Time allows change to take place and the very evolution of the universe is what requires some conception of time. Mathematically can we write down a universe that doesn't have time? Sure. Do we think that would be realised in the larger reality that is out there? None of us take that possibility seriously.

Many different planets are many different distances from their host star; we find ourselves at this distance because if we were closer or farther away, the temperature would be hotter or colder, eliminating liquid water, an essential ingredient for our survival.

Art makes us human, music makes us human, and I deeply feel that science makes us human.

The revelation we've come to is that we can trust our memories of a past with lower, not higher, entropy only if the big bang - the process, event, or happening that brought the universe into existence - started off the universe in an extraordinarily special, highly ordered state of low entropy.

I believe we owe our young an education that captures the exhilarating drama of science.

Our eyes only see the big dimensions, but beyond those there are others that escape detection because they are so small.

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.