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Faster-Than-Light Particle Results To Be Re-Tested

samzenpus posted about 3 years ago | from the check-your-work dept.

Science 412

surewouldoutlaw writes "After the astonishing news from CERN that the OPERA experiment had detected neutrinos traveling faster than light speed, challenging Einstein's theory of special relativity, there has been some skepticism over the results. Now Fermilab, near Chicago, has announced it will attempt to replicate the experimental results within four to six months."

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First post! (0, Funny)

Anonymous Coward | about 3 years ago | (#37515188)

And I posted it tomorrow, as well!

Re:First post! (0)

Joce640k (829181) | about 3 years ago | (#37515394)

Never mind that, did anybody post the XKCD link yet...?

Re:First post! (1)

geogob (569250) | about 3 years ago | (#37515448)

In doubt, repost it with the obligatory [/obligatory] remark. That's how this place works from the looks of it.

Re:First post! (2)

bhcompy (1877290) | about 3 years ago | (#37515662)

I like this one better(for FTL): Light year long stick [memepics.com]

Results (1)

AdamJS (2466928) | about 3 years ago | (#37515238)

So if we don't get the results by next month, we can assume the experiments failed to hold up?

Re:Results (2)

michelcolman (1208008) | about 3 years ago | (#37515926)

Actually, if the results are correct, we should be getting the reply by yesterday at the latest.

Yet another example.. (0)

Moheeheeko (1682914) | about 3 years ago | (#37515244)

of Tesla being right. Hopefully people look into more of his research in the future.

Re:Yet another example.. (2)

RoccamOccam (953524) | about 3 years ago | (#37515464)

Could you elaborate, please?

Re:Yet another example.. (2)

Gerzel (240421) | about 3 years ago | (#37515862)

I don't know about Tesla, but this is Yet Another Example... Of the standard scientific method.

You never trust a single result, the experiment always has to be repeated especially in the case of unexpected findings. What I'm really waiting for is data from other accelerators, or experiments (given this experiment may be prohibitively difficult to properly replicate) to corroborate the findings.

HOLY REPLICABLE RESULTS BATMAN! (1, Insightful)

snowgirl (978879) | about 3 years ago | (#37515246)

If you didn't see this coming, then you don't understand science...

Re:HOLY REPLICABLE RESULTS BATMAN! (5, Funny)

flaming error (1041742) | about 3 years ago | (#37515276)

How could we see it coming, if it's traveling faster than light?

Re:HOLY REPLICABLE RESULTS BATMAN! (4, Funny)

RivenAleem (1590553) | about 3 years ago | (#37515306)

You deduced its pending arrival by virtue of it having arrived.

Re:HOLY REPLICABLE RESULTS BATMAN! (5, Funny)

Abstrackt (609015) | about 3 years ago | (#37515424)

I see what you [are going to do] there.

Re:HOLY REPLICABLE RESULTS BATMAN! (5, Informative)

tomhudson (43916) | about 3 years ago | (#37515580)

There once was a lady named Bright,
Who could travel faster than light.
She left one day
In a relative way
And came back the previous night.

So, either you already saw it coming, or you didn't :-)

Now, to understand it better, read All You Zombies [polvoestelar.com.mx] by Robert Heinlein (pdf of complete story). Considered by many to be the greatest time travel short story ever.

And... (1)

felipekk (1007591) | about 3 years ago | (#37515284)

The results are in!

Original contents here (-1)

Anonymous Coward | about 3 years ago | (#37515318)

check out the real news here. http://adf.ly/2uKbK

... walks into a bar. (5, Funny)

Anonymous Coward | about 3 years ago | (#37515322)

The barkeep says 'We don't serve faster-than-light particles in here'. A neutrino walks into a bar.

Re:... walks into a bar. (1)

Lord Lode (1290856) | about 3 years ago | (#37515356)

Congratulations, you made me laugh! I wish I had mod points.

Re:... walks into a bar. (1)

Rik Sweeney (471717) | about 3 years ago | (#37515360)

Either I'm missing something or this joke isn't correct.

How does the barman see the neutrino before it enters the bar? If anything, the Neutrino will walk into the bar, have a drink and leave before the barman notices it arriving.

Re:... walks into a bar. (4, Funny)

Lord Lode (1290856) | about 3 years ago | (#37515566)

The joke is too fast for you.

Re:... walks into a bar. (0)

Anonymous Coward | about 3 years ago | (#37515688)

Whoosh!

Re:... walks into a bar. (-1)

Anonymous Coward | about 3 years ago | (#37515802)

You are correct, because everyone knows that jokes have to stick to reality to be funny.

Re:... walks into a bar. (3, Informative)

felipekk (1007591) | about 3 years ago | (#37515858)

He doesn't (see).

The neutrino enters and asks for a beer. The barman hears the request and, since he can't see anything, assumes it is a neutrino and answers.

And then we finally see the neutrino entering...

Re:... walks into a bar. (4, Funny)

imakemusic (1164993) | about 3 years ago | (#37515372)

Did you hear the one about the neutrino?

