Intelligent life on other planets and what to do.

I thought of this because of an article from Stephen Hawking in the Times recently in which he stated that we shouldn't talk to aliens for risk of their coming to get us.

He stated that it was pretty likely that intelligent life exists out there someplace.

My problem with this is not so much that we shouldn't be attempting to contact them, but rather that the likelihood of intelligent life coexisting in the same time and approximate space seems incredibly unlikely.

Here's a serious question. If intelligent life had visited earth in the past, would we know? The answer seems obvious until you do the math. In the 4.55 billion years the earth has been in existence, life has been on it about 3.4 billion. Of that 3.4 billion, the genus homo has only been in existence for 2.5 million (with an M). Of that 2.5 million years, we have only had the ability to pass generational knowledge for about the last 10,000. The universe itself is over 13 billion years old.

Considering the VAST stretch of time in which intelligent life is possible, the likelihood of it occurring coincidentally inside a time slice of 10,000 years and within proximity to contact one another seems rather slim.

If we wanted to leave a lasting monument to human existence for an alien visitor some 2 million years from now, how would we go about it? Nothing we have ever constructed will be around then. What could we possibly leave that they would find and identify as evidence of intelligence and existence? If we were to visit a barren rock that would, in 2 billion years time develop intelligent life of an unpredictable form, how would we leave evidence of our visit? Why would we bother?

If their giant bugs, we nuke em.

But with only one sample, and no idea whether intelligent life has existed before on the planet, or how often it arises elsewhere, etc, etc, it's just speculation. You could as well argue that with millions of stars in the galaxy, it could be quite crowded in a 10,000 year span.

One theory holds that civilizations are quiet because they are silenced. A cloud of near-lightspeed mass asteroids sent to intercept after detection of the appropriate radiation would do it quite handily.

Statistically, it's almost certain there is intelligent life out there somewhere. It's equally certain they will never come into contact with Earth. Not just humans. Not just the remnants of human civilization. The whole planet. The whole system, for that matter.

If we really want to leave a lasting message, I think our best chance is DNA. Tack it on as inert junk data, like the remnants of a virus that's no longer active but still getting replicated. Preferably to something ubiquitous and durable that aliens might be looking for, like a bacteria.

That's a lot of effort just to scrawl "Kilroy Was Here." Still, it's nice to have a chance to not be forgotten and I'm sure the aliens would get a kick out of it.

Paleocon wrote:

If we wanted to leave a lasting monument to human existence for an alien visitor some 2 million years from now, how would we go about it? Nothing we have ever constructed will be around then. What could we possibly leave that they would find and identify as evidence of intelligence and existence? If we were to visit a barren rock that would, in 2 billion years time develop intelligent life of an unpredictable form, how would we leave evidence of our visit? Why would we bother?

I seem to recall that some particularly "human" humans were trying to come up with a way to mark toxic waste sites in such a way that even a totally non-human intelligence could understand that there's some nasty stuff buried there.

I can't help but think the extra terrestrials would regard our warnings with as much reverence as we regard those of evil spirits at ancient burial sites. Hopefully the waste will be safe by then, or at the very least the aliens will realize that we weren't messing around.

Robear wrote:

One theory holds that civilizations are quiet because they are silenced. A cloud of near-lightspeed mass asteroids sent to intercept after detection of the appropriate radiation would do it quite handily.

Or because humans are pretty damn stupid. If alien sentience became public knowledge just think of the fallout. I'm not saying we HAVE successfully contacted any alien races. Just that those on the line might wish to keep that knowledge to themselves.

LobsterMobster wrote:

Statistically, it's almost certain there is intelligent life out there somewhere. It's equally certain they will never come into contact with Earth. Not just humans. Not just the remnants of human civilization. The whole planet. The whole system, for that matter.

If only someone would build a hyperspatial express route passing by earth, that'd be great.

I agree with Stephen Hawking's point that if we were found by aliens things could go quite badly for us. I also think that the chances of that happening are virtually zero, unless we have a radical upshift in our technological capabilities, and that won't happen for quite a while. What I think Stephen is not mentioning is that it could go quite the other way too: humanity has a terrible track record when it comes to tolerance of anything strange or foreign. I would bet there is an equal chance of us attempting to wipe out the aliens as there is of them trying to kill us.

