then some observer would say that the message was received before it arrived -- which violates Causality for that observer, which would violate Relativity. With a few messages between ships traveling at relativistic speeds, it is possible to craft a scenario where the ship that sends the first message receives a response prior to having sent it -- Causality is then broken according to all observers.
Any method of information transfer that occurs FTL -- regardless of method -- breaks causality, and thus Special Relativity.
However if no information is sent, then this isn't a problem. This is why Quantum Entanglement experiments do not violate SR, because no information transfer, and thus causality violation, is possible.
Tachyons that can be used to send information contradict SR.
There are other formulations of tachyons which do not allow information transfer, and they are the ones that are consistent with SR.
This experiment, however, definitely involved information transfer. If its results hold up, then SR and one of its basic assumptions is in trouble. It could be Causality. How effin' weird would that be?
But most likely we live in a causal universe, and they did not send information FTL.
The enemies of Democracy are
Maybe, but the promise of "emit once, observe everywhere" never panned out....
The enemies of Democracy are
"Basically, a theory that has never been proved says it to be so"
Only if you forget the minor detail that it *has* been proved... by predicting everything that Newton's did and then something where Newton was wrong (i.e. Mercury's orbit). Now it's your turn.
"So, let's just say some faster than light strings perturbed the sensors"
Let' say so, why not... Oh, wait! We already stated that it was your turn! It is YOU the one that has to tell us how these "some" particles look like and how an experiment should have to be laid out to offer different results than those predicted by Einstein's, oec else Mr. Occam will get really ungry.
The first AC comment I've ever seen worthy of an upmod. I don't have points...but I salute you, AC!
Santa Claus has mass and can go faster than C. I think it is explained by string theory or something.
Your knowledge is outdated. Today we know that neutrinos do have mass.
The Tao of math: The numbers you can count are not the real numbers.
Wouldn't help. Imaginary mass, however, would.
The Tao of math: The numbers you can count are not the real numbers.
no experiment has yet to show that photons have no mass.
That's because it's a very hard thing to show. What they have shown experimentally is that the mass has to be smaller than 10^-18 eV/c, which is 1.782662 x 10^-54 kg, which is 1 / 10^-24th the mass of an electron which is by far the lightest particle predicted.
And I'd be interested to hear how E=mc^2, a central component of special relativity, causes it to conflict with general relativity. Do tell!
Basically the sun revolves around the earth - what ever we think now is correct no matter what anyone else says.
We used to think the earth was flat, and we were wrong. Then we thought the earth was a sphere and we were wrong (it's actually an oblate spheroid). But if you think believing the earth is a sphere is just as wrong as thinking the earth is flat, then you're wronger than the both of them. (paraphrased from Asimov). We know Newtonian physics is wrong, relativity significantly improves on the accuracy of Newtons predictions. That doesn't mean I drop an apple and expect it not to fall because Newton was wrong. Similarly, we know that relativity is wrong (the predictions break down in several extreme situations), but that doesn't mean that I expect E=mc^2 to be wrong tomorrow or time dilation to be proven wrong or any of the other well known relativistic effects. They have been shown empirically to be correct to fractions of fractions of a percentage point, that evidence doesn't just go 'poof' when a more refined theory comes along.
If C# is now the speed of light- does that mean that Java exceeds the speed of light?
No, Java is still slow.
But then when in stronger gravity you'll have to slow it down again. It's not just the clocks speeding up and slowing down. The gravity from stars and other massive astronomical objects wouldn't bend light if gravity didn't affect its speed too. The same principle that makes a refracting medium bend light can be used to explain how light bends in a vacuum in the presence of strong gravity.
In other words, c isn't a constant in all cases depending on the frame of reference. At least for now that's my opinion, and there has been an oversight.
Seems to me c is a constant across all reference frames, and that's exactly the property that caused this observation.
They measured neutrinos.
Checked the speed and saw it was > c.
Said "OH SHIT!".
Observers see a particle traveling at c.
They check with their buddies who sent it.
To the people measuring the shit, that incoming particle (which they observed at speed c) had to have been sent 60 nanoseconds (or whatever it was) before their buddies claimed to have sent it.
But according to the timestamps, the speed must have been > c.
The timestamps were inaccurate because they didn't account for gravity's effect on time.
The difference in the gravitational field at the source and detectr (actually along the whole path), caused a difference in the time field, while the neutrinos happily moved along at slightly less than c.
I was about to mod you funny but then I tought it better: while he's not on peasant wages, the fact remains that even "just" senior engineers from Opera will probably earn more than that guy.
How the hell am I going to mod something funny when it makes me feel so depressed?
More importantly, there doesn't yet exist a single experiment which is inconsistent with zero photon mass.
The Tao of math: The numbers you can count are not the real numbers.
