Going back in time?
Clearly the neutrinos that arrived too fast in the first experiment were actually the ones from this second experiment going back in time.
Have they tried reversing the polarity of the neutrino flow?
The boffins who sent sub-atomic particles on a faster-than-light journey into the past have done another successful experiment that confirms the results. In the original test, 15,000 beams of neutrinos were fired over three years from CERN near Geneva 720km to Gran Sasso in Italy and the particles arrived at their destination …
From the beeb article after the first experiment:
"The scientists are right to be extremely cautious about interpreting these findings," said Jim Al-Khalili, a physicist from the University of Surrey, who suggested that a simple error in the measurement is probably the source of all the fuss.
But he has gone further.
"So let me put my money where my mouth is: if the Cern experiment proves to be correct and neutrinos have broken the speed of light, I will eat my boxer shorts on live TV."
Time to break out the popcorn. I hope he washes them first…
The paper has been submitted, but hasn't yet been peer reviewed or published, and you can bet that the scrutiny this experiment gets will be greater than pretty much anything that's gone before.
I'm happy to wait until it appears with the name of a prestigious journal to add credibility. I'll be even happier when someone comes up with a theoretical or (better) practical explanation. Until then, we've got nothing.
Well, we may not have the final answer, but that doesn't mean we have nothing. We have a question and a possible path we can follow to answer it. Maybe the answer is mundane, such as systematic experimental error, or maybe it's something new an amazing that we never knew existed before. Either way, isn't science about the journey at least as much as the destination?
In this particular case, the journey is even more interesting because the journey is being shared among so many people, including both experts and El Regers. Of course I look forward to hearing what they find, but I also enjoy hearing about the entire process. Or to put it another way: http://xkcd.com/54/
Jacques Martino, director of France's National Institute of Nuclear and Particle Physics (CNRS), said another possible error of the experiment, that the clocks at CERN and Gran Sasso were on an ever so slightly different time due to gravitational time dilation, could also going to be looked into soon.
could also going to be looked into soon? seriously?
a) The Neutrino detector and emitter are big and heavy and expensive.
b) Because of (a) above there are only a few places on earth where the experiment can be done
c) There is no tunnel between the emitter and the detector, the neutrinos are fired through solid rock, which to a neutrino has all the stopping power of a wet tissue trying to stop a high speed train at maximum velocity.
d) Because of (a) and (c) we can't send light at the same time as the neutrinos
e) Even if we didn't have the problem of (d) because of Heisenberg's uncertainty principle we can't be sure of exactly when the neutrinos left the emitter and arrived at the detector, which is why they use pulses of neutrinos and a lot of Boffin Class Maths to work out the result.
Because there isn't a physical link between the two sites. Neutrinos have almost zero mass, no charge and pass through pretty much any material as if it wasn't there.
The beams are being fired at a detector that interleaves lead plates with emulsion films to detect the neutrinos. IIRC the detector weighs something like 1300 tonnes (not really relevant, but gives you an idea of it's size).
By having synchronised clocks you know that the "beam start time" and "beam detection time" are effectively being recorded by the same clock without having to do any calculations or measurements for lag caused by stuff like wiring and distance.
At the moment it seems like the most likely reason for the current measurements are the clocks being slightly out of sync; I'm a bit mystified as to why this hasn't been checked already as they've had the discrepancy for months now.
(Of course, I have no idea how difficult that particular task is.)
These neutrinos aren't being beamed down a pipe, but rather through the earth, which is just as good as a vacuum filled pipe to a neutrino.
However, since light, unlike neutrinos, does interact significantly with things like rock, you cannot just fire a laser along the same path.
There are *no* pipes between CERN (on French/Swiss border) and Gran Sasso! Neutrinos have the disconcerting ability to pass completely through most solids. That's why they are so hard to detect. All the detectors (like the one at Boulby Potash mine in Cleveland UK) are deep underground to screen out background cosmic radiation. They are also made of very dense materials - Gran Sasso is made up of a number of lead/photgraphic film bricks weighing a total of 1250 tonnes - to maximise the chance of a neutrino hitting an atomic nucleus and crating a "spark" of sub-atomic particles that can be detected.
Hope that helps.
<end of particle detector 101>
They could branch off from an existing fiber link and add their own extensions to it to calculate from or just lay the fiber shallow and use it as an experimental approach while recouping the cost later on costing a large amount of cash but not a huge amount about $9 Million or so.
