The universe is computing its own destiny.

Tiny differences in input could quickly become overwhelming differences in output.... In weather, for example, this translates into what is only half-jokingly known as the Butter- fly Effect—the notion that a butterfly stirring the air today in Peking can transform storm systems next month in New York.

The library will endure; it is the universe... We walk the corridors, searching the shelves and rearranging them, looking for lines of meaning amid leagues of cacophony and incoherence, reading the history of the past and of the future, collecting our thoughts and collecting the thoughts of others, and every so often glimpsing mirrors, in which we may recognize creatures of the information.

The basic idea of Western science is that you don't have to take into account the falling of a leaf on some planet in another galaxy when you're trying to account for the motion of a billiard ball on a pool table on earth. Very small influences can be neglected. There's a convergence in the way things work, and arbitrarily small influences don't blow up to have arbitrarily large effects.

When information is cheap, attention becomes expensive.

Intuition was not just visual but also auditory and kinesthetic. Those who watched Feynman in moments of intense concentration came away with a strong, even disturbing sense of the physicality of the process, as though his brain did not stop with the grey matter but extended through every muscle in his body.

I can't remember the last book that taught me so much, and so well, about what it means to be human.