SETI is very much an ingenious way of trying to "spot" ET.  I just wonder if ET would be communicating using methods that we could detect.  You would have to be lucky enough to get a civilization that is about as advanced as we are, maybe slightly more, but not much more.  Already, we are experimenting with methods of communication where the signal is indistinguishable from noise.  By spreading out the signal power over a large range of frequencies, you still have the same energy, but no longer the obvious "spike" at some center frequency.  And, this ultra-wideband technology allows for far better throughput and is immune to many of the physical destructors of narrow-band communications.  It is also more secure since the signal exists below the noise-floor.  It seems like ET would have figured this out at some point, understood the benefits, and quickly adopted such a technology.

So after that bit of useless information, I would imagine that SETI would have a low probability of finding a signal they could recognize.  But then again, if there are a lot of industrial-age civilizations out there, perhaps we will hear something.  On the other hand, there are a lot of very gifted engineers out there and I'm sure they know a lot more about detecting such things than I do........

Maybe we will hear about something exciting in the coming years.

The really amazing thing about SETI is how big a failure it has been. Decades of searching with no results. It has made more than one scientist speculate that we may be the first. The first in all the universe. Even if E.T. civilizations had become extinct through massive scale war, there still would have been detectable signals of that civilization. And the odds are that not every E.T. civilization would have blown itself up, if there were any out there in the first place. So the utter silence out there starts to suggests, not only are we alone but possibly the very first.

How do you figure it's a failure? The idea is simply to put your ear to the sky and listen. Considering messeges or transmissions could take hundreds of years to get here how can 'not hearing anything' be construed as a failure, or proof that there's no "ET"?

Dont get me wrong, if you just kinda think it's a waste of money I could definately see your point, but failure? It never had much chance at 'success' in terms of finding aliens, but it is a success insomuch as the system works -- it is listening. It just seems to me that 'failure' in this case is definied as not winning the lottery when the only idea ever was to play.


Ahk

SETI to me is in a situation where even a "failure" to find something should be considered success. 

Think about it.  If SETI hears something, then the idea that we are not the only intelligent species in the universe will be Earth-shattering (figuratively speaking hopefully).

But to me, a realization that we are the only intelligent species in the universe is far more profound.  If we are "alone", perhaps we now know what our purpose is - to spread life around the universe.  If it is just us, and intelligent life exists nowhere else - then SETI gives us some small bit of evidence that what we have here is so unique, and so precious, that we can't afford to squander it. 

If you believe absense of evidence is evidence of absence, then the failure of SETI should give humanity pause and we should be rethinking our priorities.......

Major Zee Lee the premise of SETI is a little different from how you have framed it, in terms of a message. Radio waves are light speed transmissions, their use for communication is supposed to be a very probable in any advanced society at some point in it's development. SETI is not aimed at capturing focused or directed signals. It is trying to pick up evidence of the use of radio waves anywhere in the universe. But the sky is utterly quiet. No noise. No radio waves anywhere. This is considered to be very significant. Very improbable based on our previous assumptions about the ubiquitous presence of intelligent life in the universe.

Considering we have only been looking for other intelligent life for... less than 100 years I think it is too early to call it a failure.

I have no idea how my refrigerator works, but I really never considered worshiping the guy who gave it to me. On the scale of our solar system the earth holds chumpchange resources, 20million lightyears is a long way to go just to pick a fight.

We've been looking for et radios for a few decades, but we've checked only a tiny percent of the sky. And it's certainly not the darkest hole we're throwing money down.

on Cryptomainac's point about not sending recognizable signals; We are sending out am and fm raidio and tv signals without compression or spread spectrum so they would look like signals.