Just how hard are exoplanets observations? What kind of telescope will it take to find life? And how much information can we get out of a single pixel of light?
What was the big deal about Chandrasekhar’s discovery? Why did he meet so much resistance? How is his work tied to everything from supernovae to black holes?
What does high-speed motion through the universe do to your perspective? What is the Rindler horizon, and how does it appear? Would you get vaporized by a high-energy bath of radiation?
What really keeps the Sun shining? How long would it stay warm if fusion stopped? How long would it take before we noticed?
What are the weaknesses of inflation theory? How did the ekpyrotic theory attempt to improve it? How did it open up its own can of worms?