What if they oscillate into some form that is slightly faster than light? They'd be traveling slightly slower than light part of the time, faster than light part of the time, and their average speed might be exactly the speed of light. The amount of time spent on the other side of the lightspeed barrier would never be enough to be exploited to violate causality. But, the oscillations would cause some curious results that might sometimes show some neutrinos exceeding the speed of light.
The universe would give us hints of tachyons while at the same time not vanishing in a puff of logic, and would also demonstrate a means by which something that has mass could travel at light speed.
Not that I'm saying this is what's going on. I don't have the background; I follow what I can of these things as a hobby. It's just fun to think about.
Fun with Anagarams! LADS HOST, SHALT DOS. HAS DOLTS. AD SLOTHS, HATS SOLD. ASS HO, LTD.
It seems to make sense, the neutrino particle is just smaller than the light 'particle', therefore it has less mass, and can go faster. That's why all our current calculations for light etc. still work and are valid, the formula e=mc^2 is just bound to the resolution of light 'particles'. Maybe the 'constant' c needs to be re-evaluated so it takes particle size into account? It should be more of an asymptotic relationship: Q: Whats faster than light? A: The closest thing to 'nothing' (i.e. the mathematical limit in calculus)
REST mass... </pedantic>
I did my physics degree about 10 years ago, and the concept of rest mass was already deprecated then. A particle has only one mass, the one formerly called rest mass.
The notion of mass increasing with velocity makes sense as a kind of Newtonian analogy. You could use Newtonian mechanics in limited ways to explain the mechanics of a particle, if you replaced the mass with a relativistically varying mass. One problem is that the conversion factor varies according to the direction, and you get confusing terms like transverse mass and longitudinal mass. But the simple fact is that Newtonian mechanics no longer applies at relativistic velocities.
Escher was the first MC and Giger invented the HR department.
It's explained by Rudolf the Redshift Reindeer.
Escher was the first MC and Giger invented the HR department.
Santa Claus is completely imaginary, and therefore also has a completely imaginary mass. It is well known that objects with imaginary mass are tachyonic. Being tachyonic, Santa Claus can even be at two places at the same time!
The Tao of math: The numbers you can count are not the real numbers.
Well, I will grant you that the notion of "rest mass" is as odd a notion as distinguishing between spacial and temporal dimensions. But the distinction is there (even if only by archaic categorization).
From what I was reading there is a distinction made between rest mass and relativistic mass. Rest mass being a hypothetical value that represents the minimum mass that a particle could possibly have, while everything else in reality deals with the relativistic mass.
But I take all your criticism to heart, you're absolutely right, but the pedant in me still notes that rest mass is a distinct category from "relativistic" mass, which sure varies transverse vs. longitudinal, but then both of those are distinct categories of relativistic mass. ... What can I say? Pedants are overly obsessed with details...
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Meaning: Contaldi didn't understand how OPERA did it, and thought they had commited a somewhat stupid mistake. OPERA says they didn't make that error.
OPERA says that they didn't make that error. But, they also learned about the mistake only through Contaldi's challenge.
Causality has been a bit off recently.
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Photons, having no mass, have no rest energy by definition.
Photons are at rest in their frame of reference. They still have energy.
Give me Classic Slashdot or give me death!
What?
Well, if you formulate relativity properly in 4 dimensions, nowhere does a "relativistic mass", a "longitudinal mass" or a "transversal mass" show up. Indeed, the relation between 4-velocity and 4-momentum is p=mu, where p is the 4-momentum, u is the 4-velocity and m is the Lorentz-invariant "rest" mass.
The Tao of math: The numbers you can count are not the real numbers.
Physics allows for a clown to be in my basement, but that doesn't mean there IS a clown in my basement.
Conversely, there is nothing preventing a clown from being in your basement, so you should engage in scientific testing of that idea and go check for one.
I am fascinated by your 'clown in the basement' metaphor. I think I need to work on integrating this into everyday conversation.
HA! I just wasted some of your bandwidth with a frivolous sig!
Magnetic field has nothing to do with this. The speed of light is constant, no matter what "absolute origin" you are measuring from. That's the whole "relative" part about relativity. Where exactly is this "absolute origin" you speak of?
mod me funny
The neutrinos are quite magnetically neutral, and thus not affected by the Earth's magnetic field.
To put it in a car analogy, as is the custom here: They are not passengers in this car.
The Earth moved in space while the neutrino was thrusting forwards. Even if the absolute momentum stayed within the constraint given by the 'speed of light'-- the Earth still moved its target closer to it's absolute origin, thus the neutrino traveled less than 720km. This way your calculations match and speed of light remains unbroken.
Have a nice day,
-j
All you've proven is that you don't understand relativity.
The Tao of math: The numbers you can count are not the real numbers.