I'm guessing $20K a mile for the fiber link, they'd also have some valuable dark fiber for future experiments or just peering links for their existing costs.
I would hope they are already doing something akin to this to account for timing variance.
Still contend that there is no such thing as time, its purely a human construct, an observation of movements in reference to another. Time cant move different because its not something that is there... matter can move differently due to gravity, but time doesn't enter into it.
I respect Einstein, and believe that the general theory of relativity is mostly correct, but I am afraid it has become religious for scientists. I find it much more plausible that there aspects he didn't understand, and things we have yet to learn, that will correct and refine his original theories.
imagine if Psychology just decided that Freud must have gotten everything right, and spent all there time trying to prove why his theories were correct. I am sure if he were still alive, and had access to modern information even Einstein would not agree with his old conjectures completely.
He never got comfortable with the idea of quantum, remember? "God does not play dice with the universe" and all that.
As for the rest, why should anyone take you seriously for a minute? You can't even get your punctuation straight, and that's before the point where, in the same breath, you talk about how relativity's become a religion for scientists, and how you "believe that [it] is mostly correct". You're almost as bad as the twat who was pissing at me here a few months ago about being dismissive of anarchists like him, and who immediately thereafter spent several paragraphs fondling the EU's tumescent genitalia as though that were anything remotely sensible or consistent for a fervently self-declared anti-statist to do.
I heard Galileo had the same problem with his punctuation and they put him under house arrest for it.
This is petty point scoring which attempts to destroy another serious argument with less than intelligent ad hominem attacks. How can a point of view be taken seriously when it's self-justification is based on insults? Get your mind out of the playground and try some real scientific debate,
Like most serious science, Einstein's theories and formulae have earned great respect because they have proven to be tremendously useful and accurate in modeling a great number of experiments and observations. That's real science, kids. It attempts to describe how things happen and allows you to predict the outcome of experiments. As more and more experiments and measurements turn out to give exactly the results predicted by the theory, the theory gains credibility. Consider as an example the theories and formulas that allow boffins to predict when the moon will be full, or when So-and-So's comet will pass the earth.
If this neutrino mess proves that some part of relativity theory is incorrect by producing verified results that are inconsistent with the predicted or expected results, then somebody needs to come up with new theories or formulas that match the success of all other aspects of relativity, but also accurately describe this neutrino observation. That will be tricky, but it will be exciting for fans of real science.
Not very practical, and not much point in doing it. The speed of light in a vacuum is not being questioned by this experiment - the speed of neutrinos is. Since they know how far apart CERN and Gran Sasso are (d), there's not much point in measuring how long light takes to get there - it's d/c.
Drilling a hole 700Km long and firing a laser down it is probably not the easiest way to eliminate errors in the measurement of the distance between neutrino source and detector.
Einstein said that nothing can travel faster than the speed of light which he defined as c. As far as I can remember I don't think he ever said what the particular numerical value c takes. It varies with the medium in which it travels e.g water, atmosphere, vacuum, void space etc.
The people at Opera can bang on about their measurements like veritable pilgrims but the ultimate clash at demonhead won't occur until they measure the unimpeded speed of light in void space and until then the register should not let them get away scot free with their claims!
Just because in Einstein's time we were not aware of a more pure form of energy does mean we should hold to his observation like a religion....it is completely possible that other forms of energy are more "pure" than light, and therefore could move faster...Einstein just wasn't aware of them, so he assumed light was the fastest. He also thought time was a medium, and not a human construct...
c is the speed of light in a vacuum. It was specified.
However, I do wonder if Einstein would have presented a different theory had he known about the speed these neutrinos travel at. After all, he presented a THEORY based on what was known and conjecture at that time. We now know a lot more, and science has moved on.
Einstein defined things in mathematical terms and whilst a mathematically defined vacuum is truly empty, a physical vacuum is not as it contains quantum particles popping in and out of existence.
Einstein based his theory on equations that work beautifully in accordance with the underlying mathematical assumptions and until the Opera people can physically conduct their experiments within that mathematical framework or break one his underlying assumptions, I'd say Einstein wins!
"The boffins who sent sub-atomic particles on a faster-than-light journey into the past have done another successful experiment that confirms the results."
Sensational but not true. The particles arrived sooner than they would have had they travelled at the speed of light, but still *after* they were transmitted. They did not arrive before they set off, they did not 'journey into the past'.
I don't see how getting rid of one source of error is enough for a press release. Surely they should wait until they've eliminated all sources of error? After all, science isn't a desperate attempt to grab headlines with iffy results.
