Science cuts two ways, of course; its products can be used for both good and evil. But there's no turning back from science. The early warnings about technological dangers also come from science.

Somewhere, something incredible is waiting to be known.

It is far better to grasp the universe as it really is than to persist in delusion, however satisfying and reassuring.

The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff.

Imagination will often carry us to worlds that never were. But without it we go nowhere.

I don't want to believe. I want to know.

The absence of evidence is not the evidence of absence.

The brain is like a muscle. When it is in use we feel very good. Understanding is joyous.

We live in a society exquisitely dependent on science and technology, in which hardly anyone knows anything about science and technology.

For small creatures such as we the vastness is bearable only through love.

You have to know the past to understand the present.

The world encyclopedia, the universal library, exists, and it is the world itself.

Have an open mind! Have an empty cup!

I thought: 'My education is driving a wedge between me and the people I love.' And then I wondered: 'What would happen if it were possible to increase a person's intelligence?'

The best way to fill time is to waste it.

While I take inspiration from the past, like most Americans, I live for the future.

I love to work out and do cardio and have a healthy, active lifestyle, but I also am not going to, like, freak out over food.

One of America's strengths has always been its openness to the new: both new ideas and new people.

It's as certain that as long as fossil fuels are the cheapest energy, we will just keep burning them.

I hate being told I can't do something because I'm a girl!

The recognition that things that are not sustainable will eventually come to an end does not give us much of a guide to whether the transition will be calm or exciting.