In any case, the leading edge of our "on purpose" radio signals is 30 light-years away and, if intercepted, may mend the aliens' image of us based on the radio bubble of our television shows. But this will happen only if the aliens can somehow determine which type of signal comes closer to the truth of who we are, and what our cosmic identity deserves to be.

Astrophysicists perfected navigation. We perfected all these things that matter to the power of nations manifest on the world stage. So we want to go into space. That's the new high ground, right? We care about multispectral imaging of things. Well, that's what reconnaissance wants to do. So our expertise has been in bed with national security needs forever. So maybe, secretly, that's why they keep us employed.

I don't want to go back into space for military reasons, but the economic driver still remains. And so it's a matter of people understanding how that economic driver is revealed with healthy investments on the space frontier.

People generally don't recognize how long it takes to conceive, publish, and write a book.

I [do not know] when the end of science will come. ... What I do know is that our species is dumber than we normally admit to ourselves. This limit of our mental faculties, and not necessarily of science itself, ensures to me that we have only just begun to figure out the universe.

Some air you inhale was exhaled by Cleopatra.

Our planet has been around only for four and a half billion years. Let's imagine a planet that has life on it such as life is on Earth and it's seven billion years old. Let's say that planet evolved intelligence. Well, that intelligence would be way more advanced than what we call intelligence here on Earth. How long has intelligence been around on Earth as we've come to define it?