CERN team claims measurement of neutrino speed >c

[miguel_barros]

Sorry, I re-read the intro again, and it contained numerous mentions of the 'dedicated geodesy campaign' and a brief explanation, I'll do some research on the precise methods elsewhere, sorry too quick to ask... Disregard last question.

The distance from the FOCAL POINT (T40S target) to OPERA seems FLAWLESS

http://www.google.com/url?sa=t&rct=j&q=opera%20geodesy&source=web&cd=2&ved=0CCEQFjAB&url=http%3A%2F%2Foperaweb.lngs.infn.it%2FOpera%2Fpublicnotes%2Fnote132.pdf&ei=zAXQTrb5HMeN-was_NzNDg&usg=AFQjCNG_yCiIm6YGOfACSORKKKozV-syAQ&cad=rja

Nevertheless I wouldn't put the rest of calibrations and assumptions on the same level.
(as stated before)

 

[Angry Citizen]

Then you understand more than I as in my understanding c is the speed of light in vacuum.

That's correct, but the point I was trying to make is that c is not always the actual speed of light - c is the speed of light in a vacuum. But light actually slows down when it passes through material. Since these neutrinos are apparently going faster through a material than light could travel in a vacuum, this experiment is very interesting.

The idea of the 'cosmic speed limit' discussed in popular science is actually a great metaphor. Nothing can exceed c, even though sometimes particles can travel faster than the speed of light. An example of the latter is Cherenkov radiation. c has nothing to do with the speed of light, although of course the speed of light has everything to do with c. It's an independent value. The two quantities do not have to match, and in fact when light passes through a medium, they never do.

Apologies if this is all elementary, and if I'm repeating things you've heard ages ago. I just wish to fully explore the significance of this result by illustrating its impossibility under special relativity.

 

[danR]

I don't get the feeling we're looking at the same paper. Clearly they are generalizing the notion of 'refractive index', but that is nothing new. There is an acoustic 'refractive index', for example.

In summary: a refractive index different from 1, should imply an interaction with matter as well as an absorption.

>>A classical refractive index indeed implies interaction (EM) interaction with matter. It does not require absorption, unless I misunderstand your meaning of absorption. How can light travel through glass if it's absorbed? Or sound with respect to an acoustic refractive index?​

Knowing the extremely weak interaction of neutrinos with matter, I can't see how this could lead to a refractive index, even 10^-5 close to 1.

>>I'm sure the authors are not talking classical refractive indices (EM), but something analogous.​

If the neutrinos have a FTL light, this can in no way be "explained" by a "refractive index".
The presence of rocks should therefore play no role in the FTL velocity of neutrino, and the same result should be expected for neutrino propagating through vacuum.

>>It is precisely analogous to light propagating through a vacuum vs light propagating through glass. The main egregious, and admittedly speculative, element being a negative refractive index.​

Therefore this "refractive index" is even not related to the "rocks", which is a strange syntax for a refractive index.
You could of course call v/c a "refractive index", but this would explain nothing.
I could as well say that I am driving my car at a very low refractive index.

>>This part has lost me entirely. Have you read the paper?​

late Edit: sorry, I wasn't paying attention to the paper myself. They are specifically saying group-velocity >c. Apart from that, I don't see how I can speak better for their paper, speculative though it may be. It is the CERN results they are speaking to. That said, I'm not sure how the new, shorter, pulses would strengthen their explanation.

It's certainly an extraordinary explanation. But to alter an old truism: extraordinary evidence (may) require extraordinary claims.

 

[OnlyMe]

late Edit: sorry, I wasn't paying attention to the paper myself. They are specifically saying group-velocity >c. Apart from that, I don't see how I can speak better for their paper, speculative though it may be. It is the CERN results they are speaking to. That said, I'm not sure how the new, shorter, pulses would strengthen their explanation.

By using the short pulse neutrino beam they rule out some of the previous speculations for some systematic error. They also are able to in essence time single neutrino velocities rather than a group velocity. Kind of...

In the original data there was a long start time for the neutrino beam and a long detection period. This added to uncertainty of the actual individual velocity. By cutting the proton beam to 3 ns, that both shortened the start time and the detection time. Also I believe this was a test run for the modified experiment. Given the results, it is my understanding that a proton beam will be made available again next year for a long experiment.

I also understand that MINOS is also gearing up to run the experiment.

