Here's a cool site from the University of Toronto. It features stuff like:
These days astronomers aren't just picking up signals from a time shortly after the universe began – they're creating maps of those signals to answer some of our deepest questions about the cosmos.Just remember that when deciding how to dispose of Grandpa's old TV in an environmentally friendly manner.
An old-fashioned TV with rabbit ears is designed to pick up very high frequency radio waves. When the TV is tuned to a channel for which there is no nearby broadcaster, the screen shows a lot of static. The static – also known as noise – is caused by random radio waves coming towards the TV from various manmade and natural sources, including deep space.
In the 1960's, Arno Penzias and Robert Wilson, two researchers at Bell Laboratories in New Jersey, began searching for sources of static for the purpose of improving satellite communication. They were searching in the "microwave" part of the radio spectrum, which lies at a somewhat higher frequency than a typical TV receives. What they discovered was that no matter where in the sky they pointed their special antenna it always picked up some microwave noise that could not be accounted for. Astrophysicists eventually realized that this noise was a predicted side effect of the birth of the universe billions of years ago.
