Quote:
Originally Posted by jyl
I don't remember the physics, but doesn't the strength of a omnidirectional radio signal diminish with the square of the distance from its origin? Has to do with the formula for surface of a sphere? So if a radio signal is "X" strong 1 mile from the transmitter, it will be 6 trillion squared or 4 x 10^25 times weaker when it reaches Alpha Centuari? I don't really see how such a weak signal can be distinguished from background noise, including that produced by Alpha Centuari itself? I can see if the signal is a supernova, but some local FM station broadcasting "Dancing Queen"? Anyone who knows the math, please explain. Thanks.
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I think your diminishing radio signal really only applies when said radio signal is in an atmosphere. In a vacum, there is no friction, allowing the radio wave to continue to propegate at the same wavelength and frequency. But solar wind and gravity may effect it a bit...
That said, anyone see the flick, "Contact" with Jodie Foster? Definately a "makes you think" movie...
-Z