It seems impossible that you could get something from nothing, but the fact that once there was nothing and now there is a universe is evident proof that you can.

Physics is really nothing more than a search for ultimate simplicity, but so far all we have is a kind of elegant messiness.

In terms of adaptability, humans are pretty amazingly useless.

Energy is liberated matter, matter is energy waiting to happen.

Consider the Lichen. Lichens are just about the hardiest visible organisms on Earth, but the least ambitious.

The universe is an amazingly fickle and eventful place, and our existence within is a wonder.

On a cooler sun on a primordial earth: "I later learned that biologists, when they are feeling jocose, refer to this as the 'Chinese Resaturant Problem'--because we has a dim sun.

Worse still, it isn’t actually necessary to look to space for petrifying danger. As we are about to see, Earth can provide plenty of danger of its own.

For the moment we might very well can them DUNNOS (for Dark Unknown Nonreflective Nondetectable Objects Somewhere).

Be positive at all times! Leave out the negatives.

It is hard to talk about a middle ground for something that is a fundamental right.

Back in the mid-1970s, we adopted some fairly ambitious goals to improve efficiency of our cars. What did we get? We got a tremendous boost in efficiency.

You must have something new in a landscape as well as something old, something that's dying and something that's being born.

My point is, if you want to achieve anything in life, it is not enough to merely wish for it. You must develop that kind of 4:30 AM discipline that distinguishes you from others.

Weariness is the shortest path to equality and fraternity-and finally liberty is bestowed by sleep.

You can't put civil rights on the ballot.

Are we defined by our choices? Our behavior? Our actions? No. I don't believe that defines our worth.

Actually we're very lucky John McCain is not in charge because I think we would be in perpetual war.

If your judgement is clouded, you must be carrying too many things which are being a burden to you.