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CERN discovers lead-footed neutrinos

Started by Oniya, September 22, 2011, 06:26:45 PM

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Oniya

The short version of the article is that, while conducting experiments involving muon-neutrinos switching to tau-neutrinos, some of the particles arrived at the other end faster than they should have been able to.  In fact, Officer Einstein might have some speeding tickets to write.

http://www.bbc.co.uk/news/science-environment-15017484
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Martee

That's some pretty fantastic stuff right there. The cautious skeptic in me keeps thinking that the measurements are off, or something is miscalibrated, or they're picking up something else...

Oh, but the rest of me is pretty blown away by the potential ramifications. Like, hair-tingling blown away. Thanks for linking that article, Oniya. Definitely something to watch.

Status as of March 5th: In like a lion - only one response outstanding

Oniya

I'm with you on the cautious skepticism (otherwise I would have called it 'CERN discovers tachyons'), but you've got to admit it's great to see the top researchers in the field scratching their heads over something.
"Language was invented for one reason, boys - to woo women.~*~*~Don't think it's all been done before
And in that endeavor, laziness will not do." ~*~*~*~*~*~*~*~*~*~*~Don't think we're never gonna win this war
Robin Williams-Dead Poets Society ~*~*~*~*~*~*~*~*~*~*~*~*~*~Don't think your world's gonna fall apart
I do have a cause, though.  It's obscenity.  I'm for it.  - Tom Lehrer~*~All you need is your beautiful heart
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gaggedLouise

Even more intriguingly, particles moving faster than light (as the CERN team claims those neutrinos did, if only marginally) would open a potential window to objects travelling backwards in time, or travelling through space at a speed thousands of times faster than light (in their own timespace room).

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Oniya

Precisely.  Tachyons (from Gr. tachy- meaning fast) are theoretical faster-than-light particles.  According to one theory, just as it takes more and more energy for normal particles to speed up towards c, it takes more and more energy for tachyons to slow down towards c.  I'm trying to remember whether I read this in one of my Asimov (non-fiction) books or one of Charles Pickover's.  It might have been Rucker, but one of the books that I don't own.  *pouts*
"Language was invented for one reason, boys - to woo women.~*~*~Don't think it's all been done before
And in that endeavor, laziness will not do." ~*~*~*~*~*~*~*~*~*~*~Don't think we're never gonna win this war
Robin Williams-Dead Poets Society ~*~*~*~*~*~*~*~*~*~*~*~*~*~Don't think your world's gonna fall apart
I do have a cause, though.  It's obscenity.  I'm for it.  - Tom Lehrer~*~All you need is your beautiful heart
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DarklingAlice

Quote from: gaggedLouise on September 22, 2011, 08:23:06 PM
Even more intriguingly, particles moving faster than light (as the CERN team claims those neutrinos did, if only marginally) would open a potential window to objects travelling backwards in time, or travelling through space at a speed thousands of times faster than light (in their own timespace room).

No and yes respectively. Ftl particles open up the possibility of what is essentially teleportation, which is to say lateral movement beyond the light-cone in space-time, and widens the potential causal field (formerly described by that light-cone). However, it does not open up the possibility of anything more than asymptotic approach to the axis of the current moment.

Quote from: Oniya on September 22, 2011, 08:43:48 PM
Precisely.  Tachyons (from Gr. tachy- meaning fast) are theoretical faster-than-light particles.  According to one theory, just as it takes more and more energy for normal particles to speed up towards c, it takes more and more energy for tachyons to slow down towards c.  I'm trying to remember whether I read this in one of my Asimov (non-fiction) books or one of Charles Pickover's.  It might have been Rucker, but one of the books that I don't own.  *pouts*

It sounds familiar to me. So probably Asimov. He had lots of fun theories about breaking the c-barrier.
For every complex problem there is a solution that is simple, elegant, and wrong.


Vekseid

Quote from: DarklingAlice on September 22, 2011, 09:28:32 PM
No and yes respectively. Ftl particles open up the possibility of what is essentially teleportation, which is to say lateral movement beyond the light-cone in space-time, and widens the potential causal field (formerly described by that light-cone). However, it does not open up the possibility of anything more than asymptotic approach to the axis of the current moment.