Most assumptions of intelligent life (and, specifically, contacting that life) rely heavily on the extraterrestrial existence of FTL travel. Without that assumption, there could be alien miners in a neighoring star system a few dozen light years away and we'd be unaware of their existence -- especially if their communication didn't develop through the use of signal's we're adept at picking out from the general noise of the universe.

Paleocon wrote:

If we were to visit a barren rock that would, in 2 billion years time develop intelligent life of an unpredictable form, how would we leave evidence of our visit?...

IMAGE(http://benroe.co.uk/files/2001MoonMonolith.jpg)?

Are they hot blue alien chicks who can manipulate mass effect fields? 'Cause that would be awesome.

Paleocon wrote:

If we wanted to leave a lasting monument to human existence for an alien visitor some 2 million years from now, how would we go about it? Nothing we have ever constructed will be around then. What could we possibly leave that they would find and identify as evidence of intelligence and existence? If we were to visit a barren rock that would, in 2 billion years time develop intelligent life of an unpredictable form, how would we leave evidence of our visit?

Probably some sort of monument on the moon, ironically enough; the side facing the Earth is generally well-protected from meteor strikes. There's very little erosion, very little tectonic activity. It could last a very long time.

Why would we bother?

Why do people do anything?

Quintin_Stone wrote:
Why would we bother?
Why do people do anything? :lol:

Because we hope it will get us laid eventually. Or make more money.

I realize that just looking at the Hubble Deep Field, one knows that probability basically says there *has* to be life out there, elsewhere.

More and more of what we discover about life continually adds to the idea that life can survive some not only harsh, but previously-thought-to-be impossible conditions.

That said, what is the real probability that there is another civilization nearby that is still alive? Or fully developed?

I've heard theories posited that life has existed like us elsewhere and probably will exist elsewhere in the future, but the probability that they're on a developmentally-similar cycle to us is extremely low. It's likely that we'd have to look in another galaxy to find such a civilization.

My point is that it is entirely possible that our planet was visited thousands or even hundreds of thousands of times by different civilizations in galactic history, but the "sea of time" is so large that finding evidence of any of their visits would be like finding a single unique water molecule in the ocean.

Insert funny picture of www.latinumpalace.com inscribed on the surface of the moon.

EDIT:
We've been blasting the Universe with noise for years now. No sense worrying about it now. It's too late. If they're listening, then they'll hear it sooner or later. Our only chance is to not be here when the near-light speed asteroids make mince-meat out of our solar system.

According to Scorpius, a PK Command Carrier traveling at top speed could reach Earth within 80 years.

IMAGE(http://www.tvscape.net/wp-content/uploads/2009/08/Scorpius.jpg)

If you want to tell him he's wrong, go ahead.

Rezzy wrote:

Insert funny picture of www.latinumpalace.com inscribed on the surface of the moon.

EDIT:
We've been blasting the Universe with noise for years now. No sense worrying about it now. It's too late. If they're listening, then they'll hear it sooner or later. Our only chance is to not be here when the near-light speed asteroids make mince-meat out of our solar system.

The problem is that we're running face first into the inverse square law and the power of transmissions into space has actually gone down as terrestrial network technologies have improved. If there is a civilization with electronics technology out there that knows to listen and is close enough to receive our signal, they would have about a 40 year window in which to receive anything at all.

Plus there is the fact that even if we were still blasting all out signals into outer space at full strength, we've only been doing that for (very roughly) two hundred years. That's a bubble of two hundred light years around earth in which we are detectable by alien civilizations. Again, the chances of aliens living within that bubble are so minuscule it's hardly worth considering.

So you're saying that it's more likely that ET life has already visited earth, and, bored by our lifeless planet, threw down some beacon (that, after a billion years of erosion, disappeared) and left without another thought.

That "Earth" is classified as an uninhabitable planet in some alien's "Primer to Orion Arm, Milky Way Galaxy, Volume II."

Given your timeline on the existence of cognitive life on earth, that's probably significantly more likely than one assumes.

I saw a picture somewhere that illustrated just how far human radio signals have penetrated into the cosmos... On a galactic scale, it's not very much. Measure the distance which you could throw a football, and compare that relative to the size of the entire planet, and you get an idea of the scale. We really have not even begun to knock on the door of a potential sentient neighbor.

