LogFAQs > #964783460

captpackrat posted...

So our radio signals have now traveled over 100 light years and encompasses a volume of over 4 million cubic light years. There are at LEAST 59,722 visible stars within this range

The problem there is, contrary to science fiction and laypeople's understanding of science, radio waves aren't really infinite. While they do travel outwards at the speed of light, it wouldn't necessarily radiate outward as a perfect sphere, and they suffer from signal degradation (weaker signals are also distorted and absorbed into the atmosphere to some degree, and potentially drowned out by the "louder" radiation from the sun). The farther away radio waves get, the more diffuse they get, which means the more garbled and static-y they get, until you reach a certain point where they'd become almost indistinguishable from the general background radiation of the universe.

It's currently theorized that you wouldn't be able to really receive any useful information from normal radio waves beyond the range of our own solar system - even Alpha Centauri (the closest star to us) is too far away to actually detect our radio waves in any meaningful way. By that point all they'd really be able to pick up is a single photon or two, not enough to actually detect anything resembling a coherent pattern. Definitely not enough to then assume it was a sign of life (and in the same vein, we won't be detecting anyone else's radio waves either, for the same reason).

About the only way you'd detect anything is if we (or "they") deliberately sent a tight-beam direct transmission aimed at a specific star (and remember, space is moving, so we'd have to aim at where it's going to be, not at where it appears to be now). Even then it would still potentially diffuse over time and distance, so you still only have a limited range you could feasibly reach. And you'd have to be sending repeated bursts at every star you can see in the sky and hope you get lucky that one of them has a civilization that is capable of detecting your signal and willing to try and respond.

It's the equivalent of throwing a message in a bottle into the sea off the coast of England and assuming it will eventually be found by someone in New York. Sure, it could happen... but it probably won't.



GGuirao13 posted...

Only Earth has intelligent life.

I've seen no evidence of it.