'Now' is relative. If there is no special superframe (as described in Ian Banks' Culture novels), then yes, it would mean that time travel is possible. Relativity explicitly denies special frames, and no such frame can exist in our Universe (which also means that measuring such speeds in terms of multiples of the speed of light is just silly), so the existence of detectible FTL particles would mean that either causality can be violated or Relativity is incomplete for describing such situations.

DarklingAlice

Quote from: Vekseid on September 24, 2011, 09:46:31 AM
'Now' is relative. If there is no special superframe (as described in Ian Banks' Culture novels), then yes, it would mean that time travel is possible. Relativity explicitly denies special frames, and no such frame can exist in our Universe (which also means that measuring such speeds in terms of multiples of the speed of light is just silly), so the existence of detectible FTL particles would mean that either causality can be violated or Relativity is incomplete for describing such situations.

'Now' is not relative to anyone sharing your inertial reference frame and without significant gravitic variation. So for the purposes of 'local' space (and even non-local space without significant gravitic variation) we use a simple Minkowski (flat) space-time which has a well defined 'now' that we all share. These very experiments and a lot of fun physics tech would be impossible if that weren't true.

Even in cases where this isn't true, let's say you and I were across the universe from each other instead of just across the country, particles from my now could only time travel relative to yours but not relative to my viewpoint (and in that case this has less to do with 'time travel' and more to do with space-time being curved by gravity between us. Which is hardly what most people who are crowing about time travel in relation to this result mean.

The big bit is that latter point. If these results are accurate then it means that we change what we mean by causality. Since causality is defined by the light-cone emanating from the observer, we would have to redefine it as some kind of accelerated neutrino cone (provided the speed of the accelerated neutrinos is constant from all inertial viewpoints), change it to a more complex fluctuating causality surface, or stick with the light-cone but admit that causality can be violated. But even if we found higher and higher speed particles, no rate exists that would make them more than parallel with the space-time surface that is the observer's now (e.g. no effects proceeding causes, e.g. no time travel).
For every complex problem there is a solution that is simple, elegant, and wrong.


Oniya

For the non-physicists/non-mathematicians, I would highly recommend Rudy Rucker's 'The 4th Dimension' as a jumping-off point.  Yes, it's got a number of the more scientific diagrams (like Minkowitz and Feynmann,) but it also has a down-to-earth way of speaking, and explanatory illustrations that remind me of the illustrations in James Thurber's works as well.

It's also a lot of fun if you do understand math and physics.
"Language was invented for one reason, boys - to woo women.~*~*~Don't think it's all been done before
And in that endeavor, laziness will not do." ~*~*~*~*~*~*~*~*~*~*~Don't think we're never gonna win this war
Robin Williams-Dead Poets Society ~*~*~*~*~*~*~*~*~*~*~*~*~*~Don't think your world's gonna fall apart
I do have a cause, though.  It's obscenity.  I'm for it.  - Tom Lehrer~*~All you need is your beautiful heart
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DarklingAlice

Quote from: Oniya on September 24, 2011, 01:12:19 PM
For the non-physicists/non-mathematicians, I would highly recommend Rudy Rucker's 'The 4th Dimension' as a jumping-off point.  Yes, it's got a number of the more scientific diagrams (like Minkowitz and Feynmann,) but it also has a down-to-earth way of speaking, and explanatory illustrations that remind me of the illustrations in James Thurber's works as well.

It's also a lot of fun if you do understand math and physics.

Just cause of the way I was educated I am always going to push for original sources as trumping newer ones. Einstein himself wrote a book called Relativity: The Special and General Theory (subtitled: A Clear Explanation that Anyone can Understand) which serves as an excellent introduction either on its own or read in parallel with his academic papers on the subject, and was specifically written to be understood by the general public.
For every complex problem there is a solution that is simple, elegant, and wrong.


Vekseid

Quote from: DarklingAlice on September 24, 2011, 12:01:09 PM
'Now' is not relative to anyone sharing your inertial reference frame and without significant gravitic variation. So for the purposes of 'local' space (and even non-local space without significant gravitic variation) we use a simple Minkowski (flat) space-time which has a well defined 'now' that we all share. These very experiments and a lot of fun physics tech would be impossible if that weren't true.

