Speed of Light Exceeded? - LHC Announcement

[michael.h.f.wilkinson]

I think most scientists are very excited about the findings of the OPERA team. We must be cautious however. It ain't over till the fat lady sings.

Sorry, couldn't resist

[JamesF]

I presume the phrase you were trying to type was the innocent - albeit cliché - "ch¡nk in the armour". I share your annoyance. It is time that a modicum of common sense were restored to what is in all other respects a very good forum.

The Law of Unintended Consequences. All too common when you try to fix a social problem with a technological solution

James

[michael.h.f.wilkinson]

The Law of Unintended Consequences. All too common when you try to fix a social problem with a technological solution

James

I once quoted Shakespeare (guess, hints: Shylock, Merchant of Venice, something to do with blood ). That got clobbered by the autocensor. It actually made it look rude. You have to laugh.

[dave1978]

Surely the difference is within their +/- margin for error. If they have their distance off by even a few feet it would throw their results off.

[michael.h.f.wilkinson]

Surely the difference is within their +/- margin for error. If they have their distance off by even a few feet it would throw their results off.

It is possible I suppose. According to their measurements, they have a margin of error of 10 ns, or about 3 m (10 feet) distance. The difference in arrival time is 60 ns giving a 6 sigma margin, which is pretty big.

[todd8137]

on the subject of the speed of light if we could travel this fast ,lets say for this in a car, and we was traveling at the speed of light ,if we switched the car headlights on what would happen would we see the light from the car headlights ?

[Ptarmigan]

I think they will be presenting the results formally later today.

Particles break light-speed limit : Nature News

Thanks for that link pbd, that is a much better read than the BBC stuff.

[JulianO]

I'm also betting on systematic error. There is a lot of data from supernova being preceeded by neutrino bursts. They arrive at just about the right time, despite crossing millions of light years. As noted the 1987a is the principal benchmark with well recorded data tying neutrino arrival to the following light flash.

[michael.h.f.wilkinson]

on the subject of the speed of light if we could travel this fast ,lets say for this in a car, and we was traveling at the speed of light ,if we switched the car headlights on what would happen would we see the light from the car headlights ?

Actually, Einstein claimed he got many of his ideas from musing on what things would look like if you traveled with the speed of light along a ray of light. When you see the light from your car's headlights, you are actually seeing the light reflected off objects. If they are dead ahead, you would hit the object at the same time the light from you headlights hit them.

[JulianO]

on the subject of the speed of light if we could travel this fast ,lets say for this in a car, and we was traveling at the speed of light ,if we switched the car headlights on what would happen would we see the light from the car headlights ?

Depends on your frame of reference, in the car you'd see the light from the headlamps leave at the speed of light. Light always travels at the speed of light no matter where or what you're doing.

[dave1978]

Depends on your frame of reference, in the car you'd see the light from the headlamps leave at the speed of light. Light always travels at the speed of light no matter where or what you're doing.

Im sure Prof Brian Cox covered this in one of his shows, if i remember rightly the light from the headlights would still beam away at the speed of light from the car.

[Macavity]

I think one of the BIG advantages of working in a "Foreign Lab" is that you can (chose to) be fairly insulated from shouty, cynical, Anglo Saxon, "internet culture" and vacuous tabloids... <G> I empathise with the (probably?) grad-students, research associates etc. who have stayed up late (all night) to understand the results. On a (political) "hiding to nothing", I suspect, but mostly in the true, HONEST spirit of scientific inquiry...

[661-pete]

Actually, Einstein claimed he got many of his ideas from musing on what things would look like if you traveled with the speed of light along a ray of light. When you see the light from your car's headlights, you are actually seeing the light reflected off objects. If they are dead ahead, you would hit the object at the same time the light from you headlights hit them.

No: keeping within the constraints of SR, suppose that you are travelling at almost the speed of light, which is possible, rather than exactly at the speed of light, which is impossible.

The ray of light from the headlamp would still appear to emerge at the speed of light relative to your car.

However, if whatever the light bounces off to be reflected into your eyes is stationary with respect to the Earth, i.e. closing in on you at almost light speed, the light will be savagely doppler-shifted. You will need X-ray eyes at the very least, to see anything at all!

[palebluedot]

I'm also betting on systematic error.

If it is must must be pretty deep rooted. Over 16000 similar results over a number of years, you would have though that they would have found it by now.

[661-pete]

Actually, I've just remembered, there is nothing new here. Who else remembers the opening sequence of the Lone Ranger on TV?

A fiery horse with the speed of light, a cloud of dust, and a hearty 'Hiyo Silver!'

So the three bullets which the LR fires from his trusty revolver in the same sequence, must evidently be going a lot FTL!

[michael.h.f.wilkinson]

No: keeping within the constraints of SR, suppose that you are travelling at almost the speed of light, which is possible, rather than exactly at the speed of light, which is impossible.

The ray of light from the headlamp would still appear to emerge at the speed of light relative to your car.

However, if whatever the light bounces off to be reflected into your eyes is stationary with respect to the Earth, i.e. closing in on you at almost light speed, the light will be savagely doppler-shifted. You will need X-ray eyes at the very least, to see anything at all!

For a non-zero rest-mass car you are right, the question was what happens AT the speed of light. Infinitessimally below, the headlight beam would indeed still move at the speed of light in your frame of reference.

