[CZARCAR]

mAYBE ITS A NEWTRINO?

[lightarrow]

On a more serious note: When was the last time that they measured that distance to San Grasso, Italy?

Gran Sasso.
"Gran" --> "Grande" = Big
"Sasso" = Rock.

[JP (OP)]

Geezer, it's rather pointless to argue over whether they made a mistake in measuring distance or not, since we don't have their data.  (And I highly doubt if we're experts enough to offer any useful comments if we did have their distance measurement data).  They claim that by using GPS units placed in tunnels and optical triangulation, they have an accuracy of 20 cm.  They also say that's the largest source of error in the measurement, so no doubt it's been checked and rechecked many times.  (I'd put even money on the error being somewhere else that they didn't check as thoroughly.)

You can check out that section of their talk, where they (roughly) explain their techniques.  Click the link in the first post to check out the talk, and it's on slides 32-33.  Actually, even if you don't want to listen to the talk, it's worth checking out just for the cool web interface they have.  You can click on each slide and it brings up a picture of the slide along with a video of the presenter during the portion of the talk for which that slide was shown.

But there's always a slim chance they discovered something new, and since they did a very thorough job of checking their work, it will no doubt be taken seriously and rechecked by others who are a bit more expert than us. 

[CPT ArkAngel]

Official article:

http://static.arxiv.org/pdf/1109.4897.pdf

[Geezer]

Geezer, it's rather pointless to argue over whether they made a mistake in measuring distance or not, since we don't have their data.  (And I highly doubt if we're experts enough to offer any useful comments if we did have their distance measurement data).  They claim that by using GPS units placed in tunnels and optical triangulation, they have an accuracy of 20 cm.  They also say that's the largest source of error in the measurement, so no doubt it's been checked and rechecked many times.  (I'd put even money on the error being somewhere else that they didn't check as thoroughly.)

You can check out that section of their talk, where they (roughly) explain their techniques.  Click the link in the first post to check out the talk, and it's on slides 32-33.  Actually, even if you don't want to listen to the talk, it's worth checking out just for the cool web interface they have.  You can click on each slide and it brings up a picture of the slide along with a video of the presenter during the portion of the talk for which that slide was shown.

But there's always a slim chance they discovered something new, and since they did a very thorough job of checking their work, it will no doubt be taken seriously and rechecked by others who are a bit more expert than us. 

JP -  It's not so much a question of distance. It's a question of radius (or angles if you prefer).

The arc length is very short. A very small change in radius will produce a significant change in chord length. If the Earth's surface between the two points turns out to be slightly more curved than the value they used, the real chord length will be shortened significantly. I suppose I'll have to listen to the thing to find out how they determined the radius. If it's based on GPS data, I think they are up a tree.

As you tell us often, extraordinary claims require extrordinary evidence. Mr Ocam tells us that the simplest explanation probably applies. It's very difficult to measure the chord length accurately (unless, of course, you use neutrinos), therefore............

[JP (OP)]

Official article:

http://static.arxiv.org/pdf/1109.4897.pdf

Thanks!

[Geezer]

I went over the paper. There is hardly anything about how they determined the accuracy of the distance measurement. It's nearly all about timing accuracy.

I did find this statement on page 9:

"and by transposing their positions with a terrestrial traverse down to the OPERA detector."

I think that means people with theodelites.

[JP (OP)]

Yeah, they said something similar in the talk.  I have no idea how much error a "terrestrial traverse" causes.

[Geezer]

Yeah, they said something similar in the talk.  I have no idea how much error a "terrestrial traverse" causes.

Hopefully not much! It would be a bit embarrassing if the whole business was mucked up by a bit of sloppy surveying. Considering how critical the path length measurement is, I was a bit surprised that they don't go into it in a lot more detail. That's likely to be the thing skeptics (like me) pounce on first.

We'll have to wait and see if similar results can be produced elsewhere.

[Soul Surfer]

They must have a reasonable confidence that their measurement accuracies are sufficient to allow this time difference to be quoted and with modern kit it should be well within a foot over this distance.  Let us have a think about other reasons why there might be a small difference. 

Firstly from supernova 1987a  where a neutrino pulse was measured we have good evidence that neutrinos travel through EMPTY SPACE at very close to the velocity of light.  The  velocity error observed in the experiment is 4 parts in 10,000.  This supernova was around 160,000 light years away so if the velocity error was that great through empty space  the neutrino pulse would have come  ABOUT FOUR YEARS before the light pulse appeared!  Instead it was in effect just a few days before.  Just about the time that it would take for the explosion to blow up the star big enough to be recognised as a supernova.

Could it then be that neutrinos travel faster through dense matter than empty space.  that is the refractive index for neutrinos is negative.   How could this possibly be.

Now solid matter consists mostly of empty space together with nucleons which the neutrinos also have to pass through  now the nucleons represent only a tiny part of the matter.  funnily enough this is around one part in 10.000 of the size of the atoms so if in effect the neutrinos travel through this material "faster" (I use the inverted commas with intent) this might just be possible.

