[steve19]

We have been leaking analog radio transmissions for such a short period of time during the lifetime of the universe that any other life out there would most likely be either underdeveloped or overdeveloped to receive the transmissions.

We have barely uttered a sound in the universe.

[khafra]

The mind-blowingly relevant picture: http://proto-knowledge.blogspot.com/2011/02/human-radio-bubb...

Of course, light goes really, really fast compared to anything physics says we can possibly manage for things with more rest mass than photons. Although there could be aliens on another spiral arm, or Andromeda, communication would take longer than the lifetime of our civilization; and material trade would take longer than the lifetime of our species.

[barisme]

Yes. Why do people assume you can just make a phone call to Andromeda? 'Ya, hi ET, what's new?' If Andromeda disappeared into a black hole 1 million years ago, we wouldn't even know yet. We have to wait 2.5 million years for news from Andromeda, assuming the news can't transcend the speed of light.

[metageek]

That's true, but the same would apply to any deliberate attempt to reach other life.