In preparation for a career in academic medicine, I worked as a medical house officer at Columbia-Presbyterian Hospital from 1966 to 1968 and then joined Ira Pastan's laboratory at the National Institutes of Health as a Clinical Associate.

I had learned that science is a rewarding, active process of discovery, not the passive absorption of what others had discovered.

Anyone graduating from medical school in 1966 had first to fulfill military service before launching a career. Fiercely opposed to the Vietnam War, I sought to avoid it through an assignment to the Public Health Service.

The public schools I attended were dominated by athletics and rarely inspiring intellectually, but I enjoyed a small circle of interesting friends despite my ineptitude at team sports and my preference for reading.

I was doing chemistry in Research Triangle Park in North Carolina. It was the first time I'd lived alone, and I had an epiphany while I was spending a lot of time watching TV and decided I wanted try acting.

I've always thought of science fiction as being, at some level, a 19th-century business.

My father spent his entire early career as an illustrator for comic books: EC Comics like 'Tales from the Crypt' and 'Creepshow,' then moving on to such magazines as 'Mad' and 'Weird Science.'

Globalisation means many other countries are asserting themselves and trying to take over leadership. Please don't ask Americans to let others assume the leadership of human exploration. We can do wonderful science on the Moon, and wonderful commercial things. Then we can pack up and move on to Mars.