40 replies to this topic

[Mind]

Saw this today and thought it was quite interesting

From these two facts it follows that the evolutionary path to life-forms capable of space colonization leads through a "Great Filter," which can be thought of as a probability barrier. (I borrow this term from Robin Hanson, an economist at George Mason University.) The filter consists of one or more evolutionary transitions or steps that must be traversed at great odds in order for an Earth-like planet to produce a civilization capable of exploring distant solar systems. You start with billions and billions of potential germination points for life, and you end up with a sum total of zero extraterrestrial civilizations that we can observe. The Great Filter must therefore be sufficiently powerful--which is to say, passing the critical points must be sufficiently improbable--that even with many billions of rolls of the dice, one ends up with nothing: no aliens, no spacecraft, no signals. At least, none that we can detect in our neck of the woods.

The Great Filter, then, would have to be something more dramatic than run-of-the mill societal collapse: it would have to be a terminal global cataclysm, an existential catastrophe. An existential risk is one that threatens to annihilate intelligent life or permanently and drastically curtail its potential for future development. In our own case, we can identify a number of potential existential risks: a nuclear war fought with arms stockpiles much larger than today's (perhaps resulting from future arms races); a genetically engineered superbug; environmental disaster; an asteroid impact; wars or terrorist acts committed with powerful future weapons; super­intelligent general artificial intelligence with destructive goals; or high-energy physics experiments. These are just some of the existential risks that have been discussed in the literature, and considering that many of these have been proposed only in recent decades, it is plausible to assume that there are further existential risks we have not yet thought of.

What I think is a fatal or very serious flaw in The Great Filter hypothesis is that all the existential risks we can currently comprehend do not necessarily lead to the extinction of evolution. Evolution would continue after a nuclear war. Evolution would most likely accelerate after super­intelligent general artificial intelligence with destructive goals took over the planet. The only event that would guarantee an end to evolution is the accidental creation of a black hole or if some type II civilization accidentally blew up their home star. Of course, by the time they have enough capability to become a solid type I or type II civilization they should be detectable, so some of the "far-out" existential risks become a mute/irrelevant points. Thus, nearly every catastrophic event we can envision would only be a temporary set-back to the evolution of intelligent beings.

[bgwowk]

That a Great Filter or Filters exist is an observational fact. However, we know less about past filters than future filters. Therefore, if future filters don't seem to be especially threatening, the most likely location for the Great Filter is behind us. We may be the first life in this part of the universe to advance this far.

[eternaltraveler]

That a Great Filter or Filters exist is an observational fact. However, we know less about past filters than future filters. Therefore, if future filters don't seem to be especially threatening, the most likely location for the Great Filter is behind us. We may be the first life in this part of the universe to advance this far.

or maybe a significant portion of stars in our galaxy are circled by blobs of grey goo that were once worlds.

We need to get people off earth in a sustainable way as soon as possible, even if it would be more economical to wait a little bit longer.

[niner]

Interesting thesis. I think there's a fundamental problem though, in that it assumes our present technology is adequate for detection of other life. It's as though a couple primitive men were standing in a field looking out into the sky and saying "Hmm. No smoke signals. Me think we are alone in universe." It may be that the galaxy is humming with chatter on communication channels that we have yet to conceive of. I mean, really, why would anyone use photons for communication? They're insanely slow. Or maybe there are vast civilizations in other parts of the universe where life forms chortle over jokes about how the Milky Way sucks and no one ever goes there.

[eternaltraveler]

Interesting thesis. I think there's a fundamental problem though, in that it assumes our present technology is adequate for detection of other life. It's as though a couple primitive men were standing in a field looking out into the sky and saying "Hmm. No smoke signals. Me think we are alone in universe." It may be that the galaxy is humming with chatter on communication channels that we have yet to conceive of. I mean, really, why would anyone use photons for communication? They're insanely slow. Or maybe there are vast civilizations in other parts of the universe where life forms chortle over jokes about how the Milky Way sucks and no one ever goes there.

the issue isn't whether we can detect them. the issue is why aren't they here?

