> What forms of communication they might be using is
> anybody's guess.
Marconi wouldn't have been able to detect ETs on the moon,
if they were using GSM, TDMA or GPRS. Nonetheless, our
culture, 100 years later, is still using some AM that even
Marconi could detect. But will we in 200 years? 500? 1000?
Our signal encodings on earth are increasingly looking
more and more like low power noise, and are often
deliberately encyrpted to prevent casual receivers
from extracting information. What will our wireless look
like a few centuries hence? Will it even be EM?
If ETs Out There are still using some legacy comms,we
just might detect one. As long as the funding for looking
is voluntary, or a trivial fraction of NASA's budget,
I have no problem with it. We'd really feel silly if we
didn't look, and later discovered that latent value was
there all along had we bothered.
But the odds, distances, noise, and time suggest no joy.
And the results to date are consistent with the estimated
odds.
"But I am not really willing to accept your premise, because it may well be that the means of communications they have are of a kind that we do not know how to receive, and that they would not have the means of communicating with sufficiently powerful radio or optical signals. That is something which, technologically, is too difficult for them but they would have some other means we would not recognize." -- Thomas J. Gold (Communication with Extraterrestial Intelligence)