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Oscar_Cunningham comments on Particles break light-speed limit? - Less Wrong
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Comments (170)
The neutrinos are not going faster than light. P = 1-10^-8
Error caused by some novel physical effect: P = 0.15
Human error accounts for the effect (i.e. no new physics): P= 0.85
This isn't even worth talking about unless you know a serious amount about the precise details of the experiment.
EDIT: Serious updating on the papers Jack links to downthread. I hadn't realised that neutrinos have never been observed going slower than light. P = no clue whatsoever.
I'm stupid so I shouldn't talk about physics? That's absurd, Less Wrong is devoted to discussing exactly this kind of thing. Like... really? I'm really confused by your comment. Do you think the author of the Nature News piece should not have written for fear of causing people to think about a result?
This kind of comment you made is one of the most perniciously negative types of things you could say here. Please try not to stop discussion before it even starts.
Instead of shutting down discussion and saying it isn't worth talking about, maybe you should try and expand on "Error caused by some novel physical effect".
You're not stupid, but we're not (as far as I know) qualified to talk about this particular experiment. There's no hope in hell that the particles are going faster than light, so the only interesting discussion is what else could be causing the effect. This would involve an in depth knowledge of particle physics, as well as the details of the experiment, how the speed was calculated, the type of detector being used, etc. I don't work at CERN, and I don't think many LessWrongers do either.
LessWrong is for discussing rationality not physics. Assigning probabilities to the outcomes stretched my rationalist muscles (I wasn't sure about 10^-8. Too high? Too low?), but that's the only relevance this post has (and yes, I did downvote it).
It would be fine to report the anomalous result, and give an interesting exploration of what faster than light particles would imply, making it clear that it's horrendously unlikely. But presenting it as if the particles might actually be going faster than light is misleading.
I've heard that the detector works by having the neutrinos hit a block where they produce some secondary particles, the results are then inferred from these particles. If these particles are doing something novel, or if the neutrinos are producing an unexpected kind of particle, then this could lead to the errors observed.
EDIT: I'm being too harsh. LessWrongers with less knowledge of the relevant physics would be perfectly justified in assigning a much higher probability to FTL than I do, and they've got no particular reason to update on my belief. Similarly, I expect my probability assignment would change if I learnt more physics.
I believe I am more skeptical than the average educated person about press releases claiming some fundamental facet of physics is wrong. But I would happily bet $1 against $10,000,000 that they have, indeed, observed neutrinos going faster than the currently understood speed of light.
Taken! Paypal address?
I'd rather do it through an avenue other than Paypal, since I give odds near unity that if I won, Paypal would freeze my account before I could withdraw the $10 million. Also, considering that less than .01% of the world's population has access to $10 million USD in a reasonably liquid form, there's some counterparty risk.
But, IIRC, you're confident you have the resources to produce a subplanetary mass of paperclips within a few decades, so let's do it!
Oh, sorry, I was confused and thought you were offering the bet the other way around.
I apologize for being ambiguous; I should have been more clear that 10^-8 was way too low. Hopefully you weren't counting on those resources for manufacturing paperclips.
Sadly I'm not in possession of even 10^8 cents, so I can't make this bet.
If you have a bitcoin address, the smallest subdivision of a bitcoin against 1 bitcoin (historically, 1 bitcoin has been worth somewhere within $10 of $10) would do the tric.
From here.
Which part of my post is this addressed to? I don't see any direct relevance.
Or the light is slightly subluminal and the nevtrinos are (almost) luminal at their speed.
May be a bunch of reasons, more probable than the assumed one.
What do you mean by that light is subluminal? Literally it means that light travels slower than light, which is probably not the intended meaning.
I suspect he means that light maybe travels slightly slower than the constant c used in relativity. Maybe photons actually have a really tiny rest-mass. Maybe our measurements of the speed of light are all in non-perfect vacuum which makes it slow down a little bit.
If they had tiny mass, we would observe variance in measured values of c, since less energetic photons would move slower. Measurements of c have relative precision of at least 10^-7 and no dependence on energy has been observed in the vacuum. Therefore the measured speed of light doesn't differ from the relativistic c more than by 10^-7. The relative difference which is reported in the neutrinost seems to be 10^-5.
Kloth answerd as I would.
By the way, electrons in water can be faster than photons in water. No big surprise maybe, if this hapens with neutrinos and photons in a (near) vacuum.
Light can move more slowly while not in a vacuum, maybe this light was held up by something. That said, I don't understand the paper well enough to tell if they are directly racing the neutrinos against some actual light, or if they're just comparing it to an earlier mesurement.
I don't know whether this guy knows what he's talking about, but it sounds plausible:
Steven Sudit:
There have been no indications that one can transmit information FTL using the Casimir effect, the work he mentions was on quantum tunneling time, which is a different beast.
That doesn't work. They didn't race the neutrinos against a light beam. They measured the distance to the detector using sensitive GPS.
Are they THAT sensitive? Possibly not.
In order for this to be from an error in measurement you need to be a few meters off (18 meters if that's the only problem). There are standard GPS techniques and surveying techniques which can be used to get very precise values. They state in the paper and elsewhere that they are confident to around 30 cm. Differential GPS can have accuracy down to about 10-15 cm, and careful averaging of standard GPS can get you in the range of 20 cm, so this isn't at all implausible but it is still a definite potential source of error.
A more plausible issue is that since parts of the detectors are underground they didn't actively use GPS for those parts. But even then, a multiple meter error seems unlikely, and 18 meters is a lot. It is possible that there's a combination of errors all going in the same direction, say a meter error in the distance, a small error in the clock calibration, etc. And all of that add up even as each error remains small enough that it is difficult to detect. But they've been looking at things really closely so one would then think that at least one of the errors would turn up.