Rallick wrote:

Plus there is the fact that even if we were still blasting all out signals into outer space at full strength, we've only been doing that for (very roughly) two hundred years. That's a bubble of two hundred light years around earth in which we are detectable by alien civilizations. Again, the chances of aliens living within that bubble are so minuscule it's hardly worth considering.

Whoa, what powerful radio signals were we sending out in 1810? It's my understanding that we've only been putting out any kind of signal that would be relatively indistinguishable from background noise for less than 100 years.

According to Carl Sagan, he thinks the first images and data another civilization will receive is Hitler at the 1936 Olympics. That will be our introduction.

Seth wrote:

So you're saying that it's more likely that ET life has already visited earth, and, bored by our lifeless planet, threw down some beacon (that, after a billion years of erosion, disappeared) and left without another thought.

That "Earth" is classified as an uninhabitable planet in some alien's "Primer to Orion Arm, Milky Way Galaxy, Volume II."

Given your timeline on the existence of cognitive life on earth, that's probably significantly more likely than one assumes.

Mostly harmless?

The difficulty in travelling interstellar distances probably does mean that any species sufficiently advanced to show up at Earth would be capable of crushing us like bugs, if they wanted to. Non-human intelligent life on Earth is most likely going to come from advancing technology to the point where neural nets achieve sentience; there's no way that can go badly, right?

I'm not sure I buy the theory that it won't go well for us. Why would aliens even bother us? What's in it for them?

Assuming they have the technology to get to us, why should they use that technology to come visit us instead of any of the other squillion uninhabited planets closer to them? I'm going to assume that Earth doesn't have any precious and rare resource that isn't found elsewhere in similar or greater abundance.

So the only difference between our planet and an uninhabited Earth-like planet elsewhere is us. And we're not that great. Unless the aliens want us for food, the only other interest would be our culture, whether to study, assimilate or impose their own upon it.

So unless our supposed aliens are ravenous carnivores in the midst of a serious food shortage, curious scholars or interstellar missionaries, I doubt they'll be paying us a visit.

THEY DONE BEEN HERE.

http://www.youtube.com/watch?v=xz7sBTHtcLU

Kids in the Hall, probably NSFW.

NSMike wrote:

Whoa, what powerful radio signals were we sending out in 1810? It's my understanding that we've only been putting out any kind of signal that would be relatively indistinguishable from background noise for less than 100 years.

Well, I know my estimation was wildly optimistic, but that emphasizes the point we were both trying to make!

Seth wrote:

So you're saying that it's more likely that ET life has already visited earth, and, bored by our lifeless planet, threw down some beacon (that, after a billion years of erosion, disappeared) and left without another thought.

More likely in the sense that being struck by lightning, having a tiger jump out of nowhere to maul your corpse only to be crushed by a stray boulder which is then struck by lightning is more likely than said situation with an albino tiger.

The most likely scenario is that they've never been here.

Here's my buddy's take on things:

OK, here's one science guy's analysis. We may *be* the aliens, if Crick's panspermia hypothesis is true. But if we're talking a tourist-like visit involving a small number of organisms who do not colonize, I'd have to think it could be hard to detect. If they are made of distinctive organic material, it could conceivably be preserved for tens of millions of years if encased in amber, but they might be careful enough not to leave well-preserved evidence, which would otherwise degrade after shorter periods of time. Assuming they return to their origin, their spaceship would have to leave Earth. and the light and other electromagnetic radiation from their spaceship making this return trip could be detectable in the future, but only for the number of light years equivalent to the distance of their final destination. And since it's hard to detect anything outside our solar system smaller than a large planet right now, this would be almost impossible with current technology...
We've been blasting the Universe with noise for years now. No sense worrying about it now. It's too late. If they're listening, then they'll hear it sooner or later.

Well, but we haven't. The power of the tv and radio signals sent out so far would be infinitesimal even at the edge of our solar system. Narrow-beam is the way to go, but the problem is, that's got to be aimed. What are the odds that someone is aiming at us, or we at them.

Still, there's been one "Wow!" signal. That was received in West Virginia in 1977. Also, [email protected] has identified some number of locations in the sky for further analysis, based on results well out of the norm (but still potentially natural.)

I side with the "there are many civilizations out there", and tend to think that the EM spectrum is an unlikely one for interstellar communication, due to the limitations of light speed.