 

[new_r]

Why everywhere data is written in seconds and distance.
Just let's calculate it in terms of c+v
and you will get v = about 8km/s

That is exactly the amount of velocity necessary to spin circularly around the Earth.
I think some type of mater (something like dark energy or dark mater or something unknown)
spinning around big masses in all possible directions and drags neutrinos with it.

 

[miguel_barros]

Another 8 km/s of Earth spin?

That would be the worst possible explanation

Not only could neutrinos go faster than light but their speed wouldn't be invariant.

 

[Galteeth]

Layman question: Does the gravitational curve of the Earth have effect on the neutrinos path?

 

[new_r]

Layman question: Does the gravitational curve of the Earth have effect on the neutrinos path?

If I am right this would be equivalent to Shapiro delay which is far too small for this case.

 

[nitsuj]

Another layman question: How do they know how long the neutrino's journey was in time and distance? And which of those two would be more difficult to measure?

 

[Vanadium 50]

Before posting in this thread, we'd like to ask readers to read three things:

• The PF Rules. Don't forget the section on overly speculative posts.
• The paper http://arxiv.org/abs/1109.4897
• he previous posts in this thread

We think this will make the discussion go smoother.

V50, for the Mentors.

 

[Centri-Fagin]

So they don't really know how fast they are going before they leave CERN?

 

[new_r]

Not only could neutrinos go faster than light but their speed wouldn't be invariant.

Yes, you are right, not invariant.
Do you know to which directions neutrinos will be send by other laboratories?
If some of new experiment's will be along the Earth rotation will be nice to compare the results.

 

[miguel_barros]

But at the direction of CERN to OPERA you wouldn't get the full rotacional effect of 8km/s it's SW not W. And they don't follow the earth, they go right through, neutrinos don't interact much.

Sorry but can't see your effect happening.

 

[lalbatros]

Why everywhere data is written in seconds and distance.
Just let's calculate it in terms of c+v
and you will get v = about 8km/s

That is exactly the amount of velocity necessary to spin circularly around the Earth.
I think some type of mater (something like dark energy or dark mater or something unknown)
spinning around big masses in all possible directions and drags neutrinos with it.

The equatorial radius of Earth is: 6,378.1370 km . (1)
The Earth sidereal day is 23.9344696 h . (2,3)
The Earth average distance from the sun is 150 million kilometers. (4)

From this we can get:

The sidereal Earth rotational speed: 1674 km/h = 0.465 km/s
The Earth speed around the sun: 107589 km/h = 29.9 km /s

What's this story with these 8 km/s?
Is that one more Pentcho Valev story?
I don't get it.

Michel

1/ http://en.wikipedia.org/wiki/Earth_radius
2/ http://en.wikipedia.org/wiki/Sidereal_time
3/ http://www.google.com/search?q=sidereal+day
4/ http://en.wikipedia.org/wiki/Earth's_orbit

 

[miguel_barros]

Before putting to sleep one of my first doubts.

could someone:

1. confirm the coordinates of the proton release point (should be close to this point but any correction would be most welcome). This relates to the additional 730m tunnel

http://maps.google.com/maps?q=4http:%2F%2Fmaps.google.com%2Fmaps%3Fq%3D46.235,6.0425&ll=46.246039,6.070343&spn=0.003688,0.006899&t=h&z=17&vpsrc=6

2. Indicate the coordinates of the T40-S Focal point and muon deterctors

3.AND/OR the Coordinates of the OPERA detector (it should be on the western/northern side of the A24 at the campo imperatore level, close to this point)

http://maps.google.com/maps?q=4http:%2F%2Fmaps.google.com%2Fmaps%3Fq%3D46.235,6.0425&ll=42.445208,13.564435&spn=0.003935,0.006899&t=h&z=17&vpsrc=6

Any information (with or without source) would be apreciated

 

[new_r]

Thank you Michel for your post.
But I am not about the rotation of the Earth,
I am about possible rotation of some type of (dark) mater around the Earth.
Due gravitation particles of such matter would have velocity about 8km/s to hold circular motion.
We call it first space velocity in my language, but I am not sure how it names properly in English.

(For example second space velocity in my language is equal to escape velocity in English)

 

[BobCastleman]

Thank you Michel for your post.
But I am not about the rotation of the Earth,
I am about possible rotation of some type of (dark) mater around the Earth.
Due gravitation particles of such matter would have velocity about 8km/s to hold circular motion.
We call it first space velocity in my language, but I am not sure how it names properly in English.

(For example second space velocity in my language is equal to escape velocity in English)

Suppose we were in such a cloud of dark matter, wouldn't both ends of the experiment be equally affected as well as every point in between? Even if this dark matter accelerated the neutrinos, how did it accelerate them above c?