No, wait, it is.
[Paris, because she's a desperate attempt to grab headlines]
In case anybody is wondering, when Jacques Martino said "eventual systematic errors" he meant "possible systematic errors". It's a very common mistake when native French speakers speak English as a second language because the French word is "éventuel" (the French call words like that "faux amis" -- false friends).
...but be careful if you ever feel embarassed in Spain and feel the urge to communicate this in Spanish.
embarazada = pregnant
On the neutrino topic - this is something that has the potential for a paradigm shift in physics, even IF (big if) it's true, it won't be confirmed for years (they'd have to repeat the experiment with consistent results in 2 or 3 other locations), and it won't be for many, many years until it is fully accepted or understood.
Science works the same as society - new ideas aren't just accepted by everyone immediately, it's just that the old people with the old paradigm eventually die and the new generations accept as normal the findings that were revolutionary to their elders.
If a respected scientist claims something is possible, he is very probably right.
If a respected scientist claims something is *impossible* he is very probably wrong.
Am I alone in seeing this as just another rung on the ladder ? We went from Aristotle to Newton, Newton to Einstein, and now Einstein to beyond ?
Or is there some absolute somewhere I missed ?
What i want to know is how they have managed to accurately measure the distance between CERN and Italy. Surely the whole thing despends on accurate distance divided by accurate time. The timing I can understand but the accurate distance seems to be the difficult item. I would double check the ruler if it was me.
One would think they checked carefully using acceptable techniques. After all, they're expecting to measure to the nanosecond, so everything would have to be calibrated carefully and accurately to give any credence to the results.
Of cause, what should happen now is the test needs running elsewhere and confirming. Unfortunately the only place I can think where there might be a facility capable of running the same tests would be in the US.
Some of the commenters here seem to think CERN are timing these experiments with wind-up alarm clocks and measuring the distance with string...
60ns at light speed is about 17m from memory. Your hand-held GPS is already an order of magnitude more accurate than that.
Oh and as no one else has said it so far, I will. They're firing these neutrinos through solid rock, which is why they're not measuring light. Because rock will stop light. As well as beating scissors.
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Neutrinos don't really react very well with other matter, that's why they are ably to pass straight through the Earth. You can't bounce them back as you have nothing that will act as a reflector. If your idea was to send another separate neutrino back to CERN each time the detector detected a neutrino then this factors in a lot more uncertainty about timing and would also require another Large Hadron Collider to be built under the Italian Alps.
Thing is you need to build a particle accelerator over in Italy as well then - and those are neither small nor cheap.
In addition, the neutrino pulses can only be created when you whack a "bunch" of protons from the ring into the neutrino-makery-thingy - the beam isn't constant, so you'd have to wait until a bunch is in the right place on the ring, and you'd have some even more fun errors taking into account the time for the system to react to the incoming signal and the time for the bunch to reach the target to be neutrino-ised.
Also, not quite sure what this would achieve anyway, other than showing that the effect happens both ways, rather than in only one!
OK, at the risk of looking really stupid... Am I right in thinking that sound goes faster thru a solid that it does through air? I know that the speed of light measure is through a vacuum... So, you can't send light through a solid BUT could it be that we're seeing how fast light is through a solid (mountain)??
err... why does FTL = backwards in time? A fanciful notion but impossible, the Universe forbids it.
The concept of Time, usually labeled as a "dimension" is, therefore, the FIRST dimension, not the FOURTH.
There is, and always will be in any dimension you care to theorise or imagine, always Time and always flowing toward the future, or forward as you may conceive it.
So give up those romantic dreams of travelling backwards in Time, you cannot.
Relativity, as far as measured/observed sub-light speeds, fits the theoretical equation that implies time-reversal (or at least breaking causality) when v > c (look up "tachyonic antitelephone").
But of course it is not known if the theory holds outside of our experience, and thus if faster than light *is* capable of time-reversal.
General relativity permits time travel in certain extreme circumstances. It is (theoretically) possible to travel along a space-like path around a rapidly spinning black hole* that would allow you to return to your starting point before you set off. Most likely, this indicates that relativity breaks down near black holes. But anyone who's taken relevant undergraduate physics classes will be aware that relativity and quantum mechanics are incompatible - even though they have both passed every experimental test we have been able to construct.
* a stellar-mass black hole won't work, the tidal effects would destroy any physical object trying to follow such a path. It could be possible with a galactic-mass black hole, but they are not likely to spin sufficiently rapidly.