Re:... walks into a bar. (1)

jez9999 (618189) | about 3 years ago | (#37515706)

Got any good new jokes?

Re:... walks into a bar. (2)

Anne_Nonymous (313852) | about 3 years ago | (#37515918)

First post.

Re:... walks into a bar. (3, Funny)

artor3 (1344997) | about 3 years ago | (#37515454)

A neutrino walks into a bar and out the other side.

Re:... walks into a bar. (1)

Tharsis (7591) | about 3 years ago | (#37515904)

That one was old the first time I read it.

Re:... walks into a bar. (5, Funny)

iggymanz (596061) | about 3 years ago | (#37515922)

I like tasteful jokes but that was a tachyon

Standard practice (3, Informative)

dnewt (2457806) | about 3 years ago | (#37515334)

Confirmation of the results of an experiment by an independent party is standard practice in the scientific community. Without it, the findings wouldn't even be considered completely valid! Nothing to see here...

Damn straight (4, Informative)

mbone (558574) | about 3 years ago | (#37515342)

They already did the experiment, and actually found similar results [arxiv.org] but did not claim any significance. Of course they are going to repeat this, once they finish kicking themselves.

Re:Damn straight (4, Informative)

LeDopore (898286) | about 3 years ago | (#37515404)

From TFA: “We should have a result in 4-6 months as the data is already taken. We just have to measure some of our delays more carefully,” - Jenny Thomas.

MINOS was already repeating their measurements, but CERN got the jump on them. It's anyone's guess too whether there was a back channel of information from OPERA to MINOS that might have tipped them off and encouraged them to start taking data early. With so many people involved, you almost have to assume that preliminary findings migrate across the Atlantic pretty quickly.

Re:Damn straight (4, Interesting)

mbone (558574) | about 3 years ago | (#37515602)

Yes, I would agree. 184 coauthors can keep a secret, if 183 are dead.

Note that there is already a theoretical paper out on these results [arxiv.org] , so it has been percolating around a little. Note also that this paper says

The MINOS collaboration reported a measurement of the muonic neutrino velocities that hints to super-luminal propagation, very recently confirmed at 6 [sigma] by OPERA.

Do I smell a priority fight coming ?

We'll find out soon enough... (0)

GameboyRMH (1153867) | about 3 years ago | (#37515348)

...if the Neutrino was a filthy cheat running a hidden nitrous bottle.

Good (5, Insightful)

Ironhandx (1762146) | about 3 years ago | (#37515368)

The process is working.

The scientists at CERN asked for peer review and checking of their methodology. This announcement means that at least on paper the method was near-perfect for Fermilab to be committing resources in the near future to prove/disprove it.

Re:Good (1)

sakdoctor (1087155) | about 3 years ago | (#37515534)

Professor Brian Cox explains [bbc.co.uk]
Hope this works for non-UK IPs; It's interesting.

Re:Good (1)

DigitalNate (773666) | about 3 years ago | (#37515786)

Nice, it shows me the video box but when I press play it says "Not available in your area".

Re:Good (2)

pacinpm (631330) | about 3 years ago | (#37515790)

Hope this works for non-UK IPs;

It doesn't. At least not for Poland. I hate regionalization of content.

Re:Good (1)

Extremus (1043274) | about 3 years ago | (#37515584)

People at OPERA project are having an exemplar scientific conduct. It is amazing how they actively refused to elaborate any theories on their findings, restating their job as unbiased experimental physicists. This is pure scientific method.

Re:Good (3, Informative)

Artraze (600366) | about 3 years ago | (#37515828)

I somewhat disagree. Their results met the criteria of scientific discovery and they (well, I certainly hope!) reviewed their process for any error. So even though they literally, by scientific standard, discovered FTL particles, they explicitly state that they don't actually think they did because it disagrees with existing theories. This is *biased* experimental physics.
Yes, relativity has a good track record, and they likely missed something. OTOH, neutrinos are still a pretty new research topic and maybe relativity doesn't cover all the universe has to offer. I do think that these results should be retested, verified, and studied as much as possible. But I'm also seriously disappointed that an ostensibly legitimate discovery has to be presented as 'we screwed up but we don't know why so look at these' in order to avoid raeg from close minded scientists.

Re:Good (0)

Anonymous Coward | about 3 years ago | (#37515750)

Absolutely. I was just going to say that this is why the world needs more than one accelerator. And a healthy dose of competition helps as well.

Re:Good - time to search for gravitational waves (1)

kubitus (927806) | about 3 years ago | (#37515852)

with v > C

Isn't the problem c? (-1)

Progman3K (515744) | about 3 years ago | (#37515370)

If they succeed in recreating the measurements, doesn't it just mean that c was set at too low a value, and that the true speed to light in a vacuum is slightly faster than originally thought?

Maybe neutrinos travel closer to c because they are less slowed by the absence of vacuum than other particles.

Also, why do people say that it is like going back in time? Was the message received before it was sent?