 

[new_r]

Suppose we were in such a cloud of dark matter, wouldn't both ends of the experiment be equally affected as well as every point in between? Even if this dark matter accelerated the neutrinos, how did it accelerate them above c?

I am not who can know everything. :)
Just a guess.
But apart of this:
If you would calculate overage velocity of c+v and c-v , where v is the first space velocity,
then you will get c-v^2 /c which is equivalent to Shapiro delay in this direction.

Similarly Shapiro delay can be calculated vertically if you will take v equal to escape velocity (sharp orbit of dark mater).

So maybe particles of such dark mater interact only when they moves to the same direction with neutrinos.
But with photon they interacts in both directions, therefore photon gets Shapiro delay.

 

[BobCastleman]

So maybe particles of such dark mater interact only when they moves to the same direction with neutrinos.
But with photon they interacts in both directions, therefore photon gets Shapiro delay.

I'm really new to this entire subject, but even to me, this seems overly speculative. Is there any force that acts in one direction like that? And further, acts in two directions on photons? Invoking special forces and unknown interactions doesn't clear things up. It just clouds the issue.

 

[Angry Citizen]

Is there any force that acts in one direction like that?

Friction. Perhaps dark matter has an opposite coulomb interaction to that of normal matter. But I agree it is far too speculative. Neutrino velocity exceeding c must first be confirmed before any serious attempts at theoretical explanation occur.

All I can say is, if c really has been broken, then I'm glad I'm not a physicist. For me, it'd be like watching everything we know about airplanes go 'poof', and us having to start back at square one...

 

[Drakkith]

All I can say is, if c really has been broken, then I'm glad I'm not a physicist. For me, it'd be like watching everything we know about airplanes go 'poof', and us having to start back at square one...

Why would we go back to square one? We didn't need to do that for Classical physics when Special/General Relativity and Quantum Mechanics were developed. It was simply realized that it classical physics only worked in certain areas to a certain accuracy. I see no difference here. And contrary to your view, if c is really not the speed limit for neutrinos I wish I WAS a physicist working in that field.

 

[Passionflower]

And contrary to your view, if c is really not the speed limit for neutrinos I wish I WAS a physicist working in that field.

I second that, we surely could use some spice in the world of science, just like we had in the beginning of the 20th century!

 

[lalbatros]

...
you will get v = about 8km/s .
That is exactly the amount of velocity necessary to spin circularly around the Earth.
...

...
I am about possible rotation of some type of (dark) mater around the Earth.
Due gravitation particles of such matter would have velocity about 8km/s to hold circular motion.
...
QUOTE]

OK, I understand now what you meant.
Note, however, that at Earth's surface, the escape velocity is 11.2 km/s (1) .
Therefore, the match is not as "exact" as it would seem.

In addition, if such a cloud of dark matter would exist around the earth, I would not picture it as a flowing around an axis (and even less around the earth' rotation axis).
I would consider it more likely as a gas of dark particles with velocities of 11.2 km/s in random directions. (a bit like a swarm of satellites) In the average, there would be no advance or delay, but only maybe a spreading of the speed of the neutrinos around the speed of light.

If the "swarm of dark particles" picture was not correct, then anyway, it would be unlikely that the trajectories of those dark particles would be just parallel to the Cern-Gran Sasso direction. But it would be useful to repeat this experiment for another direction and location.

The dark matter idea, a revival of the aether theory, is indeed quite speculative.
At this moment, it is much more useful to scrutinize the experimental results.

Michel


(1) http://en.wikipedia.org/wiki/Escape_velocity

 

[lalbatros]

...
All I can say is, if c really has been broken, then I'm glad I'm not a physicist. For me, it'd be like watching everything we know about airplanes go 'poof', and us having to start back at square one...

Quite the opposite.
If this was confirmed, you would see many more young people embracing physics.
And the older people would only enjoy this existing period.
Physicists enjoy new challenges.

 

[new_r]

Note, however, that at Earth's surface, the escape velocity is 11.2 km/s (1) .

Dear Michel,
I am sorry, but for circular motion you will need only 8km/s which is (GM/R)^(1/2)
(It is strange that English have not even a special name for it.)

For maximum sharp orbit you will need almost escape velocity which is (2GM/R)^(1/2) = 11km/s
as you mentioned.

This idea can be easy tested by an other laboratory if they will send neutrinos to an other direction.

