Pharyngula

Posted by: Rheinhard | June 16, 2009 12:52 PM

The problem wouldn't be space missionaries knocking on the door... the problem would be the space missionaries acting like human missionaries have for much of history; i.e., believe our way or we declare you non-people that we can do whatever we like to! When the space missionaries insist "we can only respect beings that are of 'the tentacle'", and will enslave or kill everyone else, well, most people will have a problem...

Posted by: Ompompanoosuc | June 16, 2009 12:56 PM

I am hoping we are contacted by aliens and they simply tell the world there are no supernatural entities. Even Faux news would have to cover it, wouldn't they?

I can hear it now "Why should we believe them? The aliens are just doing the devil's bidding and trying to undermine our faith."

Posted by: FastLane | June 16, 2009 12:59 PM

This was actually the major theme of an entire campaign for the "Starfire" game about a decade ago. An alien, but only slightly technologically superior, race decided that Earth needed to be 'brought into the fold'... =)

Posted by: Brownian, Most Vicious & Petty of Pharyngulites | June 16, 2009 1:00 PM

I can't wait until the Space Missionaries show up and force us all to marry exactly 12.25 people (every four marriages shares a thirteenth person), go to space church once an hour and march those of us they don't kill off with spacepox infected blankets to live in residential space stations and speak X'chchk, lest we have our bottoms zorped.

They may be ready for the Rapture, but are the Abrahamists ready to languish in forced-labour zlods?

Posted by: Bodach | June 16, 2009 1:00 PM

"Domini domini domini; you're all Catholics now." Or maybe something quite worse from frocked aliens showing up at the door.

Posted by: Patness | June 16, 2009 1:01 PM

An obligatory reference to the xkcd comic should appear here: http://xkcd.com/384/

#4: I totally agree. Fox would be the first people to stir up nationalism and demonize them (up to and including describing them as agents of Satan).

What would be interesting, however, is an alien religion that is not centered around them, but around some other civilization unlike them.

Posted by: Michelle | June 16, 2009 1:06 PM

Makes me think of Star Trek.

Some of my favorite all-time comments from any Trek series (or any series at all) were from the episode "Who Watches the Watchers":

Commander William T. Riker: [to Picard] It's worse than we suspected. The Mintakans are beginning to believe in a God.

Captain Jean-Luc Picard: Horrifying... Dr. Barron, your report describes how rational these people are. Millennia ago, they abandoned their belief in the supernatural. Now you are asking me to sabotage that achievement, to send them back into the dark ages of superstition and ignorance and fear? No!

I knew I loved Star Trek.

Posted by: Moggie | June 16, 2009 1:11 PM

But what if aliens come to Earth to serve Man? Wouldn't that be great?

Posted by: Celtic_Evolution | June 16, 2009 1:16 PM

But what if aliens come to Earth to serve Man? Wouldn't that be great?

What makes you think that wouldn't be the default position of most xians? Why else would the almighty sky genie see fit to send them to us? Damn progressives, humanists and freethinkers won't allow good, bible abiding christians their human slaves anymore... but god and the constitution don't say nothin' about all non-humans being created equally... right?

Posted by: a_ray_in_dilbert_space | June 16, 2009 1:18 PM

My favorite Drake equation reference in popular culture was in an episode of the Big Bang Theory where Howard Wolowitz adapts it to estimate the number of women out there willing to have sex with him. His version includes a Wolowitz factor, which has to do with alcohol consumption vs time.

Posted by: Knockgoats | June 16, 2009 1:20 PM

I'm with Dave G. - the Fermi paradox indicates that there are almost certainly no technological civilizations in this galaxy (or the local group) other than ours. Evidence for this gets stronger as SETI searches continue to fail, alien probes are not found in the solar system, and better telescopes show no obvious signs of macro-engineering.
My hunch is that:
1) Planets suitable for life are abundant - this should be confirmed or refuted within a couple of decades.
2) Life is quite easy to start - didn't take long on Earth - and hence abundant. Again, likely to be confirmed within a few decades.
3) But macroscopic life with complex developmental schemas is hard - took another 3 billion years or so on Earth. Maybe most biospheres get snuffed out, either by a strengthening sun or astronomical mishaps, before this happens.
4) Once you've got complex developmental schemas, evolution of a technological species is quite likely (the upper limit of braininess, hence presumably behavioural complexity, increases fairly smoothly from the Cambrian explosion on).
5) But such species always discover capitalism, and environmental destruction and extinction follow before they can launch von Neumann probes. Likely to be exemplified or at least partially refuted within a century or two.

Posted by: xebecs | June 16, 2009 1:21 PM

What a useless formula!

Not only does it not explain what "N" means -- what about all those little x-es?

Math is hard!

Posted by: qbsmd | June 16, 2009 1:22 PM

Dave G
"The Drake equation is all well and good, but it completely ignores the Fermi paradox - if the galaxy is teeming with life, then where is everybody?"

The Drake equation is what it is, you can't really argue with it. Like PZ said, it's the guesses for the numbers you plug into the equation that are the source of uncertainty. And the Fermi paradox was in part based on the Drake equation, because someone's best guesses for the values suggested intelligent life should be common. It would be kind of hard for the Drake equation to take into account something that was later derived from it.

Posted by: llewelly | June 16, 2009 1:24 PM

I'm pretty sure they wouldn't believe in Jesus, Mohammed, Vishnu, or Xenu. And all I need is space missionaries knocking on my door on Saturday mornings.

Ah... reminds me of the wonderful classic science fiction novel Cosmic Crusaders (L'Empire du Baphomet in the original French edition) by Pierre Barbet.

In which an alien tries to manipulate the Knights Templar into building an empire ... which they do, but alien dies along the way. The Knights Templar take over a few worlds populated by aliens for which strict adherence to the Templar's religion is biologically insane.

Posted by: Ted Dahlberg | June 16, 2009 1:29 PM

I think we're forgetting an important topic regarding aliens and religion here; what are the possible repercussions for Earth from the Mi-Go (or Fungi from Yuggoth if you prefer) war against the Elder Gods?

Posted by: natural cynic | June 16, 2009 1:30 PM

I'm not one of the charitable estimators: I'd guess very low on those last 3 parameters, and get an N of less than one.

You sayin' something about ... us?

Posted by: Ben | June 16, 2009 1:31 PM

May the Prophets guide you, PZ.

Posted by: Glen Davidson | June 16, 2009 1:38 PM

I'm not one of the charitable estimators: I'd guess very low on those last 3 parameters, and get an N of less than one.

Fermi, etc., it's probably not very high, indeed.

I really don't understand the desire for ETI anyway, except that they could radio information that would be very difficult for us to gather.

Another ecosystem, another example of evolution, that would extremely interesting, especially if it were filled with multicellular organisms. And still very interesting if the organisms were all single-celled.

So we need to get to Mars and Europa with good equipment (and no humans--unavoidable "contamination"), and we need fantastic interferometers.

Glen D
http://tinyurl.com/6mb592

Posted by: Seth | June 16, 2009 1:40 PM

Don't forget the galaxy is a huge place and has huge potential as a giant open ecosystem. Anything smart enough to make it off its home planet and venture out into the galaxy is probably terrifying.

I suspect anything we run into 'out there' will probably try to eat or nuke us without a second thought and they are right to do so.

The whole 'enlightened brotherhood' idea of aliens just doesn't jive with what we see in nature and in ourselves. Technology exists to flatten and break the sharp edges of the world and any race or species with the cunning and patience to master interstellar travel will have little use for planet earth and its people.

Sometimes I hope we are the only inhabited planet because I don't want our entire history nuked from orbit by a race of sociopathic super geniuses from Sirius.

But hopefully that's not the case, I guess we'll just have to wait and see.

Posted by: raven | June 16, 2009 1:41 PM

And all I need is space missionaries knocking on my door on Saturday mornings.

But what if that UFO missionary has a large number (from our viewpoint) of tentacles?

Posted by: Mike Caton | June 16, 2009 1:44 PM

1) PZ is certainly right. You don't want to meet aliens. They won't be the extraterrestrial grandparents coming to shepherd us into a new dawn of peace and tranquility. They won't even be Cortez and Pizarro. They'll be great white sharks or mountain lions with space ships, and they'll be just as interested (and able!) to talk to us as sharks and lions are. Get over the idea that intelligence equals morality, and think of it in terms of Darwinism.

2) I don't think Drake has to worry. Religion is a product of our particular nervous system's short circuits. It might actually be very revealing of some of the general principles of cognition if we could see what weird short circuits and delusions appear in the aliens' behavior.

Posted by: Holbach | June 16, 2009 1:49 PM

Carl Sagan did a nice depiction of the Drake Equation on his Cosmos series. Heck, if there is a chance for discovering intelligent life elsewhere, then I am banking on the Andromeda Galaxy, my favorite after our own Milky Way Galaxy. Of course we will never hear from Andromeda, just as we will never hear from the religionists imaginary god. Time and distance are a lot more realistic than proving that human made nonsense. That's what I like about the Universe: it has no understanding whether we exist or not.

