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PostPosted: Fri, 07-10-11, 13:03 GMT 
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I wonder what could happens to neutrinos which falls into a black hole, then. Albeit their capture should be at subluminal speed, they would quickly ACCELERATES also, besides "moving" onto something much more "dense" than the Earth' crust. Could make sense such a thought?

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PostPosted: Fri, 07-10-11, 15:38 GMT 
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cartrite wrote:
t00fri wrote:
Here is another intriguing theoretical paper from 2 days ago:

http://arxiv.org/pdf/arXiv:1110.0234

Superluminal neutrinos without violation of special relativity! Since the neutrino beam travels large distances between CERN and Gran Sasso within the Earth's crust, one can consider an imaginary 'optical' potential describing the corresponding beam attenuation. It is shown that in this case superluminal speed is possible, leaving the 'holy cow' alive ;-)


Fridger


I'm not sure I understood everything written in that paper but it sounds like neutrinos travel faster through matter than a vacuum. Maybe a good test of this would be to send a "neutrino beam" through the "Sonne" to a spacecraft orbiting another planet / moon like the Moon, Venus, Mars, Jupiter, or Saturn during the time the planet / moon was on the opposite side of the "Sonne" from Earth. Of course this would probably cost more than it's worth.......... :wink: But maybe it could increase communication speeds and who knows what else. :D

cartrite


Yes, the superluminal velocity is associated here with the beam attenuation in a medium. Traveling in a medium is one of the few options we have for superluminal velocities without violating basic concepts like causality and Special Relativity!

Already in optics we know that effect of superluminal speed in a medium e.g. for the familiar Cherenkov light (http://en.wikipedia.org/wiki/Cherenkov_radiation), It is electromagnetic radiation emitted when a charged particle (such as an electron) passes through a dielectric medium at a speed greater than the phase velocity of light in that medium.

Yesterday appeared already a responding paper, suggesting how J. Franklin's explanation above could easily be further tested:

"Comment on Jerrold Franklin, Superluminal neutrinos, arXiv:1110.0234v1"
http://xxx.lanl.gov/pdf/1110.0970

Generally phase or group velocities can exceed the speed of light in vacuum, since no information is transferred this way at superluminal velocity.

Also this group velocity option for neutrinos was exploited in a paper today (that I didn't read yet, however):

"Superluminal group velocity of neutrinos"
http://xxx.lanl.gov/pdf/1110.1253


Last edited by t00fri on Fri, 07-10-11, 15:47 GMT, edited 2 times in total.

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PostPosted: Fri, 07-10-11, 15:40 GMT 
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fenerit wrote:
I wonder what could happens to neutrinos which falls into a black hole, then. Albeit their capture should be at subluminal speed, they would quickly ACCELERATES also, besides "moving" onto something much more "dense" than the Earth' crust. Could make sense such a thought?


I'll respond to that one, once we have understood what was going on at Gran Sasso ;-)

Fridger


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PostPosted: Fri, 07-10-11, 19:36 GMT 
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:)


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PostPosted: Fri, 18-11-11, 17:18 GMT 
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Today, the final write-up by the OPERA Collaboration appeared. The claim has not changed. The preprint is located here:

http://xxx.lanl.gov/pdf/1109.4897

While a number of further tests done in the recent past have strengthened the correctness of the claim (superluminal speed of neutrinos), the enormous significance of such a result urgently requires further clarifying work before the community will accept it...

NB: while the original announcement of the result on Fri, Sep 23 was only signed by part of the OPERA collaboration, now virtually all collaboration members appear as co-authors.


Fridger


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PostPosted: Sun, 15-01-12, 16:43 GMT 
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For people who want to keep in touch, here is a nice summary page from MIT with links to relevant references both OBSERVATIONAL / EXPERIMENTAL and THEORETICAL!

http://web.mit.edu/redingtn/www/netadv/XftlNu.html
(THE NET ADVANCE OF PHYSICS )

Notably, the THEORETICAL: section is most useful, since there the various attempts of explanation have been grouped already according to the underlying principles that are exploited!

Fridger


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PostPosted: Mon, 16-01-12, 7:00 GMT 
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Fridger,

Shatters is down again. Therefore I would like to continue the conversation here at CelestialMatters (hoping for your approval).