Your claim is false. If someone moves at .86 of c with respect to you for two years, then stops, you think they have gone through a year of time dilation and they think the same of you. Who, actually, is one year ahead of the other? You both share the same inertial frame.

By Relativity, there is no special ordering. Both are equally true. It can only be reconciled by one of you moving to the other, and at that point someone is two years younger.

Quote
Even in cases where this isn't true, let's say you and I were across the universe from each other instead of just across the country, particles from my now could only time travel relative to yours but not relative to my viewpoint (and in that case this has less to do with 'time travel' and more to do with space-time being curved by gravity between us. Which is hardly what most people who are crowing about time travel in relation to this result mean.

The big bit is that latter point. If these results are accurate then it means that we change what we mean by causality. Since causality is defined by the light-cone emanating from the observer, we would have to redefine it as some kind of accelerated neutrino cone (provided the speed of the accelerated neutrinos is constant from all inertial viewpoints), change it to a more complex fluctuating causality surface, or stick with the light-cone but admit that causality can be violated. But even if we found higher and higher speed particles, no rate exists that would make them more than parallel with the space-time surface that is the observer's now (e.g. no effects proceeding causes, e.g. no time travel).

This is false.

c = 299,792,458 meters per second is not changed just because we discover something that propagates faster. Our equations are based on this variable and have been tested to an insane degree of precision, and don't model the concept of something going faster at all.

WhiteyChan

I'm skeptical about it. They say that the error in the ToF measurement is 10ns, and the neutrinos are only going faster by 60ns - same order of magnitude. The problem is that the OPERA experiment is currently the neutrino experiment with the longest ToF (or distance between source and detector, 730km), and thus its hard for any other lab to validate these results with a similar error margin, as is necessary for it to be fully realised as a discovery (regardless of the sigma level OPERA believes it has). Until the Long-baseline Neutrino Experiment is built in America (with a source-detector gap of over 1000km), which may not even be built, then we won't know for certain whether its a systematic error in the ToF measurement or not.

Either way, it is an interesting result - though even if it is true, I'd be hesitant about dismissing relativity right away. Its a regular occurrence that a particle travels faster than the speed of light in a medium, under special circumstances, and its been shown that its possible for the speed of light through a medium to be manipulated; maybe neutrinos interact with matter in a way that we don't know about yet that allows them to occasionally break the speed of light barrier. Besides, even if neutrinos can do it, that doesn't mean that any other form of matter can manage to do so, thus time machines are still implausible.

But what do I know, I'm only a 3rd year physics undergrad.

Oniya

Quote from: WhiteyChan on September 25, 2011, 10:53:53 AM
I'm skeptical about it. They say that the error in the ToF measurement is 10ns, and the neutrinos are only going faster by 60ns - same order of magnitude. The problem is that the OPERA experiment is currently the neutrino experiment with the longest ToF (or distance between source and detector, 730km), and thus its hard for any other lab to validate these results with a similar error margin, as is necessary for it to be fully realised as a discovery (regardless of the sigma level OPERA believes it has). Until the Long-baseline Neutrino Experiment is built in America (with a source-detector gap of over 1000km), which may not even be built, then we won't know for certain whether its a systematic error in the ToF measurement or not.

Either way, it is an interesting result - though even if it is true, I'd be hesitant about dismissing relativity right away. Its a regular occurrence that a particle travels faster than the speed of light in a medium, under special circumstances, and its been shown that its possible for the speed of light through a medium to be manipulated; maybe neutrinos interact with matter in a way that we don't know about yet that allows them to occasionally break the speed of light barrier. Besides, even if neutrinos can do it, that doesn't mean that any other form of matter can manage to do so, thus time machines are still implausible.

But what do I know, I'm only a 3rd year physics undergrad.