Posted by: Brain Hertz | June 16, 2009 1:52 PM

The Drake equation is all well and good, but it completely ignores the Fermi paradox - if the galaxy is teeming with life, then where is everybody?

I think Frank already explained that one: they're out there and detected our transmissions, and they're now rolling thier eyes and waiting for us to get over our ridiculous superstitions before they risk making contact...

Knockgoats:

Evidence for this gets stronger as SETI searches continue to fail, alien probes are not found in the solar system, and better telescopes show no obvious signs of macro-engineering.

I agree with most of your points, but not this one. Unfortunately, our current SETI capabilities are limited to detecting signals which are being deliberately beamed at us, and not just inadvertent leakage.

Posted by: uncle frogy | June 16, 2009 1:55 PM

PZ said, "I suspect that if the human race could leave our solar system, we'd be a rather rapacious horde in our little corner of the galaxy, so I think that human temperament and history argues against that hopeful wish."

That we will become some benign species like the Star Trek's Vulcans is the dream that tends to overshadow my thinking on space and space travel.
I do not want to look at our history from both sides but only on the "victories" and forget that we keep doing the same kinds if things over and over. There are no wars to end all wars yet.
Slavery and exploitation still continue in different forms even where they are not sanctioned by society.
If we look at the history of human culture and technology, at the rise and fall of "civilizations" one thing we see regardless of religion or political organization is a steady degradation of the environment. From the deforestation of Greece and the collapse of the Maya and Angkor Wat to our present situation it does not look at all that we are a benign force at all. In fact we seem to me to be ignorantly and willfully self destructive.

Posted by: Celtic_Evolution | June 16, 2009 1:57 PM

DaveG

I believe that anything that can be imagined is possible, perhaps even likely,

Oh, come on... no you don't... really? Cause I can imagine some pretty crazy shit. If you imagine that you can breathe in space, does that mean it's possible?

The universe was not designed to make it easy to meet.

The universe wasn't designed, period.

Posted by: M31 | June 16, 2009 1:58 PM

#35 (I hope the aliens have bacon.
Or even better, ARE bacon.)

That's what they're saying about us.

Posted by: Jim | June 16, 2009 2:11 PM

That was pretty much the basis of the Halo series of computer games, actually. The enemy is a theocratic crusade of various alien races. Their first message to humanity is essentially "We are killing you in the name of our God".

In real life, I don't see that an alien race would necessarily be hostile, any more than it would necessarily be friendly. Both positions depend far too much on assumptions that we have no real data to support.

Posted by: Nominal Egg | June 16, 2009 2:19 PM

I have a hard time taking the Drake Equation seriously.
I mean, how accurate an estimate can one get when 4 of the 7 variables are simply pulled from one's ass?

Posted by: Celtic_Evolution | June 16, 2009 2:20 PM

to myself @ #50

Before someone else gets this and misses the point let me clarify:

If you imagine that you can breathe in space, does that mean it's possible?

more specifically, in space without the help of any space-suit or breathing apparatus.

Posted by: Brain Hertz | June 16, 2009 2:27 PM

That's so only until they develop von Neumann probes (self-replicating spaceships). If our technological civilisation survives, these will almost certainly be feasible within a few centuries at most. Once you have them, they could reach every part of the galaxy within a few million years, without any need for faster-than-light travel or other implausibilities. So, where are they?

That assumes that a civilization sufficiently advanced to build such a thing (and, incidentally, I actually doubt this is possible) would still think that sending out such a probe would be a good idea.

Setting in motion something which implies exponential consumption of scarce resources just doesn't sound that smart to me...

Posted by: tomh | June 16, 2009 2:28 PM

...the Fermi paradox - if the galaxy is teeming with life, then where is everybody?

I never understood the rationale behind this. The answer seems obvious, they're anywhere from dozens to thousands of light years away, or, in the case of the billions of other galaxies, millions and billions of light years away. Unless there is a convincing explanation for how to surpass the speed of light, why would we expect any contact ever?

Posted by: steve_h | June 16, 2009 2:33 PM

The style sheet scienceblogs/-/css/screen/reset.css "turns off" the standard behaviour of most/all HTML tags by assigning new defaults. main.css then restores the behaviour of sup but not sub.

Posted by: apthorp | June 16, 2009 2:41 PM

If religion is a natural and intrinsic part of a sapient's way of thinking (which I don't believe, by the way, but I'm often told by the pro-religion camp that it is)

This misstates the point. What seems essential to sapience is a sense of causality (as opposed to simple reaction), leading to sequence, leading to narrative. I think this is a pretty helpful characteristic. If you have causality there is something like a 'causal agent'. Without some understanding of phase transition is water, the 'rain causal agent that i can't see but must be there to make it rain' make some sense. The naturalist explanation is just as narrative.

I think it's important to recognize the religious argument often amounts to "we got narrative, you got narrative, same thing". Of course this misses the interesting requirement that all narratives be connected and consistent with each other. :)

Posted by: Ericb | June 16, 2009 2:45 PM

"If our technological civilisation survives, these will almost certainly be feasible within a few centuries at most. Once you have them, they could reach every part of the galaxy within a few million years, without any need for faster-than-light travel or other implausibilities. So, where are they?"

Since we've only been broadcasting for a few decades there would be no reason for them to come here. What's the point of traveling to a solar system if you aren't certain of finding anything interesting there?

Posted by: Kingasaurus | June 16, 2009 2:49 PM

I have a hard time taking the Drake Equation seriously.
I mean, how accurate an estimate can one get when 4 of the 7 variables are simply pulled from one's ass?

Because the manner in which you take the Drake equation seriously is simply as a methodical way of thinking about the problem and its variables. It isn't intended at this point for you to plug in the "right" answers.

And didn't Sagan also mention that even if the optimistic estimates for the Drake equation were correct, and these civilizations were distributed more or less randomly through the galaxy, we shouldn't expect the nearest one to be any closer than 200 light years away. If that were the case, the aliens in question would be in the midst of hundreds of thousands of stars within that 200 LY radius. They would have no reason to think anything interesting was going on here, and they might consider all of those stars equally worthy of interest/exploration. Even a close-by spacefaring alien race wouldn't stumble upon us easily.

I'm not a fan of those optimistic estimates, but even if there were dozens of ET's more advanced than us in the Milky Way, the nearest one might still be ridiculously far away.

I also don't think we can just assume that a really advanced ET would be all over the galaxy by now and be obvious to us already. Too many unknowns to flatly state that. Maybe at a certain level of advancement they stop being interested in space exploration at all in favor of other pursuits.

I think we are often guilty of placing our own desires and inclinations in the minds of these potential ET's. Who the heck knows what would really interest them?

Posted by: tsg | June 16, 2009 2:51 PM

Now, replace the term "solar systems" with "continents," and imagine this being spoken by a non-European person in the 16th century. Still unlikely?

If you ignore the fact that space travel is orders of magnitude more complicated than ocean travel, no. But I'm not.

Posted by: Nominal Egg | June 16, 2009 2:52 PM

If the content of the radio signals we've been broadcasting has any effect on alien attitudes towards earthlings we'll be in big trouble when they start receiving Celine Dion signals.

Assuming the Lawrence Welk they received earlier hasn't already driven them into a rage-induced human-killing frenzy.

Posted by: Nominal Egg | June 16, 2009 3:00 PM

I can't see us getting as far as serious inter-stellar travel unless we get over these self-destructive issues we have.

Posted by: amk | June 16, 2009 3:03 PM

Atomic Rocket is a hard SF resource including a good discussion on aliens, including potential for conflict. The website's a mess though.

The Killing Star book suggests that the only rational response for civilisation A when it discovers civilisation B is for A to fire a relativistic missile at B, destroying its homeworld without warning, just in case B may do the same to A.

"Do unto the other fellow as he would do unto you and do it first."

This though ignores the possibility of civilisation C, who may see the first strike relativistic missile, trace its flight path back to A and decide that it would be best if A weren't there any more.

Other than kill-them-before-they-can-kill-us paranoia and religion I don't see why there should ever be interstellar conflict. A planet's ecosystem is unlikely to be suitable for aliens, most life bearing planets will not have a technological civilisation anyway, and raw materials can be more easily had for a space faring race from asteroids than planets. If you've spent the energy to escape one gravity well why enter another?

Posted by: TheThomas | June 16, 2009 3:05 PM

My understanding of history is that warlike peoples will be stuck in the first stages of societal growth. The Native Americans of North America were warlike and remained in tepees. The Native Americans of Latin America and South America were less warlike and built huge societies.

No human society has grown to the point of being an intergalactic power, and part of that may be we haven't evolved away from war and towards cooperation.

Posted by: Faithless | June 16, 2009 3:18 PM

I read only a little while ago in Scientific American or New Scientist that recent evaluations suggest that only laser communication directly aimed at the solar system would be effective in getting our attention.

There's this old thing about how our communications bubble - beginning with the first radio transmissions - is a sphere of radius about 100 light years. However, this recent evaluation suggests that within about 5 light years the communications bubble would be so attenuated as to be indistinguishable from background noise.

