TOP > Special > Stephen Hawking - Stephen Hawking Ponders the Universe -
——What made you choose physics and cosmology?
I studied physics and cosmology because I wanted answers to the big questions: Why are we here? Where did we come from? I would encourage other young people to do the same. There's nothing like the thrill of discovery, when you find something that no one knew before.
——What are you working on now?
I am working on black holes, and on how the very early universe led to what we have today. And especially, I'm working on how the universe was spontaneously created out of nothing and on how information gets out of black holes.
——Have you ever seen the data of Japanese X-ray satellites, such as ASCA? What do you think of X-ray astronomy and astrophysics in Japan?
The data from the Japanese and other x-ray satellites are very useful for detecting black holes. Black holes do not give off x-rays themselves, but they are often surrounded by a disk of gas, which is spiraling down into the black hole. The gas gets very hot, and radiates x-rays. In this way, we have observed large numbers of black holes, ranging in diameter from a few kilometers to millions of kilometers. Japan has a fine tradition of theoretical work in astronomy, stretching back many years. Observational and x-ray astronomy came later, but are now very active.
ASCA (Advanced Satellite for Cosmology and Astrophysics, formerly ASTRO-D), a Japanese X-ray astronomy satellite (left)
An image of the central galaxy captured by ASCA SIS (right). Scientists believe there is a supermassive black hole at the core.