Because imaginary time behaves like another direction in space, histories in imaginary time can be closed surfaces, like the surface of the Earth, with no [existential] beginning or end.
Stephen HawkingThe rate of progress is so rapid that what one learns at school or university is always a bit out of date. Only a few people can keep up with the rapidly advancing frontier of knowledge, and they have to devote their whole time to it and specialize in a small area. The rest of the population has little idea of the advances that are being made or the excitement they are generating.
Stephen HawkingI would like nuclear fusion to become a practical power source. It would provide an inexhaustible supply of energy, without pollution or global warming.
Stephen Hawking