I find Australia compelling and vexatious at the best of times; I've never been able to get it out of my system since going there as a young lecturer, and yet however much I love revisiting it, I always feel I have to leave again.

I wish I could shut up, but I can't, and I won't.

The greatest and most important problems of life are all fundamentally insoluble. They can never be solved but only outgrown.

I think we are at the dawn of a new era in commercial space exploration.

We prefer world law in the age of self-determination to world war in the age of mass extermination.