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ncjunk

Neutrinos moving faster than light?

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I would have thought that for him he would arrive at the Sun instantly and that we would see him arrive 8 minutes later?

If he's going at twice the speed of light, it will take him 4 minutes to get there. He can't get there instantly unless he's going infinitely fast.

Its like - say the speed limit on the motorway is 70mph, and I go faster than that, I don't get there instantly.

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as a Physicist i'd LOVE to live in times when everything changes (cf. the early 20th century with relativity and quantum physics) and i'm always rather baffled when people make claims that the "professionals" want to maintain the scientific orthodoxy, in general it's the reverse, but the standard for proof is pretty high in this respect.

Well said.

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If he's going at twice the speed of light, it will take him 4 minutes to get there. He can't get there instantly unless he's going infinitely fast.

Its like - say the speed limit on the motorway is 70mph, and I go faster than that, I don't get there instantly.

But for him time wouldn't exist, therefore for him he would get there instantly, yet for us it would take the light from his spaceship 8 minutes to reach us.

Sent from my X10i using Tapatalk

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Brian Cox's point about the possibility of the neutrinos taking shortcuts through extra dimensions is tantalizing. Given the way such dimensions are often talked about, some kind of experimental evidence for their existence would be exciting...

Olly

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So why didn't the neutrinos from SN1987a get he long before the visual evidence?

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But for him time wouldn't exist, therefore for him he would get there instantly, yet for us it would take the light from his spaceship 8 minutes to reach us.

Why wouldn't time exist? Maybe if he was a photon that might be true, but in his space ship, time will tick away.

If you bring relativity into it, then I think weird things will happen, but then the equations go funny above the speed of light. You get imaginary time

DeltaT' = DeltaT / sqrt(1 - v^2/c^2)

so going at twice the speed of light this means the time dilation is

DeltaT' = DeltaT/sqrt(1 - 4/1) = DeltaT/sqrt(-3)

and I don't know what that means!

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I don't understand why people talk of a speed-of-light "limit".

How quickly do you want to get to the other side of universe? Relativity says you can do it in as little time as you like, just keep going faster. In what sense is there such a "limit"?

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I don't understand why people talk of a speed-of-light "limit".

How quickly do you want to get to the other side of universe? Relativity says you can do it in as little time as you like, just keep going faster. In what sense is there such a "limit"?

Suppose you take a trip to a distant, accessible galaxy. You can make this trip in an arbitrarily small, but non-zero, interval of your proper time. However, a light signal sent when you leave and pointed in the right direct will beat you there.

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I don't understand why people talk of a speed-of-light "limit".

How quickly do you want to get to the other side of universe? Relativity says you can do it in as little time as you like, just keep going faster. In what sense is there such a "limit"?

It's not really about light! It's about mass-less stuff. Nothing can have less than zero mass.

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For anyone with a spare 1 hour 53 minutes it's well worth a look. It's the press conference cern held this afternoon, very detailed, informative and confusing. A lot of work has gone in to this announcement and they have covered a lot of bases, if it's an error well they can't come up with a reason why it would be.

http://cdsweb.cern.ch/record/1384486

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Wow some of this is embarrassing people clinging onto this nothing travels faster than light for dear life....:glasses2:

So much stuff travels faster than life....:rolleyes:

Were just on the tip of finding but a fraction of it....

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Has there been anything further on this or will we be waiting some months as the "Number Crunchers" investigate the data?

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Has there been anything further on this or will we be waiting some months as the "Number Crunchers" investigate the data?

The results haven't even been officially published - they just put the data out there for other people to pick holes in.

Months and months and months I suspect :p

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Brian Cox's point about the possibility of the neutrinos taking shortcuts through extra dimensions is tantalizing. Given the way such dimensions are often talked about, some kind of experimental evidence for their existence would be exciting...

Olly

Is a neutrino affected by gravity?

If it isn't then the difference could be explained by taking the shortest path between two points.. a straight line.. rather than having to deal with curved space/time.

Or a doppler error in the calculations.. Did they take into account the speed of the rotation of the earth, therefore, changing the distance between the two points over time?

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Wonder if they've measured the distance between CERN an the detector along the curvature of the surface of the Earth rather than the direct route? Will have to do some calcs to see if this would account for the difference....

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Wonder if they've measured the distance between CERN an the detector along the curvature of the surface of the Earth rather than the direct route? Will have to do some calcs to see if this would account for the difference....

OPERA’s neutrinos were born from protons smashed into a chunk of graphite at CERN. They then traveled underground to Italy’s National Gran Sasso Laboratory beneath the Apennines Mountains. A detector spotted the arrival of a small fraction of the particles — about 16,000 in total between 2009 and 2011.

Thanks to GPS devices, the distance of this trip, about 730 kilometers, is known to within 20 centimeters — a feat of accuracy that required closing a lane of traffic for a week in a tunnel above the detector in Italy.

“We could have done an even better job if we stopped all the traffic,” says Dario Autiero, an OPERA team member and a physicist at the Institute of Nuclear Physics of Lyon in France.

Light traveling in a vacuum would have made this trip in 2.43 milliseconds. The neutrinos shaved about 60 nanoseconds off that time, according to atomic clocks at either end synchronized by a satellite. Divide distance by time, and the particles must have been traveling 0.0025 percent faster than the speed of light in a vacuum.

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Is a neutrino affected by gravity?

Yes - but not much - like light.

Or a doppler error in the calculations.. Did they take into account the speed of the rotation of the earth, therefore, changing the distance between the two points over time?

Yes - they even looked at the effect of the moon on the crust distorting it slightly as it passes.

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Did they synchronise the atomic clocks at the same lab at Cern and then move one to Italy? Would the fact it had travelled at speed and distance be enough to put it slightly "out-of-sync" again with the other?

I take it some sort of synchronising of time was involved over the two sites.

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They had a whole team working on accurate time synchronising. I forget the details, but thats something they worked hard at.

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The neutrinos shaved about 60 nanoseconds off that time, according to atomic clocks at either end synchronized by a satellite.

Ok.. I missed that bit. :p

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I was watching a few Walter Lewin lectures on you tube and i suppose this comes under a basic part of physics that i saw him go through. Any calculation is meaningless unless you can define the accuracies of the measurements made. Therefore this result would be defined as 60ns plus or minus "x" where x represents the combined maximum possible error due to measurement of length, time and any external influences.

I assume they state all assumptions in their press release so what they are looking for is any affect that they have not taken into account or any error they could have manually introduced but missed in their tests (or they have measured everything correctly and there is something new here that needs adding to Einsteins theory)

Anyone know what they think this 60ns value is acurate to?

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