This experiment is one that sounds strange, but it actually is very simple. You can broadcast radio waves with your socks. You can also broadcast with your shirt, a pair of pants, or a wool sweater, but socks work very nicely, and it sounds more unusual.
For this experiment, you will need:
- a clothes drier
- a variety of clean laundry, including some socks
- a portable radio
First put the laundry into the drier. Your mother will appreciate this, but be sure to check the labels first, so you don't shrink someone's favorite dress (I know this from experience. Just ask my wife!) Do not put any of the anti-static products in the drier, as we want as much static as possible. Run the drier, just as you would for a normal load of laundry.
Once you have a drier full of hot, dry clothes, you are ready to begin broadcasting. Turn on your portable radio and place it near the drier. It is best to tune your radio to an AM station. As you remove the clothes from the drier, you will find that the clothes are sticking together, especially the socks. When you pull the socks away from the other clothes, you will hear a faint crackling sound. At the same time, you will hear a lot of static on the radio. Your socks are sending out radio waves, which the radio is picking up.
If you don't get enough static from the drier, try rubbing a balloon on a wool sweater. This should also produce static on your radio.
How can your socks broadcast radio? As the clothing is tumbled in the drier, it builds up a charge of static electricity. Depending on the kind of material, some of the clothes will get a positive static charge and some of them will get a negative static charge. The two different charges stick together. When you pull the socks away from the other clothing, the static charges produce small sparks. These sparks cause the crackling sound. Any time you make an electric spark, you produce radio waves. The sparks from your socks only make very weak radio waves, but they are strong enough for a nearby radio to pick up.
Now that you have gone this far, finish unloading the drier and put the clothes away. Again, your mom will appreciate it.