This is a good summation of why CERN is turning the results over - it's responsible peer review.  It's unexpected, they've checked their results as well as they can, and now they want to see if others in their field can see anything wrong with it (or if others can duplicate it).  One thing that you brought up just sparked something in my mind - I've seen others talking about how this 'could affect c', but it's important to remember that c is the speed of light in a vacuum.  There's nothing indicating that a vacuum was involved, or that they clocked photons arriving before they should have.  The neutrinos were traveling through rock.
"Language was invented for one reason, boys - to woo women.~*~*~Don't think it's all been done before
And in that endeavor, laziness will not do." ~*~*~*~*~*~*~*~*~*~*~Don't think we're never gonna win this war
Robin Williams-Dead Poets Society ~*~*~*~*~*~*~*~*~*~*~*~*~*~Don't think your world's gonna fall apart
I do have a cause, though.  It's obscenity.  I'm for it.  - Tom Lehrer~*~All you need is your beautiful heart
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WhiteyChan

Quote from: Oniya on September 25, 2011, 11:18:17 AM
This is a good summation of why CERN is turning the results over - it's responsible peer review.  It's unexpected, they've checked their results as well as they can, and now they want to see if others in their field can see anything wrong with it (or if others can duplicate it).  One thing that you brought up just sparked something in my mind - I've seen others talking about how this 'could affect c', but it's important to remember that c is the speed of light in a vacuum.  There's nothing indicating that a vacuum was involved, or that they clocked photons arriving before they should have.  The neutrinos were traveling through rock.

I'm glad I could add to the discussion Oniya :D Yeah, you're right, in that c is still the same constant - that's not open to any sort of interpretation. Typical 'scientific' journalism there, saying otherwise.

The discovery is also quite funny for me personally - I actually visited CERN on Wednesday with my university's physics society. Evidently I'm so awesome I bend the laws of physics around my vicinity... ;D

DarklingAlice

Quote from: Vekseid on September 25, 2011, 08:32:22 AM
Your claim is false. If someone moves at .86 of c with respect to you for two years, then stops, you think they have gone through a year of time dilation and they think the same of you. Who, actually, is one year ahead of the other? You both share the same inertial frame.

No, we don't. The acceleration to .86c would change our reference frames. This is why you would have to use the Lorentz transformations to convert between them. We currently share one inertial reference frame as we are under constant gravity and motion both of the earth and galaxy and neither of us is capable of moving at a significant fraction of c. Thus there is a consensus 'now'. I explicitly laid out that I am talking in real world terms here, not sci-fi or counterfactuals. My intent is to address the respond to the ideas of those people who feel this putative discovery will lead to Star Trek style FTL travel or time machines, for humans, in the foreseeable future.

Quote from: Vekseid on September 25, 2011, 08:32:22 AM
c = 299,792,458 meters per second is not changed just because we discover something that propagates faster. Our equations are based on this variable and have been tested to an insane degree of precision, and don't model the concept of something going faster at all.

I am afraid you are uninformed. This is exactly what Minkowski does in his September 1908 address in Cologne, the lecture in which the modern concept of space-time was first explored and defined. He evaluates what happens to space-time and causality for a causality determinant (fastest propagating cause) < c; c; > c; infinity. Nothing about the original math or models used by Einstein, Lorentz, or Minkowski requires that you use the speed of light in a vacuum, that is merely what the observational science supported (and probably still does, I am remaining skeptical about the CERN observation). Minkowski even makes the comment in the lecture that such models are perfectly possible just as you can use geometry to model counter-factual space structures and algebra to model higher and imaginary dimensions (however, he continues on to assure us that there will never be a need to since the speed of light will never be surpassed).
For every complex problem there is a solution that is simple, elegant, and wrong.


Vekseid

Quote from: DarklingAlice on September 25, 2011, 02:37:06 PM
No, we don't. The acceleration to .86c would change our reference frames. This is why you would have to use the Lorentz transformations to convert between them. We currently share one inertial reference frame as we are under constant gravity and motion both of the earth and galaxy and neither of us is capable of moving at a significant fraction of c. Thus there is a consensus 'now'. I explicitly laid out that I am talking in real world terms here, not sci-fi or counterfactuals. My intent is to address the respond to the ideas of those people who feel this putative discovery will lead to Star Trek style FTL travel or time machines, for humans, in the foreseeable future.

And I said 'stopped'. Two objects fixed with respect to each other share an inertial frame - that is the definition. They do not necessarily share a 'now', and will in fact disagree as to what is 'now' - each thinks they are one year 'older' than the other. If one accelerates back to the other, one will have experienced two more years of time passing, even though they are in thee exact same spot and again moving at the exact same speed, their clocks show different times.

