That is, more tests are needed, and on other experimental setups. There is still a large crowd of skeptical physicists who suspect that the original measurement done in September was an error.
This at least is what gives me some confidence in the experiments. That and the statement that they are looking for ways to identify and eliminate any possible error.
Ultimately, either it will hold up or something will be identified which falsifies it, but it’s going to be interesting to watch and potentially very exciting if it stands.
There is still the question of entanglement at large distances. But that brings another question.
How do we know that entanglement happens at FTL? How could we possibly ever know? Even if we could travel at the speed of light, we would arrives at the entangled particle at the same time as any information travelling at SOL. We could never establish that the information (travelling at FTL) arrived before we did.
There is still the question of entanglement at large distances. But that brings another question.
How do we know that entanglement happens at FTL? How could we possibly ever know? Even if we could travel at the speed of light, we would arrives at the entangled particle at the same time as any information travelling at SOL. We could never establish that the information (travelling at FTL) arrived before we did.
Entanglement is a different issue that has nothing to do with the present case.
And you could tell if you had set up verifiable timekeepers at each end, so that you wouldn’t have to travel, except to see what the timekeepers said. (AFAIK this has already been verified).
There is still the question of entanglement at large distances. But that brings another question.
How do we know that entanglement happens at FTL? How could we possibly ever know? Even if we could travel at the speed of light, we would arrives at the entangled particle at the same time as any information travelling at SOL. We could never establish that the information (travelling at FTL) arrived before we did.
Entanglement is a different issue that has nothing to do with the present case.
And you could tell if you had set up verifiable timekeepers at each end, so that you wouldn’t have to travel, except to see what the timekeepers said. (AFAIK this has already been verified).
The subject is FTL, no? Apparent entanglement is the only known form of transferring information at FTL.
I am confident that they have figured it out but, by my limited knowledge, even synchronizing time measuring devices would present an inevitable and insurmountable obstacle. I understand that atomic clocks can count at near SOL speed, but they cannot count at an FTL rate, which would be required to measure FTL with any kind of certainty. As long as there is a miniscule mis-synchronization of nano-seconds between atomic clocks, no perfect synchronization would be possible. Then there is the environmental gravitational impact on time to consider. A nano second here, a nano second there may well be different in duration. A problem which is amplified by shorter distances, such as the few hundred kilometers from CERN to the other receptor.
Help….?
I am sure that I am overlooking something, I just can’t imagine what….
Write, why are you so obsessed by FTL? I can only say: forget it. Until we have an established proof it makes not really sense to speculate about it. The RT is so fundamental, SRT is used daily in CERN and similar laboratories and explains so many phenomena, GRT and SRT are needed for GPS etc etc, that you can take it for granted that they are correct.
And just to correct (not the first time in this forum): in entanglement no information is traveling faster than light.
Write, why are you so obsessed by FTL? I can only say: forget it. Until we have an established proof it makes not really sense to speculate about it. The RT is so fundamental, SRT is used daily in CERN and similar laboratories and explains so many phenomena, GRT and SRT are needed for GPS etc etc, that you can take it for granted that they are correct.
And just to correct (not the first time in this forum): in entanglement no information is traveling faster than light.
From wiki,
Experimental results have demonstrated that effects due to entanglement travel at least thousands of times faster than the speed of light
What, as a layman, am I to think of that?
GdB, I am not obsessed with FTL, it does not affect my worldview in the least. This thread is talking about CERN having discovered a particle that apparently seems to travel at FTL. It is the scientists who are making the assertion (pending further research). I am interested in the contradictions this seems to generate in the worldview of Physicists! And they are rightly obsessed with the notion of FTL.
Pardon me for asking stupid questions, but they are questions, not assertions. And a wise teacher once told me that it is better to ask a question from ignorance than to make an assertion from ignorance.
At least I am not asserting that “god works in mysterious ways”.
Experimental results have demonstrated that effects due to entanglement travel at least thousands of times faster than the speed of light
What, as a layman, am I to think of that?
To get information through an entanglement setup from Alice to Bob, they must use a second and independent channel, and this channel can at most use the speed of light.
It’s fine to ask ‘stupid questions’, but I just notice that you are speculating an awful lot about concepts that nearly have no place in science: tachyons, FLT in general, negative mass, etc. Why are you so highly interested in such stuff?
This is an interesting note in your wiki article:
David Kaiser of MIT mentioned in his book, How the Hippies Saved Physics, that the possibilities of instantaneous long-range communication derived from Bell’s theorem stirred interest among hippies, psychics, and even the CIA, with the counter-cultural playing a critical role in its development toward practical use.
In the context of this article, FTL is the transmission of information or matter faster than c, a constant equal to the speed of light in a vacuum, which is 299,792,458 meters per second or about 186,282.4 miles per second. This is not quite the same as traveling faster than light, since:
Some processes propagate faster than c, but cannot carry information (see examples section immediately following).
Light travels at speed c/n when not in a vacuum but travelling through a medium with refractive index = n (causing refraction), and in some materials other particles can travel faster than c/n (but still slower than c), leading to Cherenkov radiation (see phase velocity below).
Neither of these phenomena violates special relativity or creates problems with causality, and thus neither qualifies as FTL as described here.
In the following examples, certain influences may appear to travel faster than light, but they do not convey energy or information faster than light, so they do not violate special relativity.
<snip>
There have been various reports in the popular press of experiments on faster-than-light transmission in optics—most often in the context of a kind of quantum tunnelling phenomenon. Usually, such reports deal with a phase velocity or group velocity faster than the vacuum velocity of light. However, as stated above, a superluminal phase velocity cannot be used for faster-than-light transmission of information. There has sometimes been confusion concerning the latter point. Additionally a channel that permits such propagation cannot be laid out faster than the speed of light.
Quantum teleportation transmits quantum information at whatever speed is used to transmit the same amount of classical information, likely the speed of light. This quantum information may theoretically be used in ways that classical information can not, such as in quantum computations involving quantum information only available to the recipient.
GdB, my interest is to eliminate the woo from my intuitive worldview of the universe and physics. I am not a hippie, trying to change the world or science, just an enthusiastic supporter of science and the scientific method. Unfortunately I am too old to study this in a formal setting and try to take advantage of the accumulated knowledge here in CFI.
Thanks for the link re FTL and the way it can be explained without violating general relativity. That kind of informed reference is what saves me hours of muddling through websites dealing with such issues.
Yes, GdB is right: no information is passed faster than light through entanglement. There is no way to use it to transmit a message. The point of the present thread is that if the folks at CERN had been right, there would have been a method to transmit messages (very slightly) FTL, through a method that has nothing to do with entanglement. As many of us noted, the CERN result was very low probability true: most likely it was due to experimental error, which appears now to have been the case.
For those who are interested (most is technical, but not all). Here are the presentations about the Opera experiments and the error sources (I don’t know how long they keep them online).
Under the title ‘Science and ethics’ (in the second presentation):
Publication of a discovery. Discoveries
must first be published in peer-review
journals and only later given to the Media.
1965: ! (1st example of Nuclear Antimatter)
CERN submitted to scientific journal
(March). 3 month later ! “discovered” at
BNL-USA and given to Media. Claim we
are first, therefore this is USA discovery.
30th anniversary celebration only CERN.
<snip>
Reproducibility of a discovery.
1967: S0 discovered in USA (the old version
of the God-particle announced and
published).
Experiment: repeated at CERN and proved
to be wrong. The S0 does not exist.
