Einstein for ever?
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Racers
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Hi,
Download the paper here http://arxiv.org/ftp/arxiv/papers/1109/1109.4897.pdf
Makes fun reading :shock: :wink:
Pete
Download the paper here http://arxiv.org/ftp/arxiv/papers/1109/1109.4897.pdf
Makes fun reading :shock: :wink:
Pete
All I'm getting is a list of names Pete.
Einstein's conclusions have been challenged pretty much from when he published them. There was a Society dedicated to over throwing his conclusions at one time.
I recall his conclusions being challenged when I was a student on the then theory of propogation of electro-magnetic waves in wave guides.
Whether that has been resolved or not I know not.
Roy.
Einstein's conclusions have been challenged pretty much from when he published them. There was a Society dedicated to over throwing his conclusions at one time.
I recall his conclusions being challenged when I was a student on the then theory of propogation of electro-magnetic waves in wave guides.
Whether that has been resolved or not I know not.
Roy.
wobblycogs
Established Member
Bah, there's a very very long way to go before we start saying the speed of light isn't the fastest information / matter can travel. This will almost certainly turn out to be a systematic error somewhere in the experiment. There have been literally thousands of experiments that all indicate that c is as fast as information can travel and none have given even the faintest hint that anything faster is achievable. Our current understanding of physics would even seem to indicate that cause and effect would be broken if this result is true so we could know nothing for certain.
There was actually a natural experiment fairly recently. A star was seen to go supernova which causes a large neutrino flux. Detectors on earth spotted the light and the neutrinos at exactly the same time. If neutrinos really did travel faster than light then how come the light and neutrinos from this supernova arrived at the same time? As the star is many light years away you'd expect the neutrinos to have arrived significantly before the light. The only possible explanation is that neutrinos somehow speed up when passing through matter as that is the only difference between this experiment and the supernova result.
There was actually a natural experiment fairly recently. A star was seen to go supernova which causes a large neutrino flux. Detectors on earth spotted the light and the neutrinos at exactly the same time. If neutrinos really did travel faster than light then how come the light and neutrinos from this supernova arrived at the same time? As the star is many light years away you'd expect the neutrinos to have arrived significantly before the light. The only possible explanation is that neutrinos somehow speed up when passing through matter as that is the only difference between this experiment and the supernova result.
monkeybiter
Established Member
Exciting news if corroborated.
As the suggested difference is only 60 billionths of sec slower/faster WC the observers would not have registered any delay.
You'd need some pretty sophisticated measuring tools for that I would think.
But time will reveal all.
Roy.
wobblycogs
Established Member
The point is that they observed a huge difference of 60ns over a distance of about 750km. The supernova happened many light years away so the difference would have been measurable with stone henge let alone an atomic clock (this link indicates the difference would have been about 3.2 years: http://usersguidetotheuniverse.com/?p=2169)!
60ns might not sound very much but it's measurable with the computer you are sitting in front of. A typical modern processor is running at 2GHz so a single cycle takes 0.5ns making it accurate enough to measure 60ns - I admit the error margin would be fairly large, in reality you would probably use dedicated hardware.
60ns might not sound very much but it's measurable with the computer you are sitting in front of. A typical modern processor is running at 2GHz so a single cycle takes 0.5ns making it accurate enough to measure 60ns - I admit the error margin would be fairly large, in reality you would probably use dedicated hardware.
I don't get it!
The neutrinos arrived first for reasons I fully understand, but once both light and Neutrinos are arriving how does the delay work?
Imagine two trains, one at 0.1 MPH faster than the other, the fast one arrives first, now imagine they pass you together at that speed difference, you'd need to measure the difference, you wouldn't see one.
Roy.
The neutrinos arrived first for reasons I fully understand, but once both light and Neutrinos are arriving how does the delay work?
Imagine two trains, one at 0.1 MPH faster than the other, the fast one arrives first, now imagine they pass you together at that speed difference, you'd need to measure the difference, you wouldn't see one.
Roy.
wobblycogs
Established Member
The supernova produces, at the same time, a huge burst of both light and neutrinos which then start spreading out through space. If both neutrinos and light travel at the same speed you would expect to detect them at the same instant on earth. If one is travelling even slightly faster than the other you would detect the faster one than then some time later the slower one. The difference in detection time combined with knowledge of how far away the supernova was tells you how much faster one was than the other.
To use the train analogy: two trains N and L leave London at bang on midday, you are standing at Cardiff station waiting for the trains. If both trains travel at the same speed both should arrive in at Cardiff at the same time. What this team are reporting is that the N train arrived first by quite a margin.