[niner]

the issue isn't whether we can detect them. the issue is why aren't they here?

Maybe they are here, and we still can't detect them. Or maybe it's just that Earth sucks, and no one wants to come here. The idea that all life forms would want to spread inexorably throughout the universe seems like anthropomorphizing, imho. Maybe growing beyond all bounds like a cancer is something that an advanced civilization just wouldn't do.

[eternaltraveler]

The idea that all life forms would want to spread inexorably throughout the universe seems like anthropomorphizing, imho.

Doesn't take all. Just one.

[Shannon Vyff]

Advanced civilizations may adopt a more sustainable view. In the ultimate pursuit of intelligence, and the advancement of computation/storage I don't currently see how this could be possible. Science Fiction has addressed this in a multitude of ways, limits being imposed in various manners by authoritarian societies, democratic societies, and simply the self limitations inherent in the construct of our Universe. Seeing how things turn out was a motivating factor as I was a child, to try and see the future by becoming a cryonicist--supporting ending aging and A.I, as I became an adult and joined the transhumanist movement I realized that humans are actually engaged in the creation of the far future through their dialogs, planning, research and implementation.

Would we agree with advanced civilizations that we met? Would we expect them to adopt our own philosophies?

I feel there most likely is life advanced well beyond what we can imagine, god-like even--but we really can not know, I'm not going to transform the feeling into any belief.

[forever freedom]

I don't think that just because we can't detect other life forms in the universe, they don't exist. As someone said above, how can we be sure that we are using the right methods of search? Maybe advanced civilizations exist in higher dimensions; who knows?

[bgwowk]

While some may feel strongly that the galaxy should be preserved in a natural state, the harsh reality is that non-expansionist memes are quickly squashed by evolution. It doesn't matter that expansionism arbitrary, unenlightened, or even "cancerous." All it takes is ONE small group of beings with sufficient technology to replicate themselves and their technology from natural sources that doesn't see things that way, and they will soon be everywhere.

What about a police force to stop inappropriate expansion or exploitation of space resources? Sure, but cops and robbers, or any spacefaring groups that disagree with each other, drive expansion even faster as they compete for control of the frontier. There is no avoiding expansion except by collapse of civilization into a totalitarian regime that allows no groups of self-sustainable size to ever arise.

[niner]

Most of our models for the behavior of alien life come from our own experience and culture. This might be Biblical (go forth and multiply), ecological (bacteria populating all available niches), or based on observed human behavior, but the ultimate evolutionary state of life might not even involve matter. Mos Eisley Cantina notwithstanding, I can't really see advanced life forms replicating behavior from the Wild West, or any other period of our recent history. The pinnacle of evolution may be pure consciousness that has no need for metal ores or slave labor.

[bgwowk]

Most of our models for the behavior of alien life come from our own experience and culture.

Our model of life is variation and selection of von Neumann replicators, known more commonly as the theory of evolution. Culture is itself a product of evolution. That Earth is full of bacteria and people that biologically and culturally like replicating themselves is not an arbitrary attribute of life here. Life everywhere will be the same as long as it's subject to variation and selection.

As long as consciousness requires matter and energy, and as long as there are beings that want more consciousness (immortality being a classic example), they are going to expand outward. According to all known laws of physics, to be still is to die. Of course, according to all known laws of physics, you die anyway, but with mobility it takes longer.

Edited by bgwowk, 30 April 2008 - 05:43 AM.

[JonesGuy]

I think the most common "Filter" would be an overconsumption of energy resources before alternatives are discovered and exploited (either through biological innovation or intelligence). Heck, we might be seeing it today. We're well on the way to exhausting all of our 'low-hanging fruit' (ecological/energy resources) and we certainly need loads of alternates if we're to progress.