Re:Isn't the problem c? (3, Insightful)

Remus Shepherd (32833) | about 3 years ago | (#37515468)

Having neutrinos fly at 'true c' rather than a lower 'apparent c' isn't a good solution, because it doesn't take in account neutrino bursts from supernova 1987A. The neutrinos from that supernova were detected only four hours before the light from it. That's explainable with what we know about internal stellar processes. But if the neutrinos were flying FTL then they should have arrived four years earlier.

The most likely explanation for the CERN results (apart from experimental error) is that neutrinos are tachyonic -- they have imaginary mass, and naturally fly faster than light. The higher their energy, the closer to lightspeed they travel.

That's not a trivial situation. To use a technical term, it breaks relativity into itty bitty pieces. We will have to change a lot of theories around. But it's unlikely that the value of c is going to change.

Re:Isn't the problem c? (1)

Progman3K (515744) | about 3 years ago | (#37515626)

Again, don't the neutrinos arriving before the light from SN1987A simply mean that the neutrinos got here at closer to c than the actual light?

I mean the light from SN1987A had to travel through a non-vacuum (space, which is never really empty) and the neutrinos on the other hand were simply less obstructed.

Re:Isn't the problem c? (2)

Remus Shepherd (32833) | about 3 years ago | (#37515844)

To a neutrino, space and the planet Earth are almost equally transparent. The neutrinos from OPERA and the neutrinos from SN1987A should be travelling at the same c, and they (apparently) aren't.

The one real difference is that the planet has a gravitational field. That could support some theories which suggest that neutrinos are able to take shortcuts through extra dimensions, but only in the presence of a gravity field. That result would still make relativity choke and turn blue, but it might make sense.

Either way, it doesn't look like a tweaking of the value of c is likely.

Re:Isn't the problem c? (0)

Anonymous Coward | about 3 years ago | (#37515524)

I think they're more interested in what could be slowing down the rest of the universe and NOT neutrinos.

Re:Isn't the problem c? (3, Informative)

vlm (69642) | about 3 years ago | (#37515646)

If they succeed in recreating the measurements, doesn't it just mean that c was set at too low a value, and that the true speed to light in a vacuum is slightly faster than originally thought?

c is not a fundamental value, its a function of the permeability and permittivity of either empty space or some dielectric (something like inside a piece of coaxial cable, etc). Or rephrased, you are arguing the impedance of free space is wrong, and generations of antenna and RF engineers would disagree with you. Also c shows up in energy mass equivalance e=mc2 and all that which seems quite accurate. And in time dilation experiments it seems to work quite well. Astrophysics "stuff" thats far away seems to confirm that neutrinos do not exceed light speed in vacuum; this test involved blasting thru rock instead of vacuum so that is no huge problem; theres a long history of shoving light thru materials results in weird behavior. Given how many decimal places that kind of stuff has been verified, more than this result which was only 6 sigma or whatever, I'm thinking fundamental constant fine tuning is awful unlikely.

In summary, either its wrong (which seems unlikely given all the verification they did) or its new physics. Simply tuning up the known constants is just not gonna work.

To fit other, higher precision experiments, its gotta boil down to something like the logical inverse of the light refraction law, where light slows down in certain materials (like, say, glass) resulting in refraction and timing issues (like pulse dispersion in optical fiber). The analogy is maybe neutrinos "speed up" when rammed thru solid rock due to some strange property of rocks, or floating about in a rock-produced gravity well, or something like that.

I can totally see how previous subatomic experiments would miss the neutrino effect; after all its hard to shove gammas or plain ole light quanta thru a couple zillion KM of solid rock... Its too technologically hard to do, until trying out the neutrinos...

A good example of how F-ing around in the lab doing blue sky stuff simply because you can, is the primary source of interesting ideas.

Re:Isn't the problem c? (1)

Progman3K (515744) | about 3 years ago | (#37515770)

Thanks for taking the time to reply, vim.

Why can't c be just slightly faster than it has been estimated at?
I mean no one has ever been able to measure the speed of light in a true vacuum, right? A true vacuum would contain absolutely no particles and no electromagnetic waves. That is impossible to obtain, so how does anyone really know how fast c really is?

Maybe neutrinos are simply lithe enough that they are almost unaffected by the non-vacuum, I mean it has been theorized that to completely block a neutrino, you'd need a block of lead one light-year thick.

Re:Isn't the problem c? (1)

GodInHell (258915) | about 3 years ago | (#37515654)

Because relativity starts to break down when things exceed the speed of light.

Wikipedia sez [wikipedia.org] that going faster than the speed of light breaks causality -- so signals can be received before they're sent. However, as you suggest there is plenty of room to rework the theory rather than throwing up our hands and declaring reality broken.

