: I don't think that a black whole so far away would afect us. A black hole is not like a vacuum you know. A black hole only effects objects that are beyond the event horizen : so even if our sun were to become a black hole, the earth would not be affected.

Actually, at the event horizon, the escape velocity is equal to the speed of light. The black hole would still exert some force on a body out of this distance, but you are right in saying that it is not a cosmic vacuum cleaner. For a 3 solar mass black hole, the horizon would be about 3000km, so it would rip up things inside this. But with very large black holes like several billion solar masses, objects could survive even when crossing the event horizon, located at the Schwartzchild Radius.

• Re: Supermassive Black holes at the center of galaxies - omar - February 15, 2000 - 23:52 UTC