“If, years later, I do use the slit detector to observe which way the electron went, it will mean that many years earlier the electron must have passed through one slit or the other. But if I don't ...”

“If I keep observing the uranium, which means a little more than keeping my eyes on the pot on my desk and involves something akin to surrounding it with a whole system of Geiger counters, I can fre...”

“It does appear that some parts of our evolutionary process seem inevitable. It is striking that throughout evolutionary history, the eye evolved independently fifty to a hundred times. This is stro...”

“One of the most curious consequences of quantum physics is that a particle like an electron can seemingly be in more than one place at the same time until it is observed, at which point there seems...”

“To understand this new frontier, I will have to try to master one of the most difficult and counterintuitive theories ever recorded in the annals of science: quantum physics. Listen to those who ha...”

“Some might question whether it makes sense to talk about setting up the experiment and running it again with exactly the same conditions--that it is, in fact, impossible. Locally, you might get the...”