Neutrinos will not let you read this article any earlier
October 15, 2011 5:09 AM   Subscribe

Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity (arxiv posting). When the results about faster than light neutrinos initially came out the attitude was very much "We think there's a mistake here. We can't find it. Lend a hand, guys". Someone seems to have come up with a plausible explanation that doesn't require any new physics.

The claim is as follows: The GPS satellites used to calibrate the two atomic clocks used to time the experiment are moving at high speeds, and thus subject to significant effects from special relativity. This puts the clocks slightly out of sync - enough to account for the discrepancy.

It still needs fact checking and peer review, but if correct would be a pleasantly mundane explanation for the mystery.

(previously on metafilter)
posted by DRMacIver (13 comments total)

This post was deleted for the following reason: This seems like one of many circulating theories, but not a definitive "Answer Has Been Found!" so I think this can go into the open thread, at least for now. -- taz

This is YARWICHP - yet another reason why I couldn't hack physics. They deserve an acronym because there are so many of them. Calculate tension but ignore friction, calculate friction but ignore tension, look at the relativistic effects here, you need to ignore relativistic effects there. I always got it wrong.
posted by benito.strauss at 5:18 AM on October 15, 2011

This is very satisfying if true. Curious that the OPERA team wouldn't have factored in the time-of-travel of the GPS signals to the ground. van Eburg seems to be saying that they treated the satellite-based clock signals as if they were anchored to the ground, i.e. no relative velocity to the source or detector.
posted by unSane at 5:25 AM on October 15, 2011

Now will the yahoos claiming that climate change isn't happening because the speed of light was violated publish retractions?
posted by fleetmouse at 5:31 AM on October 15, 2011

top comment at the r/askscience thread poses some doubts about this claim
posted by valdesm at 5:35 AM on October 15, 2011

unSane: I don't *think* that's what's being said. Time-of-travel is being taken into account, but difference of reference frame of the GPS satellites is not.

But it's possible I've totally misunderstood what's going on here. I've not done any non-trivial physics in 6 or 7 years.
posted by DRMacIver at 5:36 AM on October 15, 2011

They did figure the distance of the GPS to the ground, but there's something funny going on because the ultimate clock source is moving with respect to the detectors, and it's that speed that's somehow bollixing up the results. But I do not understand the article's explanation.
posted by Malor at 5:37 AM on October 15, 2011

valdesm: Ah, thanks for that link. That's interesting.

Apologies if this turns out to be a bogus posting. :-(
posted by DRMacIver at 5:39 AM on October 15, 2011

Makes sense, as neutrinos were observed as containing mass, which was slowed down by the passage through the Earth itself.
A flow of superluminal particles would have a noticable delay in their motion at a rate measurable by astronomical units (AU), rather than tens of kilometers (km).
posted by Smart Dalek at 5:42 AM on October 15, 2011

you know that the previous thread about this is still open, right?
posted by HuronBob at 5:42 AM on October 15, 2011 [1 favorite]

Relatedly, another recent paper on the super-speedy neutrinos has the best abstract for a paper that I've seen in a long time.
posted by metaBugs at 5:43 AM on October 15, 2011 [1 favorite]

I would also be surprised if it was this simple an error and yet not spotted more quickly.
posted by edd at 5:47 AM on October 15, 2011

this seemed understandable to me.
posted by victors at 5:49 AM on October 15, 2011

"So from the point of view of a clock on board a GPS satellite, the positions of the neutrino source and detector are changing. "From the perspective of the clock, the detector is moving towards the source and consequently the distance travelled by the particles as observed from the clock is shorter," says van Elburg."

This is the key point from the article. From my understanding, the timing signal of the gps clock is being sent sooner in the earth's frame reference than one would expect because the clock is traveling the same direction as the neutron beam. A good example of this is the Ladder Paradox.
posted by roguewraith at 5:55 AM on October 15, 2011

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