If so, that would suggest that the Fermi paradox is not so paradoxical.

I would expect any intelligent species that had discovered there were other intelligent species in the galaxy would be keeping very quiet. There are good reasons for thinking that it is the only rational response: don't you think the 15th century American Indians would have hidden the North America from Europeans, at least until they had got approximate technological parity?

There are great science-fiction stories about this sort of first contact - not melodramatic, like Alien and Predator, nor overly romantic, like CE3K. My favourite would be And I awoke and found me here, on the cold hill's side, by James Tiptree Jr.

Posted by: Nominal Egg | June 16, 2009 3:18 PM

If you ignore the fact that space travel is orders of magnitude more complicated than ocean travel

Posted by: Rev. BigDumbChimp | June 16, 2009 3:21 PM

Imagine the reaction of, say, the Vatican, if the bug-eyed monsters turn up and either have no god, or a different one.

Well one thing we can be sure of is that it will be no god or a different one.

Posted by: Ryogam | June 16, 2009 3:25 PM

OH, this reminds me of a sci-fi story I read years ago.

Basic story, E.T.s come to Earth and they are all Jewish. So, can any one name the story and remember what the resolution of the story is? Because I sure don't, and it's killing me.

Posted by: Gingerbaker | June 16, 2009 3:29 PM

Evidently, the human race never invents time travel. Otherwise, we would be meeting human time travelers, wouldn't we.

And if we can't bend time, we can't bend space, for they are the same thing.

And if we can't bend space-time, then we will never explore the stars.

And evidently, no ET's came here by bending space-time and taught us how to do it, other wise we would be meeting time travelers.

And since space is really really big, it is almost inconceivable that we will ever meet an ET who doesn't use faster than light travel anyway.

And it seems pretty unlikely that ET's might even exist during the same time frame that we as a species exist. Because when you look into just how lucky we are to have this planet, with its particular orbit around its particular sun, its makeup of atomic constituents, its spinning molten metallic core, its particularly sized non spinning moon derived from an interplanetary collision, the right amount of water delivered by comets at just the right time of galaxy and solar system formation, and all the incredibly lucky species extinction events that led to small intelligent mammals evolving - we appear to be quite stupendously unlikely ourselves.

When I look up to the heavens and see the stars and galaxies and the essentially infinite expanse of the Universe, I feel not only a sense of wonder and awe, but a distinct feeling of sadness. Because it seems likely that humans will never explore these reaches.

Posted by: Kingasaurus | June 16, 2009 3:33 PM

I don't think we can just assume that ET's would build things like Von Neumann machines. We're totally guessing about stuff like that. Maybe they would, but maybe they wouldn't for reasons we haven't thought of yet.

One more thing:

Even if the universe exists in such a way that it is statistically probable that our galaxy will be the home to many technologically advanced civilizations throughout the galactic lifetime, it's also possible that we are the first one to emerge.

Somebody has to be the first one, and if we are, there'll be nobody to talk to but ourselves.

Posted by: amk | June 16, 2009 3:34 PM

I replied with one earlier: specifically, that launching an autonomous, self replicating machine which consumes resources at an exponential rate is an extremely dumb idea.

Resources may be finite, but they're pretty bloody big.

Posted by: skoonz | June 16, 2009 3:39 PM

And if we can't bend time, we can't bend space, for they are the same thing.

Uh, not so fast. Time travel isn't about bending space or time. We can do that! The essence of General Relativity is that anything that has mass and moves is bending spacetime.

Time travel is about bending spacetime so much that it loops back on itself. You're not deforming it... you're creating topological holes in the spacetime manifold.

Posted by: tsg | June 16, 2009 3:41 PM

I'm not sure I agree with this. Ocean travel in Columbus' or Magellan's day was extremely complicated. And expensive. And risky.

Ocean travel is just an extension of what humans have been doing since there were humans: floating on water. The rest is just extending the range of that capability. We've only been able to get off the ground for the last 100 years, escaped Earth's atmosphere for the last 50, and have yet to send humans out of Earth's gravity (not counting the Moon, which, not being an astrophysicist, I'm not sure should count anyway). Compared to ocean travel, we're still floating around on rafts made of trees lashed together and it's taken us hundreds of thousands of years to get that far.

I'm not saying ocean travel wasn't complicated, expensive and risky in Magellan's day, only that space travel is much, much more so and requires a level of technology that hasn't existed until very recently.

Posted by: Nominal Egg | June 16, 2009 3:52 PM

I'm not saying ocean travel wasn't complicated, expensive and risky in Magellan's day, only that space travel is much, much more so and requires a level of technology that hasn't existed until very recently.

Right! It's the level of technology that needs to be sufficiently advanced. Not necessarily the "morality" or "maturity" of the travelers.

Posted by: --E | June 16, 2009 3:53 PM

Part of the problem is that even people who understand concepts such as "geologic time" and "millions of light years" still get stuck in thinking of space as very small.

We humans take up nothing of space. Why would we think other sentient species take up more than we do?

Even if they do, there is so freaking much space. I can't find my car keys in the finite, well-known space of my own apartment. Stumbling across a sentient species in an enormous space that is ever-expanding at an increasing rate seems extremely unlikely, even if they're not hiding.

Posted by: Gingerbaker | June 16, 2009 3:57 PM

skoonz said:

"Uh, not so fast. Time travel isn't about bending space or time. We can do that! The essence of General Relativity is that anything that has mass and moves is bending spacetime.

Time travel is about bending spacetime so much that it loops back on itself. You're not deforming it... you're creating topological holes in the spacetime manifold."

But it looks like we can't (will never) do that, though, since we don't meet time travelers, right?

Posted by: tsg | June 16, 2009 3:58 PM

That's exactly my point. There is no reason to suspect that a space-faring species will have put their war-like tendencies behind them (assuming they ever had them in the first place). That kind of competition is great for advancing technology.

Except that the advances in technology usually take the direction of aiming it at the other guys or stopping theirs from hitting you. Yes, you can argue that launching a missile with a warhead attached can teach you how to launch a rocket with a crew aboard, but it doesn't tell you how to stop it from exploding when it gets there or how to get it back.

Posted by: Nominal Egg | June 16, 2009 4:01 PM

It's really hard to see how any of these would apply between aliens

Posted by: tsg | June 16, 2009 4:03 PM

Right! It's the level of technology that needs to be sufficiently advanced. Not necessarily the "morality" or "maturity" of the travelers.

That isn't my argument. I think that until a race stops trying to kill each other they aren't likely have the time or the resources to develop the technology to go kill other people.

Posted by: Neil | June 16, 2009 4:06 PM

I love discussions on this subject. It can open up the imagination as well as sharpen critical thinking skills. It can reveal hidden attitudes about life and mankind, challenge one's faith in and assumptions about life, the universe, and everything: and all this can occur without one single shred of evidence for any given position on the subject. It's much better than trying to debate or define god, as long as you're willing to think.
Just for shits and giggles, I'm putting a link to one of the first blogs I really liked when I first discovered what I call the "atheist underground" of the internet a few years ago. This particular post is one take on the same idea that P.Z. expressed at the end of this post. Martin Willett bets that if and when aliens arrive, at least some of them will be believers. Willett's Wager:

http://www.mwillett.org/atheism/wager1.htm

Posted by: Bill Dauphin, OM | June 16, 2009 4:10 PM

Nominal Egg:

I'm not sure I agree with this. Ocean travel in Columbus' or Magellan's day was extremely complicated. And expensive. And risky.

It was certainly all that... relative to the technological level of the contemporaneous society... but in absolute terms, crossing the Atlantic is trivially easy compared to a human mission to even the nearest other star. The whole point is that if interstellar travel ever matches, in relative terms, the difficulty (or ease, depending on how you look at it) of 16th century sea travel, it will mean that human society is vastly more advanced than it was in the 16th century, or that it is today.

And if there is, in fact, any correlation between technological advancement and species/societal maturity (admittedly that's not certain), we will also be vastly wiser, as well.

Posted by: skoonz | June 16, 2009 4:11 PM

@Gingerbaker:

But it looks like we can't (will never) do that, though, since we don't meet time travelers, right?

I would agree that it is extremely unlikely that (backward) time travel is possible, theoretically or practically. And I agree the fact we don't meet time travellers is good evidence towards this. But it's also possible that time travel becomes achievable, but it is either deemed extremely unwise to make use of it, or all precaution is taken to ensure time travellers are undetected by contemporaneous society. Just because time travel is possible doesn't mean it is possible to predict the consequences of messing with history.

Posted by: Knockgoats | June 16, 2009 4:17 PM

My understanding of history is that warlike peoples will be stuck in the first stages of societal growth nil. - TheThomas

Fixed for you. You think the ancient Greeks were a peaceful crowd? The Romans? The British? The Americans?