Quote
I am afraid you are uninformed. This is exactly what Minkowski does in his September 1908 address in Cologne, the lecture in which the modern concept of space-time was first explored and defined.

1) Minkowski space is not our modern concept of space-time. It is for special relativity only, which pretends that gravity does not exist.

Quote
He evaluates what happens to space-time and causality for a causality determinant (fastest propagating cause) < c; c; > c; infinity.

2) In which case you would know that it is trivially easy to show a causality violation in Minkowski spacetime. Your ship sends a message through an ansible to a ship moving at .86 c away from you at t=10 seconds. They receive it at their t=5 seconds, and send you the reply, which you receive at t=2.5 seconds.

There is no reasonable room with which c can be extended. The mass of a photon has been ridiculously constrained, and the possible variance in c with a massive photon is some 30 orders of magnitude too small to account for these results.

Quote
Nothing about the original math or models used by Einstein, Lorentz, or Minkowski requires that you use the speed of light in a vacuum, that is merely what the observational science supported (and probably still does, I am remaining skeptical about the CERN observation). Minkowski even makes the comment in the lecture that such models are perfectly possible just as you can use geometry to model counter-factual space structures and algebra to model higher and imaginary dimensions (however, he continues on to assure us that there will never be a need to since the speed of light will never be surpassed).

c's limit is based on the assumption that light propogates at said velocity, which is based on the assumption that photons are massless. This is close enough to true, as referenced above, as to make no difference for the purpose of these results. Even if c is slightly faster than light, if these results are verified these neutrinos are still faster than c, and unless some external special ordering exists, then yes, that means there is a potential for causality violation.

DarklingAlice

@Veks
Okay, we're getting nowhere so lets see if we can clear a couple of points up:

1) 'Now' has nothing to do with how much time has passed. That's kind of the point. Let's use one of Einstein's examples: Take a disc shaped plane. Draw a radius and label the outer point A and the inner point B. Now, spin the disc in its own plane at a significant fraction of the speed of light. In accordance with the predictions of Lorentz, a clock at point A will always experience time more slowly than a clock at point B. Further a measuring rod tangent to A will always be shortened in the direction of the spin (as a fun consequence the ratio between the circumference of the disc and the diameter is no longer pi); however, the radius itself does not change. That radius is the 'now'. It's important not to get hung up into elapsed time or even the simultaneity of observed events. The basic model of a (Euclidean for special/Gaussian for general) space manifold comprising the present instant (our radius) compounded with a time parameter should always hold.

2) Minkowski's work is the basis of our modern concept of spacetime. We have built on his model, but not supplanted it. That's like saying that Darwin's theory of evolution by selection isn't the basis of our modern evolutionary biology just because we have built on it. Or the ideal gas law. Or electrostatics. Einstein himself said that without the Minkowski space-time continuum the general theory of relativity would have "got no further than its long clothes". All that is required for a shift from special to general considerations is the conversion from a Euclidean to non-euclidean continuum (the parameters of the shift based on the apparent gravitation from your reference frame).

3) I care as much about ansibles as I do about rubber-forehead aliens.  If you want to talk about sci-fi, fine, but it is not a response to anything I am saying. I'm talking about the implications of current science on current theories. Neutrino's moving faster than the speed of light means that they may be able to move in a Galelei-Newtonian fashion. Which means they would violate what we have defined causality (roughly speaking a Minkowski light-cone) at sufficiently differing reference frames (that we personally are in no way capable of achieving). That's not time travel or FTL travel in any conventional sense (either in the sense used by overenthusiastic geeks and the press, or in the literal sense of transversing the manifold of the present). It also does not violate the principle of relativity.




So has anyone heard any follow up? I know they held an open meeting a while back, was anyone able to catch it (or maybe have a link)? I have been so swamped with work that I haven't been able to follow this.
For every complex problem there is a solution that is simple, elegant, and wrong.