[Mind]

Any "filter" would have to completely stop/destroy the process of evolution in order to account for the lack alien life we can observe in the universe. Here on earth we resources are scarce, populations crash. We see boom and bust predator/prey cycles all the time in nature, every day, every year, every eon. Yet this does not stop evolution. Even if humans used up every last drop of oil tomorrow, evolution would continue - so I don't think it is anything close to the type of filter Bostrom envisions.

I still think the only filter that would extinguish evolution on this planet is the accidental creation of a black hole - which is an extremely remote possibilty, but its out there, as we keep pushing the limits of physics.

[JonesGuy]

Remember that Evolution needn't have intelligence as an endgoal. Okay, yeah, it crops up quite a bit in our own history, but mostly from select branches of the evolutionary tree. It's not preordained. Intelligence is like pointy teeth. It can come-and-go in the timecourse of a species.

Of course we'd continue to have evolution on Earth if every drop of oil was exhausted. But it might be geometrically harder to accumulate suffiencient resources to become space-faring without a cheap abundance of resources. If we were to snap our fingers and erase humans, the next species to evolve technology-capable cognition (a hand-wavey term!), might not be able to get space-faring technology because there aren't enough low-hanging resource fruits to pluck. And then we get into self-caused extinction events in the meantime. We're currently at a relatively high level of technology, but it's certainly been subsidized by fossil fuels. We can make it to alternatives, but it's not going to be easy. And if we descend into mad-max tribalism, I don't see a reason why we'd pull back out.

[Mind]

In the billions of years that the universe has been around, any one particular resource shortage causing very tiny short term set-backs to evolution, should not explain the complete absence of life in the universe outside of the earth.

[JonesGuy]

I dunno. I think we're quite lucky that a resource shortage didn't end the first bit of evolution in our planet. In order for 'evolution to continue' after a specific resource shortage, you need to have (already) a multitude of life around that can survive without the missing shortage. A really simplistic point, but you'll never get much evolution on a petridish. The bacteria consume all the resources and then die.

Life seems to be decently improbable. But life that grows in an environment that is large enough for some diversity is of course much rarer.

I don't really know what you mean by "setback to evolution". Evolution doesn't have an endgoal, it doesn't have a direction. As long as you have reproducing life, you have evolution - but that's it. You can kill 99% of a biosphere, but as long as the remaining life can adapt, you'll continue to have evolution.

Now, technology kinda does have a direction. And it kinda has an end-point. Especially with our discussion. But in order for technology to progress there needs to be sufficient intelligence and sufficient resources. If the resources are not sufficient, it's quite possible for the intelligence to disappear from a species through regular natural selection. But remember that intelligence is not predetermined or preordained, it's just one feature of many.

[Shannon Vyff]

I had the funny experience when doing a presentation on my book, at the South West District Unitarian Universalist Church conference being hosted at my church--of a woman coming up to me, having read my book and strongly believing in Urantia herself, that I had been abducted by aliens and was a higher consciousness--I actually didn't know much about Urantia, had heard about it once but just read up on it, controversies and all, reads like a good blend of sci-fi and religion to me. I kind of figured I might get that response from someone reading "21st Century Kids" it was just weird, to have someone live-time, seriously believing it. I nicely told her (a much older woman, in her 70's) all about cryonics--and my hope to see the future, trying to pique her interest Interesting indeed.

[niner]

Most of our models for the behavior of alien life come from our own experience and culture.

Our model of life is variation and selection of von Neumann replicators, known more commonly as the theory of evolution. Culture is itself a product of evolution. That Earth is full of bacteria and people that biologically and culturally like replicating themselves is not an arbitrary attribute of life here. Life everywhere will be the same as long as it's subject to variation and selection.

I don't doubt that lower life forms everywhere in the universe, assuming they exist, replicate to fill niches. However, once a culture is sufficiently advanced to colonize deep space, the observed behavior of lower life forms on Earth simply might not hold. We have yet to observe such a culture, so we don't really know how they might behave.

...according to all known laws of physics...

known so far, anyway.

