Eureka! I've Figured Out Why We Can't Detect Alien Communications!
You heard it here first, folks.
It has just dawned on me why in all our years of searching the skies, we have not been able to detect any communications from an alien civilization. I've read just about everything by Carl Sagan on this matter, and several other authors, and I've never heard this from any of them, but it seems suddenly obvious to me!
1. The universe being so big, with new planets orbiting far away stars being discovered all the time, and billions of billions of stars out there, it seems reasonable (whether you're a creationist or an evolutionist) to expect there to be innumerable civilizations out there, at all levels of development.
2. Radio is the fastest, and indeed only, way we know of for these civilizations to communicate with one another, and with us, over the vast distances of space, so we have been scanning the heavens for an alien signal for quite a few years now looking for an extraterrestrial signal.
3. In all our searching we have not been able to detect a single artificial alien radio signal.
The reason is: there exists a means of communication over large distances that is faster and more reliable than radio! That's it!
Imagine a Native American living several hundred years ago. He looks up into space and somehow deduces that the stars up there are far away suns with people like himself living near them. What might he do? He might call to them, shouting at the top of his voice, then listen carefully for some dim response. But what is his best means of communication over such large distances? Smoke signals! His people communicate over distances far too large for shouting by means of smoke signals. Of course, he knows that the people living out near those stars won't understand his own tribe's signals, but they'll use something similar. So he'll look carefully at the star, looking for some detectable signals. He'll climb up the highest mountain and try to send some signals of his own, hoping they'll be looking.
It might seem absurd, but what's wrong with his idea, really? Maybe with time this Native American and his fellow believers will develop powerful telescopes able to see far away planets, so that they can scan them for any answering signals. Yet after years of scanning planets at the far reaches of the galaxy, he still hasn't detected an alien smoke signal. Why?
The reason is simple: any civilization that develops smoke signals as a means of communication will shortly (within a matter of a few hundred years) develop radio. When they do that, the value of smoke signals for communication over distances will immediately disappear. So the odds of actually witnessing a smoke signal anywhere in our vast universe is extremely remote.
So, here we are, probably the laughing stock of advanced civilizations throughout our universe, as we scan the heavens for radio signals of all things, while all along the universe is crowded with... subspace, or whatever... signals everywhere you look!
So, the obvious conclusion of all this is that whatever money we are spending today to search for extraterrestrial radio signals ought to be immediately diverted to research into faster-than-light means of communications, so we can join the party!