An international team of researchers has used a new spectrometer to find and set an upper limit for the mass of a neutrino. In their paper published in the journal Physical Review Letters, the group describes how they came up with the new limit...
[...] The researchers carried out their work as part of the Karlsruhe Tritium Neutrino Experiment (KATRIN) on the campus of the Karlsruhe Institute of Technology in Germany. The core piece of equipment used at the site is a 200-ton electron spectrometer. The researchers used it to study the decay of tritium—a radioactive type of hydrogen. When it decays, it emits a single electron and a neutrino at the same time. By measuring the energy of the released electron using the spectrometer, they were able to calculate an estimate of the mass of the neutrino to a greater precision than was possible before. They found its upper limited to be 1.1 electronvolts, approximately half of the previously determined upper limit. It is also extremely tiny—approximately 500,000 times smaller than an electron.
More information: M. Aker et al. Improved Upper Limit on the Neutrino Mass from a Direct Kinematic Method by KATRIN, Physical Review Letters (2019). DOI: 10.1103/PhysRevLett.123.221802 . On Arxiv: https://arxiv.org/abs/1909.06048
(Score: 1, Insightful) by Anonymous Coward on Thursday November 28 2019, @03:27AM
Please stop using GPS or other satellite navigation if you really think that general relativity has never made any useful predictions. GPS and other satellite navigation systems make use of the predictions of general relativity to work as well as they do. If they didn't incorporate the predictions of GR (gravitational time dilation for instance), they would give a position that was wrong by several kilometres. More importantly, stop using your computer. Semiconductor components like transistors were developed on the principles of quantum mechanics, which you say hasn't made any useful predictions. The predictions of QM are absolutely fundamental in modern microelectronics.