Gary McConkey from Knightdale, N.C., writes:
I often park my car in the sun. When I get back inside, it feels warmer than the outside temperature. Why is that?
This is a good example of the “greenhouse effect,” which is essential to life on Earth. Without it, our planet wouldn’t be warm enough for living things to survive.
In the case of a car, the sun’s rays enter through the window glass. Some of the heat is absorbed by interior components, such as the dashboard, seats, and carpeting. But the heat they radiate is a different wavelength from the rays of the sun that got through the glass, and it doesn’t let as much of the rays pass back out. As a result, more energy goes into the car than goes out, and the inside temperature increases.