If you want to see a black hole tonight, tonight just look in the direction of Sagittarius, the constellation. That's the center of the Milky Way Galaxy and there's a raging black hole at the very center of that constellation that holds the galaxy together.

We need more concept-development and active involvement, less tuning forks, pulleys, and friction formulas - students know they'll never use those. They need more study of outer space and DNA. They need more exciting teaching, more fair-minded encouragement, more career guidance, more mentorship. Both students and teachers need more feedback. It would help if we stopped protecting bad teachers - It's very difficult to get rid of even sexual perverts let alone just bad teachers.

As Heinz Pagels has said, The challenge to our civilization which has come from our knowledge of the cosmic energies that fuels the stars, the movement of light and electrons through matter, the intricate molecular order which is the biological basis of life, must be met by the creation of a moral and political order which will accommodate these forces or we shall be destroyed. It will try our deepest resources of reason and compassion.

When I get bored, or get stuck on an equation, I like to go ice skating, but it makes you forget your problem. Then you can tackle the problem with a fresh new insight. Einstein liked to play the violin to relax. Every physicist likes to have a past time. Mine is ice skating.

In some sense, gravity does not exist; what moves the planets and the stars is the distortion of space and time.

Eternal life does not violate the laws of physics. After all, we only die because of one word: "error." The longer we live, the more errors there are that are made by our bodies when they read our genes. That means cells get sluggish. The body doesn't function as well as it could, which is why the skin ages. Then organs eventually fail, so that's why we die.

The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe.