faster than light?

Discussion in 'Fred's House of Pancakes' started by hyo silver, Sep 23, 2011.

  1. qbee42

    qbee42 My other car is a boat

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    Cherenkov radiation. I like to think of it as an optical shock wave: kind of like a sonic boom, but in light. It is cool stuff, forming the blue light commonly depicted in reactor pools:

    [​IMG]

    Tom
     
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  2. fuzzy1

    fuzzy1 Senior Member

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    I actually did get to see it directly in a reactor pool, once, decades ago. That particular opportunity is long gone.
     
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  3. markderail

    markderail I do 45 mins @ 3200 PSI

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    Need to photoshop an Alien in there waiting in ambush, this pic looks like it could have been part of Alien (1) Aliens (2), but not 3,4,5,6,7,8,9

     
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  4. davesrose

    davesrose Active Member

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    Seems like it would be at home on the set of Alien 4:

    [​IMG]


    Or Splash :D

    [​IMG]
     
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  5. amm0bob

    amm0bob Permanently Junior...

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    You are right Bra...


    That would be religion. :pray2:
     
  6. daniel

    daniel Cat Lovers Against the Bomb

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    It's looking like a very good candidate for the error is that the GPS satellite is moving with respect to the relevant locations on the Earth. This introduces a small but real amount of relativistic time dilation, making it appear that the neutrinos' flight time was a tiny bit less than it really was. With times this short, relativity must be taken into account, and when it is, the discrepancy goes away and the neutrinos were not traveling faster than light after all.

    Source: Skeptics Guide to the Universe podcast #327. (Available free from the iTunes store or from the SGU web site. SGU is an informative and entertaining podcast.)
     
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  7. markderail

    markderail I do 45 mins @ 3200 PSI

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    That's what I said above, in some 90 less words.

    You guys were so picky with the details...

     
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  8. qbee42

    qbee42 My other car is a boat

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    I thought you said that the researchers used metric photons, while the GPS, being from the USA, used English photons.

    ;)

    Tom
     
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  9. daniel

    daniel Cat Lovers Against the Bomb

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    I believe the term is "imperial."
     
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  10. fuzzy1

    fuzzy1 Senior Member

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    That must be it. Metric 'c' of 299792458 m/s is slightly faster than Imperial 'c' of 186282 miles/second.
     
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  11. airportkid

    airportkid Will Fly For Food

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    A lot of this mile/meter conversion trouble could have been easily avoided by using units of measure with more "give". The speed of light is 1,802,617,499,785 furlongs, 2 and 1/2 chains per fortnight, as any competent surveyor could tell you, if not actually pace off.
     
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  12. qbee42

    qbee42 My other car is a boat

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    It is. We used to call it the English system, but they wised up and moved over to SI years ago.

    Tom
     
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  13. daniel

    daniel Cat Lovers Against the Bomb

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    I just round off to 300,000 km/s. It makes it easier to do the math. And if those guys had used my method, and just rounded off, they would have seen that even with their calculation error, the neutrinos would still have been going slower than light.

    Note: Rounding works for metric. If they'd rounded the imperial value to 186,000 miles/s they'd still be claiming Relativity violation today. This is one more way that metric is superior to imperial.
     
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  14. amm0bob

    amm0bob Permanently Junior...

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  15. sipnfuel

    sipnfuel New Member

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    From the link above:

     
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  16. daniel

    daniel Cat Lovers Against the Bomb

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    Re: faster than light? New opinions...

    Until it's in a peer-reviewed journal, it's just the popular press passing on misunderstanding. Extraordinary claims require extraordinary evidence, and there is already a mountain of evidence that neutrinos do not travel faster than light. This is ONE (questionable) study.

    ALL the evidence must be weighed, and it must be done in a per-reviewed journal, not in the popular press.

    Faster-than-light neutrinos have not been "confirmed." They've only been reported, by one team, at one site, with a clear interest in defending its findings. There is nothing at all wrong with that. That's how science works. But the press is an imbecile for taking ONE study as proof of something which is contradicted by hundreds of other studies.
     
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  17. Trebuchet

    Trebuchet Senior Member

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    I wouldn't bet the farm on 'peer review' but it's definitely the first step. In any case this entire discussion may be moot as far as FTL travel is concerned. For some time now it's been understood, and more than likely, the universe is flat. Therefore getting from one side of the universe to the other is no big deal as long as you're traveling in the right direction. :p
     
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  18. FL_Prius_Driver

    FL_Prius_Driver Senior Member

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    Note that while experimentally generated neutrinos in this experiment are causing all the excitement, naturally generated neutrinos from supernova do travel at the speed of light. When a supernova occurs, both a neutrino blast and a light blast occur. Many years later when the neutrino blast is detected and the light blast is detected, they occur at the same time. Even the slightest difference in speed would show up as a timing difference in these two blasts of months, weeks, or days. That means that if FTL is occurring in this experiment, how come it is not occurring in nature has to be explained as well.
     
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  19. amm0bob

    amm0bob Permanently Junior...

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    ^^^
    This...
     
  20. daniel

    daniel Cat Lovers Against the Bomb

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    WRONG.

    Neutrinos travel at very slightly less than the speed of light. And they do NOT reach the Earth at the same time as the visible flash from super-novas. The neutrinos arrive first! This is because, generated at the center of the supernova, they travel through the body of the remnant unimpeded, whereas the light flash is delayed by some considerable time as visible light is bounced around inside the remnant before it can escape.
     
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