[phreeza]

Perhaps a good moment to re-read this:

Why I Hope the Search for Extraterrestrial Life Finds Nothing: http://www.nickbostrom.com/extraterrestrial.pdf

tl;dr: "Because it means life is not incredibly unlikely (after all, it occurred on two planets in our own solar system); ergo what must instead be incredibly unlikely is the ability for life to progress to the point where it can spread across the galaxy (after all, no other life form has contacted us); ergo we are doomed."

[PostOnce]

The other theory being that galaxy-spanning life is incredibly common, it's just that we're too immature/uninteresting to bother coming to visit.

How often do you stop and try to communicate with the queen of a particular anthill?

[jonah]

Well, my dad's (tongue-in-cheek) theory is that all these UFO sightings are them coming over and cruising through the slums. ;)

[patrickaljord]

The article mentions this theory, it says that if life is incredibly common, it would only take one civilization to be curious and come visit us.

[blhack]

I feel like I'm playing into a cliche by even giving this response, but:

Would we recognize it? Would we even know that it had happened? Consider that if there is a civilization capable of traveling across inter-stellar distances, they very likely have got a very different sort of life-span that people on earth. Because of this, their language (if they have something we would recognize as language) could be dramatically different than ours.

Honestly their brains, or "mechanism of creativity" as I guess you could call it, could be something that we would never be able to communicate with.

There are biochemical reasons why extra-terrestrial life would probably be similar to ours, but I can think of no reason why they would be neurologically or psychologically anything like us.

Think about the ants again. Ants have communications, sure, but it's not language, at least not in the human sense. Ants very probably don't have thoughts, and because they don't have thoughts, they don't have a reason to abstract them to words.

This hasn't prevented ants (or bees) from building incredibly interesting and complicated physical and organizational structures.

We've contacted bees. Do you suppose that they realize it?

[jacobn]

What if interstellar travel is just really hard (= no advanced life form has figured it out, and it might just be impossible/not economical), and whatever signals their civilizations generate just aren't strong enough to be picked up by e.g. SETI?

It wouldn't spell "doom" unless you count the sun running out of juice/going supernova. The universe might be packed with life, each such patch effectively isolated to it's own little corner.

[mikeknoop]

But how often are the ants in the presence of another living species?

If the ants were to one day take note of the living creatures around them they would most certainly come to the conclusion that they are not alone.

[PostOnce]

How often do the ants realize they're in the presence of another living species? Do they know humans are alive?

Maybe the aliens have been here all along and we just didn't realize it, heh.

[J3L2404]

It's even beyond that. Learning to write software it seems that some solutions are too involved to even begin to try to explain, so they might not find us uninteresting, they are just lost in thought.

[mixmax]

Or a good moment to remember what happens when a less advanced civilization meets a more advanced one.

It never goes well for the less advanced civilization.

[btilly]

Someone should go back in time and tell the Goths that before they make contact with the Romans. Also the Mongolians should have been told to leave China alone.

:-)

[othello]

The comparison does not really hold: you would be hard pressed to find a single first point of contact between Goths and the Roman Empire or Mongolians and China.

In both cases, fighting had been going on for centuries before the empires were finally toppled. Thus even if overall less advanced, the "barbarians" had comparable warfare technology.

In most known cases where a true first encounter event occured - such as Columbus arrival in Hispaniola, Pizarro in Peru or Cook in Australia - the less advanced civilization was indeed overrun if not exterminated by the more advanced one.

[wlievens]

So basically you're saying that if you make your sample size small enough, you can prove your point? :-)

[phreeza]

In the words of Iain M. Banks, the kind of problem "most civilisations would encounter just once, and which they tended to encounter rather in the same way a sentence encountered a full stop."

[anthonyb]

He calls it an "Out of Context Problem".

[GCU_Arbitrary]

So do we!

[Keyframe]

It never goes well for the less advanced civilization.

... on Earth. Let's be optimists for a change. :)

[jimbokun]

Same goes for a Singularity.

[retube]

2 planets? what would be number 2? Martian life has never been confirmed if this is what is being referred to.

[wwrap]

"two planets"? Is he is writing from the perspective of a future event of life being discovered on another planet besides Earth, or is there some underground news about life being discovered on another planet besides Earth?

[Benjo]

See also, essays on the Great Filter: http://en.wikipedia.org/wiki/Great_Filter

[Keyframe]

after all, no other life form has contacted us

A bit far-fetched, but it could also mean we are the first. If there were/are sufficiently advanced civilizations in the past that could engineer on the scale of star systems or above (singularity hypothesis), there would be a certain probability that we would detect that (so far or in the future), no?

[Kliment]

That's a bullshit argument. If we find life very close to us, it's very likely there is a common origin, and this gives us no information on the Great Filter.

[khafra]

1. If we find life very close to us, that does indeed increase the probability of the panspermia hypothesis.

2. The probability of panspermia will still not be 1, or even approaching 1. That leaves enough room to avoid "bullshit argument" in favor of "questionable argument," which is a caveat Bostrom (and Hanson, in his Great Filter) would happily agree to.

3. Even if single-origin life has seeded multiple planets, if the seeding occurred far enough in the past and widely enough, that still leaves us with an anthropic filter problem.

[Kliment]

I'm not seeing the "widely enough" in this case. Finding life on the one moon in the solar system that could support it, specifically finding life that is organic, would very much suggest single origin. The original Hanson paper sounded almost like it was actively avoiding that possibility. Thus my impulse to state it more strongly than is strictly necessary. Finding life close to us may increase P(panspermic hypothesis), but it increases P(common origin) more, and this ratio diminishes as we find life further and further away.

[sgibat]

Maybe no one has contacted us because we haven't been broadcasting our existence for long enough.