-GiH

Re:Isn't the problem c? (3, Interesting)

JustinOpinion (1246824) | about 3 years ago | (#37515712)

It's not so simple. We've measured the speed of light to great precision. We know what that speed is, and we know photons are massless, so we know with very high confidence what the speed of massless particles is. If neutrinos travel faster than light, then this is very surprising and points to something new and interesting. I'm avoiding referring to 'c' because it would be ambiguous: in traditional relativity, the constant speed of light is equal to the maximum possible speed, which is also in essence the ratio between space-like and time-like variables in the theory (the slope of light-cones and all that). It's a constant that reappears over and over again, and marvelously it's precisely equal to the speed of light. It can't be as simple as just "we were wrong, c is a bit higher than we thought" because it would immediately mean that "c" isn't as universal as we thought: the symmetry of the universe must be somehow different so that photons and neutrinos (and probably other particles) follow slightly different rules.

But if this result is indeed true, and neutrinos travel faster than light, then this is truly amazing and could mean different things. One possibility is that different particles actually have different 'speed limits' (and different causal cones), so there is c_light, c_neutrinos, etc. There are many other possibilities (extra dimensions, breaking of Lorentz invariance, imaginary mass, closed timelike curves, etc.). All of them amount to a substantial rethinking to some aspect of physics. This is definitely exciting, since it could be telling us something very new! And it won't be as simple as just adjusting a constant a bit. (If we tweak the value of "c" in our equations even just a bit, all kinds of well-tested observations, in everything from cosmology to the functioning of transistors, would come out wrong...).

Lastly, it's worth keeping in mind that it's probably a subtle experimental error (very subtle!). This is still useful, because it will teach us something new about experiment design and possibly even teach us something about particle physics. For instance, the timing calculation is based on certain models of the packet of neutrinos that are generated. But, it could be that the packet that arrives at the end is slightly different than the one sent out at the beginning, thus altering the way one should compute the flight time. This could point to some interesting, previously unknown, ways in which neutrinos are generated, or interact with matter, or interact with each other. In any case it will be interesting.

Re:Isn't the problem c? (2)

mbone (558574) | about 3 years ago | (#37515924)

If they succeed in recreating the measurements, doesn't it just mean that c was set at too low a value, and that the true speed to light in a vacuum is slightly faster than originally thought?

No, probably not. Einstein came up with relativity after a thought experiment concerning what a light wave would look like if you were traveling at its velocity. Electro-magnetisim does not allow for a stationary vacuum solution, so he figured out that the way out was to have time stopped at the speed of light. If the speed of light isn't the speed of light, this problem reoccurs. Now, you could postulate a material (let's call it the... ether), so that light is traveling slow, while neutrino's bound on ahead, but that also would disagree with various experiments.

One way out is to have the neutrinos be tachyons, traveling faster than light, but that does allow for causality violations [theculture.org] . (Read the link.) That is based on pretty basic stuff, so it's hard to escape it. That would trouble a lot of people, but it would allow for neutrino oscillations (changes from one type to another). You can't do that at the speed of light, as time is frozen there. (As oscillations have been observed, that is additional strong evidence that the neutrino velocity is not the new "speed of light.")

And, there is also the Supernova 1987a results, which conflict with these results [arxiv.org] (as the 1987A neutrinos do travel near c). Maybe there are oscillations between tachyonic neutrinos and non-tachyonic ones, which would be mind-blowing all by itself.

I think that a bunch of theorists will spin their wheels until this is better constrained experimentally.

Science: it works, bitches! (0)

arikol (728226) | about 3 years ago | (#37515414)

Science: it works, bitches!

http://xkcd.com/54/ [xkcd.com]

Faster than light? (2)

wfstanle (1188751) | about 3 years ago | (#37515452)

I did have a college physics covering relativity but it was a long time ago. Correct me if I am wrong, but Einsteins Special Relativity theory doesn't prohibit speeds faster than light. It just prohibits speeds EQUAL to the speed of light. If so, It would be problematic to accelerate past the speed pf light or to decelerate to slower than the speed of light.

Re:Faster than light? (0)

Anonymous Coward | about 3 years ago | (#37515502)

Plenty of particles travel at the speed of light.

Light, for example.

Re:Faster than light? (0)

Anonymous Coward | about 3 years ago | (#37515568)

My understanding (and I'm not a physicist) is that an object (under the rules of special relativity) can't accelerate to the speed of light. So accelerating to it is out. And if you can't accelerate to it, it stands to reason that you'll never have the opportunity to decelerate from it.

Re:Faster than light? (2)

locofungus (179280) | about 3 years ago | (#37515752)

Special relativity prohibits faster than light travel unless you don't care about causality.

Given that it's hard to do science at all without causality that's going to be a hard sell. So the alternative is to throw out (tweak) special relativity.

Maxwell's equations imply special relativity imply nothing can travel faster than light.

There's a lot of very established physics that is going to need rethinking if this result is real.

Tim.

Re:Faster than light? (1)

AlecC (512609) | about 3 years ago | (#37515794)

Thing travelling at the speed of light produce infinities in predicted measurable quantities. Things travelling faster than light produce i (sqrt(-1)) in predicted measurable quantities. Most physicists say that anything that produces i in a measurable result, as opposed to some intermediate value which eventually gets squared, is probably not a reflection of the real world.

