America has had many other discoverers besides Columbus, but he seems to have made more satisfactory arrangements with the historians than any of the others.

The information you get from social media is not a substitute for academic discipline at all.

Intuitively you want some place [such as your phone] to store phone numbers, so you have that part of your brain to do other tasks.

The most serious problem facing humankind is climate change. All of these people breathing and burning our atmosphere has led to an extraordinarily dangerous situation. I hope next generation will emerge and produce technology, regulations, and a worldview that enable as many of us as possible to live happy healthy lives.

It is my mission to change the world. I'm not kidding: Make no small plans, dream mighty things. I feel if we get enough people engaged in climate change, we will get enough people to change the world. We will revolutionize the way we produce electricity and provide clean water to people.

As my old professor Carl Sagan said so often, 'When you’re in love, you want to tell the world.’ And I base my beliefs on the information and the process that we call science. It fills me with joy to make discoveries every day of things I’ve never seen before. It fills me with joy to know that we can pursue these answers. It is an astonishing thing that we are — you and I are one of the ways the universe knows itself.

Bicycling is a big part of the future. It has to be. There's something wrong with a society that drives a car to work out in a gym.