Earth: Hot and Cold
Earth is hot on the inside, so hot that iron melts. And it is much cooler on the surface. Since heat always flows from high temperature to low temperature, that means the Earth is slowly cooling. How quickly is the Earth cooling? How does heat get from the inside to the outside? What is the temperature at the very center of the Earth? Why is this important to us, living at the surface? In my talk, I will address these questions, and have time to take lots of questions from the audience.