New generations of humans inherit the acquired discoveries of generations past, allowing cosmic insight to accumulate without limit. Each discovery of science therefore adds a rung to a ladder of knowledge whose end is not in sight because we are building the ladder as we go along. As far as I can tell, as we assemble and ascend this ladder, we will forever uncover the secrets of the universe - one by one.

All tweets are tasty. Any tweet anybody writes is tasty. So, I try to have each tweet not simply be informative, but have some outlook, some perspective that you might not otherwise had.

Science literacy is a vaccine against the charlatans of the world that would exploit your ignorance.

I try to write in a way where you care deeply what the next paragraph will be. I hear the rhythm of prose and that, to me, distinguishes great writing from ordinary writing. By the way, I don't even claim that I'm good. I claim that I value it.

I've accomplished enough in life so that I do not fear death.

Everything we do, every thought we've ever had, is produced by the human brain. But exactly how it operates remains one of the biggest unsolved mysteries, and it seems the more we probe its secrets, the more surprises we find.

When Kennedy said, 'Let's go to the moon,' we didn't yet have a vehicle that wouldn't kill you on launch. He said we'll land a man on the moon in eight years and bring him back. That was an audacious goal to put forth in front of the American people.