If anyone doesn't know by now, he died 2 nights ago. So here's him singing the Monty Python Galaxy Song.

https://www.youtube.com/watch?v=XfcC6FYyL4U

## Stephen Hawking

- MattShizzle
**Posts:**18963**Joined:**Sun Aug 22, 2010 6:22 pm**Location:**Bernville, PA

- Minnemooseus
**Posts:**47**Joined:**Thu May 22, 2014 9:17 am**Location:**Northern Minnesota, USA

### On a related note

"I know a little about a lot of things, and a lot about a few things, but I'm highly ignorant about everything." - Moose

He did some important scientific work.

His first big success was on general-relativity singularity theories. He showed that singularities, regions with infinite curvature, would form under a variety of circumstances, and he did so with techniques that were not restricted to special cases like spherical symmetry.

He then worked out the thermodynamics of black holes. Applying quantum mechanics to them, he showed that they have well-defined temperatures, and that they emit particles -- "Hawking radiation". A colleague of his, Jacob Bekenstein, showed that black holes have some thermodynamics-like properties, and SH's work confirmed this analogy.

Essentially,

- Black-hole temperature ~ its surface gravity at its event horizon
- Black-hole entropy ~ its event horizon's area

He also got into popularization, writing books like "A Brief History of Time".

Entropy = that's the number of bits of description for going from a full microscopic description from a macroscopic description. Consider throwing a pair of six-sided dice. There are six ways of rolling a seven, but only one way of rolling a two or a twelve. That means that one needs about 2.5 bits of description to get from a seven to which numbers were on each die, and 0 bits for a two or a twelve.

Event horizon = that's the point of no return for a black hole, or more precisely, the surface formed by all such points.