I don't think we can just assume that ET's would build things like Von Neumann machines. We're totally guessing about stuff like that. Maybe they would, but maybe they wouldn't for reasons we haven't thought of yet. - Kingasaurus

That's just repeating what you've already said. So I'll repeat what I've already said: a reason not to do so has got to apply to every technological civilisation. And we're not just guessing. We know self-reproducing machines can be built. We know they can be pretty small (look at bacteria). We know lasers could be used to accelerate a small probe to a good fraction of the speed of light. We know many stars have planets, which almost certainly means they have lots of debris around them to build new probes, as our solar system does.

Even if the universe exists in such a way that it is statistically probable that our galaxy will be the home to many technologically advanced civilizations throughout the galactic lifetime, it's also possible that we are the first one to emerge. - Kingasaurus

Sure, but that would mean that right now, N=1 - which is exactly what I'm arguing is almost certainly the case.

I replied with one earlier: specifically, that launching an autonomous, self replicating machine which consumes resources at an exponential rate is an extremely dumb idea. - Brian Hertz

Well (a) No, it isn't, if you put a stop condition in; and (b) you think a technological civilization would never do anything extremely dumb? Really? If there's lots of them (and remember, that's what I'm arguing against), the chances that at least one of them would, approach 1. So where are the galaxy's dumb bricks' von Neumann probes?

Posted by: Jadehawk, OM | June 16, 2009 4:21 PM

1. So where are the galaxy's dumb bricks' von Neumann probes?

we haven't built them yet ;-)

Posted by: Nominal Egg | June 16, 2009 4:30 PM

And if there is, in fact, any correlation between technological advancement and species/societal maturity (admittedly that's not certain)[what does this even mean, anyway?], we will also be vastly wiser, as well.

Posted by: Knockgoats | June 16, 2009 4:34 PM

there are a million reasons not to care, or not to want to spend resources, on what's physically unreachable. Earth-life is hideously curious. WE want to know, even if knowing this will probably not work out in our best benefit. And maybe curiosity is essential to intelligent, sapient life. - Jadehawk

Well first, I think curiosity is essential to intelligent, sapient life - after all, pretty much all mammals and birds show it - not sure about other groups. Second, if they're not curious and communicative, they wouldn't have developed "a technology that releases detectable signs of their existence into space" - see the penultimate term of the Drake equation. Third, even if curiosity is not essential to sentient intelligent life, it only has to be one other, earlier example that had it - and survived capitalism - for the galaxy to be swarming with their machines, if not themselves.

in absolute terms, crossing the Atlantic is trivially easy compared to a human mission to even the nearest other star. - Bill Dauphin

IIRC from an earlier conversation, Bill, you're a carbon chauvinist - for you, it just has to be biological humans that do the interstellar travel, not machines. But this is just your prejudice. A small, laser-accelerated interstellar probe should be possible within a century or two if technological advance continues:
Deep space probes.

Posted by: Dave G | June 16, 2009 4:38 PM

Just remembered a good series of novels - the Manifold trilogy (Time, Space and Origin) by Stephen Baxter that explore possible resolutions to the Fermi paradox. The first novel was particularly memorable as it had humanity reaching into space by the proxy of modified squid.

Might be a popular book in these parts...

Posted by: DGKnipfer | June 16, 2009 4:41 PM

"We are here to take back Glenn Beck"

YES!!! Please let it be!!!

Posted by: tsg | June 16, 2009 4:45 PM

Actually ours seems to be doing a pretty good job of proving that it's possible to do both simultaneously.

Last I checked, funding for space exploration (and science in general) was being slashed while we seem to have unlimited funds to spend on war. We have weapons that can destroy all life on the planet in a matter of minutes and have yet to get people out of Earth's gravity. No, I don't think we're going any kind of a job as far as space exploration is concerned.

Posted by: Kismet | June 16, 2009 5:02 PM

Ginger, you argument breaks down (I'm not even sure if you were serious to begin with?) because this sentence
"And if we can't bend space-time, then we will never explore the stars." doesn't make any sense.
Why do we need to? You can travel everywhere if you have the time. Are you still somehow trapped in the world view that people necessarily have to die around the age of 80? Life extension + relativisitic effects and you can visit the galaxy in no time (assuming you got the technology to do so).

It certainly makes contact by ETI less likely, though.

Posted by: Bill Dauphin, OM | June 16, 2009 5:13 PM

KG:

in absolute terms, crossing the Atlantic is trivially easy compared to a human mission to even the nearest other star. - Bill Dauphin

IIRC from an earlier conversation, Bill, you're a carbon chauvinist - for you, it just has to be biological humans that do the interstellar travel, not machines.

Well, gee, that's a pretty harsh way of saying that I think a big point of the trip is being on the bus! Do I call you a "silicon chauvinist"? ;^)

But yeah, you're right... sorta: I think human presence is the primary motivation for human exploration. Now, "human presence" doesn't necessarily imply biology, but telepresence is infeasible over interstellar distances, and I'm less sanguine than you are about how soon we'll truly be able to upload human consciousness to nonbiological brains (if ever). Robotic surrogates don't scratch my itch: I could mail my camera to France, but that's not the same as being there. All that said, though...

A small, laser-accelerated interstellar probe should be possible within a century or two if technological advance continues

[a] Even this more modest accomplishment is still many, many orders of magnitude more difficult than 16th century sea travel, so my basic point stands, and [b] the conversation was about the consequences of a potential meeting of two mutually alien intelligent civilizations... and I'm not sure a single small robotic probe would count as that encounter, even if it were found by ET.

But it's fun to speculate, innit?

Posted by: Steve | June 16, 2009 5:21 PM

I recommend Killing Star by Pellegrino. He's a bit flaky, but he explains how the number of habitable planets could be increased, and what sort of society might arise from them.
Good book.

Posted by: Dianne | June 16, 2009 5:31 PM

Eating and enslaving earthlings? Surely they would be better at handling their labor and nutrients needs with technology close to home?

Their needs, yes. But can they fill the universal*, ever present desire for more and more exotic pets and/or cuisine without continuous travel? I don't think so.

*It's universal and all species will have it. Because I say so.

Posted by: Nominal Egg | June 16, 2009 5:31 PM

I think a big point of the trip is being on the bus!...I think human presence is the primary motivation for human exploration.

Posted by: Knockgoats | June 16, 2009 5:40 PM

Just curious, why do you think capitalism is inevitable? - Nominal Egg

I deduce it from the absence of alien von Neumann probes ;-)

Seriously, I'm not sure it is, but there has been a very general positive feedback loop between increasing population and sociotechnical innovation in human history, plus a general tendency for surplus production to be commandeered by elites and used to enhance their own wealth and power. I'm guessing that these mechanisms are sufficiently general to apply to any intelligent social species. Once the surplus is large and mobile enough, and technical advance fast enough, competition between and within social groups is likely to produce an elite which is clever, ruthless, greedy, innovative and short-termist: a capitalist ruling class, or something very like it. These features will make it very difficult to displace or control, and very likely to over-exploit its environment.

Posted by: Marcus Ranum | June 16, 2009 5:42 PM

Kismet writes:
Life extension + relativisitic effects and you can visit the galaxy in no time (assuming you got the technology to do so).

Assuming you're at relativistic speeds what's the point of travelling the galaxy? Everything you see is gone pretty much by the time you've passed it. I suppose you could give a big ole red-shifted drive-by "hi!" to any life-forms you saw on the way, but what's the point? (Perhaps this has already happened? How would we know?)

Life extension is irrelevant; the meat would have to survive getting up to relativistic speeds without turning flat. We evolved in a world where things don't really go very fast and aren't suited for interstellar travel. Meat is heavy and requires all kind of meat-support systems that electronic systems don't. We might be able to extend our life-spans but it'd have to be practically immortality to be of any use because we're talking some really gnarly time-scales unless you assume Star Trek physics.

Posted by: Greg F. | June 16, 2009 5:44 PM

After doing enough research on astrobiology, I would lean to Phil Plait's side and say that any advanced civilization would be as hostile and militant as we are if not more. Surely when Drake talks about species getting past their violent instincts, he can't forget that the real reason why space flight even began was to deliver nuclear-tipped ICBM across the world...

Posted by: Nominal Egg | June 16, 2009 6:00 PM

at first the population-pressures will spill us all over the solar system, and (if we survive that long) eventually out of it. humans spread. it's what we do.

Posted by: MrMarkAZ | June 16, 2009 6:14 PM

So maybe the folks at Bungie had it right after all. SETI will one day intercept a transmission similar to this: "Your destruction is the Will of the Gods, and We are Their Instrument!"

If they speak of lighting the Sacred Rings to pave the way for a Great Journey, we're seriously frakked.

Posted by: Desert Son, OM | June 16, 2009 6:21 PM

If they speak of lighting the Sacred Rings to pave the way for a Great Journey, we're seriously frakked.

Not if we have the Master Chief.

I hate to bring up the bad news again, but did everyone miss the part where Nominal Egg mentioned the aliens are coming for the hot dogs and the bacon? The bacon, people! Jesus Christ the fucking aliens are coming for the bacon! We have to do something! It's our bacon! Forget all the panic over the gays dancing, this is the bacon we're talking about!

