The boundary condition of the universe is that it has no boundary.

Life would be tragic if it weren't funny.

The increase of disorder or entropy with time is one example of what is called an arrow of time, something that distinguishes the past from the future, giving a direction to time.

For years, my early work with Roger Penrose seemed to be a disaster for science. It showed that the universe must have begun with a singularity, if Einstein's general theory of relativity is correct. That appeared to indicate that science could not predict how the universe would begin.

I am just a child who has never grown up. I still keep asking these 'how' and 'why' questions. Occasionally, I find an answer.

I'm not afraid of death, but I'm in no hurry to die. I have so much I want to do first.

When something is made idiot proof, they will just make better idiots.