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On February 24 2012 23:28 Antisocialmunky wrote:On a side note, sometimes its nice to real TL between the times of 5AM and 9AM CDT because its generally more respectful and informative. So I'll ask this: The ScienceMag article that the link broke referenced an exact 60ns compensation when the cable was tightened, what's the exact source? Would have thought it would have been mentioned in Nature/New Scientist/Scientific American etc if it wasn't just a rumor. Not sure, but don't list New scientist together with Nature please. It is very desired by most groups to publish in nature, while new scientist is a bunch of lying smoking hippies that noone cares about. I agree that it is very interesting information though, if it is indeed 60ns. We will see in May. Edit: Actually I should call them smoking or hippies. That could give a too innocent impression. Replace those with "greedy" and "sensationalists" respectively. Also add profanities according to taste.
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On February 24 2012 23:28 Antisocialmunky wrote:On a side note, sometimes its nice to real TL between the times of 5AM and 9AM CDT because its generally more respectful and informative. So I'll ask this: The ScienceMag article that the link broke referenced an exact 60ns compensation when the cable was tightened, what's the exact source? Would have thought it would have been mentioned in Nature/New Scientist/Scientific American etc if it wasn't just a rumor.
The exact number is not public (AFAIK), there are in fact two different sources of timing errors, they work in opposite direction (this is public I think).
This might make the particle speedier (as the CBS article linked earlier in this thread hypothesizes), or it might make it actually slower than the speed of light in vacuum (most other articles). Given the nature/language of the press release sent by CERN/OPERA, it seems reasonable that the numbers are with some reasonable accuracy known to the experimenters, and that they think these errors are responsible for the faster than light result.
More precision about the numbers is probably needed, and a re-measurement is happening in May. I'm guessing they will notify again afterwards.
There is a perfectly valid reason for not posting the numbers yet. For all these experiments, the aim is to minimize the statistical and systematical error in a measurement. If a source of error is found, you have to also see how well you know that error. So, they might have measured a problem with the cable, and found a difference 60ns. That is a pretty clear indication that that might be the problem. However, you cannot use a number just like that. First you have to remeasure at least once with the same setup (statistical error), then you remeasure at least once with a different measuring setup (systematical error), and then you can say something like "The flaw in the cable caused a delay of 60 ns +- 5 ns (statistical) +- 2 ns (systematic)." Until you have such measurements, having found the flaw is a really good thing, but you cannot really put a precise number on the delay, and you cannot correct for it. You might very well say that it works in one or the other direction though.
And for those wondering, I am a (theoretical) particle physicist, not affiliated with the experiment.
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On February 24 2012 23:44 Cascade wrote:Show nested quote +On February 24 2012 23:28 Antisocialmunky wrote:On a side note, sometimes its nice to real TL between the times of 5AM and 9AM CDT because its generally more respectful and informative. So I'll ask this: The ScienceMag article that the link broke referenced an exact 60ns compensation when the cable was tightened, what's the exact source? Would have thought it would have been mentioned in Nature/New Scientist/Scientific American etc if it wasn't just a rumor. Not sure, but don't list New scientist together with Nature please. It is very desired by most groups to publish in nature, while new scientist is a bunch of lying smoking hippies that noone cares about. I agree that it is very interesting information though, if it is indeed 60ns. We will see in May. Edit: Actually I should call them smoking or hippies. That could give a too innocent impression. Replace those with "greedy" and "sensationalists" respectively. Also add profanities according to taste. While I don't personally read the New Scientist, I think you are being a bit harsh. I read the Scientific American and afaik the New Scientist is simply the British equivalent of that? SciAm is not sensationalist, nor greedy, smoking hippies. It is a popular science magazine: new work is not published in SciAm and insofar as I know it's not even peer reviewed. However, it does let scientists explain their research to an educated public. However, they pick up news articles from Nature (same publisher) and editors rewrite them to be understandable to the non-expert public. Insofar as I know, New Scientist is the same deal (and I'm sure every country has a similar magazine, which may be better or worse, depending on the editorial board). For seriously BAD scientific press I would refer you to most of the regular newspapers. Especially hilarious is the Daily Mail. Here's an example of how bad they are: http://kill-or-cure.heroku.com/
EDIT: and of course a paper published in Nature is not the same as a paper published in New Scientist. The former is a scientific journal and the latter a popular science magazine. But that doesn't make the latter sensationalist, greedy, smoking hippies.