Tanglebones wrote:
Seth wrote:

So you're saying that it's more likely that ET life has already visited earth, and, bored by our lifeless planet, threw down some beacon (that, after a billion years of erosion, disappeared) and left without another thought.

That "Earth" is classified as an uninhabitable planet in some alien's "Primer to Orion Arm, Milky Way Galaxy, Volume II."

Given your timeline on the existence of cognitive life on earth, that's probably significantly more likely than one assumes.

Mostly harmless?

The difficulty in travelling interstellar distances probably does mean that any species sufficiently advanced to show up at Earth would be capable of crushing us like bugs, if they wanted to. Non-human intelligent life on Earth is most likely going to come from advancing technology to the point where neural nets achieve sentience; there's no way that can go badly, right?

We'll fight for our Independence Day! And then Jeff Goldblume will infect their computers with a virus.

Edit: I agree with the statements that a meeting between us and aliens would not end well, for one or the other or both. Reading the Imperial Cruise, knowing Native American history (and other native cultures that continue to be wiped out to this day), and having seen Avatar I know that as a species we have always developed the "Us vs. Them" mentality.

Jonman wrote:

I'm not sure I buy the theory that it won't go well for us. Why would aliens even bother us? What's in it for them?

Assuming they have the technology to get to us, why should they use that technology to come visit us instead of any of the other squillion uninhabited planets closer to them? I'm going to assume that Earth doesn't have any precious and rare resource that isn't found elsewhere in similar or greater abundance.

So the only difference between our planet and an uninhabited Earth-like planet elsewhere is us. And we're not that great. Unless the aliens want us for food, the only other interest would be our culture, whether to study, assimilate or impose their own upon it.

So unless our supposed aliens are ravenous carnivores in the midst of a serious food shortage, curious scholars or interstellar missionaries, I doubt they'll be paying us a visit.

Why did Columbus cross the Atlantic? Why did Louis & Clark cross the west? Why do we climb mountains? Why did we go to the moon?

Perhaps being curious about new things, places, and cultures is a side effect of intelligence. If so, then we're going to be the natives and the aliens will be the small pox blanket bearing white men. Just imagine if their religion told them they have to bring their god to Earth and convert the heathens...

Our planet might be enough. Out of the hundreds of planets we've found so far, there hasn't been one close to Earth-like conditions. If a not-to-hot-not-to-cold planet with liquid water is needed for intelligent life and rare, then we're sitting on one valuable piece of real estate.

OG_slinger wrote:
Jonman wrote:

I'm not sure I buy the theory that it won't go well for us. Why would aliens even bother us? What's in it for them?

Assuming they have the technology to get to us, why should they use that technology to come visit us instead of any of the other squillion uninhabited planets closer to them? I'm going to assume that Earth doesn't have any precious and rare resource that isn't found elsewhere in similar or greater abundance.

So the only difference between our planet and an uninhabited Earth-like planet elsewhere is us. And we're not that great. Unless the aliens want us for food, the only other interest would be our culture, whether to study, assimilate or impose their own upon it.

So unless our supposed aliens are ravenous carnivores in the midst of a serious food shortage, curious scholars or interstellar missionaries, I doubt they'll be paying us a visit.

Why did Columbus cross the Atlantic? Why did Louis & Clark cross the west? Why do we climb mountains? Why did we go to the moon?

Perhaps being curious about new things, places, and cultures is a side effect of intelligence. If so, then we're going to be the natives and the aliens will be the small pox blanket bearing white men. Just imagine if their religion told them they have to bring their god to Earth and convert the heathens...

Our planet might be enough. Out of the hundreds of planets we've found so far, there hasn't been one close to Earth-like conditions. If a not-to-hot-not-to-cold planet with liquid water is needed for intelligent life and rare, then we're sitting on one valuable piece of real estate.

Maybe they're just looking for someone...um..something good to eat.

Realistically speaking (or vaguely close to "realistically"), I would think that immune systems alone would be reason to stay the heck away from other species. When Europeans came to the Americas, they brought things like smallpox, measles, and a host of other unpleasant things that devastated the native population. Any foreign species coming to the Earth would assumably run into the same sorts of problems. I'd have to think any alien population would have a godawful time adapting to our particular bugs and vice-versa.