When you buy a jacket, you pick the size to ensure it fits. Similarly, we live in a universe in which the amount of dark energy fits our biological make-up. If the amount of dark energy were substantially different from what we've measured, the environmental conditions would be inhospitable to our form of life.

My emotional investment is in finding truth. If string theory is wrong, I'd like to have known that yesterday. But if we can show it today or tomorrow, fantastic.

It's hard to teach passionately about something that you don't have a passion for.

The idea that there could be other universes out there is really one that stretches the mind in a great way.

In my own research when I'm working with equations, I never feel like I really understand what I'm doing if I'm solely relying on the mathematics for my understanding. I need to have a visual picture in my mind. I'm constantly translating from the math to some intuitive mind's-eye picture.

There are many of us thinking of one version of parallel universe theory or another. If it's all a lot of nonsense, then it's a lot of wasted effort going into this far-out idea. But if this idea is correct, it is a fantastic upheaval in our understanding.

Science is the greatest of all adventure stories, one that's been unfolding for thousands of years as we have sought to understand ourselves and our surroundings.