However, I only vaguely remember your comments there (But as far as I remember, I can agree with the things written there).

First, to avoid misunderstandings: Since my childhood I am interested in physics and astronomy (and Quantum mechanics, too).
For me, physics is like a fairytale, EVERYTHING has a secure, orderly place. Is (at least for some time) verifiable at any time anywhere. A self-contained, air-tight, explainable world. just follow the (experimentally verifiable) laws of causes and effects.

Though, - and at this point I would like to add - our real world isn't just the subject of causes and effects.

eg: where is "cause and effect" with which skin color, ethnic origin or nationality someone is born. Where is "causes and effects", whether one was born rich or poor, intelligent or stupid? Oh, I know what you'll probably answer: "causes and effects are their parents..." But is this always true? Because "why" do I have this parents and you and you others - just a coincidence? OK, out of context...

So, here's the question you're waiting for: Where do you seek the causes and effects regarding the Big Bang? (He,he... just a polemical phrase; nothing more than joking irony) :wink:


Back to "Nothing is faster than light"; In principle I agree, too. What I mean is, however, that there (as mentioned before) must be at least a mathematical option, which allows it to perform calculations, with which we can operate with a higher speed than the the speed of light. Here is an example (see map):

------ ooops - I can not place a picture here; now, I'm not prepared... will add the image maybe later (or at shatters - if it runs again) :(

But here's the short description...
Imagine: not far from our planet (in my example 24 light years away) ignites a new star. The light needs 24 years until we can see it on earth. Well situated - across from the earth - an exoplanet, also 24 light years away from the new star. Also on this exoplanet light takes 24 years.

Accordingly, the speed BETWEEN the first light waves (photons) which reaches Earth and exoplanet exactly after 24 years must have twice the normal speed of light. (This is the mathematical option I was talking about...)

I hope my letter does not sound too rude. If so, it is due to my lack of knowledge of the English language. I appreciate your work for Celestia, and may say "Thank you" for your answers and informations.

Michael


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PostPosted: Mon, 16-01-12, 22:02 GMT 
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Michael,

MiR wrote:
Fridger,

Shatters is down again. Therefore I would like to continue the conversation here at CelestialMatters (hoping for your approval).

Of course, you are very welcome! Since I attended the original announcement seminar (OPERA) at CERN on Sep 23, 2011 and started this thread the same day, you are at the right address here ;-)
Quote:
However, I only vaguely remember your comments there (But as far as I remember, I can agree with the things written there).

Perhaps it's better to wait until you can refresh what I wrote at shatters.net. It seems to me that you are mixing up the rigorous issue of causality (causes MUST be earlier than the corresponding effects) with contemplating the fact that sometimes we don't know the causes of certain effects. The latter is true but entirely irrelevant for the discussion of possibly superluminal neutrinos.
Quote:
First, to avoid misunderstandings: Since my childhood I am interested in physics and astronomy (and Quantum mechanics, too).
For me, physics is like a fairytale, EVERYTHING has a secure, orderly place. Is (at least for some time) verifiable at any time anywhere. A self-contained, air-tight, explainable world. just follow the (experimentally verifiable) laws of causes and effects.

Unfortunately besides an interest in physics, this subject requires quite a lot of solid knowledge, too... Otherwise it is virtually impossible to appreciate this beautiful, very rigid construct of scientific cognition that rests on a number of very general "pilars". What is crucial to realize is that one cannot just modify this "pyramid of knowledge" a bit here and there. There are so many logical cross-connections and a huge number of independent experimental observations that the danger of destroying the internal consistency through modifications is extremely high.

At shatters.net, my saying was illustrated by the fact that giving up special relativity (by allowing superluminal velocities) will immediately confront you with an imminent danger of violating causality which really nobody wants!
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But here's the short description...
Imagine: not far from our planet (in my example 24 light years away) ignites a new star. The light needs 24 years until we can see it on earth. Well situated - across from the earth - an exoplanet, also 24 light years away from the new star. Also on this exoplanet light takes 24 years.

Accordingly, the speed BETWEEN the first light waves (photons) which reaches Earth and exoplanet exactly after 24 years must have twice the normal speed of light. (This is the mathematical option I was talking about...)

