The Fermi Paradox - If There Are So Many Civilizations Out There, Where Are They?

[srfoskey]

One thing I wonder about is if interstellar travel is too costly. Maybe alien civilizations have attempted it, only to figure out it required too much effort and/or resources and gave up. Considering how hard it is for humans to simply return to the Moon, I don't see why aliens might not have similar issues convincing their species to spread beyond their home planet.

I don't think we really have a good idea of how much effort it takes to colonize other worlds.

[Woof]

Originally Posted by srfoskey

One thing I wonder about is if interstellar travel is too costly. Maybe alien civilizations have attempted it, only to figure out it required too much effort and/or resources and gave up. Considering how hard it is for humans to simply return to the Moon, I don't see why aliens might not have similar issues convincing their species to spread beyond their home planet.

I don't think we really have a good idea of how much effort it takes to colonize other worlds.

It's feasible economically if we only aim at one of the closest stars ..... though I don't know how engineers would cope with collisions of small particles. Other than that, it would take a long time, many years, to get to a star that is, say, 7 light years away going at an appreciable fraction of the speed of light.

On the other hand, it wouldn't be as long a time for the astronauts as it would be for us.

[Klambo]

Originally Posted by statisticsnerd

Humans have been around for millions of years and have only broadcasted radio signals into space since the 1930s. .

Not quite as long as that............more like 200,000 years.

[The_Southpaw]

Originally Posted by Adric

Fermi paradox:
The Fermi paradox (or Fermi's paradox) is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilization and humanity's lack of contact with, or evidence for, such civilizations.

Before I start, here's a really good blog-article on the topic:
The Fermi Paradox

We've been listening to space for a while now, and outside of the "WOW!" signal anomaly back in 1977 (The Wow! Signal-Wikipedia), there has been little evidence of any intelligent life out there. This seems to fly in the face of estimates that as many as 100,000 civilizations could exist in our Milky Way galaxy alone. Where is everyone?

There are a number of possibilities. Despite the fact that documentaries will tell you that space is full of stuff, the reality is that space is big and the vast majority of it is empty by conventional standards (key word, "conventional"). Take for example the impending collision of the Milky Way and Andromeda galaxies; there is so much empty space between stars that it is highly unlikely that any of them will even touch each other when the galaxies collide in about 4 billion years. With that much space to look at and listen to, we have only begun to scratch the surface of the observable galaxy.

Another possibility is that we have grossly overestimated the number of civilizations out there. This leads into "The Great Filter", which is a conceptual idea that states that life (of any kind) generally hits a wall of evolution that only a tiny percentage ever seem to get past. "The Great Filter" could be ahead of us signaling that we are a doomed species or behind us signaling that we are a fluke and although we still might not be alone, we would be one of only a handful of species in the universe that got past it. Either possibility is not a fun thought.

Then of course there is the hot-button third possibility, that we have already contacted or received contact from alien civilizations and the government is covering it up. I won't go into this too much because that's more of a conspiracies topic rather than science but a whole lot of people seem to buy into it. I leave it to everyone to draw their own conclusions.

For more information, I highly recommend that you read the article posted at the top of this post and feel free to post your own thoughts!

Great post! thank you.

I just did another post on a different thread--one concerning the Search For Intelligent Life. Should we try to contact them or not? But in that post I alluded to the fact that I believe explains, or debunks the so-called Fermi Paradox. I don't personally think it's a "paradox" at all, but is rather easily explained, why we have had not contact with other civilizations. And that answer is..."the vast distances involved in our Known Universe." I myself believe the universe is absolutely teeming with Life--including that of the Intelligent variety.

Here is an excerpt from that post that pertains to your OP............

Remember the distances involved here! We know for certain there is not Intelligent life in our own Solar System. The planets are simply too un-hospitable to support that kind of life. Or ANY life other than the microbial variety that is perhaps nesting in some ice glacier somewhere. So....Intel Life coming to us would have to, at the very closest, come from our nearest star--other then our Sun, of course. This is actually a binary star system called Alpha Proxima/Alpha Centauri. It is 4.3 light-years away! Meaning of course that even travelling at the speed of light, 186,000 miles per second, it would take them over four years to get here. With our current fastest space peopulsion technology, it would take us about 20,000 years to get there!

So anybody coming here, by necessity, has evolved past what we think of as conventional propulsion systems. They have to be using some sort of non-materialistic travel. Maybe at a quantum mechanical teleportation level, like the old Star Trek "Beam me up, Scotty!" LOL. Or perhaps they are folding the Space Time Continuum. Or using a wormhole as a short-cut conduit. This to us is right now only the stuff of Science fiction! We're not even close to it. it exists to us only in abstract mathematical equations. Far from reality, even on a robotic level. let alone human conveyance methods.

So they would be as far above us in intellect as you are to your pet gold fish!

Don't get me wrong: I personally believe the universe is teeming with life. Including that of the Intelligent Variety. There are 400 Billion Stars with planets in our own Milky Way Galaxy. And then factor is a couple hundred billion more Galaxies. If even one out of a billion stars in the Universe had planets and one out a billion of those planets had primal life, and one out of a billion of THOSE had intelligent life--that STILL leaves billions and billions of planets with Intelligent Life. It would be a waste of space on the most unreal level for us to be the only intelligent life in the Universe.

But those damn distances, man. They'll get you every time. And these numbers allude to only our Known Universe. If we are indeed a small part of a Multi-Verse, as some Cosmologists claim, then the candidates for Intelligent Life get even MORE mind-blowing.

[Woof]

Well, it's only been a hundred years since Einstein and a few thousand years for civilization. Yet we're already making tiny inroads into wormholes and quantum entanglement thingies even though we're just at the beginning of physics. If there are, say, a thousand sentient races of our intelligence or greater in our galaxy alone .... a few might be less advanced, but most might be considerably more intelligent if they have been reasonably stable and clever in their scientific advancement. There might be some over 10 million years old ..... plenty of time to solve the mysteries of faster than light travel.

[biggunsmallbrains]

Pretty interesting stuff but it all seems a bit too hypothetical to me. I mean why stop at a type 3 civilization that can harness all the power of our galaxy and just go to type 4 that can harness all the power in the entire universe. Maybe some sort of god like civilization.

Also, why do we assume that an intelligent civilization doesn't eventually annihilate itself from existence in the same way that we nearly have with thermo nuculear war or what not. Sure we are smart but we also are humans with all the good and bad that that can bring. Maybe there have been extraterrestrial civilizations that were on a path to being a type 1 or 2 civilization but through an accident or war or whatever blew themselves out of existence too.

Personally, I'm inclined to believe in the first one, there's just a lot of **** out there and we have had the power to only begin to sift through it for the last 50 years or so. If there are more stars than grains of sands on all the worlds beaches (and that doesn't even include habitable planets) and you're looking for a few thousand "special" grains of sands buried in there...well good luck. Not to say we shouldn't try but it has to be considered a long, maybe excrutiatingly long, term goal.

PS What if a superior civilization doesn't want to broadcast their existence either?