To complicate matters slightly there isn't actually an L train, we know exactly how fast the L train travels so we can calculate it's arrive time.
To use the train analogy: two trains N and L leave London at bang on midday, you are standing at Cardiff station waiting for the trains. If both trains travel at the same speed both should arrive in at Cardiff at the same time. What this team are reporting is that the N train arrived first by quite a margin.
To complicate matters slightly there isn't actually an L train, we know exactly how fast the L train travels so we can calculate it's arrive time.
Yep! Understood, so how were the neutrinos and light detected from the SN at the same time?
Even if both escaped the gravity well etc at exactly the same time the neutrinos should arrive at 60ns X time/distance involved.
This is IMO impossible as the observer would have to know the exact second that the first burst of neutrinos were due to arrive. As this clearly isn't possible we are back to my analagy of the two trains actually passing you, in other words the first observed sign would have been the visible flare of the SN explosion, obsevations of the neutrinos would then logically follow once the visible flare was observed.
This would make the speed differences difficult to measure, firstly the observers would need a reason for the measurement, unlikely as they wouldn't be expecting any difference, as per General Theory, and the equipment to hand.
I don't know of any optical observatory with neutrino detectors on site, are there any?
Hence my not 'getting it!'
Roy.
Even if both escaped the gravity well etc at exactly the same time the neutrinos should arrive at 60ns X time/distance involved.
This is IMO impossible as the observer would have to know the exact second that the first burst of neutrinos were due to arrive. As this clearly isn't possible we are back to my analagy of the two trains actually passing you, in other words the first observed sign would have been the visible flare of the SN explosion, obsevations of the neutrinos would then logically follow once the visible flare was observed.
This would make the speed differences difficult to measure, firstly the observers would need a reason for the measurement, unlikely as they wouldn't be expecting any difference, as per General Theory, and the equipment to hand.
I don't know of any optical observatory with neutrino detectors on site, are there any?
Hence my not 'getting it!'
Roy.
Dibs-h
Established Member
I don't really see it as "wow this is awesome!" Considering how long it's been since that theory was postulated\accepted and it wasn't until some decades later Neutrinos that were confirmed.
It has taken a great deal longer for an event to occur where a 60ns time difference has been reported. Considering the phenomenal distances involved, it's an interesting result, but not much until the phenomena\results are repeatable. This I seriously doubt - but I'm sure that Gov't funding somewhere may occur for this little (extremely expensive) pursuit to take place.
My 2c worth
Dibs
It has taken a great deal longer for an event to occur where a 60ns time difference has been reported. Considering the phenomenal distances involved, it's an interesting result, but not much until the phenomena\results are repeatable. This I seriously doubt - but I'm sure that Gov't funding somewhere may occur for this little (extremely expensive) pursuit to take place.
My 2c worth
Dibs
wobblycogs
Established Member
Dibs: the 60ns difference from expected travel time is from an experiment solely based on earth. Neutrinos were produced at CERN and detected in Italy 750km ish away. There are already other places on earth where this experiment could, conceivably, be reproduced so the cost should be fairly minimal. The most likely site for a duplicate experiment is in Japan but the facility is currently shut down due to the problems they are having with power.
Roy: there are a number of neutrino detectors dotted around the earth that run 24/7. When an event is detected it measures the exact time of the event, the direction the neutrino was moving in and the energy of the particle. Combining the data from more than one neutrino detector lets us calculate where the event that caused the neutrinos occurred. Likewise there are plenty of telescopes that would also have recorded the location and time of the light from the supernova. Both sets of observatories should record the same time for the explosion and, indeed, this was the case.
Although the neutrino and optical observatories aren't located in the same place the distance apart is so tiny compared to the distance to this supernova it would make no noticeable difference and the error could be removed with calculation anyway.
Roy: there are a number of neutrino detectors dotted around the earth that run 24/7. When an event is detected it measures the exact time of the event, the direction the neutrino was moving in and the energy of the particle. Combining the data from more than one neutrino detector lets us calculate where the event that caused the neutrinos occurred. Likewise there are plenty of telescopes that would also have recorded the location and time of the light from the supernova. Both sets of observatories should record the same time for the explosion and, indeed, this was the case.
Although the neutrino and optical observatories aren't located in the same place the distance apart is so tiny compared to the distance to this supernova it would make no noticeable difference and the error could be removed with calculation anyway.
Fair enough wc, so how does the first neutrino arrive at the same time as the visible light from a distant object? Doesn't add up surely?
Frankly the suggestion of something FTL causes me no problems, the oft quoted formula, E=MC2 makes no mention of light, the C is for Constant, so if neutrinos are FTL there is no contradiction. Neutrinos become C.
