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  #11  
Old Sep 29th 2011, 09:55 PM
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Default Re: Faster than the speed of light?

Physicists' joke:

The bartender says : We don't serve neutrino's.
A neutrino walks into a bar.

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  #12  
Old Sep 29th 2011, 10:49 PM
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Default Re: Faster than the speed of light?

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Originally Posted by Dominick View Post
Physicists' joke:

The bartender says : We don't serve neutrino's.
A neutrino walks into a bar.

A cop stops Heisenberg for speeding.

Cop: Do you know how fast you were going?

Heisenberg: No. But I know where I am.
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Old Sep 30th 2011, 01:51 PM
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Default Re: Faster than the speed of light?

In the mean time the Tevatron, the US predecessor of the LHC will be taken offline right about now:
http://www-visualmedia.fnal.gov/live/110930Tev.htm

I don't know who's responsible for it but it's a bad decision.
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Old Oct 16th 2011, 09:59 PM
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Default Re: Faster than the speed of light?

By the way, this case, of the FTL neutrino's, is resolved. It turns out that in one of the many many steps and calculations of this complex experiment the effects of....relativity were not taken into account.
This is embarrassing for the OPERA group but not for science as such. A good challenge and ruffling of the feathers is a good thing.
Though I want to bet a fair amount that for years to come the meme that the speed of light is no longer an absolute barrier will remain with us, at least in environments such as internet fora.
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Old Oct 16th 2011, 10:05 PM
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Default Re: Faster than the speed of light?

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Originally Posted by Dominick View Post
By the way, this case, of the FTL neutrino's, is resolved. It turns out that in one of the many many steps and calculations of this complex experiment the effects of....relativity were not taken into account.
This is embarrassing for the OPERA group but not for science as such. A good challenge and ruffling of the feathers is a good thing.
Though I want to bet a fair amount that for years to come the meme that the speed of light is no longer an absolute barrier will remain with us, at least in environments such as internet fora.
Sad... I was getting my warp drive ready.
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Old Oct 16th 2011, 10:47 PM
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Default Re: Faster than the speed of light?

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Originally Posted by Dominick View Post
By the way, this case, of the FTL neutrino's, is resolved. It turns out that in one of the many many steps and calculations of this complex experiment the effects of....relativity were not taken into account.
This is embarrassing for the OPERA group but not for science as such. A good challenge and ruffling of the feathers is a good thing.
Though I want to bet a fair amount that for years to come the meme that the speed of light is no longer an absolute barrier will remain with us, at least in environments such as internet fora.
Oh dear. I'm surprised it took someone this long to notice.
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  #17  
Old Oct 19th 2011, 10:47 PM
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Default Re: Faster than the speed of light?

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Sad... I was getting my warp drive ready.
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Originally Posted by Donkey View Post
Oh dear. I'm surprised it took someone this long to notice.
Well, maybe that warp drive will come in handy after all. There's now as much debate about the solution as there was about the initial problem. The case is not closed after all.

These certainly are exciting times in physics. Not only is there no clarity about the solution, there still isn't any on the nature of the problem. It seems that every physicist that has an unexplained problem in the cupboard is linking it to this issue. There are even some string theorists out there that claim this is proof of the extra six dimensions that string theory require. And not only the establishment in physics is getting involved from every conceivable angle, every wanna-be or would-be physicist is throwing oil on the fire with contributions. Contributions that are 99.9% junk but who knows. Einstein was considered a wanna-be too initially.

Some of the angles considered in the discussion are:
  • Place and time
    Contrary to Newtonian mechanics there's nothing straightforward about establishing when and where the muon neutrinos depart from CERN or arrive at Gran Sasso. Merely synchronizing the clocks between the two locations is complex. You can't just take two clocks, synchronize them and send one to either locations. These clocks are so accurate that the relativistic effects of their transportation, be it with a car, train or plane, suffices to put them out of sync. What happened was that a third clock was used to 'carry' the information' from one clock to another. It's not clear whether the relativistic effects of this transfer have been calculated correctly.
    Place is also problematic. At the extreme precision level this experiment used location is ill-defined too. For instance, there is general acknowledgment that the continental drift (!) between Switzerland and Italy has been taken into account correctly.
    But there's no unanimity whether this is the case with the relativistic effect of all the GPS satellites involved in pinpointing the location. Each of these has its own reference frame and they all, plus the location of the emitter and receiver of the neutrinos, have to be mathematically unified through Lorentz transformations which is a lot more tricky than one would think.

  • Tachyons
    Faster than light particles are actually not new. At least not theoretically. Tachyons comply with Einstein's equations but can nevertheless travel faster than light because their mass is imaginary. Don't get carried away with the term 'imaginary', there's nothing spooky about it, it's merely a mathematical term indicating a number that has the square root of -1 in its composition. Imaginary numbers have been used in mathematics and its applications for centuries.
    Some propose that muon neutrinos are tachyons or at least show tachyonic behaviour.

  • Energy dependent behaviour
    There have been other speed measurements of muon neutrinos:
    SN 1987a was a supernova (a cataclysmic explosion of a huge star to put it simply) observed in 1987. It emitted a massive amount of neutrinos. Some of these neutrinos, coming from 168,000 lightyears away, were registered on Earth. They did come earlier than the light and particles of other wavelengths from the supernova but only by three hours which was easily explained by the mechanics of a supernova where the neutrinos are emitted before or at the moment of the collapse of the outer shell of the star while everything else is emitted when the inner core explodes. If these neutrinos had shown the same speed difference as the OPERA neutrinos allegedly have they would have arrived at Earth four years too early instead of three hours.
    On the other hand there was the MINOS experiment which also seemed to indicate FTL neutrinos but the experiment wasn't precise enough to conclude anything with any kind of certainty.
    The question arises thus why neutrinos from a supernova seem to act differently from those of local experiments. The answer may be in the fact that they are of different energy levels and that the weird behaviour is linked to that.

