We discussed distances and learned about the inverse square law. We discussed the electromagnetic spectrum and learned how scientists use light to figure out what stars are made of and how far away they are. We learned about the speed of light. We learned that the Universe is a really big place and still getting bigger. It wasn't very long ago that scientists didn't understand any of what we learned today.
Science is a continuing process, and to continue the process one needs an inquisitive mind.
The Universe is a strange and wonderful place, filled with mysteries just waiting for us to figure out.