“Keeping an active mind has been vital to my survival, as has been maintaining a sense of humor.”

If time travel is possible, where are the tourists from the future?

Look up at the stars, not down at your feet.

While there’s life, there is hope.

What I have learned from life is to make the most of what you have got.

Latest survey shows that 3 out of 4 people make up 75% of the world’s population.

So next time someone complains that you have made a mistake, tell him that may be a good thing. Because without imperfection, neither you nor I would exist.

What was God doing before the divine creation? Was he preparing hell for people who asked such questions?

I would rather be right than rigorous.

The increase of disorder or entropy is what distinguishes the past from the future, giving a direction to time.

It is reasonable to ask who or what created the universe, but if the answer is God, then the question has merely been deflected to that of who created God.

I don’t want to write an autobiography because I would become public property with no privacy left.

We have made remarkable progress in the last hundred years, but if we want to continue, our future is in space.

The idea that we are alone in the universe seems to me completely implausible and arrogant, considering the number of planets and stars that we know exist, it’s extremely unlikely that we are the only form of evolved life.

Disability need not be an obstacle to success.

You cannot understand the glories of the universe without believing there is some Supreme Power behind it.

The laws of science do not distinguish between the past and the future.