| | #:'''Update:''' The problem seems to have been caused by a faulty cable connection between a computer and a GPS unit. When the connection was repaired, the travel time increased by 60 nanoseconds, which had been the amount of the anomaly <ref>http://www.cbc.ca/news/world/story/2012/02/22/technology-faster-than-light-neutrinos.html</ref> <ref>http://www.foxnews.com/scitech/2012/02/22/loose-wire-led-to-stunning-faster-than-light-particle-finding/?intcmp=features</ref>. The claims of faster-than-light neutrinos have now been refuted very thoroughly<ref>http://news.sciencemag.org/scienceinsider/2012/02/breaking-news-error-undoes-faster.html</ref><ref>http://news.sciencemag.org/scienceinsider/2012/06/once-again-physicists-debunk.html</ref>. | | #:'''Update:''' The problem seems to have been caused by a faulty cable connection between a computer and a GPS unit. When the connection was repaired, the travel time increased by 60 nanoseconds, which had been the amount of the anomaly <ref>http://www.cbc.ca/news/world/story/2012/02/22/technology-faster-than-light-neutrinos.html</ref> <ref>http://www.foxnews.com/scitech/2012/02/22/loose-wire-led-to-stunning-faster-than-light-particle-finding/?intcmp=features</ref>. The claims of faster-than-light neutrinos have now been refuted very thoroughly<ref>http://news.sciencemag.org/scienceinsider/2012/02/breaking-news-error-undoes-faster.html</ref><ref>http://news.sciencemag.org/scienceinsider/2012/06/once-again-physicists-debunk.html</ref>. |
| | #:The objection has been raised that a recent news report from the BBC ("now we are 100% sure that the speed of light is the speed of neutrinos") is also contradictory, since neutrinos have mass and are therefore forbidden by relativity to travel at exactly the speed of light. Since the neutrino energies were 17GeV, and the current estimate for the neutrino mass is about 0.25eV, the deviation from the speed of light would be about 1 part in 10<sup>22</sup>. This means that the neutrinos would arrive at the detector about .26x10<sup>-24</sup> seconds (.26 yoctoseconds) later than the speed of light itself. This is one quarter of a billionth of a femtosecond, or about .26x10<sup>-15</sup> of a nanosecond. The accuracy of the GPS units and cesium clocks used in the measurement is greater than a nanosecond, so the discrepancy cannot possibly be detected. It is unfortunate that the claim "the speed of light is the speed of neutrinos" was taken so literally. | | #:The objection has been raised that a recent news report from the BBC ("now we are 100% sure that the speed of light is the speed of neutrinos") is also contradictory, since neutrinos have mass and are therefore forbidden by relativity to travel at exactly the speed of light. Since the neutrino energies were 17GeV, and the current estimate for the neutrino mass is about 0.25eV, the deviation from the speed of light would be about 1 part in 10<sup>22</sup>. This means that the neutrinos would arrive at the detector about .26x10<sup>-24</sup> seconds (.26 yoctoseconds) later than the speed of light itself. This is one quarter of a billionth of a femtosecond, or about .26x10<sup>-15</sup> of a nanosecond. The accuracy of the GPS units and cesium clocks used in the measurement is greater than a nanosecond, so the discrepancy cannot possibly be detected. It is unfortunate that the claim "the speed of light is the speed of neutrinos" was taken so literally. |
| | #:This may be another case of the Pioneer anomaly, or it may be something else. However, it is very unlikely that it shows that relativity is wrong and Newtonian mechanics is correct. Saying that, every time someone finds some phenomenon that is puzzling, that shows that relativity is wrong, is not a convincing way to do science. The cited paper is about unexpected behavior of some spacecraft as they use "gravity assists" in near-Earth flybys. The hypothesized causes involve errors in the mathematical models to calculate such effects as relativistic effects (the detailed calculation of them, not the question of whether they exist), tidal effects, Earth radiation pressure, or atmospheric drag. The paper suggests that most of those can be ruled out, though there could be round-off and integration errors, or errors in the spherical harmonic representation of Earth's gravity field. | | #:This may be another case of the Pioneer anomaly, or it may be something else. However, it is very unlikely that it shows that relativity is wrong and Newtonian mechanics is correct. Saying that, every time someone finds some phenomenon that is puzzling, that shows that relativity is wrong, is not a convincing way to do science. The cited paper is about unexpected behavior of some spacecraft as they use "gravity assists" in near-Earth flybys. The hypothesized causes involve errors in the mathematical models to calculate such effects as relativistic effects (the detailed calculation of them, not the question of whether they exist), tidal effects, Earth radiation pressure, or atmospheric drag. The paper suggests that most of those can be ruled out, though there could be round-off and integration errors, or errors in the spherical harmonic representation of Earth's gravity field. |