I have no knowledge myself of Einstein mentioning light speed.
Roy.
Frankly the suggestion of something FTL causes me no problems, the oft quoted formula, E=MC2 makes no mention of light, the C is for Constant, so if neutrinos are FTL there is no contradiction. Neutrinos become C.
I have no knowledge myself of Einstein mentioning light speed.
Roy.
Like I said Karl, I have never heard of Einstein suggesting so.
He used E= Energy, M= Mass why use C for light speed? I reckon the crafty old sod was covering himself from just such a possibility as we may now be facing.
I use Occam's Razor and look for simplicity, as with wc, to me it's a simple matter. If two objects start from point A at the same time, and one is faster than the other, they cannot then arrive at point B simeltaneously!
Roy.
He used E= Energy, M= Mass why use C for light speed? I reckon the crafty old sod was covering himself from just such a possibility as we may now be facing.
I use Occam's Razor and look for simplicity, as with wc, to me it's a simple matter. If two objects start from point A at the same time, and one is faster than the other, they cannot then arrive at point B simeltaneously!
Roy.
wobblycogs
Established Member
The c in E=mc^2 is the speed of light (which admittedly happens to be a constant as far as we can tell). The theory of relativity, which is the combination of Einstein's general and special relativities, is completely based around the speed of light - it all gets very complex around this point but it's to do with how fast information can travel.
The neutrinos and light arrive at the same time because they are travelling at the same speed and were created by the same event. Imagine blowing up a big bag full of black and white marbles*. Chances are you would get hit by both a black an a white marble at the same time.
Physics has a really massive problem with FTL. Nearly all of modern physics in one way or another relies on the speed of light being the maximum speed possible. If nothing else this result would cause us to have to completely revise how we think of cause and effect since it would, in theory at least, mean that they would no longer have a simple relationship - this is because neutrinos could be used to send information back in time and therefore change the past.
* An explosion isn't a terribly good analogy because it would cause a normal distribution of marble speeds. I'll gloss over that for the moment and pretend that every marble is going at the same speed after the explosion. In the case of the supernova the light and the neutrinos are going at the same speed.
The neutrinos and light arrive at the same time because they are travelling at the same speed and were created by the same event. Imagine blowing up a big bag full of black and white marbles*. Chances are you would get hit by both a black an a white marble at the same time.
Physics has a really massive problem with FTL. Nearly all of modern physics in one way or another relies on the speed of light being the maximum speed possible. If nothing else this result would cause us to have to completely revise how we think of cause and effect since it would, in theory at least, mean that they would no longer have a simple relationship - this is because neutrinos could be used to send information back in time and therefore change the past.
* An explosion isn't a terribly good analogy because it would cause a normal distribution of marble speeds. I'll gloss over that for the moment and pretend that every marble is going at the same speed after the explosion. In the case of the supernova the light and the neutrinos are going at the same speed.
Roy - have a read of the excellent book "Why E=MC2 and why you should care" by Brian Cox - explains it all in great, easy(ish) to understand detail.
I'd post my copy to you for you to read, but you could probably buy a copy cheaper than the postage costs.
Cheers
Karl
I'd post my copy to you for you to read, but you could probably buy a copy cheaper than the postage costs.
Cheers
Karl
I understand all that wc, I've been there before, but my point was that IF neutrinos travel faster then their arrival cannot be simultaneous with visible light.
Somebody, somewhere is measuring inaccurately or something we don't yet understand is in action.
They cannot both be correct!
Let us assume a fresh experiment comes up with the same result, E=MC2 would still stand as a formula.
As regards C being the speed of light have you seen any ref to Einstein suggesting that?
Karl, does Brian Cox's book answer any of my points?
Roy.
Somebody, somewhere is measuring inaccurately or something we don't yet understand is in action.
They cannot both be correct!
Let us assume a fresh experiment comes up with the same result, E=MC2 would still stand as a formula.
As regards C being the speed of light have you seen any ref to Einstein suggesting that?
Karl, does Brian Cox's book answer any of my points?
Roy.
As I recall from my student days Karl Einstein had no difficulty with things moving beyond the speed of light, only how to accelerate them, the mass/energy conversion makes such impossible.
The idea of particles with a minimum speed equal to C has been postulated.
There's a 'debate' raging elswhere 'cos one poster has asked the same question as me. What did Einstein acually say?
These things take on a life of their own eventually.
Roy.
The idea of particles with a minimum speed equal to C has been postulated.
There's a 'debate' raging elswhere 'cos one poster has asked the same question as me. What did Einstein acually say?
These things take on a life of their own eventually.
Roy.