Re:Faster than light? (0)

Anonymous Coward | about 3 years ago | (#37515842)

In rough form, we can say that particles with mass can travel anywhere from 0 to a speed that approaches (but does not reach) c. Massless particles have to travel at exactly c. They can't go faster or slower. Mathematically, the theory does allow you to plug in a particle with "imaginary mass", in which case the solution will suggest that the particle travels faster than light, which is the same as saying it travels backwards in time (a speed from 0 to almost-c, but in opposite space-time direction). Such particles are called tachyons, but there's no experimental evidence for them, so it's likely that there's some other physical rule that prohibits tachyons from existing. (Or maybe not... maybe this current result is telling us that neutrinos have imaginary mass.)

So it is possible to have imaginary-mass particles that travel faster than c in relativity, and that's indeed one possible explanation for these results. However adding imaginary mass to our theories opens the door to all kinds of other phenomena. It will take some effort for theorists to check whether the current result is really consistent with all the other things we know. (E.g. other tests of neutrino speed didn't show any superluminal behavior... but maybe that's because it's energy-dependent, etc. It's not yet clear how to make sense of this result.)

Re:Faster than light? (0)

Anonymous Coward | about 3 years ago | (#37515874)

My limited, mathematical understanding is that the energy requirements and weight of a particle going faster than the speed of light goes into infinite and imaginary numbers. Something a long the lines of x / sqrt(1 - (v / c) ^ 2)

That is,
if v = c, then it's x / sqrt(1 - 1) = x / 0 = undefined or infinity
if v > c, then it's x / sqrt(1 - [something larger than 1]) = x / ( sqrt(y) i )
where i = sqrt(-1)

I should hope so! (0)

Anonymous Coward | about 3 years ago | (#37515458)

And re-tested and re-tested and re-tested.

Four months if they do travel faster than light .. (2)

DikSeaCup (767041) | about 3 years ago | (#37515494)

Six if they don't. ;)

What if light travels at slightly less than c? (5, Interesting)

LeDopore (898286) | about 3 years ago | (#37515506)

OPERA has just found that either neutrinos travel 0.03% faster than photons we've measured, or their equipment has an unknown systematic error. Assuming there's no equipment error, I would find it more palatable to assume that light around Earth travels a bit below c and that neutrinos travel closer to c. What we think of as vacuum could really be a medium with refractive index 1.0003, perhaps due to a uniform background of weakly-interacting particles (maybe even dark matter) that affect photons but not neutrinos.

I have a physics undergrad degree; if there's someone here with better qualifications, would you care to weigh in on the idea that c could be 0.03% faster than the speed of light we measure on Earth?

Re:What if light travels at slightly less than c? (1)

rwa2 (4391) | about 3 years ago | (#37515610)

My only regret is that the only people who might actually want to invest in 0.03% faster neutrino communication technology are HF traders, so they can shave another 60ns or so advantage from their competitors :-/

But who knows, maybe the galaxy is filled with neutrino-based communications we haven't been tuned into, and someday SETI will pick up their messages of "sell! sell!"

Re:What if light travels at slightly less than c? (1)

GameboyRMH (1153867) | about 3 years ago | (#37515724)

I'd be surprised if they weren't designing a neutrino-based network already. Either neutrinos move faster than light or neutrino detectors have less lag than fiber-optic NICs. It's a win-win.

Re:What if light travels at slightly less than c? (3, Interesting)

Artraze (600366) | about 3 years ago | (#37515666)

It's an interesting idea, but quite unlikely... Remember that the speed of light is (supposedly!) an absolute, somewhat like absolute zero, and thing tend to approach it asymptotically. One can therefore tend to see where exactly the asymptote lies, and we'd quite likely notice the difference. For example, particles in the LHC travel at c - 0.0000009% and have the corresponding properties as predicted by relativity. If they were, in fact, traveling at c - 0.03% our calculations should be / are off by over 3 orders of magnitude (gamma 7500 vs 4).

In short, that much error in c would pretty much wreck relativity anyways.

With the caveat that I don't really have better qualifications than you :).

Re:What if light travels at slightly less than c? (2)

evanbd (210358) | about 3 years ago | (#37515718)

If that were the case, we should be able to accelerate particles to faster than light speeds. There's nothing that prevents a particle from traveling above c in a material with an index of refraction > 1; see Cherenkov radiation [wikimedia.org] .

Re:What if light travels at slightly less than c? (1)

TheDarkMaster (1292526) | about 3 years ago | (#37515726)

Plausible, but will be really interesting if the neutrinos can travel faster than light. Why? Imagine the possibilities. And I could put another possibility: What if the photon have mass (really small, but not zero) and this mass is slightly larger than that of a neutrino? This would cause the neutrino to be faster than the photon.

