Save that old TV - there's a message in the 'snow'

By Paul Saffo

Digital TV is wonderful, but there is one feature from the age of Analog TV that I will miss - snow. Yes, that warm white hiss that appeared whenever reception was bad, or a station went off the air. Back in the rabbit ear days before cable, snow was an irritating distraction or downright annoyance when it interfered with the Super Bowl or an episode of Gilligan's Island, but even then, snow was misunderstood.

Consider the cause of snow. A TV antenna is a sponge for radio energy, collecting lots more than just the desired signal. Snow is the result of the TV attempting to turn stray signals into an image, signals from radio stations, emissions from power lines, transformers or appliances, or even from the electrical noise of the circuits in the TV itself. The result is the strangely-calming ant-dance of black on white that we call snow.

But snow has another source, a source far from this planet in both time and space. Mixed in with the noise of Earthling civilization are radio echoes of the Big Bang, the moment of the Universe's creation 13 Billion years ago. The universe started out very small and very hot, and has been expanding and cooling ever since. As it cools, the Big Bang's fossil radiation sheds radio energy in the same way a cake on a cooling rack gives up heat. And when those indescribably ancient radio waves run down the rabbit ears and into your analog TV, the TV's circuitry interprets it as an image, and voila! - Snow.

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