[grabs thread by the lapels] Get to the stores! To the stores! We don't know how much time we have left!

Help! HELP! Alert Ted Koppel! The aliens are on the way and they're coming to take our bacon!

[runs off screaming to the store]
















[slinks back dejectedly a few moments later having forgotten his wallet]

No kings,

Robert

Posted by: truthspeaker | June 16, 2009 6:24 PM

Posted by: Knockgoats | June 16, 2009 1:20 PM

I'm with Dave G. - the Fermi paradox indicates that there are almost certainly no technological civilizations in this galaxy (or the local group) other than ours.

No, it just indicates that any technological civilizations in our galaxy are less than 100,000 years old. Remember, it takes 100,000 years for a radio signal of sufficient strength to get from one end of the galaxy to another. Sending probes to other stars requires a much higher level of technological advancement than we have here.

All the Fermi "paradox" shows is that intelligent, technology-using civilizations are, at best, uncommon.

Posted by: Gingerbaker | June 16, 2009 6:36 PM

skoonz said:

Just because time travel is possible doesn't mean it is possible to predict the consequences of messing with history.

Assuming it's possible to mess with history. ;D

Besides, if we/they can figure out space/time travel, they will have figured out how to outsmart any paradoxes that pop up.

I'm hoping when they figure out how to put gravity into the Great Universal Equation of Everything it will become simple.

Now, I had a dream a few years back, where an oracle told me that The Secret was to be learned from the exact nature of what happens when matter and antimatter destroy themselves. That everybody thinks they know what happens, but that everyone only understands it in general terms, and the Ultimate Truth will only be known when the interaction is truly studied in detail.

Now that I have shared this brilliant insight with the world through this post on Pharyngula, I am sure that the major institutions will be leaping at the chance to finally spend trillions on something productive.

Either that or I will be forced to write a sternly worded letter. ;D

Posted by: Dave Cortesi | June 16, 2009 6:43 PM

Fred Pohl wrote a series of quite frightening novels based on the idea of our being visited by some aliens who were species-killing religious wackos. Search Amazon on author:Pohl and title:Eschaton.

The problem with Von Neumann (self-replicating, hence exponentially-expanding) probes is that building even one (theoretically, one is all you need, but still...) would be very expensive, and at sub-light velocities any possible payoff of info would not come in the lifetime of the person(s) doing the funding. So who'd pay to build one? The idea has other problems as well.

Posted by: llewelly | June 16, 2009 6:59 PM

All the Fermi "paradox" shows is that intelligent, technology-using civilizations are, at best, uncommon.

Posted by: DaveH | June 16, 2009 7:11 PM

There are no von Neuman machines because The Culture ^TM kills them all before they reach civilisations that can't handle the pressure. See Ian M Banks' "The State of the Art"

If you doubt this is possible, why does Smoggy Batzrubbble wake up with a sore arse from an Alien anal probe???!!one !1

Posted by: Shaun | June 16, 2009 7:19 PM

The equation is one of those things.. true but empty of meaningful content. It seems to primarily be a way to make Drake a famoous name and give first year students something to argue about.

It seems perfectly acceptable to say that 'We lack the necessary data to make meaningful estimates on this topic at this time' but that seems to scare some people. At least SETI's approach is to try to gather data not indulge in mental masturbation over non existent numbers.

Posted by: Nerd of Redhead, OM | June 16, 2009 7:21 PM

I like Answers In Genesis, but one of the places where we seperate in ideas is in the abundance of life in the universe.

Posted by: littlejohn | June 16, 2009 7:24 PM

Another problem with both Drake and SETI: The assumption that the defining characteristic of an advanced civilization is the use of electronic communications, which we could recognize using radio-telescopes.
Is it not conceivable that an advanced technology could be built around something other than electronics? Maybe most advanced technologies have no need for electronics.
For that matter, maybe many highly intelligent critters feel no need for technology (e.g., dolphins).

Posted by: bonze | June 16, 2009 7:30 PM

And since no one else has mentioned them, Greg Bear's Forge of God and Anvil of Stars make the case that when it comes to interstellar communication, Silence is Golden.

Damned scary stuff. And the aliens making Von Neumann machines? They're The Bad Guys.

Posted by: Steve Dutch | June 16, 2009 7:43 PM

In Carl Sagan's Cosmos, he guesstimates the last few terms of the Drake Equation "conservatively" as 1/10.

That's hardly conservative. He might as well have made the probability 1. There's no reason that fc or fi won't be 10^-10 or less, or L might not be 1000 years or less. Much as I'd like a Star Trek Universe, I suspect any aliens are a long way away.

Posted by: Brain Hertz | June 16, 2009 8:12 PM

Well (a) No, it isn't, if you put a stop condition in; and (b) you think a technological civilization would never do anything extremely dumb? Really? If there's lots of them (and remember, that's what I'm arguing against), the chances that at least one of them would, approach 1. So where are the galaxy's dumb bricks' von Neumann probes?

a) Yes, it is, because you still have an utterly catastrophic (consuming the entire galaxy) failure condition (the stop condition failing).

b) We're not talking about just any technological civilization, we're talking about one advanced enough to construct such a self-replicating spaceship, which is monumentally hard. And there's the conflict: to get to that level of engineering prowess, you need to be really really good at thinking through the consequences of what you're designing, otherwise you'd never be able to do it in the first place. Which kind of makes it difficult to believe that you'd miss such an obvious flaw.

By the way, what would be these creatures motivation for doing it, anyway?

Posted by: amphiox | June 16, 2009 8:39 PM

I think the L term is probably much more complicated that just 'x' number of average years for a technological civilization to exist. Because it takes a lot less to destroy a civilization than it would to exterminate a species. Earth's history is full of civilizations rising and collapsing, with the survivors eventually rebuilding, and in almost every case with only a few exceptions, reaching and surpassing their prior level of development, before crashing again.

So we're probably talking about a pattern of repeated episodes of detectability interrupted by periods of decline/collapse where they'd be undetectable.

And frankly, I think it would take something really, really bad to wipe out an intelligent species entirely. The various self-inflicted catastrophes such as environmental collapse and nuclear war are all more likely to leave a few scattered bands of survivors, who will have the opportunity to rebuild and redevelop a technological civilization, than to completely exterminate the species.

(And a robot apocalypse definitely wouldn't work, because the civilization just gets replaced with a technological machine civilization that would be just as detectable)

Posted by: Ichthyic | June 16, 2009 9:01 PM

I think we all know what happens to inferior species when a higher intelliece comes visiting

Well assuming you mean either slavery or elimination, I have to ask:
do you live in isolation?

because I would have figured just about anyone visiting you would have a higher intelligence, and yet you're still around.

Posted by: amphiox | June 16, 2009 9:12 PM

Even if all biological civilizations that don't destroy themselves eventually upload themselves into computer networks, I would point out that in doing so, they effectively turn themselves into von Neumann machines.

So if civilizations are common, Fermi's Paradox still holds, the probability that at least one of these machine civilizations would decide to start expanding across the galaxy (perhaps they grow to the point where their host star doesn't provide them with as much energy as they want?) starts to approach certainty.

Again, I think the solution to the Fermi Paradox most likely lies in the fact that the assumption that a self-replicating expanding horde must inevitably span the galaxy and colonize every single star is likely to be false.

Posted by: Nicole | June 16, 2009 9:45 PM

Maybe there is something to the rumours of atheist brainwashing cults - I chanted 'one of us.' On the flip side, I'd rather my brain was washed of delusion and given an intellectual polish than just plain washed away by religion. One of us! One of us!

Posted by: Mary | June 16, 2009 10:01 PM

Just have to correct the poster above who said that Tasmanian Aborigines were exterminated.

This is unfortunately, a persistent Imperialist myth that is completely untrue. Because of this myth, Tasmanian Aborigines have had a constant uphill battle to have their Native Title claims/rights recognised by the federal government. There are some good books, docos and museum exhibits on this issue(National museum, Canberra).

The myth was invented by british soldiers and repeated as a "colonial victory" legend for the british to feel good and superior about. But it is a BS, albeit persistent myth.

Posted by: Peter McKellar | June 16, 2009 10:19 PM

I tend to agree (these days) with Kingasaurus and Jadehawk regarding "someone has to be first". Using our own evolution as a guide, the time required to get to this stage is 3.5 billion years. Throw in essential planetary formation, takes it out to 4.5B. What about seeding the system with heavy elements from nearby supernovas, drift time, accredition etc? It could be that it takes about 13.7B yrs of time for lumpy conditions to gather enough to permit life like ours to evolve. Maybe we are just entering the spring-time of intelligent life's emergence in the universe? We could be the first or there could be waves of probes and beserker destroyers headed our way. I don't buy into the von neuman destroyers (how many lions and tigers and bears terrorise our suburbs?).

Duration of civilisations is a major stumbling block to sustained communications with an interstellar alien civilisation (Egyptians 3.5K at best, Australian Aboriginals maybe 50K, more recent, technologically advanced empires seem to last quite short periods).

