Stephen Hawking is the last of the 20th century's celebrity scientists. As did Albert Einstein, Richard Feynman, Carl Sagan and a handful of others, he has the rare gift of being able not only to think deeply about the mysteries of the cosmos, but also to capture the imagination of the public with his ideas.
That celebrity was on full display Wednesday night, when more than 2,000 people, some of whom waited in line for hours in lawn chairs, showed up at the Caltech campus in Pasadena to hear him speak.
Hawking, 66, delivered a prerecorded talk about black holes, sprinkled liberally with humor about his failure to win a Nobel Prize for his theory about Hawking radiation, a leakage of radiation from the massive gravity of a black hole.
At the end of his talk, he answered five questions submitted by Caltech students.
Hawking's close friend Kip Thorne, a Caltech physicist, described the painstaking process by which the British theoretician, who has Lou Gehrig's disease, programs his computer to speak for him.
According to Thorne, it took Hawking several days to program answers to the students' questions. "He is about the most patient, stubborn man I know," Thorne said.
Everyone depicts black holes as round objects, but are doughnut- or pretzel-shaped black holes possible?
One of the results I obtained when I was a [postdoctoral student] was that a black hole in four dimensions has to be round. There are no doughnut-shaped black holes in four dimensions. However, one of my former students found there could be doughnut-shaped black holes in five dimensions.
Given that any extraterrestrial colonies that we develop would likely be wholly dependent on Earth for support, do you think we should be involved in manned space exploration?
Any extraterrestrial colonies we establish will depend on Earth for support at first. However, the aim should be to make them self-sustaining before too long. Only then will the future of the human race be safe from disasters on Earth. It would certainly be necessary for the colonies to be self-sustaining as we go to other stellar systems. Just to send a message to Earth that more supplies were needed would take at least four years. And it would take hundreds or thousands of years to actually send the supplies.
Could the cosmic microwave background radiation be a form of Hawking radiation?
