Any physical theory is always provisional, in the sense that it is only a hypothesis: you can never prove it.

Obviously, because of my disability, I need assistance. But I have always tried to overcome the limitations of my condition and lead as full a life as possible. I have traveled the world, from the Antarctic to zero gravity.

Scientists have become the bearers of the torch of discovery in our quest for knowledge.

When the going gets tough, the tough take a coffee break.

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

Simplicity is a matter of taste

I have experimental evidence that time travel is not possible.