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On February 25 2012 00:48 Acrofales wrote:Show nested quote +On February 24 2012 23:44 Cascade wrote:On February 24 2012 23:28 Antisocialmunky wrote:On a side note, sometimes its nice to real TL between the times of 5AM and 9AM CDT because its generally more respectful and informative. So I'll ask this: The ScienceMag article that the link broke referenced an exact 60ns compensation when the cable was tightened, what's the exact source? Would have thought it would have been mentioned in Nature/New Scientist/Scientific American etc if it wasn't just a rumor. Not sure, but don't list New scientist together with Nature please. It is very desired by most groups to publish in nature, while new scientist is a bunch of lying smoking hippies that noone cares about. I agree that it is very interesting information though, if it is indeed 60ns. We will see in May. Edit: Actually I should call them smoking or hippies. That could give a too innocent impression. Replace those with "greedy" and "sensationalists" respectively. Also add profanities according to taste. While I don't personally read the New Scientist, I think you are being a bit harsh. I read the Scientific American and afaik the New Scientist is simply the British equivalent of that? SciAm is not sensationalist, nor greedy, smoking hippies. It is a popular science magazine: new work is not published in SciAm and insofar as I know it's not even peer reviewed. However, it does let scientists explain their research to an educated public. However, they pick up news articles from Nature (same publisher) and editors rewrite them to be understandable to the non-expert public. Insofar as I know, New Scientist is the same deal (and I'm sure every country has a similar magazine, which may be better or worse, depending on the editorial board). For seriously BAD scientific press I would refer you to most of the regular newspapers. Especially hilarious is the Daily Mail. Here's an example of how bad they are: http://kill-or-cure.heroku.com/EDIT: and of course a paper published in Nature is not the same as a paper published in New Scientist. The former is a scientific journal and the latter a popular science magazine. But that doesn't make the latter sensationalist, greedy, smoking hippies. I haven't read scientific american much, so I can't say. I did read new scientist though (we had it in our lunch room for a while, but not any longer ), and they are really bad. Made me go on long frustrated rants almost every lunch. This is a bit off-topic though, so maybe better to PM if you want to discuss more.
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To be quite honest, isn't it obvious that the error is AT LEAST much overstating the importance of this discovery and at worst the error IS the reason behind this?
I don't think the pillar of relativity can be toppled THAT easily...
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On February 25 2012 00:59 ymir233 wrote: To be quite honest, isn't it obvious that the error is AT LEAST much overstating the importance of this discovery and at worst the error IS the reason behind this?
I don't think the pillar of relativity can be toppled THAT easily...
Apparently they used GPS, which is a relativistic system..based on relativity, try and defeat relativity.
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On February 24 2012 02:32 Cascade wrote:Show nested quote +On February 24 2012 01:27 Abraxas514 wrote: (this post is about special relativity, which relates entirely to the experiment in the OP)
Personally, I believe the entire special relativity concept, especially the whole lorentz transformation when measuring size or speed, is something born out of observation and not really there. In mechanical engineering, it is shown that the total force minus the "intertial force" acting on an object equals zero.
This means as it accelerates forward, it's mass*acceleration = the force applied. In order for this object to not accelerate at this rate, something must be preventing it's motion. Special relativity predicts temporal phenomena affecting objects travelling near c, and this has been shown (short lived particles in accelerators existing orders of magnitude of time longer than when they are at lower velocities) but only for certain particles.
The biggest problems I see with the theory are:
- What is physically slowing the acceleration of matter as it approaches c? - Where is the absolute frame of reference at rest?
And one that really bothers me:
- Why is the density of a neutron star so high that sound travels faster than light?
All measurements show special relativity to be correct... but if you've only got a meter stick you can't prove the earth is round with it either. 1) Maybe you will find this interpretation of SR helpful: Mass is just another kind of energy. So that the energy of each kg of mass corresponds to a certain number of J. Let's call this proportionality constant c^2, so that E = mc^2. That means that "a force it takes to accelerate inert mass" should be reintrepreted as "a force is needed to accelerate intert energy" in some sense. c^2 is a pretty large number, which means that the energy of most things we see are dominated by the mass type of energy. (their rest mass m_0) This is the cause that f=ma with the "usual" heavy mass rather than the "inert energy" works in everyday life (like engineering). However, when you start looking at things at very high energy, such that their kinetic energy becomes almost as large as their mass energy, then you need to take into account that you have to accelerate not only the mass, but also the kinetic energy that is carried by the object. That is a way of understanding how f=ma is changed, through a generalisation of the "m" in the formula. Not sure if it helps you... Then the lorentz transform follows from requiring that things should work the same on a train as standing still, and as on the moon, but that you know maybe? So the answer to the first question is: "the kinetic energy is slowing down the acceleration". 2) The absolute frame of reference? Entire point of SR is that there isn't one. You have observers, and if that observer is not accelerating, she describes a rest frame that she can measure stuff in, and calculate things. Another observer also not accelerating, but potentially moving at another velocity, can do the same, and both observers should be able to use the same physics in their calculations. There is no preferred observer. There is however a different from accelerating and non-accelerating observers, but that is another story. Did I answer the question? Not so sure I did. :/ 3) Not really sure what that refers to, but for sure is that the sound does not move faster than the speed of light in vacuum. Maybe it moves faster than the speed of light in that medium, which can be significantly slower than in vacuum. In water for example it is already 30% slower (one over the refractive index). in the end all physics has to be based on observations. If we can find an intuitive interpretations of what is going on, that is good, but we must accept that physics in extreme conditions (close to light speed, QM scale, black holes) can behave much different than what we find intuitive from our (non-relativistic, non-QM) experiences in real life.
