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.

In fact, if one considers the possible constants and laws that could have emerged, the odds against a universe that produced life like ours are immense.

I have to speak through a computer... in my mind, I am free. Free to explore the universe and ask the big questions...

Simplicity is a matter of taste

If it [the universe] was expanding fairly slowly, the force of gravity would cause it eventually to stop expanding and then to start contracting. However, if it was expanding at more than a certain critical rate, gravity would never be strong enough to stop it, and the universe would continue to expand forever.

Our population and our use of the finite resources of planet Earth are growing exponentially, along with our technical ability to change the environment for good or ill.

Mankind's greatest achievements have come about by talking and its greatest failures by not talking. It doesn’t have to be like this.