Re:What if light travels at slightly less than c? (3, Interesting)

vlm (69642) | about 3 years ago | (#37515772)

What we think of as vacuum could really be a medium with refractive index 1.0003

Ahh, the old subatomic ether thing. Look up michelson-morley interferometer experiment that lead to all that relativity stuff... At 300 ppm, that effect, if it existed, would prevent most interesting interferometer technology from existing. No FFT-IR spectroscopy, most inertial navigation systems would be too drifty to use, astrophysicists would not be able to do the interferometer thing using multiple scopes...

The other problem is we've verified E=mc2 and time dilation to much better than 300 ppm both of which depend on c.

Also, its expensive, and a bit beyond my basement, but your average RF engineer can build stuff to better than 300 ppm on first principles.

Then you start offending the chemists. I have to think about it a bit, but wouldn't this screw up quite a bit of chemistry (and physics) related to ferromagnetic materials? And the NMR scanners wouldn't work right, or at least how they work would depend on the phase of the moon, from memory 300 ppm is a pretty huge shift.

Who would notice a change in c is an interesting thought experiment.

Re:What if light travels at slightly less than c? (2)

tgd (2822) | about 3 years ago | (#37515796)

I've seen that mentioned a few times ... but if light travels less than C, then light would have to have a slight mass, which would mean the speed of a photon would vary by the energy it has.

It doesn't.

Re:What if light travels at slightly less than c? (1)

radtea (464814) | about 3 years ago | (#37515814)

OPERA has just found that either neutrinos travel 0.03% faster than photons we've measured, or their equipment has an unknown systematic error.

Or they screwed up the data analysis, which is my bet: http://www.tjradcliffe.com/?p=543 [tjradcliffe.com]

Re:What if light travels at slightly less than c? (1)

Anonymous Coward | about 3 years ago | (#37515816)

Keep in mind that we shouldn't expect any kind of background that would interact with light, since this should lead to some anisotropy to the the measured speed of light on earth, which classic interferometry experiments [wikipedia.org] have essentially shown to be zero.

Re:What if light travels at slightly less than c? (2)

Kristian T. (3958) | about 3 years ago | (#37515850)

Only an undergrad myself - but I was thinking the same thing. The implications of FTL would enable the creation of thought experiments breaking most known laws of physics (at least as we know them).

On the other hand, light travelling slightly slower than what maybe aught to be called the "causality propagation limit" would only challenge our knowledge about the nature of the vacuum - which is already up for debate. Light already travels slower than c in all substances other than vacuum, and Einstein certainly never took the soup of virtual particles that we call the vacuum into considerartion, when he made his famous theory.

Re:What if light travels at slightly less than c? (2)

locofungus (179280) | about 3 years ago | (#37515890)

Surely with an undergraduate degree you did the derivation of the wave equation in free space from Maxwell's equations?

The only part you might have missed (I'm sure you'll have been told it but might not have realized the significance) is that Maxwell's equations are independent of the inertial frame that you pick. And therefore light propagates at c in all inertial frames.

Special relativity is what falls out if you assume that Maxwell's equations are correct.

There's all sorts of experiments that have been done that make any of this really hard to throw out. From EM having inverse square law to half-lives of relativistic particles.

The only handle that makes me think there's a slim chance there might be something real here is that we are WAY outside the normally experienced velocities for massive particles. We're talking about a 2eV rest mass with a KE in the 17GeV range. Therefore we could be seeing new physics while still having relativity as a very good approximation for everything we've had so far much like relativity was a small correction to newtonian mechanics.

Tim.

Re:What if light travels at slightly less than c? (1)

jovius (974690) | about 3 years ago | (#37515908)

If that was the case there would be noticeable effects in satellite communications - think about time, location etc. The effect would have been observed by now.

Re:What if light travels at slightly less than c? (1)

LordNacho (1909280) | about 3 years ago | (#37515936)

Hasn't the value of c been verified to within a very tight tolerance, many times, by a great many people, and with much rigor? If we now found c to be different, you'd have to explain a mountain of evidence, ie how did everyone come up with the same number every single time, even though they were doing it in slightly different ways, in different places, and importantly in different frames of reference? Surely the systematic error would have shown up somewhere?

Various considerations such as the fact that empty space isn't empty must have been addressed by someone (would be nice to know exactly what the reason for that one is though).

Miniaturization of Fermilab (1)

Twinbee (767046) | about 3 years ago | (#37515520)

Random question:

What kind of technology and materials would we need to get the giant Fermilab etc. down from square kilometres down to square metres or even inches? Would cheap fusion energy, or room-temperature super-conductors, or limitless supplies of carbon nanotubes/diamond/graphene help reach that particular goal?

Re:Miniaturization of Fermilab (1)

janimal (172428) | about 3 years ago | (#37515604)

You would probably be looking at an inversely proportional need for power and cooling, since you will want to generate the same energies.

Re:Miniaturization of Fermilab (0)

Anonymous Coward | about 3 years ago | (#37515838)

It would require dramatically improved super conducting magnets to turn the particles in a tighter circle and dramatically improved RF generation to accelerate them. More energy would be required, but it's an issue of being able to add enough energy to overcome radiative losses and increase the particle's energy in each lap around the accelerator so just having unlimited energy won't help you.

