In the past, on Earth, it has largely been to exploit foreign resources and to expand the domestic territory.

The sun and its retinue of planets drift as a group through the vast gulfs of space that separate the stars.

Years of science fiction have produced a mindset that it is human destiny to expand from Earth, to the Moon, to Mars, to the stars.

Present annual world energy consumption is about equal to the annihilation energy of 4 tons of matter.

It may seem unfashionable to say so, but historians should seize the imagination as well as the intellect. History is, in a sense, a story, a narrative of adventure and of vision, of character and of incident. It is also a portrait of the great general drama of the human spirit.

It's all about balance, and I have so much happiness in my career and am fortunate to travel the world and see so many amazing things - it will also be nice to be anchored to something grounded and in the same place. Raising a family will be a wonderful part of that.

I like to travel, and I'm always ready for a new experience.

My most prized possession is my pillow. I can't travel or sleep without it. And it's, like, this really thin down pillow that really doesn't do anything, but it's weird: if I don't have it, I'm constantly thinking about not having it.