Why is it so hard to predict solar eclipses? How did Newton and Halley team up to solve it? What have we learned from solar eclipses since then?
How hard is interstellar travel? What are the possible ways to achieve the required energy?
What’s the deal with redshift? How can we actually interpret velocities when it comes to cosmic expansion?
Is light made of waves or particles? Is matter made of waves or particles? What does it mean for matter to “wave”, anyway?
What’s so bad about Venus, besides everything? How did it get so bad? How about Earth? @PaulMattSutter will answer the questions at #365DaysOfAstro
What is the “cosmic calendar”? What are some important scales in the universe?
What are galaxy clusters made of, besides galaxies? How can we use them to understand dark matter? And how can we make pretend ones on a computer?
What is “information” in physics? Why do we think it’s preserved, and what happens to information when it falls into a black hole? Why is this a problem? I discuss these questions and more in today’s Ask a Spaceman!