# FOOD FOR THOUGHT: Broadcasting is magic

Fact. The received power from a satellite is measured in millionths of a watt. Even after amplification and processing by your satellite dish, the signal is usually about -35dBm, which is .000000316 watts. A nightlight is 5 watts, and a full-on incandescent lightbulb is 100 watts.

So what I’m saying here is that all that digital picture and sound comes from a signal that is three ten-millionths as powerful as a light bulb. First of all it’s a miracle that you can even pick up a signal that weak from 22,000 miles away. That’s just astounding by itself, but there’s some science to it: the transmitted frequency is really high, and that keeps the signal stable. But really, 22,000 miles to a dish that’s less than 1 meter wide? Boggles the mind.

Once you get that signal, and it travels to your receiver, it’s decoded using the kind of math that would make your algebra teacher’s head explode. Decompression, error correction, remodulation and display take place 60 times a second for over 2 million individual pixels, and each pixel can be any one of 16 million colors.

Do you have a headache yet? Just imagine, all that just to bring you a show you’re not even that interested in. Just to give you the ability to channel surf takes billions of dollars of equipment and millions of watts of power on dozens of satellites, thousands of broadcast facilities, and it’s the life’s work of tens of thousands of people.

Chew on THAT the next time that you’re stuck watching reruns of Magnum, P.I.