Comment by Glyptodon | Hacker News Reader

Comment by Glyptodon | Hacker News Reader

The Milky Way is around 100000 light years wide. Humans have had the capability to look for ETs (as we expect them to sound) for what, 40-ish years?

Considering the time and space scales involved, it's hard for me to believe we have enough data for a conclusion either way, particularly without assuming faster than light travel and also given the 'youth' of the universe. Even if we did assume faster than light travel, it seems like you'd have to have insane levels of population growth to make it all that far from home without going very very slowly. And if you do start moving out, would it really be worth trying to signal home if it would take 1000 years or 100 years to reach 'home?'

Another issue I have is what I'd term anthropological environmental constraints as applied to aliens, namely it's quite conceivable that some home worlds would not offer the resources needed to make it into space, or would contain them in an inaccessible way. If a race of Einstein-like aliens is stuck on the a planetary equivalent of a desert island we'll never hear from them.

As far as the self replicating robots go, I see two issues: first, it should still be pretty slow without light speed travel, and second, if these robots don't have a realistic chance of reporting back to their source civilization, why would the civilization even bother? (We can barely understand the ancient Maya. When a robot returns after 30 million years, this problem seems like it'd only be exacerbated. Likewise, the time horizon is so far out it'd be unlikely a particular group would see an ROI argument to attempt it other than as a hobby.)

So I really feel like it's a bit premature to draw conclusions about the 'Fermi Paradox.'

If you could travel at only 1% of c you could cross from one side to the other in only 10 million years. At evolutionary time scales you could have been there and back three times since the dinosaurs disappeared. It's not hard to imagine that within a couple of centuries we could start a self-replicating robot project that would explore the entire galaxy in that time frame. We'd have the complete results within a mere 100,000 years of completion.

If you assume that aliens with the intelligence and drive to achieve star travel are common, it becomes pretty laughable to think that NONE of them had the curiosity to explore or meet other species or eradicate the competition. If you're arguing that we're the 5th such species in the galaxy then... maybe.

If you are limited to travel at 1% of c, communications at c, and self replicating probes, you'll have to wait many times 10 million years before you get more than a tiny sampling of responses from your probes.

How long is your curiosity willing to wait?

If you assume Humans are intelligent with a drive to achieve star travel, then why haven't we?

We barely visit the planets in our own solar system and we are continually reducing our radio waves. So unless someone happened to be looking at us at the right time. They might assume we don't exist.

All we know is that in the incredibly tiny parts of the universe we have looked, we haven't seen signs of US. We could have seen several signs of ET and never realized it.

You are offering three resolutions of the Fermi Paradox. All three of them are the form: some intelligent species will be unable/unwilling to communicate with us. This is incorrect. The resolution of the paradox have to be: ALL intelligent species are unable/unwilling to communicate with us.

You can try to take your probabilistic resolutions and multiply them all together to show a very low probability. But then you need an upper bound on the expected number of intelligent species. Which keeps increasing (number of Earth like planets).

(Mayans were not trying to communicate with anyone else. Those robots will be trying to. There is probably enough structure in physics and math to be the basis of communication with any alien species.)

My favorite resolution is the one where our solar system, having developed sentience, is under the protection of the galactic equivalent of the EPA, sort of a 'you can't go in there because they haven't finished hatching' sort of thing.

Please tell me that there's a short story on this. I'm envisioning a cigar-chomping developer trying to lobby for building on "prime real estate" while some nutball hippie lawyer is working tirelessly to stop him while his colleagues deride him for caring so much about "carbon-based animals."

"Well, we've done it billions of times before. What makes these ones any different?"

"It was wrong the last billions of times we did it, too."

"Well, you're living on a planet that was taken from some lesser species. And so was the planet your forefathers settled on. And them before that, and them before that. This is the natural course of things. Sucks to be them."

I'd read that.

It's a stretch, but isn't this "The Hitchhiker's Guide to the Galaxy" trilogy? :)

There is The State of the Art about the time the Culture comes to visit Earth - there is a decent BBC Radio 4 version on YouTube:

http://www.youtube.com/watch?v=IRl9D_agLbU

NB The Culture has the opposite of the Star Trek Federation's Prime Directive - they justify to themselves the hedonistic paradise that 99% of their population (biologicals and machines) live in through the interference of their Contact and Special Circumstances sections in the affairs of "lesser" civilisations.

So we are all on the Truman Show? Only it is a solar reserve instead of a movie set?

I don't think I'm offering resolutions. I'm saying that we have far too limited amounts of information to resolve things in one direction or the other.

(On the Mayan aside, I guess I do agree that there will be some basis for getting information from a returned probe, but after millions of years I doubt the home civilization will even remember that they were the ones who sent the probes out to begin with. I guess to be more precise, I expect that the home civ will have been replaced by new civs many times over.)

On the probe side, if they return to home there's also no reason to expect them to signal, and seeing one would be unlikely considering we can barely even find asteroids that pose a risk of collision with Earth. So I guess there's also some possibility that there are alien probes slipping through the solar system every so often and we just haven't been able to observe them.

You are arguing (or you were already in the last comment) that there is something 'wrong' with humans which is the reason that we have been unable to see aliens. I think this is a much stronger argument. As far as I can see, this line of reasoning only requires making two arguments about aliens: they are at most Kardashev Type II and they are not actively broadcasting their existence using EM waves.

I don't buy your arguments about memories of probes/ciz at all. I am extrapolating from human civilization. We haven't forgotten much and plan on remembering everything in the future.

Exactly this.

Go through these images: http://imgur.com/a/3Y6dB#NynTc

Then tell me we should have been contacted by now. Even with light speed travel (not faster), we're talking 13 billion years.. and this isn't including the time necessary for the civilization to advance that far.

The distance is staggering.

edit: rereading Fermi's paradox it seems they are only talking about the Milky Way, which I am not. But even if the chances of intelligent life forming are 1 in a billion.. the universe is so large that there could still be many civilizations out there (that we might never see).

Which is my point of view.. there probably is intelligent life out there but it's unlikely we will ever run into it.

Doesn't the existence of organic lifeforms (obviously an assumption which can be debated) almost surely guarantee the presence of fossil fuels? Given the average time evolution takes to produce intelligent life, won't there most likely be sufficient deceased organic matter which can be turned into a source of fuel?

>> guarantee the presence of fossil fuels

Absolutely not. Just recently a bacteria (or maybe an archae, I can't find an article) was discovered that efficiently breaks organic matter in anaerobic conditions. There is a sharp decrease in the amount of coal formed after that bacteria evolved a few dozen million years ago.

It's just an accident, that we are the 1st life form capable of extracting the energy from fossil fuels.

I remember reading that most of the fossil fuels on earth were deposited before mushrooms and other fungi evolved which break down organic matter. Before they existed, organic material did not decay nearly as fast as it does now, so it would just pile up. That's why there is so much fossil fuel around, but it probably wont ever be replenished to the same levels. I forget where I read this, so I could be misremembering. In any case, there's no guarantee that fossil fuels will exist.

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