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.

All that my work has shown is that you don't have to say that the way the universe began was the personal whim of God.

[In the Universe it may be that] Primitive life is very common and intelligent life is fairly rare. Some would say it has yet to occur on Earth.

However difficult life may seem, there is always something you can do and succeed at.

It is impossible to imagine a four-dimensional space. I personally find it hard enough to visualize a three-dimensional space!

The real challenge is to work out what aliens might actually be like.

Many people find the universe confusing - it's not.