"Sooner or later disasters such as an asteroid collision or a nuclear war could wipe us all out, But once we spread out into space and establish independent colonies, our future should be safe."

One, remember to look up at the stars and not down at your feet. Two, never give up work. Work gives you meaning and purpose and life is empty without it. Three, if you are lucky enough to find love, remember it is there and don't throw it away.

The human failing I would most like to correct is aggression.

The victim should have the right to end his life, if he wants. But I think it would be a great mistake. However bad life may seem, there is always something you can do, and succeed at. While there's life, there is hope.

People won't have time for you if you are always angry or complaining.

There is a very real danger that we will kill everything on this planet now that we have the technological power to do so.

If it were only a few degrees, that would be serious, but we could adapt to it. But the danger is the warming process might be unstable and run away. We could end up like Venus, covered in clouds and with the surface temperature of 400 degrees. It could be too late if we wait until the bad effects of warming become obvious. We need action now to reduce emission of carbon dioxide.