April 21- Science

Radios are weird. They have all sorts of strange properties, like if you grab the antenna, the reception gets better. Another strange thing, that you may or may not have noticed, is that the reception is often times better at night. Which brings me to my question of the day: Why is the reception better at night? (Hint, it has to do with the sky)







In order to find a complete answer, we need to remember a couple of things. First, the earth is constantly revolving. Second, there are several layers of the atmosphere that keep said earth from frying. One such layer is the ionosphere. This is a layer of the atmosphere that has lots of ions very close to each other. Now lets look down at the picture. (Click on it to see the image in its entirety) You can't really see some of the writing I put on there, but, you can see the earth, and that white oval around it. Inside the oval is a purple line. That represents radio waves. Now, the left side of the earth is day, and the right is night. Since the ions are so close in the ionosphere, radio waves have to bounce off them. You can see that the ionosphere is closer during the day, so the radio waves have to bounce more, giving it more opportunity to get blurred. But at night, the ionosphere is farther away, so the waves can go farther in one bounce. This means you get a clearer reception.