3 ms·

This article isn't great... > Some charged particles in the air shower travel faster than the speed of light Better article: https://attheu.utah.edu/facultyst

• dzdt 3y ago
  In reading the article that was the same sentence I copy-pasted to bring back here for discussion. Anyone have an idea what the reporter garbled into "faster than the speed of light?" I guess just "nearly the speed of light"?
  • sdflhasjd 3y ago
    Possibly "faster than the speed of light in air"
    • dzdt 3y ago
      Oh that makes a lot of sense. That actually makes a nice image for the train-wreck of cascading particle collisions that happens. Air is dense enough its impossible to move that fast thru it. But the particle hits the air moving that fast. Result: fireworks that can be detected.
      • marginalia_nu 3y ago
        Related effect, Cherenkov radiation: https://en.wikipedia.org/wiki/Cherenkov_radiation https://en.wikipedia.org/wiki/Cherenkov_radiation
  • dotsam 3y ago
    As someone else has said, the article should say "faster than the speed of light in air". The Guardian article says: > Some charged particles in the air shower travel faster than the speed of light, producing a type of electromagnetic radiation that can be detected by specialised instruments. > One such instrument is the Telescope Array observatory in Utah, which found the Amaterasu particle. The Telescope Array actually has two different types of instrument for detecting the particles. Fluorescence Telescopes and Scintillation Detectors. According to the paper the "fluorescence detectors were not operating at the time (owing to bright moonlight)". Instead the particles were detected by the plastic scintillator surface detectors. I have found more information about the surface detectors here: http://www.telescopearray.org/index.php/about/surface-detection http://www.telescopearray.org/index.php/about/surface-detect...
  • cyborgrising 3y ago
    Perhaps it's a reference to a relativistic quirk having to do with cosmic rays. When a high-energy cosmic ray hits the atmosphere, it can create a meson or something. This sub-atomic particle isn't stable and has a tiny half-life, really it is mostly just an intermediary mid-way through the feynman diagram of the cosmic particle collision interaction, where the actual result is a typical output of stable electrons or neutrinos or what have you. It gets weird because you see evidence of these mesons or whatever way down below the part of the atmosphere where cosmic rays impact. Like, if you multiply the half life of the meson with the speed of light, you get a result that should be way shorter than the actual distance you see mesons (or what have you) actually traveling. Depending on how you look at it, it's like the mesons are traveling faster than the speed of light given how far they're going before decaying. It turns out these particles are traveling so close to the speed of light that the passage of time is different for the particles than an observer on earth. Their half-life duration occurs within their frame of reference, which is different than ours. So even though the particle was traveling at (fake numbers) 1 kilometer a second and traveled 3 kilometers, it only had a lifespan of 1 second. It plays out this way because 3 seconds on earth transpired during the particle's 1 second in its own frame of reference and thus we saw it travel 3 kilometers during the particle's own 1 second, despite the speed of light being just 1 kilometer per second. So depending on how you look at the numbers it can seem like it was 3x faster than the 1km/s speed of light. I realize this almost of creates more (and bigger) questions than answers.
  • water-data-dude 3y ago
    It looks like the article has been corrected.
• huhtenberg 3y ago
  > Science paper for those with access This journal is published by "American Association for the *** Advancement of Science ***". Jesus. You can't make up this sort of irony. Open collaboration, peer efforts and all that altruist nonsense requires you having the access. No access - no science for you. Beat it.
  • freilanzer 3y ago
    OpenAI.
    • sph 3y ago
      Please let's not taint this thread as well with that nonsense.
      • benterix 3y ago
        I respectfully disagree. Bringing this issue up again and again is important even though it has almost nothing to do with the topic being discussed. They had so many options "SharedAI", "CommonAI", "ResponsibleAI", "WorldAI" - but chose the only adjective that does not reflect what they are doing. It muddles waters. It makes it more difficult for the real OpenAI organization to form (what name should they adopt - "RallyOpenAI"? "TheOpenAI"?) Yes I know the arguments they used to defend their choice but I don't find them convincing.
        • pif 3y ago
          > I respectfully disagree. Bringing this issue up again and again is important even though it has almost nothing to do with the topic being discussed. You are respectfully wrong.
          • thaumasiotes 3y ago
            It's a reasonable strategy. Cato the Elder is still famous for ending all speeches on any subject with his call for the destruction of Carthage. And it worked!