Thanks for the answer, the people who posted before you didn't understand what direction I was approaching the problem.
for your #1, I agree that the total energy of a mass increases as it's velocity increases. The mystery is why the energy increases to an asymptote and not by a power two function.
#2 is a problem concerning the size of the universe. The distribution of matter doesn't coincide with c speed limits.
#3 well,
From Ohanian & Ruffini, §8.8:
"The requirement that the speed of sound be no more than the speed of light then sets a limit on the stiffness of the material. [ Any material, in fact; see The Superluminal Scissors ] According to Rhoades and Ruffini (1974), this leads to the conclusion that the mass of a neutron star can never exceed 3.2 solar masses, independent of any assumption about the details of the equation of state at high densities."
This is what I would call backwards logic concerning SR.
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#2 it's because you forget that the frame itself of the universe is expanding, matter is not only moving. In fact this expansion is not constant, it's accelerating. as for #3, i don't understand your trouble
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Hmm wonder if the elasticity of the earth was taken into account, but I suppose they probably were measuring the length of the tunnel simultaneously with the experiment running? Man can't wait for further results by Fermilab and others later in the year.
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On February 25 2012 05:38 EtherealDeath wrote: Hmm wonder if the elasticity of the earth was taken into account, but I suppose they probably were measuring the length of the tunnel simultaneously with the experiment running? Man can't wait for further results by Fermilab and others later in the year.
Length of the tunnel? There is no tunnel. Neutrinos just pass through matter. There are currently 10^11 neutrinos passing through you per square centimeter. Neutrinos just don't interact. There is no need for a tunnel at all.
So it doesn't matter about the elasticity of the Earth. The only thing neutrinos interact with/by is the weak force in physics which is uncommon.
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On February 25 2012 05:38 EtherealDeath wrote: Hmm wonder if the elasticity of the earth was taken into account, but I suppose they probably were measuring the length of the tunnel simultaneously with the experiment running? Man can't wait for further results by Fermilab and others later in the year. If there was a tunnel it went through the tunnel had to be straight since the particles they are tracking dont give fuck about... anything and just goes through whatever it is that might be in the way.
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On February 25 2012 05:38 EtherealDeath wrote: Hmm wonder if the elasticity of the earth was taken into account, but I suppose they probably were measuring the length of the tunnel simultaneously with the experiment running? Man can't wait for further results by Fermilab and others later in the year. Look at figure 7 in the paper. They measure it daily, so they see the continental drift during the measurement over 1.5 years, and after the earthquake in 2009 they see how the distance jumped around 5cm.
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On February 25 2012 01:30 Abraxas514 wrote:Show nested quote +On February 24 2012 02:32 Cascade wrote:On February 24 2012 01:27 Abraxas514 wrote: (this post is about special relativity, which relates entirely to the experiment in the OP)
Personally, I believe the entire special relativity concept, especially the whole lorentz transformation when measuring size or speed, is something born out of observation and not really there. In mechanical engineering, it is shown that the total force minus the "intertial force" acting on an object equals zero.
This means as it accelerates forward, it's mass*acceleration = the force applied. In order for this object to not accelerate at this rate, something must be preventing it's motion. Special relativity predicts temporal phenomena affecting objects travelling near c, and this has been shown (short lived particles in accelerators existing orders of magnitude of time longer than when they are at lower velocities) but only for certain particles.
The biggest problems I see with the theory are:
- What is physically slowing the acceleration of matter as it approaches c? - Where is the absolute frame of reference at rest?
And one that really bothers me:
- Why is the density of a neutron star so high that sound travels faster than light?
