A feast devoured by a supermassive black hole a billion light-years from Earth has revealed how fast that black hole spins on its axis.
  • Krudler@lemmy.worldEnglish
    1·
    30 days ago

    Think about how fast a point on the equator of the Earth moves relative to a point a few cm away from the North Pole.

    In one full rotation of the Earth, the point on the equator will have traveled 40,000 km, and the point by the North Pole will have traveled a meter.

    So… it’s that it’s a useless way to express rotation.