Well, this could change things (neutrinos)

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A hypothesis

Postby Deadcode » Sat Oct 01, 2011 11:08 pm UTC

Here's a hypothesis I don't think anybody's brought up yet (if somebody has, I'd like to know):

What if the neutrinos oscillate between traveling slightly slower than light and slightly faster than light? Then the average speed measured in an experiment would depend on the total distance the neutrinos traveled modulo some distance.

The maximum discrepancy would then be on the order of 60 ns (probably never more than 200 ns or so) regardless of the distance, whether it is 730 km or 168,000 ly. Depending on the exact distance, neutrinos might average slightly under or slightly over the speed of light, but would never arrive more than about 100 to 200 ns earlier than light in a vacuum would (on average).

Do neutrinos oscillate at regular intervals, or random intervals? If it's the latter, then the wavefront of a neutrino burst would get more and more smeared the farther it traveled, and that would pretty much break this hypothesis. But if neutrinos oscillate regularly, they'd spend the same amount of time in the slower-than-light phase as they spent in the faster-than-light phase and keep a tight wavefront.

If this hypothesis were true, would it be possible to violate causality by sending information using neutrinos? Would it even possible in principle to make a neutrino pulse strong enough, and a neutrino detector sensitive enough, to observe the pulse and decode it in 100 ns or so, and use that to attempt to create a temporal paradox?
Last edited by Deadcode on Sun Oct 02, 2011 12:24 am UTC, edited 1 time in total.

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Re: Well, this could change things (neutrinos)

Postby Macbi » Sat Oct 01, 2011 11:57 pm UTC

To be totally clear, they send no photons from CERN to Gran Sasso, they just measure the distance (using clever GPS tricks) and then dived by the already calculated value of c.
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Re: A hypothesis

Postby gmalivuk » Sun Oct 02, 2011 2:25 am UTC

Deadcode wrote:What if the neutrinos oscillate between traveling slightly slower than light and slightly faster than light?
That seems even less likely than that neutrinos always travel a bit faster than light, actually.
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Re: A hypothesis

Postby Charlie! » Sun Oct 02, 2011 5:25 am UTC

gmalivuk wrote:
Deadcode wrote:What if the neutrinos oscillate between traveling slightly slower than light and slightly faster than light?
That seems even less likely than that neutrinos always travel a bit faster than light, actually.

I suppose you could have different flavors of neutrinos travel at different velocities.
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Re: A hypothesis

Postby Malconstant » Sun Oct 02, 2011 2:49 pm UTC

Charlie! wrote:I suppose you could have different flavors of neutrinos travel at different velocities.

That's come up, but then that has the same weirdness given neutrino oscillation. I mean if it turns out that the measurement is real, there's a good chance the result will be "neutrinos are just that much more weird than we knew before", but that doesn't make oscillating in and out of tachyons any more palatable.
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Re: A hypothesis

Postby gorcee » Sun Oct 02, 2011 4:22 pm UTC

Malconstant wrote:
Charlie! wrote:I suppose you could have different flavors of neutrinos travel at different velocities.

That's come up, but then that has the same weirdness given neutrino oscillation. I mean if it turns out that the measurement is real, there's a good chance the result will be "neutrinos are just that much more weird than we knew before", but that doesn't make oscillating in and out of tachyons any more palatable.


Perhaps they don't oscillate in and out. I think we are missing what, 1/3 of what we should be seeing from the sun? What if 2/3 of those oscillate, and 1/3 permanently become tachyonic through some hitherto unknown quantum process, and we're just seeing that process as it unfolds?

It would be pretty far-fetched, but cool.

