# The speed of light may have been broken.

Discussion in 'Physics & Math' started by Pincho Paxton, Sep 22, 2011.

1. ### RedRabbitRegistered Senior Member

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Cheers OM.

So they know exactly when that neutrino comes into being, so to speak? To the nanosecond?

Sorry for harping on, I honestly haven't a clue about this, but I thought nothing could change a neutrinos direction or velocity and if they are to measure it's speed then they would have to know it's starting position. I'm amazed if they can do that.

3. ### OnlyMeValued Senior Member

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Emil, there is no contraction of distance. The contraction is in the length of the moving ruler.
In other words, the distance between the cars, as measured by the GREEN car, is GREATER than the distance between the cars as measured by the blue car. Since we are talking about the same physical distance here, this must mean that the GREEN car's rulers, which the GREEN observer uses to measure the distance, are contracted compared to the BLUE car's rulers. Shorter rulers mean that GREEN measures a longer distance.
bold emphasis mine.

5. ### EmilValued Senior Member

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How do you define distance and length?

7. ### OnlyMeValued Senior Member

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Both news paper articles are recent and do not provide enough detail. It would be my guess, that it will be some time before any actual paper is published on this and it will have gone through some peer review by then also. Perhaps even some further experimental results added.

Timing is the whole issue I question. I can't see how they could do it, but then there are some bright young people out there.

Anyway, yes they create the neutrinos. And yes once they are created they can't do anything but wait for those few which will interact with their detectors.

There are a lot of things the news articles don't clarify.

8. ### OnlyMeValued Senior Member

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Length is a dimension of an object.

Distance is measured between two points, which may or may not be located on an object.

A ruler is 12 inches long. That is its length.

The sun is 8 light minutes from the earth. That is a distance that measures no object.

9. ### EmilValued Senior Member

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I agree.
Yet you claim that there is no distance contraction?

10. ### OnlyMeValued Senior Member

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Not unless the distance is between the ends of a ruler in motion.

Distances in space do not move, at least not with any relativistic velocity and so are not length contracted.

11. ### RedRabbitRegistered Senior Member

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Cheers again OM.

I agree with you here. I can't get my head around how they could have measured it accurately either.

I've a hunch that this might turn out to be a systematic error. Very brave of them to make it public if it is. Mind you, if it turns out that there is no such error then they get the credit. Big gamble.

12. ### wlminexBannedBanned

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Question:

When a photon propogates linearly . . . .at c . . . .are not the B and M components of that moving photon propogating at right angles to the photon's linear path? If so. . . and B and M components are sinuoidally moving WITH the photon . . . are not the B and M components circumscribing paths whose relative "lengths' exceed that of the photon during the same time interval?

13. ### kurrosRegistered Senior Member

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Here is the actual paper: http://arxiv.org/abs/1109.4897

They do not time neutrinos one by one, they use the properties of some complicated ensemble of neutrino measurements (I have not read it properly yet), partially because they don't know exactly when each neutrino is emitted. They have to work back from some probability distribution for the emission time based on the properties of the charged meson beam which is generating the neutrinos.
They describe the timing process in a lot of detail, since of course it is crucial to their claimed measurement. It looks like it involves GPS synchronisation of two atomic clocks and matching of event time distributions in some fashion.

14. ### OnlyMeValued Senior Member

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I'm really surprised it is out that fast after the news release. I also glanced through it. Some of the detail I am sure will be a bit over my pay grade and require further exploration.

Still weren't they talking about a difference of 60 nano seconds? Wouldn't that require a distance certainty somewhere in the hundredths of a foot? I'm really tired maybe my numbers are confused...

It will take me some time to digest this.

15. ### TachBannedBanned

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nope , light travels at 1ft/ns, so we are talking 60ft

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18. ### CptBorkRobbing the Shalebridge CradleValued Senior Member

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Yeah, neutrinos are a pain in the ass to measure and detect. You've got to produce zillions of them just to pick up a few at the detector, and it's really tough to recognize their signatures and pinpoint all the relevant characteristics. I very much doubt anything will come of this result once all the dust settles, but it's always nice to get a peak at new frontiers if it holds up. I've seen it proposed before that in QFT it might be possible to go just a tiny bit faster than what we conventionally refer to as lightspeed, but that wouldn't change Relativity, just shifts the value we use for $c$ by a nearly negligible amount.

19. ### Motor Daddy☼☼☼☼☼☼☼☼☼☼☼Valued Senior Member

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Sorry, I missed that.

20. ### James RJust this guy, you know?Staff Member

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Moderator note: two threads on the same topic have been merged.

21. ### AlexGLike nailing Jello to a treeValued Senior Member

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Statistical significance. Let's see how this plays out.

22. ### Captain KremmenAll aboard, me Hearties!Valued Senior Member

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What would the neutrino's mass be travelling at greater than the speed of light?
More than infinity?

You know what is going to happen now, don't you?
Every tinpot Physicist who has ever been on here banging on about how Einstein was wrong,
is going to say " See, I told you so"

Last edited: Sep 23, 2011
23. ### EmilValued Senior Member

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And what if I use instead of a ruler a laser rangefinder?