Leonard Susskind

The success of ordinary cosmology speaks against the idea that the universe was created in a random fluctuation.

Space can vibrate, space can fluctuate, space can be quantum mechanical, but what the devil is it? And, you know, everybody has their own idea about what it is, but there's no coherent final consensus on why there is space.

Why is there space rather than no space? Why is space three-dimensional? Why is space big? We have a lot of room to move around in. How come it's not tiny? We have no consensus about these things. We're still exploring them.

Unforeseen surprises are the rule in science, not the exception. Remember: Stuff happens.

I have a funny mental framework when I do physics. I create an imaginary audience in my head to explain things to - it is part of the way I think. For me, teaching and explaining, even to my imaginary audience, is part of the process.

I was from a poor Jewish family in the South Bronx. My father was a plumber, but when I was 16, he got sick and I had to take over. Being a plumber in the South Bronx wasn't fun.

Life is fragile: it thrives only in a narrow range of temperatures between freezing and boiling. How lucky that our planet is just the right distance from the sun: a little farther, and the death of the perpetual Antarctic winter - or worse - would prevail; a little closer, and the surface would truly fry anything that touched it.

You are a victim of your own neural architecture which doesn't permit you to imagine anything outside of three dimensions. Even two dimensions. People know they can't visualise four or five dimensions, but they think they can close their eyes and see two dimensions. But they can't.