There are about a dozen other angles but I've probably lost the entire audience already
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  #18  
Old Oct 20th 2011, 03:25 PM
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Default Re: Faster than the speed of light?

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Originally Posted by Dominick View Post
Well, maybe that warp drive will come in handy after all. There's now as much debate about the solution as there was about the initial problem. The case is not closed after all.

These certainly are exciting times in physics. Not only is there no clarity about the solution, there still isn't any on the nature of the problem. It seems that every physicist that has an unexplained problem in the cupboard is linking it to this issue. There are even some string theorists out there that claim this is proof of the extra six dimensions that string theory require. And not only the establishment in physics is getting involved from every conceivable angle, every wanna-be or would-be physicist is throwing oil on the fire with contributions. Contributions that are 99.9% junk but who knows. Einstein was considered a wanna-be too initially.

Some of the angles considered in the discussion are:
  • Place and time
    Contrary to Newtonian mechanics there's nothing straightforward about establishing when and where the muon neutrinos depart from CERN or arrive at Gran Sasso. Merely synchronizing the clocks between the two locations is complex. You can't just take two clocks, synchronize them and send one to either locations. These clocks are so accurate that the relativistic effects of their transportation, be it with a car, train or plane, suffices to put them out of sync. What happened was that a third clock was used to 'carry' the information' from one clock to another. It's not clear whether the relativistic effects of this transfer have been calculated correctly.
    Place is also problematic. At the extreme precision level this experiment used location is ill-defined too. For instance, there is general acknowledgment that the continental drift (!) between Switzerland and Italy has been taken into account correctly.
    But there's no unanimity whether this is the case with the relativistic effect of all the GPS satellites involved in pinpointing the location. Each of these has its own reference frame and they all, plus the location of the emitter and receiver of the neutrinos, have to be mathematically unified through Lorentz transformations which is a lot more tricky than one would think.
  • Tachyons
    Faster than light particles are actually not new. At least not theoretically. Tachyons comply with Einstein's equations but can nevertheless travel faster than light because their mass is imaginary. Don't get carried away with the term 'imaginary', there's nothing spooky about it, it's merely a mathematical term indicating a number that has the square root of -1 in its composition. Imaginary numbers have been used in mathematics and its applications for centuries.
    Some propose that muon neutrinos are tachyons or at least show tachyonic behaviour.
  • Energy dependent behaviour
    There have been other speed measurements of muon neutrinos:
    SN 1987a was a supernova (a cataclysmic explosion of a huge star to put it simply) observed in 1987. It emitted a massive amount of neutrinos. Some of these neutrinos, coming from 168,000 lightyears away, were registered on Earth. They did come earlier than the light and particles of other wavelengths from the supernova but only by three hours which was easily explained by the mechanics of a supernova where the neutrinos are emitted before or at the moment of the collapse of the outer shell of the star while everything else is emitted when the inner core explodes. If these neutrinos had shown the same speed difference as the OPERA neutrinos allegedly have they would have arrived at Earth four years too early instead of three hours.
    On the other hand there was the MINOS experiment which also seemed to indicate FTL neutrinos but the experiment wasn't precise enough to conclude anything with any kind of certainty.
    The question arises thus why neutrinos from a supernova seem to act differently from those of local experiments. The answer may be in the fact that they are of different energy levels and that the weird behaviour is linked to that.

There are about a dozen other angles but I've probably lost the entire audience already
No, no! Very interesting stuff. In another life I probably would have gone into physics and love the contemplation of this stuff. I'm actually making sense of the way you explain things so please continue if there are other contributions you feel like sharing here.
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  #19  
Old Oct 21st 2011, 08:51 AM
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Default Re: Faster than the speed of light?

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Originally Posted by Greendruid View Post
No, no! Very interesting stuff. In another life I probably would have gone into physics and love the contemplation of this stuff. I'm actually making sense of the way you explain things so please continue if there are other contributions you feel like sharing here.
Thank you.
If you're interested in the discussion with the full works, this archive of pre-prints is the place to be. In the link below I already did the search for references to 'OPERA' and as of today that yields 177 papers which is a sensational amount:
http://arxiv.org/find/all/1/all:+OPERA/0/1/0/all/0/1

Some of the papers are simple or at least relatively (sic) so, others are cutting edge specialized and more challenging than the Voynich Manuscript.

A recent favourite of mine is:
http://arxiv.org/abs/1110.3581
where the author argues that all OPERA has done is to prove that the Earth is moving .

As you may know, in relativity every observer has its own frame of reference and these different reference frames can only be reconciled by mathematical methods (Lorentz transformations). Now, when there are two observers I've always found and argued that relativity, contrary to general perception, is pretty simple and straightforward. But in a case such as this, where there are numerous frames of reference, it may be true after all that only a handful of people really understand relativity as even the whole physics community can't seem to agree on how many there actually are in this problem and how to reconcile them. Une vraie crise de confidence if you pardon my French.
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  #20  
Old Oct 24th 2011, 09:54 AM
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Default Re: Faster than the speed of light?

My own hypothesis about the origin of the discrepancy has .... failed

This morning I thought maybe it could be the Lorentz contraction of the rotating earth that caused the length measurement to be erroneous.
Alas, thrice alas, a rough calculation learns that I'm about 7-8 orders of magnitude off. The Lorentz contraction is roughly 4E-5 (0.00004) cm while the OPERA problem is equivalent to a distance of 18m.

No Nobel Prize for me this year
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