'cos they're trying to make a buck.....just like everyone else.... are you actually so naive that you believe everything you see?
It seems to me that if the time dilation of mesons about 10 km up in the atmosphere is the same for different spatial orientations that this would be evidence for the measured speed of light being a single value in 2-way tests.
Here are some results of experiments to determine the anisotropy of space with respect to the speed of light. No significant variation in the speed of light using a change in the frequency of light to indicate a change in time as the apparatus was rotated through space. It is impossible for me to determine exactly what was done in these experiments. The first experiment found a difference in the speed of light to be 0.000001 meter/second out of 300,000,000 meters/second for variations in spatial orientation. I think that these tests are variations of the Michelson-Morley experiment using an interferometer that detects interference in reflected light traveling in perpendicular paths. http://www.edu-observatory.org/physics-faq/Relativity/SR/experiments.html#Brillet A. Brillet and J.L. Hall, “Improved Laser Test of the Isotropy of Space”, Phys. Rev. Lett. 42 549–552 (1979). This is one of the most accurate limits on any anisotropy in the round-trip speed of light in a laboratory. They measured the beat-frequency between a single-mode laser on a rotating table and a single-mode laser fixed to the Earth to put a limit on such an anisotropy of 3 parts in 1015. Due to the construction of their rotating laser, this can also be interpreted as a limit on any anisotropy of space. This is a round-trip experiment because of their use of a Fabry-Perot etalon to determine the frequency of the rotating laser. Note that their limit on the round-trip anisotropy corresponds to a round-trip speed of less than 0.000001 m/s (!); in terms of the more usual one-way anisotropy it is 30 m/s. Their residual 17 Hz signal (out of ~1015 Hz) was described as “unknown”; it was fixed with respect to their laboratory and therefore could not be of cosmic origin. A. Brillet has indicated privately that this is most likely due to the rotation axis being slightly off-vertical by a few microradians. Hils and Hall, Phys. Rev. Lett. 64 (1990), pg 1697. This is similar to Brillet and Hall (above), but the lasers are fixed to the Earth for better stability. No variations were found at the level of 2×10−13. As they made observations over a year, this is not merely a limit on anisotropy, but also a limit on variations in different inertial frames. Brillet and Hall corresponds roughly to the Michelson-Morley experiment (no variations of the round-trip speed of light in different directions, with a time-scale of minutes or seconds); Hils and Hall corresponds roughly to the Kennedy-Thorndike experiment (no variations of the round-trip speed of light in different directions or for the different inertial frames occupied by the Earth during a year or so). Antonini, P., Okhapkin, M., Goklu, E., and Schiller, S., “Test of constancy of speed of light with rotating cryogenic optical resonators”, Phys. Rev. A 71, 050101(R) (2005). arXiv:gr-qc/0504109. Commented on by Tobar et al., Phys. Rev. A72, 066101 (2005). Reply by the authors Phys. Rev. A72, 066102 (2005). Herrmann et al., “Test of the Isotropy of the Speed of light using a Continuously Rotating Optical Resonator”, Phys. Rev. Lett. 95, 150401 (2005) arXivhysics/0508097. Improved limits at a level of a few parts in 10−16. Mueller et al., “Modern Michelson-Morley Experiment using Cryogenic Optical Resonators”, Phys. Rev. Lett. 91, no. 2, 020401 (2003). Anisotropy of c < (2.6 ±1.7)×10−15. Chen et al., “Experimental Test of the Isotropy of Two-way Light Speed”, A.S.N.U. Peking, 33, no. 5, pg 595 (1997). An experiment similar to Brillet and Hall, with a limit of 1×10−18 in the anisotropy of c.
Great questions to ask both of the scientists. Derek seems to me to be most likely to supply answers due to his having less on his plate than Destin has. Destin spends a good amount of time with his family. I do not know if that is true about Derek. Keep us informed if you find out. Thanks.
There is no way to "make a buck" from that. You're just proposing a totally baseless conspiracy theory. Let's remember that the topic here is not a topic of introductory physics.
There's money to be made in various ways, getting followers, getting adverts; Or maybe they just want to be noticed. You get this nonsense all the time, someone finds a link that disproves some major science fact and hey presto! it must be true. Maybe the thing was a deliberate hoax.
It can be measured but we might not find any change in the time dilation. I suspect that I am wrong about this because I would have read about it as a valid test for space isotropy. Then, there is the fact that there would still be a relativity theory if space wasn't isotropic that would probably make the result invariant for a change in space isotropy. By space being isotropic I mean with respect to the speed of light moving in different directions in space. I was thinking about measuring the time dilation from 2 different orientations on the earth, 180 degrees apart, of the earth with respect to the sun. Then the muons would be travelling in opposite directions at a speed close to c, the speed of light. Muons typically have a velocity of 0.99c and decay into an electron or a positron and neutrinos. This would help to verify the 2-way speed of light as an accurate method for measuring c. Muons are created in cosmic ray showers 10 km high. Lifetime is 2 us (microseconds) in rest frame. Travelling at 0.99c takes 15.3 lifetimes to travel 10 km. https://homepages.abdn.ac.uk/nph120/Cosmol/specrel.pdf For muons travelling at 0.99c, the time dilation factor is about 7. (γ = 7.09, to be exact). Their half-life observed in our ground frame of reference is longer by a factor of 7.09 and hence according to relativity the time needed for muons to reach the ground is not 15.3 half lives but only 15.3/7.09 = 2.18 half-lives. gamma is the symbol for the time dilation factor = 1/square root[1 -(velocity/c)squared ] = 7.09., v = velocity of muon with respect to an observer on earth. that velocity might not change if space isn't isotropic for different orientations of the earth's surface with respect to the sun because both time and length might change by the same proportion. The speed of light would change so that would cause a change in time dilation. That was my line of reasoning. My intuition tells me that v/c might be the same in both orientations, making the results identical and the test invalid. I don't know why v/c would be the same in both directions. but that would explain why I haven't read about this.
I didn't think that my first response was definitive because the Wikipedia answer mentions mass, energy, and space of the ground state of nuclei showing no evidence of anisotropic behavior without specifically addressing the anisotropy of space with respect to the speed of light. My post on page 2 with the results of Brillet & Hall plus later confirmations seems definitive.
It is probably mentioned but serves no useful purpose. It is just a curiosity. The speed of light is predicted by other variables that can be measured - the permeability and permittivity of a vaccuum. So while we can imagine models that can't be falsified [meaning that it can never be tested and therefore can never serve as a theory of science], we have a falsifiable [tesable] model that predicts the correct answers EVERY SINGLE TIME, and has for over a century. In a similar vein, you can never prove that there aren't invisible, untouchable skeletons under your bed. But it serves no useful purpose to study the problem.
I will say to you what I told others, after watching their video, be sure to explain to the two scientists with PhD degrees your findings.
Mike, after you watch the entire video or even skip to the end, you can explain that to both of the two scientists that hold PhDs in physics.