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Re: Well, this could change things (neutrinos)

Postby Technical Ben » Sun Oct 02, 2011 7:16 pm UTC

They are doing a second test at a separate facility to see if they get similar or different results. I'm guessing if the results are different, but still FTL, it suggests an error in the design of the test no one has thought of. Where as finding the same result could be an error still, or a hint at there being something else going on (IE FTL travel).
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Re: A hypothesis

Postby Carnildo » Sun Oct 02, 2011 8:18 pm UTC

gorcee wrote:
Malconstant wrote:
Charlie! wrote:I suppose you could have different flavors of neutrinos travel at different velocities.

That's come up, but then that has the same weirdness given neutrino oscillation. I mean if it turns out that the measurement is real, there's a good chance the result will be "neutrinos are just that much more weird than we knew before", but that doesn't make oscillating in and out of tachyons any more palatable.


Perhaps they don't oscillate in and out. I think we are missing what, 1/3 of what we should be seeing from the sun? What if 2/3 of those oscillate, and 1/3 permanently become tachyonic through some hitherto unknown quantum process, and we're just seeing that process as it unfolds?

It would be pretty far-fetched, but cool.

The solar neutrino problem was solved a decade ago, by the Sudbury Neutrion Observatory. The reason why about a third of the solar neutrinos were "missing" is simply because until the construction of SNO, no neutrino detector was able to detect all three types of neutrino. In 1998, observations at the Super-K observatory suggested that neutrinos could change between types, and in 2001, SNO detected exactly the predicted number of solar neutrinos -- but most of them weren't the electron neutrinos that hydrogen fusion produces, thus proving that neutrinos could change type (and therefore had non-zero rest mass).

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Re: A hypothesis

Postby Game_boy » Mon Oct 03, 2011 12:55 am UTC

Carnildo wrote:neutrinos could change type (and therefore had non-zero rest mass).


Is there an intuitive way to understand why one implies the other there?

I'm expecting something like "it's an invariant in the gauge theory field equation transformation, why'd you even need to ask?".
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Re: A hypothesis

Postby Carnildo » Mon Oct 03, 2011 1:16 am UTC

Game_boy wrote:
Carnildo wrote:neutrinos could change type (and therefore had non-zero rest mass).


Is there an intuitive way to understand why one implies the other there?

In simple terms, relativity says that particles with zero rest mass (eg. photons) don't experience time. No time means no change.

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Re: A hypothesis

Postby gorcee » Mon Oct 03, 2011 2:12 am UTC

Carnildo wrote:
gorcee wrote:
Malconstant wrote:
Charlie! wrote:I suppose you could have different flavors of neutrinos travel at different velocities.

That's come up, but then that has the same weirdness given neutrino oscillation. I mean if it turns out that the measurement is real, there's a good chance the result will be "neutrinos are just that much more weird than we knew before", but that doesn't make oscillating in and out of tachyons any more palatable.


Perhaps they don't oscillate in and out. I think we are missing what, 1/3 of what we should be seeing from the sun? What if 2/3 of those oscillate, and 1/3 permanently become tachyonic through some hitherto unknown quantum process, and we're just seeing that process as it unfolds?

It would be pretty far-fetched, but cool.

The solar neutrino problem was solved a decade ago, by the Sudbury Neutrion Observatory. The reason why about a third of the solar neutrinos were "missing" is simply because until the construction of SNO, no neutrino detector was able to detect all three types of neutrino. In 1998, observations at the Super-K observatory suggested that neutrinos could change between types, and in 2001, SNO detected exactly the predicted number of solar neutrinos -- but most of them weren't the electron neutrinos that hydrogen fusion produces, thus proving that neutrinos could change type (and therefore had non-zero rest mass).


Ah, cool! I did not know that problem was solved!

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Re: Well, this could change things (neutrinos)

Postby YoungStudent » Mon Oct 03, 2011 6:31 am UTC

What if they speed up for some time when they change between types?
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Re: Well, this could change things (neutrinos)

Postby Charlie! » Mon Oct 03, 2011 6:35 am UTC

YoungStudent wrote:What if they speed up for some time when they change between types?