Could this in effect be done without contravening the normal rules about the velocity of light?

Well maybe because particles are always waves as well and if travelling through a nucleon causes a phase change in the wave it might well be possible that the apparent "position" of the neutrino is changed and moved ahead of where it might be expected to be if the nucleon was not there and this could integrate into a significant time on a long journey through solid material.

This means that the basic laws of physics are not affected but it might have some interesting effects when it comes to modelling pulses of energy flow in condensed objects like neutron stars.

[lightarrow]

Someone says the statistical interpretation of the experiment is wrong:
http://johncostella.webs.com/neutrino-blunder.pdf

[Geezer]

Someone says the statistical interpretation of the experiment is wrong:
http://johncostella.webs.com/neutrino-blunder.pdf

Thanks Lightarrow! Very interesting.

Reducing 16,000 events with a tolerance of 10.5 microseconds to a probable tolerance of 6.9 nanoseconds obviously requires very careful analysis.

[JP (OP)]

Someone says the statistical interpretation of the experiment is wrong:
http://johncostella.webs.com/neutrino-blunder.pdf

Thanks Lightarrow! Very interesting.

Reducing 16,000 events with a tolerance of 10.5 microseconds to a probable tolerance of 6.9 nanoseconds obviously requires very careful analysis.

And the paper says virtually nothing about how they calculate statistical error...

[Jan Bruggers]

It is given that the speed of light is a barrier which is infinitely high. Up to now all experiments has proven this. But if that barrier is not infinitely high than accordance the very basis of quantum mechanics particles have a transmission change (T). For a square potential barrier a good approximation T=exp(-2Ba) where  B =((Vo-E)2m/h^2)^0.5, Vo is barrier hight, h must be h-bar. Still the barrier is extreem high but not infinitely. Is this possible ?

[Soul Surfer]

I think that the refutation of statistical accuracy paper found by light arrow is very plausible and they are pushing their theoretical accuracy far too far

[JP (OP)]

I think that the refutation of statistical accuracy paper found by light arrow is very plausible and they are pushing their theoretical accuracy far too far

It was plausible, but it had an error.  John Costella has a new paper up (same link) that explains his error and why they were right about their uncertainty...

[Geezer]

I think that the refutation of statistical accuracy paper found by light arrow is very plausible and they are pushing their theoretical accuracy far too far

It was plausible, but it had an error.  John Costella has a new paper up (same link) that explains his error and why they were right about their uncertainty...

The plot thickens  []

[neutrino]

Maybe this also blows away the theory that an object traveling at the speed of light increases in mass?
"as an object approaches the speed of light, the mass increases without limit"

and even though the mass of a  Nuetrino is extremely small - it would still increase.. to what degree???
wonder if they can detect any change in mass ( another experiment perhaps!)

But this question of light speed..... is it truly a Limit!? or just that we'v found nothing that exceeds it! ( until now that is! ) 
Speed and time dilation - perception of time changing - or factual time change when getting to speed of light or greater.. could this be the explanation?
 you go faster than the speed of light, and a "time" shift takes place!? 
but then again - does time exist? isn't it simply a measurement we devised to keep track of one day to the next, one moment to the next, a means to reference something that took place in the past, and something that will take place in the future.
"Time"  is of no consequence to the physics of the universe,  it's little more than as said, a means by which WE measure one  moment to the next?   []

[Soul Surfer]

I have to agree with what is said in the new analysis but I am still a bit unhappy about pushing the accuracy so far and the fact that only the results right at the edges of the 10 microsecond pulse are critical.

I would feel happier if it were possible to extract some details of the fine structure of the main body of the beam (mentioned in the main paper)  from the results and by using crosscorrelation show that the timing of this also demonstrated the same time of flight measurements.  This would then show that there was not some other unknown process causing any blurring of the results.

[MikeS]

Maybe this also blows away the theory that an object traveling at the speed of light increases in mass?
"as an object approaches the speed of light, the mass increases without limit"

and even though the mass of a  Nuetrino is extremely small - it would still increase.. to what degree???
wonder if they can detect any change in mass ( another experiment perhaps!)

But this question of light speed..... is it truly a Limit!? or just that we'v found nothing that exceeds it! ( until now that is! ) 
Speed and time dilation - perception of time changing - or factual time change when getting to speed of light or greater.. could this be the explanation?
 you go faster than the speed of light, and a "time" shift takes place!? 
but then again - does time exist? isn't it simply a measurement we devised to keep track of one day to the next, one moment to the next, a means to reference something that took place in the past, and something that will take place in the future.
"Time"  is of no consequence to the physics of the universe,  it's little more than as said, a means by which WE measure one  moment to the next?   []

If this were true why is it that atomic clocks can measure time dilation due to the strength of gravity varying.  The latest with an accuracy of 18 decimal places can measure as little a one millimetre in difference in height.  If time wasn't 'real' all clocks would measure the same going rate everywhere.