[sbooder]

Im not suggesting the finding is correct. Just to be mindful that there will be other discoverys in the future that turn everything on its head, its happened before steady state theory, big bang ect, some want to go back to the steady state. suggestions of impossbillities based on theorys that appear correct from one century to the next, are arogant. People may not like that suggestion. But time will prove that observation correct, even if this is not the discovery to do it.

It is not arrogant! Science can only use the parameters of existing theory to gain further knowledge and try and break those parameters.

Some people seem to think there is a big book of science the scientist delve into every now and again, there is not, science for the most part is working blind of what is ahead.

I can not stand this Daily Mail mentality that believes that scientist presume to know it all, of course they do not, but the staring point in science for each new generation is what the generations that went before have left.

[Psychobilly]

Just incase anyone wants to see how that esteemed journal is reporting the "news" and of course the priceless comments...

Speed-of-light experiments give baffling result at Cern: Did Einstein get it wrong? | Mail Online

[661-pete]

Just incase anyone wants to see how that esteemed journal is reporting the "news" and of course the priceless comments...

Speed-of-light experiments give baffling result at Cern: Did Einstein get it wrong? | Mail Online

Priceless indeed! From that 'esteemed journal':

This is not the first time that neutrinos have been recorded travelling faster than the speed of light. In earlier experiments, the detectors used to pick neutrinos up were turned towards the Earth so that the bulk of the planet could slow the neutrinos enough for them to be detected.

- Leroy Gibbs, Reading, Berks, 23/9/2011 10:21

Perhaps someone could explain how a neutrino detector - essentially a tank full of liquid - can be 'turned towards' anything? Oh, and the Earth 'slows down' the neutrinos? But even after slowing down they're still travelling FTL?

Classic! But then perhaps I shouldn't mock. I have the benefit of a scientific education: not everyone else has.

Incidentally, the reason why neutrino detectors are sited deep underground, is to shield them from other forms of radiation present at the Earth's surface (e.g. cosmic rays) which would otherwise swamp the results.

[palebluedot]

The paper is out... If you are into that sort of thing.

http://arxiv.org/ftp/arxiv/papers/1109/1109.4897.pdf

[JB80]

Not sure if it's been posted but at 16:00 CEST time you can watch the webcast of the CERN press conference here...

Live webcast

[Simms]

Maybe someone out there can answer this for me, it may well be just a hypothetical question, but I am more than happy with a hypothetical answer..

So, we know neutrinos exist and we can detect them - same goes for photons as we can `see` them and our rules of physics are built around theories that refer to the `speed of light`.. But how do we know there are not other particles out there that completely trounce these rules and move many many times faster than the speed of light? Maybe we are not advanced enough (and maybe we never will be) to build detectors that can detect these particles existence, let alone try to measure their speed. I am really trying to grasp the concepts of relativity and its associated theories, but maybe I am just too open minded to accept that the speed of light is the be all and end of all of the maximum speed `something` can travel.

Be gentle with me - words of three syllables or less please.

[Simms]

Surely the difference is within their +/- margin for error. If they have their distance off by even a few feet it would throw their results off.

Maybe they have measured the speed/time of photons between the two points (I am sure they have) so have a pretty accurate idea of the actual distance.

[sbooder]

Maybe someone out there can answer this for me, it may well be just a hypothetical question, but I am more than happy with a hypothetical answer..

So, we know neutrinos exist and we can detect them - same goes for photons as we can `see` them and our rules of physics are built around theories that refer to the `speed of light`.. But how do we know there are not other particles out there that completely trounce these rules and move many many times faster than the speed of light? Maybe we are not advanced enough (and maybe we never will be) to build detectors that can detect these particles existence, let alone try to measure their speed. I am really trying to grasp the concepts of relativity and its associated theories, but maybe I am just too open minded to accept that the speed of light is the be all and end of all of the maximum speed `something` can travel.

Be gentle with me - words of three syllables or less please.

Iin fact we are sure there are particles we have not discouvered yet, this is one of the reasons that the LHC was built, to find them.

I would suggest watching Atom with Jim Al-Khalili this will go along way to explaining Einstein's Special Theory of Relativity (and the speed of light), far better than I could using non technical words.

[michael.h.f.wilkinson]

All observations of all phenomena in physics are based directly or indirectly on forces or energy transfers (same thing really). Something exerts a force on some detector, or particle, and the result is measured. Sometimes the observation is more indirect, e.g., when neutrons decay into a proton and electron, we find both energy and angular momentum are not preserved, leading people to postulate there was a missing (neutral) particle: the neutrino. Thus for something to be noticed by physicists, it must interact with something we noticed before. Interactions need forces.

The current understanding is that there are basically four forces (some of which can be unified, one causes trouble, and might not be a force at all). These are:

1. Gravity, which is very weak, infinite range
   
2. Electromagnetism, which is strong, infinite range
   
3. the Strong nuclear force, which is strong, very short range
   
4. the Weak nuclear force, which is weak, very short range
   

All observations at the particle level concern the latter three, as gravity is so weak at those scales. There could be other unknown particles out there, but to find them, they must exert some force on some known particle. The very possibility of finding new particles is one reason to keep smashing atoms together.

Philosophically, one might argue that any particle which fundamentally cannot interact with any known physical entity (either directly or indirectly) does not belong to the same universe as these physical entities.