It Began with a Flashlight

Let’s  change gears here a bit and extend our gaze out to the stars. Back when I was a kid, somebody told me about light speed. It was on a summer night and we were outside looking up at the stars. To give me an idea of how far away they were, my companion turned on the flashlight we had been playing with, pointed it up to the sky, and flicked it on and off. He explained that in one second, that flashlight beam had traveled 186,000 miles (300,000 kilometers). I couldn’t even begin to wrap my head around the idea at the time. What came next really boggled my mind: even if that light traveled all night, it still wouldn’t have even left the solar system. It would take years to get to the next star, if it got that far.

Wow.

I played a lot with flashlights (no doubt annoying my parents who had to keep buying batteries for them) trying to figure out how we could send signals to space using them. It didn’t occur to me (because I didn’t know until much later) that most of the light would eventually be absorbed by interplanetary and (and if I was lucky) interstellar dust. So, my signals to beings on distant planets likely will never get very far.

Human beings, however, are sending out other signals that ARE getting “out there.” In fact, the leading edge of that signal “front” is about 75 years away from us. It’s a spherical “front” carrying a steady stream of signals stretching back to the first radio and TV broadcasts to signals that are just now leaving our planet. As it turns out, there are some stars with planets around them that lie inside that expanding sphere of influence. Any beings on those planets who can receive broadcasts are probably trying to puzzle out just what it is we’re trying to tell the universe. And somewhere, lost in all that noise, I’d like to imagine that my feeble little flashlight signals are limping along, telling the cosmos that I said “hi.” (Of course they’re not, but it’s kind of an awe-inspiring thought, anyway…)