I recently went back to my old high school and gave a presentation to a few classes of senior students (that’s students in their final year of school for those of you not from the USA). I did this to practice giving talks, and to share the work I’d done over the summer studying the cosmic microwave background. Using half the lesson, I gave a 20 minute whirlwind tour of the history of the early Universe, then opened up the floor to questions. The students were wonderfully engaged, and asked lots of insightful things. In this post I’m going to go through some of my favourites, as well as the answers I gave.

Topic 1: Black holes

I never actually mentioned black holes in my talk (though there are interesting things regarding black holes in the early Universe), but the most common questions I received from all three classes were about black holes. I can’t blame them for this, black holes are fascinating and worth asking about if someone who knows about astrophysics drops by to talk to you.

What is a black hole?

Topic 2: The CMB