The other problem with shrinking a particle accelerator is that the electromagnetic radiation emitted (the radiative losses) by the charged particles you're accelerating becomes an issue. This synchrotron radiation would is in the x-ray spectrum now and as you tighten the circle it'd only go up in energy. So you'd be eventually dealing with a constant emission of x-rays or gamma rays. I.e. not something you'd be able to deal with without tons of shielding.

Re:Miniaturization of Fermilab (1)

vlm (69642) | about 3 years ago | (#37515854)

Random question:

What kind of technology and materials would we need to get the giant Fermilab etc. down from square kilometres down to square metres or even inches? Would cheap fusion energy, or room-temperature super-conductors, or limitless supplies of carbon nanotubes/diamond/graphene help reach that particular goal?

A limitless supply of gold would seem to be prerequisite.

Seriously though the killer is cubed squared law problems. Dump a few megawatts into a few hundred square megameters of "stuff" and it scarcely gets above room temperature. Dump a few watts into a few square cm and you have whats known as a "soldering iron"... Of course with infinite money I suppose you could develop a semiconductor industry designed around a thousand degree operating temperature, with all new substrates and dopants and packaging... or you could go 100% nanoscale vacuum tube computing

Phil Plait (0)

Anonymous Coward | about 3 years ago | (#37515564)

Sorry guys. I'm not trying to put him down but Phil really isn't the one we should be turning to on this question. While he brings up good and valid points the bottom line is that he even said in his twitter feed that this isn't his area to speak on. I respect the man for his work with BA and in the community in general but he's just not the best source of understaing on the subject. Something tells me that better sources for information on this are keeping their mouths closed for a good reason even if it's nothing more than professionalism on their part.

faster than the speed of light??? (-1, Troll)

3seas (184403) | about 3 years ago | (#37515586)

object A moving .50001 the speed of light. Object B moving .5 the speed of light moving the exact opposite direction away from object A.
You are on object A, can you see object B?

I thought they already figured out faster than light speed via quantum physics entanglement.

Another thought experiment. a 1" rod 1 light year long. you move it 1/16 of a centimeter. How long does it take for the movement to register at the other end?
A: its instant, for it does not need to move any faster than the time it took you to move it.

Re:faster than the speed of light??? (0)

Anonymous Coward | about 3 years ago | (#37515708)

1. Yes, due to relativistic addition of velocity, neither see the other as moving over c.

2. This does not transmit information faster than light, and

3. The shockwave of you pushing the rod would propgate at the speed of sound in the material, not instantly. Until it reached the end, the rod would effectively be 1/16th of a centimeter shorter.

Re:faster than the speed of light??? (1)

Vario (120611) | about 3 years ago | (#37515742)

1. Yes, they can see each other. Why should they not? You can hear a fighter jet flying faster than the speed of sound easily, similar here. But don't get confused: you will only ever be able to see the past "image" of the other object, this image is traveling towards you with c.

2. More than 1 year. Your idea of a rod is not quite right. Think of it like a big rubber band, then make it stiffer and stiffer. If you pull too hard you would rip off one end but in any case they would probably not notice it for way more than a year (speed of sound).

Re:faster than the speed of light??? (0)

Anonymous Coward | about 3 years ago | (#37515780)

object A moving .50001 the speed of light. Object B moving .5 the speed of light moving the exact opposite direction away from object A.
You are on object A, can you see object B?

Yes.

I thought they already figured out faster than light speed via quantum physics entanglement.

No.

Another thought experiment. a 1" rod 1 light year long. you move it 1/16 of a centimeter. How long does it take for the movement to register at the other end?
A: its instant, for it does not need to move any faster than the time it took you to move it.

No.

Re:faster than the speed of light??? (0)

Anonymous Coward | about 3 years ago | (#37515824)

object A moving .50001 the speed of light. Object B moving .5 the speed of light moving the exact opposite direction away from object A.
You are on object A, can you see object B?

I thought they already figured out faster than light speed via quantum physics entanglement.

Another thought experiment. a 1" rod 1 light year long. you move it 1/16 of a centimeter. How long does it take for the movement to register at the other end?
A: its instant, for it does not need to move any faster than the time it took you to move it.

My understanding is that object B is outside the light cone and therefore is not observable from object A and visa-versa.

The rod would not move instantaneously, the movement of the rod would be transmitted from one end to the other at around the speed of sound in the material. IANAP But I guess this means it would either take a lot longer than a year to move that far (because the inertia would be so huge and waiting for the other end to start moving) or you would send a compression wave from one end of the rod to another.

Re:faster than the speed of light??? (0)

Anonymous Coward | about 3 years ago | (#37515830)

1. Yes, drastically red shifted.

2. What's the bar made of? It would have to be pure Imaginanium and impossibly rigid. Any other material? Then the movement propagates depending upon the modulus of elasticity- or the propagation of electromagnetic force between atoms. Even your two foot long one inch rod of diamond compresses a little when you push one end.