Oniya

http://www.universetoday.com/89377/astronomy-without-a-telescope-ftl-neutrinos-or-not/

Couldn't find anything about the open meeting, but this article from a couple days ago shows a number of places where measurement errors could have crept in.
"Language was invented for one reason, boys - to woo women.~*~*~Don't think it's all been done before
And in that endeavor, laziness will not do." ~*~*~*~*~*~*~*~*~*~*~Don't think we're never gonna win this war
Robin Williams-Dead Poets Society ~*~*~*~*~*~*~*~*~*~*~*~*~*~Don't think your world's gonna fall apart
I do have a cause, though.  It's obscenity.  I'm for it.  - Tom Lehrer~*~All you need is your beautiful heart
O/O's Updated 5/11/21 - A/A's - Current Status! - Writing a novel - all draws for Fool of Fire up!
Requests updated March 17

Vekseid

Quote from: DarklingAlice on October 03, 2011, 11:32:51 PM
@Veks
Okay, we're getting nowhere so lets see if we can clear a couple of points up:

1) 'Now' has nothing to do with how much time has passed. That's kind of the point. Let's use one of Einstein's examples: Take a disc shaped plane. Draw a radius and label the outer point A and the inner point B. Now, spin the disc in its own plane at a significant fraction of the speed of light. In accordance with the predictions of Lorentz, a clock at point A will always experience time more slowly than a clock at point B. Further a measuring rod tangent to A will always be shortened in the direction of the spin (as a fun consequence the ratio between the circumference of the disc and the diameter is no longer pi); however, the radius itself does not change. That radius is the 'now'. It's important not to get hung up into elapsed time or even the simultaneity of observed events. The basic model of a (Euclidean for special/Gaussian for general) space manifold comprising the present instant (our radius) compounded with a time parameter should always hold.

The purpose of that point is that there can be no special ordering between spacelike separated events according to relativity. Events A, B, and C, if spacelike, can happen in order A, B, C, or C, B, A, depending on the motion of the observer. Or some other ordering. What they consider to happen first or second is a matter of perspective and thus relative.

If a signal can move faster than c, you either get a causality violation or determine a special ordering.

Quote
2) Minkowski's work is the basis of our modern concept of spacetime. We have built on his model, but not supplanted it. That's like saying that Darwin's theory of evolution by selection isn't the basis of our modern evolutionary biology just because we have built on it. Or the ideal gas law. Or electrostatics. Einstein himself said that without the Minkowski space-time continuum the general theory of relativity would have "got no further than its long clothes". All that is required for a shift from special to general considerations is the conversion from a Euclidean to non-euclidean continuum (the parameters of the shift based on the apparent gravitation from your reference frame).

The Minkowski solution is used and taught because it is so simple - it's easy to do the transforms, and, like calling the Earth round instead of geoid, works for most purposes. This does not change the fact that it is not an accurate depiction of spacetime. It does not permit known FTL phenomenon, such as black holes or the expansion of spacetime, which general relativity does.

Quote
3) I care as much about ansibles as I do about rubber-forehead aliens.  If you want to talk about sci-fi, fine, but it is not a response to anything I am saying. I'm talking about the implications of current science on current theories. Neutrino's moving faster than the speed of light means that they may be able to move in a Galelei-Newtonian fashion. Which means they would violate what we have defined causality (roughly speaking a Minkowski light-cone) at sufficiently differing reference frames (that we personally are in no way capable of achieving). That's not time travel or FTL travel in any conventional sense (either in the sense used by overenthusiastic geeks and the press, or in the literal sense of transversing the manifold of the present). It also does not violate the principle of relativity.

You can do the experiment with any superluminal communication medium - such as these neutrinos if the experiments were verified. The math is simply easier with ansibles as you don't have to work out what a given superluminal speed means. If you have a superluminal communication method, you by definition are able to either use relativity to break causality (because there is no special ordering between the spacelike events you are communicating between), or use the subsequent experiments to determine a special ordering and thus a special frame (thus violating a central tenet of relativity). A quarter of a percent over c is still enough for a type I or so civilization to work with, so it would make an experiment feasible at least in some idealized future (you don't have to go at .999 of c to actually create a violation, just fast enough so that the contraction can be measured and see how it applies to the neutrinos).

Since the possibility that these particles are going a noticeable fraction faster than c is the central point of our argument, your comment of lumping in a confirmation with 'rubber-forehead' aliens is nothing but pure trolling, and not appreciated. In at least one typical model of a tachyon, they get faster as they bleed energy, meaning that lower-energy neutrinos would move faster still (though they are harder to detect - the Earth is actually opaque to neutrinos on the PeV scale or so). It's the entire point.