The bending of light by the deformation of space-time is completely unlike or related to the refraction of light. The first is light following the curvature of space, and all frequencies of light would follow the same path (remember Galileo's experiment from the tower of Pisa? Two different particles are accelerated by gravity in precisely the same way.) The second is a wave function across the boundary of two different optical media. Waves with longer period (lower frequency) are bent more than waves of shorter period (higher frequency.) You can do this experiment with water in a wave tank and see the phenomenon clearly. Unrelated phenomena.
"Gravity 'can' distort time..."? Gravity always distorts time.
Woosh. It's a Futurama joke.
The comment he replied to was definitely no Futurama quote. Beware of the reparenting!
The Tao of math: The numbers you can count are not the real numbers.
After I saw this quote I figured they'd have to find some error in their observations. (Emphasis added.)
"...If the observation is confirmed, it may be the most important discovery in science in the last 100 years.
"However, a big fly in the ointment is the supernova in the Large Magellanic Cloud, which sits just outside our galaxy 168,000 light-years from Earth. It was first seen by the naked eye on February 24, 1987. Three hours before the visible light reached Earth, a handful of neutrinos were detected in three independent underground detectors. If the CERN result is correct, they should have arrived in 1982. So, if I were a wagering man, I would bet the effect will go away because of some systematic error no one has yet been able to think of."
(Quote stolen from Quark Soup)
Let us be honest, a few hundred years ago they did prove the world was flat using the best science available at the time.
The world was known to be round, and even its approximate circumference calculated, around 2200 years ago at the latest (by the Greeks, the Chinese or others may have done it earlier).
This wasn't forgotten in Columbus' time. We just forgot that it wasn't forgotten at some point while romanticizing the man. So instead we think Columbus was brilliant, when really he just for some reason thought the earth was vastly smaller than the best science available at the time said it was -- science that was very close to correct.
The enemies of Democracy are
complete that C will still be a constant representing the maximum speed of the Universe, regardless of the frame of reference. It is, after all, the reciprocal of the square root of the product of two other physical constants.
Running with Linux for over 20 years!
Neutrinos do have mass, this is why they oscillate between 3 states. However the mass is very slight.
Also the neutrinos arrived ahead of the photons in SN1997 by a small amount (days, IIRC. it should be years at the speed discrepancy quoted by CERN). This different is explained by the fact that neutrinos hardly interact with matter and so could escape the core of the supernova before the photons could.
The arxiv blog recently had a roundup of papers discussing this: http://www.technologyreview.com/blog/arxiv/27212/ They fall into three groups: (1) Suggestions of how the experiment might have given a wrong result. (2) Theoretical arguments that constrain the interpretation and make the result seem implausible if taken at face value. (3) Theoretical papers saying what it could mean if it really was new physics. The Nature article seems to show that the Contaldi paper was based on a misunderstanding of how the experiment was done. However, the Nature article points to a new paper by Henri that wasn't included in the arxiv roundup: http://arxiv.org/abs/1110.0239
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Well as long as it was with in 60 nanoseconds correct let's just move on and assume we're all good :-)
It wasn't... so I guess it's panic time! =O
The enemies of Democracy are
Yes, I know photons don't have mass...
I'm trying to teach myself to set people on fire with my mind... Is it hot in here?
That's not surprising. A significant percentage of published results are wrong, even in mathematics and physics. It's not a question of "feeling", it's a fact.
Nor, for that matter, does the fact that General Relativity forbids some effects mean that they can't occur. After all, it's clear that GR is wrong somehow since it is incompatible with quantum mechanics.
Grandma got run over by a Redshift...!
sigfault (core dumped)
Stupid fucking Slashdot. The researchers made NO such claim. They KNEW they were missing something, but just couldn't find it on their own. That's why their work is being reviewed by other scientist. That's how science WORKS.
Kinda sounded like something from the Cubert episode.
"Pffft, nothing can go faster than the speed of light."
"That's why in 2233, scientists increased the speed of light!"
"People don't want to learn linux" hasn't been a valid excuse since '03.
AC you make me sad.
"People don't want to learn linux" hasn't been a valid excuse since '03.
Don't they have momentum, as observed in radiation pressure?
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
why wouldn't you have an expert on time help you with the clocks?
example:
www.nist.gov/pml/div688/grp40/tmas.cfm
neutrinos can.
I like my spaghetti with source.
Zero mass particles don't have a rest frame. Boosting into different frames -- any frame you like -- will only alter their frequency, not their velocity. They move at c in *all* inertial frames.
particles already traveling at the speed of light are allowed
. They generated them, so the neutrino's can't already have been traveling at the speed of light.
Well, I might have a way, but it only works on a semi spherical planet in a vacuum.
In what way do your clowns contradict what I wrote? I did not say that SR supports the existence of tachyons, I said it is compatible with it. The summary (and many articles) say, however, that traveling faster-than-light violates the laws of special relativity. That is false, and that is what I wrote.
