Science Questions with Surprising Answers
Answers provided by
Dr. Christopher S. Baird

How can there be anything left in the universe? Don't black holes suck everything in?

Category: Space      Published: December 16, 2012

black hole
As long as you don't get too close, a black hole acts like any other star. Objects can safely orbit around black holes like they do around stars. This artistic depiction shows the view of distant stars being altered by an intervening black hole. Public domain image, source: Christopher S. Baird.

Black holes don't suck everything in. Black holes have gravity in the same ways stars have gravity. For this reason, planets orbit safely around black holes in the same way they orbit around our sun. The only difference between a black hole and a star is that the black hole has a small enough radius that light inside this radius cannot escape. There is a gigantic black hole at the center of our galaxy, and yet we are not in any danger of being sucked into it. Our entire galaxy orbits safely around the black hole at its center, as described in the book "The Galactic Supermassive Black Hole" by Fulvio Melia. It is true that if anything gets too close to a black hole, it will "hit it" and fall in, but this is generally no different from an earth satellite crashing into the ocean after years of slowing down due to friction

Topics: black hole, black holes suck, gravity, mass, orbit, spacetime