All measurements show special relativity to be correct... but if you've only got a meter stick you can't prove the earth is round with it either. 1) Maybe you will find this interpretation of SR helpful: Mass is just another kind of energy. So that the energy of each kg of mass corresponds to a certain number of J. Let's call this proportionality constant c^2, so that E = mc^2. That means that "a force it takes to accelerate inert mass" should be reintrepreted as "a force is needed to accelerate intert energy" in some sense. c^2 is a pretty large number, which means that the energy of most things we see are dominated by the mass type of energy. (their rest mass m_0) This is the cause that f=ma with the "usual" heavy mass rather than the "inert energy" works in everyday life (like engineering). However, when you start looking at things at very high energy, such that their kinetic energy becomes almost as large as their mass energy, then you need to take into account that you have to accelerate not only the mass, but also the kinetic energy that is carried by the object. That is a way of understanding how f=ma is changed, through a generalisation of the "m" in the formula. Not sure if it helps you... Then the lorentz transform follows from requiring that things should work the same on a train as standing still, and as on the moon, but that you know maybe? So the answer to the first question is: "the kinetic energy is slowing down the acceleration". 2) The absolute frame of reference? Entire point of SR is that there isn't one. You have observers, and if that observer is not accelerating, she describes a rest frame that she can measure stuff in, and calculate things. Another observer also not accelerating, but potentially moving at another velocity, can do the same, and both observers should be able to use the same physics in their calculations. There is no preferred observer. There is however a different from accelerating and non-accelerating observers, but that is another story. Did I answer the question? Not so sure I did. :/ 3) Not really sure what that refers to, but for sure is that the sound does not move faster than the speed of light in vacuum. Maybe it moves faster than the speed of light in that medium, which can be significantly slower than in vacuum. In water for example it is already 30% slower (one over the refractive index). in the end all physics has to be based on observations. If we can find an intuitive interpretations of what is going on, that is good, but we must accept that physics in extreme conditions (close to light speed, QM scale, black holes) can behave much different than what we find intuitive from our (non-relativistic, non-QM) experiences in real life. Thanks for the answer, the people who posted before you didn't understand what direction I was approaching the problem. for your #1, I agree that the total energy of a mass increases as it's velocity increases. The mystery is why the energy increases to an asymptote and not by a power two function. #2 is a problem concerning the size of the universe. The distribution of matter doesn't coincide with c speed limits. #3 well, From Ohanian & Ruffini, §8.8: "The requirement that the speed of sound be no more than the speed of light then sets a limit on the stiffness of the material. [ Any material, in fact; see The Superluminal Scissors ] According to Rhoades and Ruffini (1974), this leads to the conclusion that the mass of a neutron star can never exceed 3.2 solar masses, independent of any assumption about the details of the equation of state at high densities." This is what I would call backwards logic concerning SR. 1) It comes from the lorentz transform, which comes from frame independence. I Can't teach you all of SR here on tjhe forum, but if you want to understand this better, i recommend that you actually go through the derivation of the lorentz transform from the mirror-on-a-train thought experiment. The mathematics are very easy, just plus and minus (and multiplication and division and squares. ) and it feels pretty convincing once you've done it yourself. For further understanding, you can think of the kinetic energy E_k = mv^2/2 as just the first term of a taylor expansion in v^2/c^2 (which again comes out from the lorentz transform).
2) this is related to general relativity and the shape of the universe. I am not sure what your question is, but I think the answer is related to the fact that speed is not the same as change in distance. Two stars can increase their relative distance my more than light speed without challenging SR. But htey could not pass close to each other with a relative speed faster than c.
3) What is the problem? Neutron stars become black holes well before 3.2 solar masses.
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The experiment was determined to be innacurate due to a loose cable.
"CERN has determined that there was a loose fibre-optic cable in the device used to measure the neutrinos' speed. The lab will undertake the experiment once again in May."
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On February 25 2012 07:43 Innovation wrote: The experiment was determined to be innacurate due to a loose cable.
"CERN has determined that there was a loose fibre-optic cable in the device used to measure the neutrinos' speed. The lab will undertake the experiment once again in May."
I want the damn things to be faster than light T_T. That would just open up so many possibilities.
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If nothing comes about it, at least they will have learned something about accuracy with equipment.
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On February 25 2012 07:35 Cascade wrote:Show nested quote +On February 25 2012 05:38 EtherealDeath wrote: Hmm wonder if the elasticity of the earth was taken into account, but I suppose they probably were measuring the length of the tunnel simultaneously with the experiment running? Man can't wait for further results by Fermilab and others later in the year. Look at figure 7 in the paper. They measure it daily, so they see the continental drift during the measurement over 1.5 years, and after the earthquake in 2009 they see how the distance jumped around 5cm. ah ok. Btw for the others, I meant tunnel in a figurative sense. Sorry for the confusion lol.
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Its pretty foolish to think "The laws of physics" (a human construct) can explain everything in the universe. Einstien knew that his theories were only theories. There are things in the universe that we don't understand. Thinking that we have everything figured out is pretty stupid. =/
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