Re:faster than the speed of light??? (0)

Anonymous Coward | about 3 years ago | (#37515914)

object A moving .50001 the speed of light. Object B moving .5 the speed of light moving the exact opposite direction away from object A.
You are on object A, can you see object B?

I am not a physicist by any means but...

Einsten told us that to add two velocities u and v the right formula is (u+v)/(1+(uv/c^2)). In your case this yields 1.00001c/(1+0.250005) =0.8c.

I thought they already figured out faster than light speed via quantum physics entanglement.

They did not. You generate the entangled particles together, you take them to different places, you read them and you see the same quantum state. After that the game is over. You cannot change the state of one expecting the other one to follow.

Another thought experiment. a 1" rod 1 light year long. you move it 1/16 of a centimeter. How long does it take for the movement to register at the other end? A: its instant, for it does not need to move any faster than the time it took you to move it.

If your rod is made out of a perfectly rigid material (unobtainium), that will work. Interactions among atoms are of electromagnetic nature and you stil have propagation of information at the speed of light

Re:faster than the speed of light??? (0)

Anonymous Coward | about 3 years ago | (#37515964)

You are wrong on both counts.

In the first example, Galilean relativity (velocities sum) is not correct at high velocities.
In the second example, objects are not perfectly rigid, the movement actually travels at the speed of sound in that medium. So much slower than light.

Re:faster than the speed of light??? (1)

Zarhan (415465) | about 3 years ago | (#37515982)

You are on object A, can you see object B?

    Yes, although it will be heavily redshifted.

Hurry up already (1)

Yvan256 (722131) | about 3 years ago | (#37515590)

I want a neutrinos modem so that my downloads are finished before I click on the links!

I wonder if... (1)

ikarys (865465) | about 3 years ago | (#37515624)

If they can go faster than light, then they may have already completed their retest. The results of that test were that they cannot go faster than light.

Relativity still holds (3, Informative)

danhaas (891773) | about 3 years ago | (#37515632)

The theory of Relativity still holds true, what this experiment (if it's accurate) changes is our idea of matter and causality: if neutrinos have imaginary mass, they are allowed to traver faster than light, as tachyons; and causality may have to be revised, from a onward moving arrow to a regular dimension, in which the future can influence the past.

General Relativity (2)

prograde (1425683) | about 3 years ago | (#37515704)

I can only assume that they've corrected for General Relativity. Everyone seems to be pointing to the obvious potential sources of error: knowing when the neutrinos are created, knowing when they arrive, knowing the distance that they've traveled.

What about variations in the Earth's gravitational field between the two clocks? Or along the path that the neutrinos follow? You can't call the planet a point-source of gravity - the density of matter is quite lumpy.

I haven't seen a back-of-the-envelope calculation for this...maybe it's orders of magnitudes impossible? Would it require a tiny black hole to throw the timing off by 60ns...or would a big uranium deposit be enough? I could probably do the Lorenz transforms for Special Relativity myself, but General is a bit beyond me!

Within four to six months... (1)

Arancaytar (966377) | about 3 years ago | (#37515762)

...ago, of course.

A million internet points (1)

Wingman 5 (551897) | about 3 years ago | (#37515808)

A million internet points for the person who commercializes this in to a faster than light inter-planatary communication network and calls it subspace [memory-alpha.org] .

2011 Electronic Law and 3e8 (0)

Anonymous Coward | about 3 years ago | (#37515820)

3e8 is here to stay in my dungeon

There is no way I am relearning electronics math after replacing 3e8 -- with what? , a new unknown variable!?
Radios and TV's will be fixed with existing 3e8 test equipment and 3e8 math.

I'll make a prediction, even if there is a particle traveling faster than 3e8,
it will be a particle which people who work with 3e8

1. don't care about, unless the discussion is shielding
2. can't measure
3. can't use
4. the timing for chips will still be timing for chips based on 3e8
5. Joe 6 Pack will be hard pressed to put a particle going faster than 3e8 to practical use

3e8 is here to stay, it's the LAW for now.

Neutrino and photons and gravity... (2)

razathorn (151590) | about 3 years ago | (#37515910)

I'm not even remotely qualified to comment on this, but I seem to remember light being affected by gravity and thus the mass around it, where as neutrinos are virtually unaffected by normal matter. What this says to me is the neutrinos are showing us what the actual speed limit of the universe is compared to what we think it should be as an observer sitting on a giant ball of gravity rich mass. Basically, in space, they go the same speed, which is why the neutrinos and photons from a distant stellar event show up here at the same time, but on earth, the results might be slightly different.

My gut tells me that this will end up shoring up special relativity and perhaps adding a new understanding of our universe without shattering everything as so many are saying.

Plate Teutonics? (1)

gpronger (1142181) | about 3 years ago | (#37515958)

With the small but consistent error in the results, what I have not seen is how you know that this isn't a measurement that the distance did not change.
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