Makes much less sense than all types travelling faster than c, and doesn't solve the problem of the measurements form the supernova.
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Re: Well, this could change things (neutrinos)

Postby Technical Ben » Mon Oct 03, 2011 7:56 am UTC

Well, could they not be unaffected by the Higgs field in certain types? Although, I would guess the avoiding the Higgs field would not allow FTL travel anyhow.
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Re: Well, this could change things (neutrinos)

Postby lorb » Mon Oct 03, 2011 10:12 am UTC

I have next to no background in physics so maybe someone can enlighten me on a kind of paradox i see here.
The outcome of this experiment is not compatible with some physics that are used to conduct the experiment. Or in other words: if it breaks relativity it is itself no longer valid because the technology used to measure is based on relativity. (GPS) And in that case we can't infer broken relativity from it ...
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Re: Well, this could change things (neutrinos)

Postby thoughtfully » Mon Oct 03, 2011 10:21 am UTC

lorb wrote:I have next to no background in physics so maybe someone can enlighten me on a kind of paradox i see here.
The outcome of this experiment is not compatible with some physics that are used to conduct the experiment. Or in other words: if it breaks relativity it is itself no longer valid because the technology used to measure is based on relativity. (GPS) And in that case we can't infer broken relativity from it ...


It's already been said a few times, but let's hear it again:

READ OUR LIPS/POSTS!! Relativity is not broken!
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Re: Well, this could change things (neutrinos)

Postby lorb » Mon Oct 03, 2011 11:09 am UTC

thoughtfully wrote:
lorb wrote:I have next to no background in physics so maybe someone can enlighten me on a kind of paradox i see here.
The outcome of this experiment is not compatible with some physics that are used to conduct the experiment. Or in other words: if it breaks relativity it is itself no longer valid because the technology used to measure is based on relativity. (GPS) And in that case we can't infer broken relativity from it ...


It's already been said a few times, but let's hear it again:

READ OUR LIPS/POSTS!! Relativity is not broken!


I am sorry for my poor wording. I had no intention to imply/state that relativity is broken. What i wanted to say is more like: If it is possible that some part of this experiments settings/tools is relying on technology that is based on knowledge that possibly could be invalidated by that same experiment it leads to a epistemologically unclear situation. My point is not based on physics but on philosophy of science. And my question is: is it possible that such a situation could be present here because my knowledge of physics is too meager to judge whether this could be the case.
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Re: Well, this could change things (neutrinos)

Postby Malconstant » Mon Oct 03, 2011 12:05 pm UTC

lorb wrote:I am sorry for my poor wording. I had no intention to imply/state that relativity is broken. What i wanted to say is more like: If it is possible that some part of this experiments settings/tools is relying on technology that is based on knowledge that possibly could be invalidated by that same experiment it leads to a epistemologically unclear situation. My point is not based on physics but on philosophy of science. And my question is: is it possible that such a situation could be present here because my knowledge of physics is too meager to judge whether this could be the case.

This idea is just straight up contradiction. If you assume a theory in designing an experiment (A) and when you find is a result which invalidates the theory (-A) then you've got A -> -A. It's just that simple. There's no paradox, it's just that if you assume something that's wrong and from that you derive a contradiction, well that's how you know that your assumption was wrong.

It's not like you get caught in a "paradoxical" loop of "well the experiment says the theory was wrong, but that means the experimental design was wrong, in which case the experimental result is invalid so that means there's no proof that the theory is wrong."

This is why people reacted as they did to your question because although you don't seem to realize it, you accepted as an implicit assumption that maybe this experiment proved relativity wrong. So just to be clear, the theory of relativity was never actually under question, it was not being tested in this experiment, it is rather being tested successfully to much greater precisions all the time in CERN at the moment. So any language which implicitly dismisses this is unproductive and silly.
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Re: Well, this could change things (neutrinos)

Postby jestingrabbit » Mon Oct 03, 2011 5:41 pm UTC

Malconstant wrote:you accepted as an implicit assumption that maybe this experiment proved relativity wrong. So just to be clear, the theory of relativity was never actually under question, it was not being tested in this experiment, it is rather being tested successfully to much greater precisions all the time in CERN at the moment. So any language which implicitly dismisses this is unproductive and silly.


