How do we explain the giant black holes appearing in the young universe? Is it possible to directly collapse a black hole, skipping the formation of stars? What does ultraviolet radiation have to do with this?
How do you measure the impact of a scientist? Does Stephen Hawking compare to Newton or Einstein? What were his contributions to black holes, the big bang, and quantum gravity?
Why is the moon so special? Why do we think a giant impact created it? Why didn’t the same thing happen to other planets?
What is 21-cm radiation? What (and who) produces it? What causes it, and what does it tell us about the universe?
What is an Alcubierre warp drive? What would it take to make it work? Could it propel spacecraft even below the speed of light?