Very few educated people expect these results to be verified. But if you are going to make the argument from the assumption that they are verified, then yes, an ansible is a mathematical toy concept that belongs in the discussion whether you care for it or not.

Anyalyss

I was wondering if I could get an easy easy eaaaasy little explanation of this neutrinos/time travel thingy/super fast speeds *giggles* so that people like me, who are terrible at maths/sciences, but still find this curiosities interesting can understand it a little better. If it's of any help, the only time travel-similar thing that I remember are the movies "Back to the future" but I imagine that they contain like zero truth, still, if the movies make the explanation easier, feel free to use them!
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Susume

this is why everyone should read flatland. not only is it a simple way of explaining varying levels of dimension awareness but the ultimate epiphany of the square is this: even if you claim that there must only be a certain number of dimensions (/rules of physics) you are basing this on your perception of existence. Just as the line man has no concept of two dimensions, so might we have no concept of the fourth dimension because we cannot perceive it. Who knows there could be a fifth dimension or even a sixth, but we might never know because we are both unable to see or even believe in such a thing.
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Oniya

I'll ditto on Flatland as one of those 'math for non-math people'.  It's also fairly easy to lay hands on.  I'd also put Zukav's The Dancing Wu Li Masters out there as 'physics for the non-physicist'.  It gets a little into Eastern philosophy, so it's not exactly a 'light' read like Flatland, but people who are more into the humanities than the sciences might grasp it better because of that.
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Anyalyss

Thanks for the advices, I will look around for both :-)
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WhiteyChan

Quote from: Anyalyss on October 05, 2011, 01:11:07 PM
I was wondering if I could get an easy easy eaaaasy little explanation of this neutrinos/time travel thingy/super fast speeds *giggles* so that people like me, who are terrible at maths/sciences, but still find this curiosities interesting can understand it a little better. If it's of any help, the only time travel-similar thing that I remember are the movies "Back to the future" but I imagine that they contain like zero truth, still, if the movies make the explanation easier, feel free to use them!

In a nutshell: neutrinos are tiny, tiny, TIIIIINY particles, that fly through other stuff as if it weren't there. We've got millions of them flying through our bodies every second from various solar sources. Under our current understanding of the universe, though, these neutrinos have mass - they weigh something, albeit such a small value that we don't actually know for certain what it is - and thus shouldn't be able to travel faster than the speed of light in a vacuum (about 300,000 km/s). However, a neutrino detector in Italy, OPERA, have calculated that some neutrinos created at CERN and fired towards them have travelled faster than this speed of light, c. This is extremely interesting, as it shouldn't be possible, and if it is then it completely ruins most accepted theories about the universe, and the scientists have to start from scratch again.

I hope this kinda helps you understand it a little better :)

I should point out too that time travel is still not possible in the science-fiction sense of the word. Nothing can travel backwards in time, it would merely be that the neutrinos arrive somewhere before electromagnetic radiation from the event. The event would have still happened X time ago, but the neutrinos might arrive before the light from the event. Sort of like when the tide goes out before a tsunami, I guess - you haven't seen the tsunami yet, but you know its going to happen because the water has receded.

On a more technical note, remember that the speed of the neutrinos was not directly measured, it was inferred from time of flight, and its hard to know exactly where the neutrinos were created due to the nature of the method by which they're created. This uncertainty, plus other errors, could easily account for the 60ns ToF difference. Random noise is random for a reason, and Gaussian distributions do have extremes; hence the bell-curve shape. Yes these extremes are rarer, but these 'FTL' neutrinos are rare compared to the velocities of the vast majority of the other neutrinos detected - and its not as if its been shown that in a straight race in a vacuum between a photon and a neutrino, the neutrino wins. I think an argument about our definition of space-time and the completely hypothetical tachyon is a little unwarranted at this juncture, as interesting for me to read as it is :-)

Anyalyss

Yup! thank you very much, it did really help! :-)

Although it's such a shame that time-travel ala science-fiction is not possible *daydreams about her own little DeLorean*
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