I'm sorry but if there is stuff traveling faster than c, then that is a pretty clear indication that there are parts of relativity that are wrong. That's why this is such an unlikely result, it directly contradicts one of the predictions that relativity makes, that c is the speed limit.

That said, it would be wrong in the way that Newtonian mechanics is wrong. It still applies and gives good predictions in a whole range of circumstances. It would still be useful in working out the time dilations that the GPS satellites are subject to, and it would therefore still be useful for working out the distance that between the emitter and detector in this experiment. So it would be more correct to describe it as incomplete rather than wrong.

Also, am I the only person here who thinks that blindly applying the relativity equations to superluminal particles, to come up with statements about negative energy and what not, isn't a really sensible thing to do? Sure, those equations are well tested for the strongly interacting particles that we're all familiar with, at speeds that are less than c. But expecting them to work outside of that tested region seems a little wrong to me. Acting like we can keep applying the same equations and coming up with sense is a little absurd to me.
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Re: Well, this could change things (neutrinos)

Postby Malconstant » Mon Oct 03, 2011 6:15 pm UTC

jestingrabbit wrote:
Malconstant wrote:you accepted as an implicit assumption that maybe this experiment proved relativity wrong. So just to be clear, the theory of relativity was never actually under question, it was not being tested in this experiment, it is rather being tested successfully to much greater precisions all the time in CERN at the moment. So any language which implicitly dismisses this is unproductive and silly.


I'm sorry but if there is stuff traveling faster than c, then that is a pretty clear indication that there are parts of relativity that are wrong. That's why this is such an unlikely result, it directly contradicts one of the predictions that relativity makes, that c is the speed limit.

Perhaps you have never heard of tachyons or extradimensional curved space (both mentioned above)? These things are consistent with relativity.
jestingrabbit wrote:That said, it would be wrong in the way that Newtonian mechanics is wrong. It still applies and gives good predictions in a whole range of circumstances. It would still be useful in working out the time dilations that the GPS satellites are subject to, and it would therefore still be useful for working out the distance that between the emitter and detector in this experiment. So it would be more correct to describe it as incomplete rather than wrong.

And what regime are your referring to? Given that the universal speed limit = c for massive objects has been experimentally verified to much greater precisions than this experiment.
jestingrabbit wrote:Also, am I the only person here who thinks that blindly applying the relativity equations to superluminal particles, to come up with statements about negative energy and what not, isn't a really sensible thing to do? Sure, those equations are well tested for the strongly interacting particles that we're all familiar with, at speeds that are less than c. But expecting them to work outside of that tested region seems a little wrong to me. Acting like we can keep applying the same equations and coming up with sense is a little absurd to me.

So you're saying "Sure, those equations work astonishingly well for every regime we've ever tested, but why on Earth would we expect them to be relevant to something like neutrinos". I just don't understand where that sentiment would come from. That tested region in which relativity seems to work happens to be every regime ever. Even with neutrinos, as measured in the past (different flavors, sure).
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Re: Well, this could change things (neutrinos)

Postby jestingrabbit » Mon Oct 03, 2011 6:56 pm UTC

Malconstant wrote:So you're saying "Sure, those equations work astonishingly well for every regime we've ever tested, but why on Earth would we expect them to be relevant to something like neutrinos". I just don't understand where that sentiment would come from.


Because if you calculate the Lorentz factor for a velocity greater than c you get an imaginary number and imaginary lengths, imaginary times, imaginary masses and imaginary energies are all meaningless as concepts. What is a duration of i seconds? What is a distance of i metres? Can imaginary energy only do imaginary work? What does conservation of mass mean when there are imaginary masses running around? Which particular root of negative 1 are they actually, i or -i? etc etc etc.

