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.

It is not the amount of knowledge that makes a brain. It is not even the distribution of knowledge. It is the interconnectedness.

One of the ways the telegraph changed us as humans was it gave us a new sense of what time it is. It gave us an understanding of simultaneity. It gave us the ability to synchronize clocks from one place to another. It made it possible for the world to have standard time and time zones and then Daylight Savings Time and then after that jetlag. All of that is due to the telegraph because, before that, the time was whatever it was wherever you were.

For [Richard] Feynman, the essence of the scientific imagination was a powerful and almost painful rule. What scientists create must match reality. It must match what is already known. Scientific creativity is imagination in a straitjacket.

Everything we care about lies somewhere in the middle, where pattern and randomness interlace.

Vengeful conquerors burn books as if the enemy's souls reside there, too.

Running for president is the new selfie.