Cosmic Noise

The popcorn noise on old TVs is caused by leftover radiation from when the Universe was very young, emitted only a few hundred thousand years after the Big Bang.

This one might take a bit of explaining, but for that I will simply direct you to NASA's excellent "Universe 101" site, set up for the WMAP satellite that precisely measured the cosmic background radiation. In the image above, the TV noise is represented by actual data from WMAP.

Thanks again to Kara for the image and Science for the cool fact about the Universe!