What cannot be known is more revealing than what can.

There was no "before" the beginning of our universe, because once upon a time there was no time.

Once upon a time when there was no time.

There is no reason that the universe should be designed for our convenience.

Some things are as they are regardless of what they were.

We are just strings of quarks living in a suburb of the local density maximum of the universe.

We can predict the present without having to know everything about the past.

If all the stars and galaxies in the universe today were smoothed out into a uniform sea of atoms, there would only be about one atom in every cubic meter of space.

There are only certain intervals of time when life of any sort is possible in an expanding universe and we can practise astronomy only during that habitable time interval in cosmic history.

When we try to observe things that are very small, the act of observation itself will significantly disturb the state we are seeking to measure.

We can never know the origins of the universe. The deepest secrets are the ones that keep themselves.

There are 2, 500 kinds of sponges, all of them consist largely of holes.

You will soon find that I am a bit obsessive about my work. And that is a little sad, one often feels strangely restricted, not finding time to simmer, although one actually has many interests.

Love the world and yourself in it, move through it as though it offers no resistance, as though the world is your natural element.

She can sit up and beg, and she can give her paw — I don't say she will, but she can.

Onwards and upwards, and never give your failures a second thought.

Scientific and philosophic truth have parted company.

What interests me is seeing a problem and doing something about it, not all of the stuff around it.

Nothing is more difficult than the art of maneuvering for advantageous positions.

It must be confessed that the inventors of the mechanical arts have been much more useful to men than the inventors of syllogisms.

I always try to go back and check my old stuff. It's like watching the tapes of the game. You want to go back and go as hard as before.