“To teach is to learn twice.” Or thrice.

So I learned something about dark matter and Type 2 civilizations last month. From students. At 6:30 in the morning. This period is what’s known as a ‘zero-hour’ class in high schools.

I had been invited to observe making presentations in a STEM class. The air was thick with magnetic fields and an ‘Oort cloud.’ It was followed by animated discussions that went on as casually as if they were…