The neutrinos in question have very definitely gone regular, real number type distances over a duration of regular, real number type seconds. That much is clear. If they have done so at speeds greater than c, then there is clearly a problem with all the dilations that you use to get Lorentz invariance, specifically, gamma should have its modulus taken.
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Re: Well, this could change things (neutrinos)

Postby doogly » Mon Oct 03, 2011 6:58 pm UTC

The imaginary Lorentz factors mean you can't boost from <c to >c. You can have tachyons which exist at >c at all times. They're weird though.
Negative energies show up in quantum field theory and actually aren't all that weird.
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Re: Well, this could change things (neutrinos)

Postby gorcee » Mon Oct 03, 2011 6:58 pm UTC

Experimental data does not necessarily lead to validation of a theory. After all, F=ma has been observed to great accuracy when not involving things the size of planets. But we know that F=ma is universally not correct. In other words, Newtonian mechanics is perfectly correct, up until the point that it is not.

The new data, if it stands, would have two possibilities. Either that it jives with relativity in a known way (although, AFAIK, relativity still prevents tardyon-tachyon conversion), or relativity is only correct up until the point that it is not.

In other words, if the data were to stand, then it is imprudent to shoot down potential new physics just because it doesn't match with relativity. On the other hand, finding a way to match it with relativity should obviously be the first step. But if we cannot reconcile the two, then we similarly cannot disregard a notion solely based on its non-compliance with relativity.

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Re: Well, this could change things (neutrinos)

Postby eSOANEM » Mon Oct 03, 2011 7:24 pm UTC

jestingrabbit wrote:Because if you calculate the Lorentz factor for a velocity greater than c you get an imaginary number and imaginary lengths, imaginary times, imaginary masses and imaginary energies are all meaningless as concepts.


Are they? In certain older formulations of minkowski spacetime, spacetime was taken to be Euclidean with the time dimension having imaginary values. This formulation is less neat than the modern one so it's fallen out favour, but the point stands that imaginary distance (and therefore times) are definitely not meaningless and could be said to just be times and distances respectively. Imaginary rest energy is harder to interpret however, but that doesn't mean it's meaningless.

gorcee wrote:In other words, if the data were to stand, then it is imprudent to shoot down potential new physics just because it doesn't match with relativity. On the other hand, finding a way to match it with relativity should obviously be the first step. But if we cannot reconcile the two, then we similarly cannot disregard a notion solely based on its non-compliance with relativity.


No-one (at least, not anyone sensible) is shooting down potential new physics just because it doesn't match relativity. All they're saying is that 1, it needs to be verified and 2, relativity is not broken, it still works in almost all cases, it just means there's something new beyond it (which everyone sensible already knew). Besides, because we know relativity works (on almost all scales), any theory which does explain the neutrinos, must in some limit(s) or another become equivalent to relativity.
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Re: Well, this could change things (neutrinos)

Postby gorcee » Mon Oct 03, 2011 7:42 pm UTC

eSOANEM wrote:
gorcee wrote:In other words, if the data were to stand, then it is imprudent to shoot down potential new physics just because it doesn't match with relativity. On the other hand, finding a way to match it with relativity should obviously be the first step. But if we cannot reconcile the two, then we similarly cannot disregard a notion solely based on its non-compliance with relativity.


No-one (at least, not anyone sensible) is shooting down potential new physics just because it doesn't match relativity. All they're saying is that 1, it needs to be verified and 2, relativity is not broken, it still works in almost all cases, it just means there's something new beyond it (which everyone sensible already knew). Besides, because we know relativity works (on almost all scales), any theory which does explain the neutrinos, must in some limit(s) or another become equivalent to relativity.


