We shouldn't be put out to pasture just because we've reached somebody's idea of retirement, which was certainly happening in Australia, and I think elsewhere as well.

[on playing Walter] It was wonderful to be able to play a character who had so many colors and who was able to play comedy, to play incredibly vulnerable, which he did a lot of the time, to play the love story, and to play the relationship with the son, which is quite unusual. That's a gift to me, as an actor. It was like everything you could possibly hope for, over five years. So, I was a very lucky actor.

A lot of the times, roles are chosen for us.

I'd never done anything that required a five-year commitment. To build a show that seems to have kept the imagination of the world so much was a bit otherworldly.

There's a certain pattern that exists with geniuses - an eccentricity, a lack of social graces and an inability to really communicate with mere mortals.

I find science really sexy and, at the time that I was a school kid, it certainly wasn't.

Working in television is very hard. I think people know that.