The issue of maintaining a dialogue is a problem at light speeds but could theoretically be overcome if we are ever able to develop quantum teleportation (of information) to a commercial level. This only works over short distances at present but if longer entanglement can be worked and pumped by a laser I could imagine in the distant future a series of relay stations establishing a near instantaneous parsec spanning internet. But someone has to build it, someone will need to send the slowships and drop the repeaters.

With self-replicating machines (eg latter generations of today's repraps, 3D printers and fablabs) already able to do limited (human) tissue printing, Venter's labs able to hand assemble a whole lifeform's DNA from 4 bottles of chemicals - and (another DNA) able to turn one species's cell into another's we will soon have the ability to transmit enough information to create a living cell at a remote location from entirely inanimate chemicals. I believe that while building infrastructure may be lengthy, even with just information and at light speed only (lasers), without the need for quantum teleportation, humanity could slowly spread by such means (probe hardware, propulsion systems etc excluded)

Even if we can't manage brain uploads, we could spread our genes, and through robot and computer instruction, spread our memes to other star systems. Once we get a handle on rapid proto-typing and 3D printing a probe could be sent (with a certain amount of raw materials) and just rebuild and reconfigure itself mid-flight as our tech improves.

Brain uploads, in this scenario would however make star travel possible by "virtual" teleportation, but doesn't address the sticky issue of what to do with the "original" back on earth ;) (assuming a non-destructive scan)

I tend to think that once we reach that level of space capability we will be more interested in observing and talking rather than exploiting. This scenario does not allow for plundered goods to be brought back either, just knowledge and data.

Posted by: Hypocee | June 16, 2009 11:34 PM

A bit about the VN machines, or rather Starchickens as that's the form ETI enthusiasts tend to point to - most of the time I hear about them they're meant to live in asteroid belts. The worst-case scenario of a failure of all their independent reproduction limits is a belt of refined materials tied up in machines instead of rocks - hardly the "consumption" of "the entire galaxy". If you're going to claim that they'll evolve the ability to individually enter atmosphere, consume under gravity and escape planetary gravity wells, then change their materials and repeat the trick to eat stars - well, obviously I read Pharyngula; given time enough and population, anything that's possible under the laws of physics is probably accessible to adaptation. But I'd say that evolution of any Starchicken population into star-eaters within the likely lifespan of our universe is rather less likely than a de novo abiogenesis of some hungry locomotive star. I'm not losing any sleep.

Posted by: Rasmus Holm | June 17, 2009 12:38 AM

I have said that I do not think space faring aliens would be religious, because they would not survive long enough to develop the technology needed if they continued to harbour under those delusions.

That being said, they might very well not be benign for other reasons.

Posted by: Uncle Glenny | June 17, 2009 1:31 AM

@ faithless #82: There's this old thing about how our communications bubble - beginning with the first radio transmissions - is a sphere of radius about 100 light years. However, this recent evaluation suggests that within about 5 light years the communications bubble would be so attenuated as to be indistinguishable from background noise.

Perhaps there a way succussion can be used to make it stronger as it gets more diffuse.

Posted by: raven | June 17, 2009 1:39 AM

Part of the Fermi paradox might be, the "primate in a can" problem.

We are realizing that manned space travel is much more difficult than we thought. Humans can't even survive weightlessness for very long, things go downhill like bone strength. A lot of our efforts lately have been robots and space probes and those like Cassini on multiyear missions are working well.

So we can shoot a primate in a can into space for a few months or even a few years maybe. So what? They can't do much other than survive. To be self sustaining we also need a biosphere in the can. As the Arizona biosphere showed, you need lots of that biosphere. Since biosphere didn't work so well, we don't even know how much.

All of that is a technical problem and capable of being solved, in theory at least. The other problem is the payoff. Humans need to see a tangible payoff from their efforts or they have a tendency to do something else. A settlement on the moon or Mars that isn't self sustaining or paying off, won't last.

All that being said, as far as we can tell, the galaxy appears essentially empty. If we figure out space travel, we could own the whole thing.

Posted by: António Martins-Tuválkin | June 17, 2009 2:30 AM

Instead this

N=R* x fp x ne x fl x fi x fc x L

better this:

N=R* × fp × ne × fl × fi × fc × L

Otherwise, great post, great blog!

Posted by: efrique | June 17, 2009 2:58 AM

I first really thought about the drake equation when reading a discussion of it by (IIRC) Asimov. I was with him until the point where he said something low "this number is likely either very high (near 1) or very low (near 0). So let's split the difference and call it 1/2."

The then-young-me did the olden-day equivalent of "WTF??"

And he then proceeded to repeat that exercise several more times. If you thought *even one* of the terms he did that with should have had a low probability, the final result was grossly inflated.

I thought all the terms from "intelligence" on were ludicrously high.

I've been leery of the Drake equation ever since, because people abuse it so easily.

With figues I can maybe believe I get N on the order of tens to hundreds... and so don't expect we'll ever make contact with an intelligent civilization.

Posted by: Knockgoats | June 17, 2009 4:18 AM

you still have an utterly catastrophic (consuming the entire galaxy) failure condition (the stop condition failing). Brain Hertz

Not really, because, as Hypocee@188 has pointed out, von Neumann probes don't consume everything. Moreover, multiple levels of safeguards could be built in. The probes would be designed to remain in touch with the home base, so "rogue probes" (even if such could not be prevented from emerging, which I doubt) could be detected by "obedient" probes, and measures taken to destroy them. Anyhow, the putative civilization would also have to consider the possible consequences of not expanding - extermination by astronomical accident, or someone else doing it first.

We're not talking about just any technological civilization, we're talking about one advanced enough to construct such a self-replicating spaceship, which is monumentally hard. - Brain Hertz

No, it really isn't. A few centuries more technical progress at most. Much easier than, say, human colonisation of the solar system, because you get to design the machine for its expected environment.

By the way, what would be these creatures motivation for doing it, anyway? - Brain Hertz

Well, apart from scientific curiosity:

An empty galaxy that we could own even if it took 50 million years. It's not like we have other plans or anything better to do. raven

To continue:
Isn't the Fermi Paradox kind of ironic and contradictory? Here's one side saying "If they're out there, they should have come here by now", and others saying "They can't get here because it's too difficult" (as per that part of skepticism of UFO reports.) It's not quite that simple, but still "they can't both be right."

No, but one of them can be. The paradox is not in the least contradictory. The reason for scepticism about UFO reports is not that it's too difficult to get here, but that the reports themselves are usually ridiculous (quasi-humanoids sticking probes up people's bums), and that if they are here, we would expect it to be bloody obvious. Of course you can invent reasons why it might not be, but since we know hoaxes, delusions and error are very common, and indeed many UFO reports have been shown to be a result of one or the other, there's no reason to.

But, the Fermi Paradox is also based on one big assumption, that the galatic 'landscape' on the large scale is neutral to colonization and/or von Neumann probes - that is the rate of expansion would be uniform and the distribution even. - amphiox

No, I don't think it is. Just that if advanced technological civilisations are common, at least one of them would have got round any such difficulties by now. The analogy with life on Earth spreading unevenly doesn't work, because we're assuming the process is intelligently guided. Besides, what reason is there to think we live in a "difficult" neighbourhood? There is, on the contrary, reason to think that we don't: our own system, with its lovely asteroid belt, would be ideal, and lots of nearby stars have planets.

To put a bit more flesh on the bones, here's my fiendish plan for galactic domination:

Stage 1: Telescopic reconnaissance. Already underway and advancing fast. Quite soon, we'll be able to detect rocky planets in other star systems, and these almost certainly mean lots of debris.
Stage 2: Non-self-reproducing fly-through probes. Small, laser-accelerated to a large fraction of C, directed at nearby stars with rocky planets, zipping through the target system and using gravitational slingshot for further acceleration to a second, third... nth target. Sending back information.
Stage 3: Von Neumann probes, sent to promising destinations as they are discovered. These would be bigger, and would need to decelerate at the target, so they'd be quite a lot slower. (Actually, thinking about it, this stage may not even be necessary. Given there are about 10^10 stars in our galaxy, and each stage 2 probe can be small and examine multiple targets, we can probably build all we need to examine every star in the galaxy right on our doorstep, in the asteroid belt.)
Stage 4: Colonisation probes. Generation ships, frozen people, cyborgs, machines, whatever. Sent to selected targets found by stage 2/3.
Stage 5: Colonised systems join in.

Now, I challenge all you Fermi-doubters: show good reason why either this is impossible (or even very difficult, for a civilisation a few centuries more technically advanced than ours), or that every such civilisation would decide not to do it.

Posted by: Knockgoats | June 17, 2009 4:33 AM

Anton Mates@147,
Interesting ideas - but you're overlooking that von Neumann probes, unlike life, would be intelligently designed! A main aim of that intelligent design would be to prevent exactly the kind of evolution you posit - probably by building in multiple parts that all have to match if the thing is to go on functioning at all - so al would have to mutate in lock-step for any evolution to occur. Remember, too, that the failure rate (the rate at which devolution to ordinary life occurs) would have to be very high, or the surviving probes would still complete the process.