Who says that the speed of light is the ultimate speed? its just the fastest thing know to man currently. The test at cern shows that its possible to go faster so im not sure why everyone is saying it can't be done.
I have watched many sciencey programs that says the big bang happened everywhere at the same time, well since space is a bit of a big area it would take something pretty damn fast to get across the universe in an instant.
my theory on the neutrinos is simply they are so small they can pass though other atoms and photons whereas light gets bounced around other atoms on the same journey, eg, straight line as apposed to a wibbly wobbly one
1) they can't send light alongside the neutrino beam because it'd mean digging a very long tunnel, which costs £££. The neutrinos go through the rock quite happily but light wouldn't play ball.
2) they can't send a beam back the opposite direction because generating a neutrino beam requires a huge accelerator a) which costs £££ and b) isn't very practical a mile underground
3) even if they had an accelerator in Gran Sasso and OPERA II in Geneva and decided to play neutrino tennis, it takes too long to prepare and fire an intense beam of protons to produce the neutrino beam. They couldn't do it so many times per second with current tech.
No, we don't. Neutrinos from 1987's supernova arrived just at the precise time on which they were expected if they were travelling at c. They arrived 3 hours before the light just because they were emitted 3 hours before the light, being the light emitted only when the shock wave reaches the exterior of the star
"Five hundred years ago, everybody knew the Earth was flat"
Almost everyone who THOUGHT about it didn't think it was flat. Most people weren't bothered either way. Sailors and anyone living near the coast knew if wasn't flat, ships would slowly 'sink' below the horizon and then come back
ok so light is 'Fast' and supposidly the fastest speed there is.
what if we think about temprature for a second.
in the universe absolute Zero is cold, but the coldest (un man made) temp is slightly warmer by a degree or so (thanks QI), so absolute Zero is slightly colder than the universes 'natural' lowest tempriture.
if you apply that logic to light, maybe light itself is ever so slightly slower than the speed of light (lets say 'top speed'), so going faster than light is possible, BUT faster than 'top speed' is not, so all the stuff/physics is correct, they are just asuming that the speed of light and top speed are the same thing.
see what i mean..?
(but what do i know)
It's worth watching the last 25 mins of that BBC programme Marcus du Satoy did about this in the last month or so.
This second expt has ruled out one of the possible causes. But who knows about whether the earth's density is accurately known enough along this path for that not to cause some GR fluctuations or something else that clearly isn't obvious.
Anyway, the the du Satoy programme said, if this is right then a prior experiment which recorded neutrinos and light arriving at the same time from a supernova must have some massive error or effect as I think it would have meant the neutrinos should have arrived 25yrs before the light.
There is no problem going faster than light. The problem is that if you have mass you can't accelerate to the speed of light in order to pass it. The maths tells you so. So conjecture on a top speed being > light speed doesn't solve anything. If this neutrino result is upheld and if we believe neutrinos have mass, then the theory may need modifying.
Current maths and theory says the speed of light in a vacuum is the max and that nothing can go faster than it. Experiments show light through other mediums can travel considerably slower, e.g. through sodium.
Fine, except current maths and theories has been updated and proved incorrect time and time again over the years. We just need to find another particle that travels faster. Maybe we have already.
"Einstein's theory of general relativity allows for time passing at different rates in regions of different gravitational potential. The differences are small, measured in nanoseconds, but could still account for the faster-than-light results. "
This is simply not the case; while gravitational differences and certain other factors could account for particles traveling SLOWER than C, none of these could cause a faster than C result according to general relativity.
Since it's generally accepted that a vacuum does not contain nothing, but rather a soup of virtual particles popping into and out of existence - perhaps this slows photons but not neutrinos - thus allowing neutrinos to be the true arbiter of "nothing travels faster than" rather then light??
While neutrino detector/generator combinations are not likely to be common it's hard to believe this set up is *unique* in the whole world.
Obviously this brings up the issue that of what happens if your results don't match those of CERN but I think that should be all part of the scientific process.
What we see as neutrinos are actually FTL particles that happen to oscillate to electron, muon or tau neutrinos during travel.
I propose a fourth neutrino type known as the "tachyon neutrino" which interacts even less strongly than any of the other three and also has imaginary mass.
Just have to hope that all this tinkering doesen't end up causing the Sun to start emitting heavy neutrinos (aka Hyperonic neutrinos) or we will get to hear "The Neutrinos have Mutated!" sometime in 2012 :-) (JOKING!)
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