I'd argue, semantically, that the claim that "relativity isn't broken" is strictly not true, if the data were to hold. What's surprising about this situation is that we're seeing anomalous behavior in an area where we should not. This is a different scenario than overhauling Newtonian mechanics with relativity. Newtonian mechanics was replaced with relativity on extreme scales. However, this recent anomaly is happening well within the realm of where relativity should work.

(Note, I'm not suggesting that relativity is broken, or that validation of the data would mean that relativity is broken everywhere. Quite clearly, it is not. I'm just arguing that it would be somewhat dented).

An apt analogy, perhaps, would be if we found supersymmetry at RHIC or something similar. It would be less surprising to see evidence of supersymmetry at LHC, because that device is designed to operate in a hitherto unseen realm. So finding the evidence at RHIC instead, when the device is less powerful, would kind of force us to say, "wait, what the fuck?"

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Re: Well, this could change things (neutrinos)

Postby Malconstant » Mon Oct 03, 2011 9:39 pm UTC

gorcee wrote:I'd argue, semantically, that the claim that "relativity isn't broken" is strictly not true, if the data were to hold.


Then you'd be wrong. Or at least you'd be presumptuous. If it turned out that, say, neutrinos needed to be accelerated from regular speeds to superluminal speeds, then I would agree that relativity had a broken dent.

gorcee wrote:An apt analogy, perhaps, would be if we found supersymmetry at RHIC or something similar. It would be less surprising to see evidence of supersymmetry at LHC, because that device is designed to operate in a hitherto unseen realm. So finding the evidence at RHIC instead, when the device is less powerful, would kind of force us to say, "wait, what the fuck?"


Two things:
1) You'd be hard pressed to find a physicist who wouldn't respond "what the fuck" if they were faced with incontrovertible proof of superluminal motion of neutrinos, especially if you encoded this information in neutrinos and sent it off to be observed a couple months ago.
2) I question the aptness. That sounds more like if we would find a proton to be accelerating superluminally in the LHC. That shit would be ridiculous. But neutrinos have always been ridiculous and hard to get a handle on. Flavor oscillations? Already ridiculous. Sometimes being tachyons maybe? Sure why not, fucking neutrinos.
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Re: Well, this could change things (neutrinos)

Postby gorcee » Mon Oct 03, 2011 10:18 pm UTC

Malconstant wrote:
gorcee wrote:I'd argue, semantically, that the claim that "relativity isn't broken" is strictly not true, if the data were to hold.


Then you'd be wrong. Or at least you'd be presumptuous. If it turned out that, say, neutrinos needed to be accelerated from regular speeds to superluminal speeds, then I would agree that relativity had a broken dent.


That's why I said, "if the data were to hold." Because barring any source of systematic error, there doesn't seem to be a whole lot of viable options out there where the neutrinos aren't crossing the light barrier.

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Re: Well, this could change things (neutrinos)

Postby BlackSails » Mon Oct 03, 2011 10:36 pm UTC

What about if the measured speed of light is off from the true speed of light? I could imagine photons interact with the background in someway such that the speed of light in vacuum is not the true speed of light, might like how the speed of light in glass is reduced.

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Re: Well, this could change things (neutrinos)

Postby jaap » Mon Oct 03, 2011 10:52 pm UTC

BlackSails wrote:What about if the measured speed of light is off from the true speed of light? I could imagine photons interact with the background in someway such that the speed of light in vacuum is not the true speed of light, might like how the speed of light in glass is reduced.

Time dilation has been accurately measured, as have other relativistic effects in many different situations. These all depend on c, but not on directly measuring the speed of photons in any medium.

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Re: Well, this could change things (neutrinos)

Postby Carnildo » Tue Oct 04, 2011 6:28 am UTC

jestingrabbit wrote:
Malconstant wrote:So you're saying "Sure, those equations work astonishingly well for every regime we've ever tested, but why on Earth would we expect them to be relevant to something like neutrinos". I just don't understand where that sentiment would come from.


