Why have we yet to discover an extraterrestrial signal with SETI or any other means?

Question

Could it be that we aren't listening in the right way, or that other intelligent life is not broadcasting, or that the lifespan of an intellegent race is very short? Could it just be that we're all alone in the Milky Way?

Answer 1

'cause Jodie Foster is not working there anymore! and the aliens and i think she is hot!

of course x-files had some luck, but Gillian Anderson is not there anymore and she is hot!

Answer 2

All of your points are potential problems. Plus, the universe is very, very big. If every person on Earth spent all of their time looking at signals from stars, one star per second, then it would take around 30,000 years to check the whole of the heavens for life.

But it is certainly true that the lifespan of advanced civilisations could be very small - of the 4 billion or so years that there has been life on Earth, only for 250,000 years or so has there been advanced intelligent life and only for 100 or so has that life been broadcasting signals. In other words, the window is 1 forty millionth the lifespan of a planet.

Answer 3

Because the only signals we have the technology to look for (SETI is always simply piggybacked onto other research instruments) are beacons in the radio spectrum. IE deliberately set up omni-directional high power radio signals designed to announce someone's presence. And for all we know, that's the equivalent of looking for smoke signals, IE there's no particular reason an advanced civilization would do that. We haven't set up such a beacon for example, and no one is even calling for the idea. It would be insanely expensive for starters, and there's plenty of people who would find the idea of deliberately signalling our presence to aliens a bad idea. So basically we haven't found anything because to date the nature of the technology we have available for SETI has limited our search to a very limited scenario of alien signals, signals that may not even exist. As our technology improves this will get better. We are also very close to being able to examine the atmospheres of planets around nearby stars for their chemical constituents for example, and industrial pollutants would be a dead giveaway. Other search technologies, like looking for laser signals, are in the pipeline. If there are aliens out there, we will eventually spot them. Basically we are in the very very early ages of SETI, it would be surprising if we had gotten results so far, that we haven't is no surprise at this point. It's entirely also possible there are no aliens, or that they are so rare that the chances of finding them are essentially zero. If 100 years from now we have found no aliens, well then you can start getting discouraged.

Answer 4

Any answers have to be guesswork--so here's mine. I think it likely that there are other civilizations out there--but there may not be very many. Here's one reason why:

Suppose that most life evolved on planets around stars similar to our sun--and followed a similar path and timetable. In that case civilizations might develop anytime in the last billion years or so--so even if the lifetime of thos civilizations is long (say 10 million years) only about 1/100 would be around right now--and theres no reason to expect all--or even a llarge percentage--of those possible planets to produce a technological civilization. That could leave many civilizations out there (the galaxy is a VERY big place) but such civilizations would be very far apart. It could be a very long time before we contact one--centuries or even longer.

The other reason is that I think SETI is on the wrong track. Civilazations out there are likely to use lasers, not conventional radio, for interstellar communication. And with so many stars in the galaxy, they'd be likely to wait until they picked up some indication (radio, etc.) that told them we were here before they'd try to contact us--tey'd have to; there's milllions of possible stars--trying to send messages to all of them all the time would be ridiculous.

So I think its going to be a long time before we get any kind of a message. And that's assuming that there isn't a way to travel faster than light (which may be the case--but the "light barrier" doesn't seem to be aas absolute as we once thought). If that's the case, we won't hear from them--they'll just wait till we come to visit!

Answer 5

We may or may not hear from them but they are surely out there.
They would probably listen and transmit in the right way but there are many things that could prevent communication.
You are right,longevity is probably the real reason we may never get a contact.

Answer 6

sound travels very slow when it comes to space. even at the speed of light( about 186,000 miles per second ) it would take forever. there are some theories that say most life started about the same time. if that is so then we are all just learning about the same speed. and who is to say they have not found proof of life and the religious people are hiding that fact.

Answer 7

due to the porcessing power required... seti looks at things for a little period and moves on to hunt more, its like focussing on a grain of sand in the sahara desert a second....

Answer 8

I'd like to focus our resources on improving life on earth first. We've got a lot of work to do and aliens aren't gonna be giving us handouts.(Don't count on it either way)

Answer 9

i would like to know what the government know about extraterrestrials i have seen and heard something that sound true to me and i know they are real because i saw a UFO and it couldn't of been from this planet

Answer 10

Humans' technologies may not compatiable with the Aliens' technologies or vice versa.