It's very important in life to know when to shut up. You should not be afraid of silence.

The atmosphere of libraries, lecture rooms and laboratories is dangerous to those who shut themselves up in them too long. It separates us from reality like a fog.

I think the key to improv is always listening. It's embracing. It's positivity. It's hearing things and not shutting them down.

When I did my spacewalks, it was during space station construction. So the shuttle was docked to the fledgling ISS at the time. So we would always stay tethered.

In the astronaut business - the shuttle is a very complicated vehicle; it's the most complicated flying machine ever built. And in the astronaut business, we have a saying, which is, 'There is no problem so bad that you can't make it worse.'

I got a film fairly quickly and felt like I was on a roll. I would walk into auditions sounding like Crocodile Dundee, thinking, 'This is going to be a novelty for them.' Then I realised that there are a million other Australians here, and I should just shut up.