Attitudes make the difference between Space and Time: we want to MAX our temporal, and MIN our spatial extension.
Seems you also got fooled by comment reparenting. Hint: He was not replying to the first post of the thread.
The Tao of math: The numbers you can count are not the real numbers.
exactly. 1/40000 is way too much. The explanation is nonsense
Yes, they do have momentum. But that doesn't imply they have mass.
The relativistic energy-momentum-relation is E^2=(mc^2)^2+(pc)^2. For photons, m=0 and therefore E=pc. This is consistent with the results for radiation pressure and field energy from classical electrodynamics.
The Tao of math: The numbers you can count are not the real numbers.
Just be happy it wasn't "BING," the results would be "Windows 7 faster than neutrinos."
Vote monkeys into Congress. They are cheaper and more trustworthy.
no, I am a unicorn, I just said so
-- no sig today
They did. Mostly.
TFPDF says that they didn't account for the unsynching of the mobile TTD (Time Trasfer Device), which was used to synchronize the atomic clocks that did the measurement. That device started loosing time as it was being transported to the LNGS facility from CERN (through some complex gravitational effects). So the timestamp LNGS used to synch their detectors was 'some time' prior of the actual synch time. This lead to the smaller travel interval which computed the erroneus speed.
At least that is what they are theorizing.
But if they are right some members should look up the deffinition of troll, because I was right.
NOTE: linked comment is this academic theory presented in very very lay man's terms.
-- no sig today
The question here's: Did the TTD stop
for lunch at a scenic spot in the Alps?
TFA convinced me.
The frequency dependence is actually dispersion, not refraction. Although the post you're replying to has more than its share of errors, thinking of time dilation causing light to bend as being *similar* to refraction is not the worst one. In each case you can think of the bending as being due to a slowing of light (although there's also the spacetime curvature effect for the gravitational case).
Either 1 / 10^24, or 10^-24. Yours is a double reciprocal...
I'm wondering if this is pedantry, or just nit-picking...
The two are nearly synonymous... I could go into the differences, but that would just be pedantic...
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Well, if you formulate relativity properly in 4 dimensions, nowhere does a "relativistic mass", a "longitudinal mass" or a "transversal mass" show up. Indeed, the relation between 4-velocity and 4-momentum is p=mu, where p is the 4-momentum, u is the 4-velocity and m is the Lorentz-invariant "rest" mass.
Huh, I hadn't thought about it that way yet. It can be difficult to fully scrape the "time is different than space" misconception off the bottom of the skillet...
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Well, if velocity is distance/time along a direction, relativity just redefines distance and time and direction rather than saying the velocity has changed. Examples: the advance of the perihelion of Mercury - relativity says that there is a shorter distance around that orbit near the bottom of a big gravity well, so Mercury has less distance to travel, thus the planet's phase advances. Relativity also says that time runs more slowly close to a sun, and the space-time warp results in the observed bending of light. But the phenomenon is essentially indistinguishable from light moving through a region with a gradient of increasing refractive index matching the gradient of gravity, and increasing the refractive index is equivalent to decreasing the speed of light. Light does not move faster than it would in "empty, field-free space" (a favorite phrase of Einstein'd, BTW), but it does move more slowly in a gravitational field if we treat it as a euclidean rather than a warped space, and the answers come out the same either way. The refractive-index view is more easily visualized, and makes a good heuristic for teaching, and doing GR in a flat spacetime is even mathematically valid. (With a mixed-signature Clifford algebra, though.)
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
No need for string theory to wrap that package.
Santa Claus is imaginary, therefore has imaginary mass, but his energy is real (causes parents to do a lot of work)
E =gamma mc^2, which can only be true if gamma is imaginary.
gamma= 1/(1- (v/c)^2)^(1/2) = an imaginary number iff v > c,
therefore
if Santa Claus is imaginary, he must move faster than light.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Thanks. :) *I* was confused for a second when I saw that reply, "Surely there's no way all that science-babble was derived from Futurama episode!?"
Whoops. Had the karma dial turned up ...
"People don't want to learn linux" hasn't been a valid excuse since '03.
The bartender shouts, "Hey! We don't allow faster-than-light particles in here!"
A neutrino walks into a bar.
Santa Claus can even be at two places at the same time!
That would violate clausality.
One line blog. I hear that they're called Twitters now.
So, as I stated, you thought out loud a lot but, again, where is the experiment that will show your theory -whatever it is, right and Einstein's wrong?
Newton's predicted Mercury would move in a particular, mensurable way, Einstein offered different numbers and, lo and behold, you go, take the measures and show Newton to be wrong and going as Einstein's predicts. Now Einstein is the champion and you the challenger. What's the experiment that will show you right and Einstein wrong? Without that experiment the champion retains the crown.