It was after watching a documentary called "WOW Signal". The receiver they built was along the edge of a field, and it's designed to pick up extremely weak variations in electrical signals/radio waves. They go into great detail about how sensitive it is. The signal itself looks like a parabola when graphed, gaining in intensity and then falling off at the same rate. Exactly what you'd expect from someone walking across the field in front of it. And if I remember correctly, the signal was more about how much it differed from what was expected, not necessarily how intense it was. My thinking is that if it can pick up on the variations in signal from a star system light-years away, it would also indicate on a Timex watch (or flashlight) a dozen meters away.

I'd like to watch this documentary. Do you know the year and/or channel where you saw it? The antenna is focused with a tremendous amount of gain towards a spot in the sky, and provides a very significant amount of rejection to signals in all other directions. I can't see how you would get a signal at 1.42 GHz from a watch or flashlight. Harmonics from something like a walkie talkie only occur when the radio is transmitting, and they would spread in bandwidth at each successive harmonic. It would have to be an extremely narrow fundamental frequency, with no audio signal on it, to get a signal with less than 10 kHz at 1.42 GHz.

> The signal itself looks like a parabola when graphed, gaining in intensity and then falling off at the same rate. Exactly what you'd expect from someone walking across the field in front of it.

Also exactly what you'd expect if aliens were beaming a search signal into their sky, no?