Because if you calculate the Lorentz factor for a velocity greater than c you get an imaginary number and imaginary lengths, imaginary times, imaginary masses and imaginary energies are all meaningless as concepts. What is a duration of i seconds? What is a distance of i metres? Can imaginary energy only do imaginary work? What does conservation of mass mean when there are imaginary masses running around? Which particular root of negative 1 are they actually, i or -i? etc etc etc.

See Tachyon: faster-than-light travel is not inherently in conflict with relativity (either special or general). What breaks is causality, the assumption that causes precede their effects. The statement "Relativity forbids faster-than-light travel" carries an unstated assumption, and would more accurately be expressed as "If causality holds, then relativity forbids faster-than-light travel".

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Re: Well, this could change things (neutrinos)

Postby Diadem » Tue Oct 04, 2011 12:25 pm UTC

Carnildo wrote:
jestingrabbit wrote:
Malconstant wrote:So you're saying "Sure, those equations work astonishingly well for every regime we've ever tested, but why on Earth would we expect them to be relevant to something like neutrinos". I just don't understand where that sentiment would come from.


Because if you calculate the Lorentz factor for a velocity greater than c you get an imaginary number and imaginary lengths, imaginary times, imaginary masses and imaginary energies are all meaningless as concepts. What is a duration of i seconds? What is a distance of i metres? Can imaginary energy only do imaginary work? What does conservation of mass mean when there are imaginary masses running around? Which particular root of negative 1 are they actually, i or -i? etc etc etc.

See Tachyon: faster-than-light travel is not inherently in conflict with relativity (either special or general). What breaks is causality, the assumption that causes precede their effects. The statement "Relativity forbids faster-than-light travel" carries an unstated assumption, and would more accurately be expressed as "If causality holds, then relativity forbids faster-than-light travel".

I'd rather break relativity than causality though.

There are in fact several alternative theories that break relativity. None of them have gained much foothold because, well, relativity has been amazingly well tested, but still, a bit of minor breakage here and there wouldn't cause too much trouble. Breaking causality however. Damn.
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Re: Well, this could change things (neutrinos)

Postby BlackSails » Tue Oct 04, 2011 1:25 pm UTC

jaap wrote:
BlackSails wrote:What about if the measured speed of light is off from the true speed of light? I could imagine photons interact with the background in someway such that the speed of light in vacuum is not the true speed of light, might like how the speed of light in glass is reduced.

Time dilation has been accurately measured, as have other relativistic effects in many different situations. These all depend on c, but not on directly measuring the speed of photons in any medium.


What if time dilation and all that depend on the "effective" c, which is screened by whatever magical vacuum effects there are that dont affect neutrinos?

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Re: Well, this could change things (neutrinos)

Postby Robert'); DROP TABLE *; » Tue Oct 04, 2011 1:32 pm UTC

BlackSails wrote:
jaap wrote:
BlackSails wrote:What about if the measured speed of light is off from the true speed of light? I could imagine photons interact with the background in someway such that the speed of light in vacuum is not the true speed of light, might like how the speed of light in glass is reduced.

Time dilation has been accurately measured, as have other relativistic effects in many different situations. These all depend on c, but not on directly measuring the speed of photons in any medium.


What if time dilation and all that depend on the "effective" c, which is screened by whatever magical vacuum effects there are that dont affect neutrinos?

I think that's was jaap's point: we've measured it accurately enough to know that that's not true.
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Re: Well, this could change things (neutrinos)

Postby Malconstant » Tue Oct 04, 2011 2:30 pm UTC

gorcee wrote:
Malconstant wrote:
gorcee wrote:I'd argue, semantically, that the claim that "relativity isn't broken" is strictly not true, if the data were to hold.


Then you'd be wrong. Or at least you'd be presumptuous. If it turned out that, say, neutrinos needed to be accelerated from regular speeds to superluminal speeds, then I would agree that relativity had a broken dent.


