Are we alone in the universe?

[baasinsimple]

but conversely, it will be mathematically damn near impossible to ever find or interact with other intelligent life

This is my thoughts, we'll never contact alien life besides that outside our own galaxy (possibly)

[miashuni]

what if weve already encontered them but they were in desguise ????????

[beta1042]

have you guys heard of fermi's paradox?

I feel like you should all go look it up ^_^

[indigodrawing]

But it leaves a problem of why we haven't detected anything, despite trying.

Because they live in the same universe we do and are bound by the same universal rules of physics!

Say, for example, there was some advanced civilisation out there that happened to have its most sensitive radio telescopes trained on Earth right now. Would they know about us? Well we invented radio about 120 years ago and radio signals can't exceed the speed of light. If the civilisation was looking at us from a planet 50 light years away they'd be just in time to eavesdrop on Apollo 8's flight around the moon. If they're 106 light years away, they might hear Titanic's distress calls. 121 light years out? Nothing. Not a peep.

And that's assuming that the inverse square law (At twice the distance a signal is 4 times as weak, at 3 times the distance it's 9 times as weak, etc) makes anything they even pick up distinguishable from the cosmic background radiation.

So yeah, detecting an alien civilisation isn't as easy as you think.

And here's a depressing thought, Enrico Fermi (who coined the Fermi paradox regarding how common alien life should be versus how much evidence we actually have for it) suggested that one reason why alien civilisations are so hard to detect is that species that advance enough to discover radio are probably already near the end of the road as far as civilisation goes. They may be polluting their planet or stripping it of its resources at such a rate as to become unsustainable, or they might invent nuclear weapons and wipe themselves out with it, or they might just be unfortunate enough to be hit by a stray rock and wiped out before their technology makes abandoning the planet and going somewhere else a viable option. Given our own current apparently inevitable march towards destruction there is some supporting evidence for this...

This means that on the off chance we actually pick up an alien radio transmission and determine it that it must have been transmitted by an alien intelligence, the intelligence that transmitted it may have been extinct for aeons.

A more optimistic possibility is that our understanding of physics is incomplete enough that the aliens might be talking to each other in a faster than light method we haven't discovered yet, but as faster than light travel is essentially time travel it would mean you could violate causality and that seems to go completely against everything we know about how the universe works.

[Jenny-Toons]

Nah -- to say we're alone in the universe is to say that we're "IT". That this is as far as life can go. And I dunno about you, but that sounds pretty damn depressing

We're probably not at that point in time to be able to contact alien lifeforms. Exploring the dark corners of space has just started to become a reality, but we're far from there yet.

That, and who's to say aliens haven't already come and visit? Often enough, cultures talk about the same events that happened 1000s of years ago, maybe more. Maybe the names are different or the messages aren't that similar, but they exist in times when communicating to different countries and sharing that information wasn't instant, if not impossible.

For all we know, they've discovered us and are just hiding for reasons we might not know.

[bakasama25]

Or maybe they should read, "Childhood's End". by Clarke.

[qwerty]

The fact that information (as far as we know) can't travel faster than the speed of light wouldn't be a major barrier to detecting alien civilizations, only to communicating with them.

We could still be able to find aliens if they were thousands or millions of light-years away, it's just that we'd be seeing evidence of aliens that existed thousands or millions of years ago, which isn't that long compared to the lifespan of the universe. They likely wouldn't still be around and we definitely couldn't talk to them, but we'd have found something at least.

The inverse square law, on the other hand... definitely something I'd overlooked, although I'm not sure how sensitive our instruments are and what kind of range we could expect from them.

I also agree that it's possible that the vast majority of intelligent life manages to wipe itself out before developing advanced space travel. I hope we're not one of them but am sadly not too optimistic XD

[yondoloki]

Statistically it doesn't make sense that we are alone. If we ever find other lifeforms is really the question, because of time and space, and the fact that the light we see from the stars and planets are millions of years behind in time. So maybe there are civilisations like ours out there, we are just not able to observe each other because Einstein is a bitch.

[indigodrawing]

Of course the other possibility is that we're the first intelligent species in the universe. There may be planets scattered through the galaxy where either intelligence was not a sufficiently important survival trait to evolve to the extent it has here (lets face it, every species on this planet other than us manages to do just fine without nylon and existential angst!) or maybe there will be more intelligent species in half a billion years' time, it's just we got past that milestone before any of them did. In which case it's possible we'll be the advanced unstoppable alien hoard at some point in the future, rather than them.

[ReroOnyx]

The chances of their being no life other than are own is both absurdly low and absurdly sad.

However, with vast distances between stars and galaxies, it would still take at hundreds of thousands of years, to even billions of years for any kind of known physics communication to reach us. The sad truth is that, as a lifeform, we're probably never going to reach past our own solar system because after that, it's hundreds of years to the nearest star. It's definitely not going to be helped with our current technology and even if we had said technology, we're still going to have to follow the basic principals of physics.

However, what's worse that, because of expanding space/time, distances between objects like stars and galaxies are getting further and further from us. An expansion that is shockingly, increasing and if it keeps up and doesn't slow down, objects like stars and galaxies will keep going further away from us.

If it keeps up, our descendants, if we have any, will look up at the night sky and see nothing but blackness or some stars from our own galaxy. Other stars or galaxies will have expanded so fast and far, they will be completely undetectable by telescopes. Whatever life might be out there, will never be able to reach us by contemporary physics.

That's the sad truth of it all. Even if there is other life, unless we find a way around the physics/light barrier, we will never be able to communicate with them. So I guess the question becomes nothing more than a Cat Box Theory. Could there be life? Absolutely nothing says there can't be but until we find it, nothing at all says there isn't.

[danitasibert]

I agree, i believe that we can't be the only organism in the galaxy there has to be others out there, and I bet they're thinking the same about us!

[Mari]

no, we're obviously not alone. Universe is expanding constantly and has been around...Well, forever. There's some life out there, be it some worm or whatever. Thinking we're alone is just foolish.