He answered confidently, "Yes, it's a bit grey."
Then after a few more quiet moments passed, he asked, "What makes the wind move?"
I distractedly answered, "I think it has something to do with temperatures and the earth turning on its axis." Then Skye joined us to explain, "Ah, good question, Aidan. It's the sun that causes wind. The sun is responsible for a lot of the things we experience on earth. Think of the food we eat. It needs the sun to grow. ... "
He asked Aidan what happens to air as it heats up. Aidan said that it rises. So Skye explained how the hot air around the equator on Earth, rises toward the cooler air at the poles.