Milky Way’s Black Hole Now Spinning At Top Speed, Are We In Danger?

The spin of a black hole is determined by an effect known as frame dragging. When the Earth spins on its axis, it twists the space around itself ever so slightly, AKA frame dragging. Black holes have no physical matter to rotate and, therefore, twist a greater portion of spacetime around themselves as they spin. Therefore, the upper limit of how fast a black hole can spin isn’t measured by the point where the whole thing would be torn apart but rather by the inherent properties of space and time itself.

A new study on the rotation of the supermassive black hole in our galaxy has determined that it’s moving at almost the highest speed possible. Einstein determined that a black hole’s spin is measured by a quantity referred to as “a,” which will always have a value between 0 and 1. If a black hole isn’t spinning at all, then a = 0. If a black hole is spinning at top speed, then a=1.