We already know the limits of Einstein's theories. From the centers of black holes at the very beginning of the universe - we call these singularities - Einstein's equations fail. In fact, people have joked that's where God is dividing by zero.

If you love what you do, you'll be your best at it compared to anything else you might have chosen as a career. Or at least you will love it more, and you won't lead a depressed day of your life.

The problem, often not discovered until late in life, is that when you look for things like love, meaning, motivation, it implies they are sitting behind a tree or under a rock. The most successful people recognize, that in life they create their own love, they manufacture their own meaning, they generate their own motivation. For me, I am driven by two main philosophies, know more today about the world than I knew yesterday. And along the way, lessen the suffering of others. You'd be surprised how far that gets you.

Imagination alone is not enough, because the reality of nature is far more wondrous than anything we can imagine

Like no other science, astrophysics cross-pollinate s the expertise of chemists, biologists, geologists and physicists, all to discover the past, present, and future of the cosmos-and our humble place within it.

These are two different exercises. One of them is, "You don't know and I know, so just shut up and listen," and the other one is, you're curious and you're learning, and I have a way where you can learn this so you'll know it as well. And when you know it, and know why you know it, then you don't have to reference me ever again because you take ownership of the knowledge, and you can then share it with someone else.

I am proud to be part of a species where a subset of its members willingly put their lives at risk to push the boundaries of our existence.