The school system is constructed to praise you if you get high grades. And if you get straight A's, you're the one that everyone puts forward, and they prognosticate that the straight-A person is the one most likely to succeed, because that's the way the school system is constructed and conceived.

If you want to assert a truth, first make sure it's not just an opinion that you desperately want to be true.

There are as many atoms in each molecule of your DNA as there are stars in the typical galaxy. This is true for dogs, and bears, and every living thing. We are, each of us, a little universe.

Nothing is a thing: it's nothing. So I can imagine a place where there's not even nothing.

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.

Nature is not here to keep you alive. It has just as many ways to kill you as it does to sustain you. And if you cherry-pick this fact, you are left thinking that earth is some haven for life, but 96, 97 percent of all species that ever lived on earth are now extinct from the actions of the earth itself and an occasional asteroid to stir the pot.

Physics is the only profession in which prophecy is not only accurate but routine.