Posted by: fyngyrz | June 17, 2009 6:07 AM

The heart of the Fermi paradox, pitiful rationalizations aside, is simply the part that asks "where are they?"

The answer is obvious: They are in the same place we are, that is, stuck to the planet, or incredibly optimistically, to the solar system, that they grew up in, well past the short window where undirected radio broadcasts are easier than directed ones, or well short of it. Those who might, by great chance, be residing *in* that window are probably not broadcasting anywhere near strongly enough for us to hear, or are at a distance that obviates the possibility.

Fermi was simply being an idiot when he dropped this pustulent postulate on the table.

As for Drake, this formula means nothing, because we have no values. You cannot make an "educated guess" about a subject you know nothing about. Well, you can, but we call that an act of "religion", and the tone of voice we use is not complementary.

Consequently, since both Drake and Fermi actually bring nothing to the table, it turns out that the question is still wide open.

Posted by: Hypocee | June 17, 2009 7:48 AM

Brad@191, as pointed out upthread the Drake equation is not aimed at intelligent life but intelligent, communicative life that's detectable on the galactic scale. Barring some really excessive radio telescopes, we don't count yet.

Posted by: Knockgoats | June 17, 2009 8:46 AM

mapinact,

Yes, it was Stross's Accelerando. A few centuries hence, practically the entire solar system, other than the sun itself, has been processed into self-aware corporations, arranged in concentric shells around the sun to catch all its radiant energy, and frantically calculating how to increase their profits from each other. However, it seems unlikely that if this is common (a) we wouldn't detect a lot of very large "stars" radiating in the infra-red (maybe we have - any astronomers around?); and (b) none of them would have sent out von Neumann probes, which would be energetically very cheap - if only to settle a bet, or as a low-cost, low-probability, but possible-high-return investment gamble!

Posted by: Bill Dauphin, OM | June 17, 2009 9:02 AM

Jadehawk (@143 and 151):

I second that emotion! What's often lost in the din of conversations about what aspects of space exploration are possible and what aspects are practical is the aspirational aspect of all human exploration (perhaps all human activity not directly related to day-to-day survival). I'm not saying our instinct to explore for its own sake trumps the technical questions of possibility and practicality... but it is a term in the equation, and on that often gets "simplified" out of the conversation, if not outright denied.

It's commonplace among a certain community of planetary scientists to declare that there's no reason for human space exploration ever: that machines will always be a more efficient way to do space science than human exploration, even at relatively "easy" targets like the Moon and Mars.

I dispute the truth of this argument, but even stipulating it, I think it misses a big point about exploration: The predicate assumption of the "robots only" argument is that doing science is the primary, if not only, motivation for exploration. I, OTOH, don't think science alone has ever been the sole motivation of exploration, howevermuch science and exploration have gone hand in hand. Amundsen and Peary and Byrd didn't head for the Poles, nor Mallory and Hillary for the summit of Everest, nor Livingstone, et al., for Africa, to do science. It seems to me that while scientific research often coincides with, and is frequently used to justify, exploration, the true motivation for much exploration is exploration itself: Humans go and look and see and touch new places in order to expand and consolidate the domain of human experience, and out of an innate curiosity that is scientifically useful, but not primarily scientific in nature.

And so, I think, we will go into space not because we must do so to gain scientific data, but because space is a place we haven't been yet... and that means that some sort of human presence (see my earlier comment on this) will always be an essential element of exploration.

The odd thing is that this is fundamentally a philosophical argument, but the counterarguments I get are almost always pragmatic rather than philosophical. People keep trying to find new ways to explain to me why robots are more efficient, completely missing my intended point that it's not about efficiency! My observation is that some scientists (not all, of course) can be a little blind to the existence of human motivations not directly related to doing science.

Posted by: amphiox | June 17, 2009 10:56 AM

Knockgoats, I agree that our solar system may well be considered desirable real estate for alien expansionists. However, I don't think that necessarily includes earth.

What and where would a technological civilization capable of interstellar flight find value in our solar system? I would say Kuiper Belt (water ice, carbon organics), Jupiter and the other gas giants (Hydrogen fuel), and their large moons (water ice, organics again), and maybe the asteroid belt (metals). Earth has all these, but far less in total that what is available in the outer solar system. Getting to earth costs more, because it is deeper in the Sun's gravity well. And, if these aliens are water/carbon based lifeforms, the specific biochemical and heavy metal makeup of earth's biosphere would be different from the one their bodies evolved for, and would likely be deadly toxic to them. For any starfaring species capable of building large self-sustaining life support systems, an already inhabited habitable planet is in fact a harder environment to colonize than a lifeless world possessing the raw materials necessary for their life and technology.

Of course it would not be impossible for them with their technology to adapt to earth, but why would they bother? For resources and living space they can get it all easier in the outer solar system. The only reason would be intellectual curiosity, if they happen to be interested in earth's biology. But much of that they can do remotely with telescope observation, etc, and if they do come in person (or machine), they would have a priori motivation to hide themselves, so as not to contaminate their observations, just as we often try to hide ourselves in blinds when we make observations of wildlife.

So the question would be, if they are out there and active in the outer solar system, would we be able to observe and recognize their activities with the technology we currently possess?

Posted by: John Scanlon, FCD | June 17, 2009 11:20 AM

Marcus Ranum:

Life extension is irrelevant; the meat would have to survive getting up to relativistic speeds without turning flat.

c / g = (3 . 10^8 / 9.8) s
= 354.3 days

I'm not saying you can get to the speed of light, but after a year, or a few decades, at earth surface gravity you'd be doing something relativistic. Dunno about you, but I think my meat could take it.

Knockgoats: I'm with those who regard the idea of releasing spaceworthy Von Neumann probes with horror because of the chance of mutation knocking out any artificial limits built into their program. (Make them dependent on lysine supplements?) There might be a civilization smart enough to be able to do it but stupid enough to go ahead, but I would not expect so. Of course, mutant probes would often become interplanetarily flightless, like birds and insects blown to isolated oceanic islands, and would specialise in surface niches such as eating each other. But those still able to get about would be strongly selected to bypass any 'stop condition'. You can send somebody on a suicide mission, but they've got no reason to follow orders to the letter.

Hypocee: I call your star-chicken and raise you a giant mutant star-goat. I've no idea what a VNP would actually look like, fresh off Dr Frankenstein's slab, and I'm sure that evolution is smarter than I am.

Raven:

As the Arizona biosphere showed, you need lots of that biosphere. Since biosphere didn't work so well, we don't even know how much.

Yeah, who's working on Biosphere 3? I guess it's being done with less hype, to avoid embarrassment if the experiment 'fails' by demonstrating another lower bound on minimum scale or complexity of a sustainable system. Give it another 30 years, like fusion power.

Even in a crowd like this one, I'm shocked how many there are who find it inconceivable that humans could find useful things to do in space for decades or more (hello? astronomy? developmental biology? anything?) or who would take a one-way trip to, for example, Mars. Some of you need to read more SF.

Posted by: Bill Dauphin, OM | June 17, 2009 12:01 PM

John Scanlon:

I'm shocked how many there are who find it inconceivable that humans could find useful things to do in space for decades or more (hello? astronomy? developmental biology? anything?) or who would take a one-way trip to, for example, Mars.

<raises hand>

If I were a single person, I would volunteer for a one-way trip to Mars, or for a decades-long deep space voyage, in a frickin' heartbeat!! Give me a few congenial companions, some sort of access to books and media, and some sort of intellectual work to do, and I'd "light out for the territories" before you could spell M A R S!

And, BTW, I'd only need to believe there was about a 60-40 chance of reaching the end of the journey in order to set out. It's not that I don't love my home country (or my home planet), nor that I have some sort of death wish... but I have dreamed of exploring space since my earliest memories, and I would take a considerable risk and give up a considerable amount to make that dream come true.

Posted by: amphiox | June 17, 2009 1:58 PM

We shouldn't be carping about the inaccuracies in the estimates of the terms of the Drake equation based on current knowledge. The equation's most important function is as a concise summary of what we need to know to answer the question. It is, in effect, a description of a research program.

We know the first term pretty well. We're starting to get a handle on the second. We're on the cusp of being able to intelligently investigate the third. We can make educated guesses about the last using ourselves as an example, admittedly a sample set of just 1. The rest we have no clue on yet, but we are in the process of figuring how we should go about trying to find them out.

Posted by: Knockgoats | June 17, 2009 3:05 PM

Knockgoats, I agree that our solar system may well be considered desirable real estate for alien expansionists. However, I don't think that necessarily includes earth.