Of course this question about neutrinos may be due some other reason.
But we really need this experiment : http://74.86.200.109/showthread.php?t=548917
Because there is no any data, that atoms with electrons can travel very close to c: http://74.86.200.109/showthread.php?p=3593967

Also you may think that c constant is supported by very very big set of experiments.
But these experiments are not classified.
Maybe first attempt to do so was done by Daniel Gezari from Goddard Space Flight Center,
http://arxiv.org/abs/0912.3818
As you see not so much.

 

[lalbatros]

...
I am sorry, but for circular motion you will need only 8km/s which is (GM/R)^(1/2)
(It is strange that English have not even a special name for it.)
...

Deeply sorry for my blunder!
Of course the circular motion speed is v = sqrt(g R) = sqrt(9.81*6350000) = 7900 m/s .
You are right.

However, I see no reason for the dark matter to have its speed aligned on the Cern - Gran Sasso direction!
What would be a plausible distribution of dark matter orbiting around the earth?
Would this dark matter behave like a fluid? Likely not as a solid!
Is it supposed to be compressible or not?
Could this fluid penetrate through the earth?
And after all, why would it be orbiting around the Earth in a circular motion?
And why not on very eccentric ellipsis?
And why would there be a specific axis of rotation, why not a random distribution of speeds for the dark matter particles?

I must say that I don't see, in these 8 km/s, more than a simple numerical coïncidence.

 

[lalbatros]

...
Also you may think that c constant is supported by very very big set of experiments.
But these experiments are not classified.
...

Indeed, direct experimental support is rather difficult.
However, there is a rather dense net of evidences.
Maybe you know already about this list:

http://www.desy.de/user/projects/Physics/Relativity/SR/experiments.html

There is another one there:

http://www2.corepower.com:8080/~relfaq/experiments.html

Michel

 

[new_r]

However, I see no reason for the dark matter to have its speed aligned on the Cern - Gran Sasso direction!
What would be a plausible distribution of dark matter orbiting around the earth?
Would this dark matter behave like a fluid? Likely not as a solid!
Is it supposed to be compressible or not?
Could this fluid penetrate through the earth?
And after all, why would it be orbiting around the Earth in a circular motion?
And why not on very eccentric ellipsis?
And why would there be a specific axis of rotation, why not a random distribution of speeds for the dark matter particles?

Yes here is difficult to be sure in something.
I guess that such particles of dark mater may spin in different directions.
Lets say something like a cloud of slow neutrinos.
But it would be much different from a gas because almost no interaction with each other.
Only gravitation prevents them from running away.

But still Earth rotation must effect the result depending on measured direction
8 +/- equatorial rotation velocity (1.6km/s)
I hope somebody will choose different direction for their experiment.

Also if you read Gezari paper:

“It is widely believed that all the early ether drift experiments (e.g., Michelson and Morley
1887, Illingworth 1927, Kennedy and Thorndyke 1932 and Joos 1933) all produced null
results, although Miller (1933) insisted that he consistently obtained ∼8 km/s drift
velocities over a period of 30 years, claims that were later discredited by Shankland, his
former student (Shankland et al. 1955). Michelson and Morley (1887) also reported a net
∼8 km/s drift velocity, which was widely interpreted as an upper limit and dismissed
because it was much smaller than the expected ∼30 km/s orbital velocity of the Earth.”

Again this magical 8km/s. All experiments later was done in vacuum.
But neutrino experiment and Miller's experiments was done not in vacuum.
Maybe it can lead to some another explanation. I do not have any opinion about it today.

 

[new_r]

Indeed, direct experimental support is rather difficult.
However, there is a rather dense net of evidences.
Maybe you know already about this list:

http://www.desy.de/user/projects/Physics/Relativity/SR/experiments.html

There is another one there:

http://www2.corepower.com:8080/~relfaq/experiments.html

Michel

Yes I know, but all of them can be classified in Gezari way, and can be explained without relativity.
(Only these which was confirmed experimentally)
Therefore I was looking for some experiment who may separate c constant theories from everything else.
The only one I was able to find is I already mentioned with 2 atomic clocks. With it can be even separated LET from SRT.
Even Henri Poincaré was thinking they are inseparable experimentally. But this is not true. These theories are perfectly separable.
I prefer other (entrained) ether version. But I can change it anytime if it will contradict to experiments :)

 

[Passionflower]

Yes I know, but all of them can be classified in Gezari way, and can be explained without relativity.

Interesting, I will certainly take a look at this paper.