That's why I said, "if the data were to hold." Because barring any source of systematic error, there doesn't seem to be a whole lot of viable options out there where the neutrinos aren't crossing the light barrier.


There's nothing about the measurement which suggests neutrinos were previously in a subluminal speed and then were accelerated to a superluminal speed. I'm saying that relativity wouldn't be broken even if it turned out that the experimentalists made no errors. This is because relativity is not the same thing as the statement "nothing can travel faster than light". Worm holes and tachyons ad nauseum.

Yes, it's possible to explain the results with non-relativity theories, but why bother when you can also explain the results with relativity?

As a side note, although I don't find the tachyon explanation to be compelling due to flavor oscillation, an experimentalist friend informed me that the best measurements of the squared mass of this flavor of neutrino have been negative, with error bars that go into the positive. So naturally the assumption was that the error bars saved the day and put a lower limit on mass, rather than just assuming tachyon imaginary mass.
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Re: Well, this could change things (neutrinos)

Postby gmalivuk » Tue Oct 04, 2011 2:31 pm UTC

For example, when things already travel faster than light in a specific medium.
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Re: Well, this could change things (neutrinos)

Postby Yakk » Tue Oct 04, 2011 3:27 pm UTC

So, the wonkiest thought I had is "what if neutrinos take a straighter route than light".

On interstellar scales this might not accumulate, as most of the space light goes through is relatively "flat". In a (relatively deep) gravity well the curved space-time might mean that the route light takes is ... less than efficient.

This of course breaks relativity. But it has a certain cuteness to it.

And, now that I think about it, I doubt space-time around earth is that bent, is it?
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Re: Well, this could change things (neutrinos)

Postby gorcee » Tue Oct 04, 2011 4:41 pm UTC

Yakk wrote:So, the wonkiest thought I had is "what if neutrinos take a straighter route than light".

On interstellar scales this might not accumulate, as most of the space light goes through is relatively "flat". In a (relatively deep) gravity well the curved space-time might mean that the route light takes is ... less than efficient.

This of course breaks relativity. But it has a certain cuteness to it.

And, now that I think about it, I doubt space-time around earth is that bent, is it?


Or could be evidence of extra dimensions, perhaps?

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Re: Well, this could change things (neutrinos)

Postby Wombat2k » Tue Oct 04, 2011 4:50 pm UTC

That`s kind of close to what a New Scientist article said this week. ( Can`t link sorry)
High energy neutrinos might switch to sterile neutrinos ( In string theory a closed loop of string) in mid flight allowing them to shortcut the distance by leaving the brane that our space-time is embedded in.
The hypothesis is from Pakvasa, pas and Weiler in 2006.
http://arxiv.org/abs/hep-ph/0611263
Part of me is hoping that the results are not repeatable. Not a big fan of string theory. :?

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Re: Well, this could change things (neutrinos)

Postby eSOANEM » Tue Oct 04, 2011 6:44 pm UTC

Diadem wrote:Breaking causality however. Damn.


Why is it such a big jump? Radiation has shown us there are effects without specific causes (or at the very least coincident with their causes), why shouldn't anticausal phenomena be allowed?
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Re: Well, this could change things (neutrinos)

Postby Technical Ben » Tue Oct 04, 2011 6:48 pm UTC

Hey, if the results give good answers, we* they could at least "fix" the problems with String theory. ;)

The idea of "jumping" branes sounds really cool and a great idea for FTL concepts.

I'm liking the ideas put forward about how Newtonian mechanics breaks down at the large scale, relativity breaks down past lightspeed. Perhaps a universal reference frame is applicable over light speed, but only to objects travelling FTL? However, I realise the real result will be that there was a test error, and the neutrinos are travelling a fraction slower than c. :oops:

PS eSOANEM, is it not because it actually breaks all the equations. It does not force us to change the rules, it removes all possible rules or systems of expression (maths, logic etc) completely.

*(Not including myself as being able to give input, just used "we" to denote mankind. :D)
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