What and where would a technological civilization capable of interstellar flight find value in our solar system? I would say Kuiper Belt (water ice, carbon organics), Jupiter and the other gas giants (Hydrogen fuel), and their large moons (water ice, organics again), and maybe the asteroid belt (metals). - Aquaria

That's a reasonable point, but I would expect the outer solar system, and parts of the inner (the moon and Mercury - stuffed with metals, and relatively low-gravity) to be littered with their artefacts, and indeed, them (if the two are distinct). At the least, I'd expect evidence of mining on some of the moons of the outer planets. Given the number of probes we've sent out, and the amount of telescopic observation, they would have to be hiding - and be pretty good at it - to evade detection if they've used the place much. However, that they are "here and hiding", is I think the next most probable solution to the Fermi paradox, after "they're not here because they don't exist". Not a comfortable thought - not that they would feel threatened by us, but they might - say - decide to turn the sun nova for some purpose of their own, such as a conceptual art installation.

Posted by: detrius | June 17, 2009 5:05 PM

All the Fermi "paradox" shows is that intelligent, technology-using civilizations are, at best, uncommon.

It also shows that warp drive is nonexistant.

Or every civilization so far has developed its own Fermi Paradox, came to the same conclusion as you and concluded that the warp drive can't be built. :)

Posted by: krusatyr | June 17, 2009 7:06 PM

If PZ is an alien, would he not downplay the likelihood of their existence?

Posted by: amphiox | June 17, 2009 7:39 PM

One plausible scenario for slowship colonization would go as follows: the civilization starts by building orbital habitats, perhaps initially just to relieve population pressure, no desire for exploration required. Over time the orbital habitats become less and less dependent on the home planet. Eventually they become almost self-sufficient. Political aspirations for independence by the habitatees might be motivation enough, again with no impulse for exploration.

Eventually someone straps an engine onto a habitat. Now the habitat can move around in its own solar system, so they could move away from the now crowded planetary orbit and perhaps move into the local Lagrange points. This also opens the possibility that the habitat, now a interplanetary space ship, could move to places where it can more easily acquire resources, like the asteroid belts, Kuiper belt, etc.

The next step is for these habitats to become von Neumann machines. They gather resources from the local solar system (moons, asteroids, comets), and build another, new habitat, into which a portion of their population can move. This can be motivated again by pure population pressure. This gets around the breakdown/failure with time problem. It would be inevitable that a complex machine like that would eventually break down, but they keep replacing themselves by building new space ships.

In time the network of habitats fills up the local solar system out to the Oort Cloud (where there is plenty of organics and water). Trade networks between habitats can also be set up to relay resources to the most remote ones.

At that point, it would not be very far to simply expand into the comet could of the nearest neighbouring star system. It wouldn't matter if there were planets in this star system either, as these habitats can sustain themselves without the need of planets anymore.

Repeat with new solar system, then the next, then the next, etc. The whole thing could be motivated by population growth and need for living space alone. A desire for exploration would not be needed at all.

Posted by: Jim Satterfield | June 17, 2009 10:32 PM

1. The Sun is a third generation star. Each generation gains more heavy elements. Would first or even second generation stars have enough heavy elements for intelligent life or for the kinds of technology necessary for communications and exploration?

2. We have no idea what we would be like if we could simply easily explore our solar system and had developed into a post scarcity society. We also have no idea where medicine will take us should it become so effective there is basically no disease or accident that isn't curable if it's not almost instantly fatal. How would any of that really affect our psychology and social systems? We don't know and history cannot provide a guide.

Posted by: Bill Dauphin, OM | June 18, 2009 12:22 PM

Amphiox:

One plausible scenario for slowship colonization would go as follows: the civilization starts by building orbital habitats, ....

Eventually someone straps an engine onto a habitat.

If you haven't already, check out Joe Haldeman's Worlds trilogy (Worlds, Worlds Apart, and Worlds Enough and Time), which is built on this spine of an idea.

Hypocee:

Orbital habitats are a great way to make new and exotic living space near resources, not such a great way to "relieve population pressure".

It's true enough that moving any appreciable fraction of the Earth's existing population off-world is infeasible in the foreseeable future. But to the extent that orbital habitats represent a first step (a sort of proof of concept) toward expanding the sphere of human habitation, they are part of a long-term approach: It's not that the current masses will ever move, but that we'll have space for new masses.

Of course, it will ultimately require engineering on a planetary or greater scale (terraforming, the building of superplanetary-scale structures like Ringworlds and Dyson spheres, etc.) to provide meaningful lebensraum... but we'll never get there if we don't start with "conventional" space habitats.

Posted by: Bill Dauphin | June 19, 2009 2:03 AM

Peter (@231):

OT, but are you any relation to actress/math ambassador Danica McKellar? I heard an interview with her today while catching up on my Science Friday podcasts, and I immediately wondered if this exchange with you counts as a Brush With Fame®. I know there must be plenty of McKellars in the world (assuming that's your real name, and not a nom de net), but it strikes me that an unapologetic math geek like her might have a brother/father/uncle/cousin of the sort that might hang out at science blogs. Jus' wondrin'

Back on topic:

With the abundant resources available in the asteroid belt, it seems sensible to start habitats from those asteroids that we have honeycombed for minerals (rather than processed completely) and then eventually discarded. Spun up these can provide "gravity" and protection against many of the hazards of space - and R&R facilities as an incentive for workers to take leave without the whole back-to-earth costs.

I recall reading a novel (whose title I can't immediately recall... IIRC, it was part of a failed attempt to start up a new series of young adult SF novels in the mold of Heinlein's "juveniles") based on exactly this model: mine the center of asteroids, then spin them up while heating with solar mirrors, then inflate the semi-molten, cored-out rocks to create habitats. Now I know sometime soon I'll have to spend hours sorting through my dusty old paperbacks trying to find that book!

Posted by: Knockgoats | June 19, 2009 6:25 AM

All the Fermi "paradox" shows is that intelligent, technology-using civilizations are, at best, uncommon.

It also shows that warp drive is nonexistant.

Or every civilization so far has developed its own Fermi Paradox, came to the same conclusion as you and concluded that the warp drive can't be built. :)

But then, why wouldn't they follow your line of reasoning and conclude that maybe it can after all ;-)

Posted by: Bill Dauphin, OM | June 19, 2009 10:03 AM

Knockgoats:

(*That hopeless conservative Bill Dauphin throws up his hands in horror at this treachery to the species* ;-)

Oh, come on! Emoticon duly noted, but you're unfairly turning me into a walking, talking strawman here. I've been arguing that human presence will always be a critical element of human exploration, but I'm hardly the "carbon chauvininst" you make me out to be: I explicitly agreed that "human presence" need not be natch'url borned meat bipeds in a previous reply to you, and then I linked back to that point, just in case anyone missed it.

As I pointed out in my earlier reply to you, I think you and I have different expectations about how soon we'll actually get to post-biological humans¹, but that's a difference of forecasting rather than of basic philosophy: I have never said, and don't believe, that the emergence of post-biological (or meta-biological) humanity would be "treachery to the species."

The distinction I've been drawing is not between meat-based and non-meat-based people, but between people and robotic surrogates that are not people. Which is to say, between people and the sort of robotic spacecraft we've launched to date, and which a certain school of scientists seems to think should be the only spacecraft we ever launch. Those probes are wonderful, vital scientific tools, but IMHO they don't really scratch the exploration itch.

BTW, for an interesting fictional treatment of the extension of human consciousness into the nonbiological sphere, check out John Barnes' Mother of Storms, a sprawling SF novel that has this idea as a critical element (though not the exclusively central theme). I think I may have recommended this book here previously.²

¹ Some of your comments suggest to me that you work in a field related to this question, and I would never put my entirely amateur opinion over that of the professionals. That said, AFAIK this is still a highly speculative field, and even the most professional forecasts are not too far removed from guesses... so maybe we all get the fun of watching to see what happens? In any case, I would love to be educated in this area.

² Fair warning: Like Joe Haldeman, Barnes has a habit of being somewhat brutal to his characters, and there are moments of unsettling violence in this book. There's also a subplot that involves a disgusting and violent sexual obsession. The "authorial voice" of the book clearly condemns this practice, and the characters involved eventually get their just due, but some readers may find this disturbing nonetheless. All that said, I have found reading and re-reading the book rewarding and thought-provoking.

Posted by: Knockgoats | June 19, 2009 10:22 AM

Bill Dauphin@236,
Sorry, I didn't understand your earlier comment that way, and in fact still don't see how it can be interpreted that way: you're talking about telepresence but, as far as I can see, assuming that it would be a natural human who's telepresent. But given your clarification, I'll stop teasing you about it!

Posted by: Thornae | June 19, 2009 5:53 PM

I'm late to the discussion, and Faithless (#82) has already mentioned James Tiptree Jr's And I awoke and found me here, on the cold hill's side, but I'm amazed that no-one's mentioned her* story Help, which posits exactly this situation - space missionaries. Behaving just like human missionaries did...

Aliens land, everyone loves them, until they start blowing up Earth temples and trying to convert the heathens. But they've got better weapons and (apparently) better gods, so we're stuffed.
Gloomy stuff, and the closing line is a killer.

*Yes, her. Look it up.

Posted by: Thornae | June 19, 2009 5:58 PM

Bollocks. Damned time-outs. Sorry about that...