In 2017, a kilonova sent light and gravitational waves across the Universe. Here on Earth, there was a 1.7 second signal arrival delay. Why?
  • John_Hasler@lemmy.oneEnglish
    1·
    1 year ago

    They are not emitted simultaneously. The collision is messy. The GRB comes from leftover bits of neutron star.

  • Chais@sh.itjust.works
    1·
    1 year ago

    Well, space isn’t a perfect vacuum, is it? It’s pretty damn close, but you’ll still encounter the occasional hydrogen molecule.
    I mean, were talking about 1.7 seconds delay over a distance of 130 million lightyears! That’s virtually nothing.

    • Treczoks@kbin.social
      1·
      1 year ago

      It also depends on the starting point. If both the gravity wave and the light start in the middle of a star or even just inside a shell of an exploding star, or, in case of black holes, inside a cloud of matter that surrounds the hole waiting to be sucked in, there is more than enough matter to delay the light.