The cores of most normal galaxies contain black holes that are millions to billions of times more massive than our Sun. Galaxies probably also contain millions of remnant stellar-mass black holes.
Ten years of painstaking measurements track the star S2 around the supermassive black hole in Sagittarius A*.
credit: ESO / Max-Planck Institute for Extraterrestrial Physics. 17 Oct 2002;
type: short;
level: popular;
duration: 0:19
category: astro; tags: galaxy, supermassive, black hole, Sagittarius, a*
category: astro; tags: galaxy, supermassive, black hole, Sagittarius, a*
For centuries, we have been trying to understand the basic laws which govern the universe. The most promising candidate for our next step forward is string theory.
credit: Harvard University. 8 Feb 2006;
type: lecture;
level: popular;
duration: 1:12:41
category: theoretical; tags: astro, string theory, relativity, black hole
category: theoretical; tags: astro, string theory, relativity, black hole