Unfortunately, your conclusion is plain wrong. I suggest you devote some more time to really understand the implications of special relativity. There is plenty of good respective literature on the Net..
Just take my word that it is consistent with ALL observations that independent of direction, the moduli of speed vectors are always <= c, the speed of light.

Fridger


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PostPosted: Tue, 17-01-12, 11:34 GMT 
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Fridger,

t00fri wrote:

Unfortunately besides an interest in physics, this subject requires quite a lot of solid knowledge, too...


But therefore we have YOU here :wink: ...to answer our stupid questions (some say; there are no stupid questions, only stupid answers)

Quote:
Unfortunately, your conclusion is plain wrong...

I'm still not sure if you understand what I mean ... Plus I have another anomaly - in terms of speed of light. But not for now (...in a hurry again :roll: )

Quote:
...one cannot just modify this "pyramid of knowledge" a bit here and there.


Very true. But I don't want revolutionize physics, rather I hope for an expert answer for those found inconsistencies (without a complete study of physics...).

But for now Thank you for your friendly reply!

Michael


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PostPosted: Wed, 18-01-12, 10:00 GMT 
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Hallo Fridger,

For publishing the picture and due further questions I am continuing with the theme at shatters.net.
And because there's a better topic for this than "Neutrinos travelling faster than light??" (does not fit so well, I think).

I would be delighted if you could take a look at it. Your opinion - especially in these special questions - is important to me and always welcome.

Regards
Michael


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PostPosted: Wed, 18-01-12, 17:41 GMT 
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MiR wrote:
Hallo Fridger,

For publishing the picture and due further questions I am continuing with the theme at shatters.net.
And because there's a better topic for this than "Neutrinos travelling faster than light??" (does not fit so well, I think).


Right, this CM thread addresses mainly people who want updates and latest results / ideas about the "speedy Neutrino" claims from OPERA. Tutorial-style explanations about textbook-level implications of Special Relativity are better located at shatters.net.

There, you now also find my detailed explanation why your above conclusion v = 2 * c is plain wrong (velocities don't add linearly in the relativistic case, where (v ~ c)!).

Fridger


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PostPosted: Thu, 23-02-12, 9:23 GMT 
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Some days ago, I heard a rumor in my laboratory that the OPERA collaboration had found a hardware error in their neutrino speed experiment: a bad fiber optics cable connection to a critical GPS receiver. It was said that after tightening that connection and re-measuring, the 60 nanosecond anomaly had vanished!

Yesterday, this was also reported here:

+++++++++++++++++++++++++++++++
BREAKING NEWS: Error Undoes Faster-Than-Light Neutrino Results
http://news.sciencemag.org/scienceinsid ... tml?ref=hp
+++++++++++++++++++++++++++++++

Neither at CERN nor on the OPERA Website one finds a respective comment yet (which is by no means surprising). Anyway, it's good to wait until there is an official statement by the OPERA collaboration.

Fridger


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PostPosted: Thu, 23-02-12, 14:56 GMT 
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Today, I received an email sent around by the Director General of CERN, Prof. Rolf Heuer, to the scientific personnel of CERN, Members and Associated Members:

++++++++++++++++++++++++++++++++++++++++++++++++++++
The OPERA collaboration has informed its funding agencies and host
laboratories that it has identified two possible effects that could have an
influence on its neutrino timing measurement. These both require further
tests with a short pulsed beam. If confirmed, one would increase the size of
the measured effect, the other would diminish it. The first possible effect
concerns an oscillator used to provide the time stamps for GPS
synchronizations. It could have led to an overestimate of the neutrino's
time of flight. The second concerns the optical fibre connector that brings
the external GPS signal to the OPERA master clock, which may not have been
functioning correctly when the measurements were taken. If this is the case,
it could have led to an underestimate of the time of flight of the
neutrinos. The potential extent of these two effects is being studied by the
OPERA collaboration. New measurements with short pulsed beams are scheduled
for May.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

This message makes things more or less official until the planned new measurement in May.


Fridger

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PostPosted: Thu, 23-02-12, 19:05 GMT 
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Dear Fridger,

many thanks for this very interesting insider information!

Regards

Andy


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PostPosted: Thu, 23-02-12, 19:44 GMT 
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Andy74 wrote:
Dear Fridger,

many thanks for this very interesting insider information!

Regards

Andy


Andy,

you are very welcome.

Fridger


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