If we went to the Moon already, why can’t we go back so easily? What technology have we lost? What are we trying to do differently?
What’s the most distant thing we can see with the naked eye? What about with a telescope? What about at other wavelengths? Is there anything more to see?
What is “emergence” in physics and why is it a big deal? What would it mean for gravity to be emergent? How would we have to rewrite the laws of physics?
How can a “big rip” tear the universe apart? What does that mean for existence itself? Is it going to happen, and what are we doing to find out?
How do we track dangerous asteroids? What can impacts do to us? What do we plan to do if The Big One is headed for us? Is Armageddon a documentary?