Until the 1990s, there were few reliable observations about movement at the scale of the entire universe, which is the only scale dark energy effects. So dark energy could not be seen until we could measure things very, very far away.

We look at distant exploding stars called supernovae, and we've developed techniques to measure how far away they are and how fast they're moving away from us.

Einstein wrestled with a problem back before we even knew the universe was expanding, and he was looking for a way to keep the universe from collapsing. And so he discovered, in his theory of gravity, something like this dark energy - he called it a cosmological constant - could play this role, pushing things away.

You don't have to go very far away from Scandinavia to realize what an idyllic society it is.

It was all so far away - there was quiet and an untouched feel to the country and I could work as I pleased.

My mind's never gone very far away from what I wanted to accomplish.