[eternaltraveler]

If filters are not very stringent, as some here seem to be suggesting, this means that all intelligent alien life universally (or nearly so) converges on non-expansionist principles. A prospect that makes way too many assumptions based on nothing more than wishful thinking. Whereas the alternate possibility; strong filters exist (or have existed until recently), and make intelligent life very rare, matches well with what we know about both about simple replicators and presently known intelligent life.

[niner]

If filters are not very stringent, as some here seem to be suggesting, this means that all intelligent alien life universally (or nearly so) converges on non-expansionist principles. A prospect that makes way too many assumptions based on nothing more than wishful thinking. Whereas the alternate possibility; strong filters exist (or have existed until recently), and make intelligent life very rare, matches well with what we know about both about simple replicators and presently known intelligent life.

Both views make assumptions. The strong filter view assumes that we understand all we need to know about physics in order to understand life, the universe, and everything, and that highly evolved forms of life behave like primitive life.

[eternaltraveler]

If filters are not very stringent, as some here seem to be suggesting, this means that all intelligent alien life universally (or nearly so) converges on non-expansionist principles. A prospect that makes way too many assumptions based on nothing more than wishful thinking. Whereas the alternate possibility; strong filters exist (or have existed until recently), and make intelligent life very rare, matches well with what we know about both about simple replicators and presently known intelligent life.

Both views make assumptions. The strong filter view assumes that we understand all we need to know about physics in order to understand life, the universe, and everything, and that highly evolved forms of life behave like primitive life.

Not really, as we already are von Neumann replicators capable of colonizing the galaxy in a few 10s of millions of years (ie nothing needed more highly evolved than we already are). The only assumption is that we will not inevitably universally transform into a non expansionist type before we start doing it.

[Brainbox]

What about synchronicity and travel distance / time? Traveling from one major centre to another takes as much time as the development cycle of an entire civilisation.

[cyborgdreamer]

Maybe there is intelligent life but they don't care to communicate. Maybe the curiosity that leads humans to seek out other civilizations is exceedingly rare. Just because a lifeform is intelligent doesn't mean it would be motivated by the same drives as humans.

[Brainbox]

Lacking intention to communicate or lacking possibilities to realise a synchronised two-way (or even one-way) communication event due to traveling distance, synchronicity of level of development and light-speed limitations?

Edited by brainbox, 01 May 2008 - 01:37 PM.

[bgwowk]

What about synchronicity and travel distance / time? Traveling from one major centre to another takes as much time as the development cycle of an entire civilisation.

Exactly. This is why there can never be a galactic empire, and why "community standards" are difficult to enforce on an interstellar scale. What if FTL travel is invented? Nothing changes. Just substitute "local group" or "super cluster" for "galaxy". An infinite frontier is the ultimate breeding ground for replicators.

[bgwowk]

Maybe there is intelligent life but they don't care to communicate. Maybe the curiosity that leads humans to seek out other civilizations is exceedingly rare. Just because a lifeform is intelligent doesn't mean it would be motivated by the same drives as humans.

Variation and selection favors replicators that like to replicate. This is as fundamental as the digits of pi. Human values have nothing to do with it, except to the extent that this fundamental principle has also shaped human values.

[niner]

Maybe there is intelligent life but they don't care to communicate. Maybe the curiosity that leads humans to seek out other civilizations is exceedingly rare. Just because a lifeform is intelligent doesn't mean it would be motivated by the same drives as humans.

Variation and selection favors replicators that like to replicate. This is as fundamental as the digits of pi. Human values have nothing to do with it, except to the extent that this fundamental principle has also shaped human values.

Yes, of course that is true; replication is an essential part of a Darwinian scheme. We don't know, however, if Darwinian evolution continues forever. It might be the case that Darwin takes us to a certain point, and something else takes over. Look at the population declines that are occurring in many developed countries. Something non-Darwinian seems to be going on already. If mankind's pinnacle is a superintelligent AGI, why exactly would it care to colonize the universe?

[niner]

If filters are not very stringent, as some here seem to be suggesting, this means that all intelligent alien life universally (or nearly so) converges on non-expansionist principles. A prospect that makes way too many assumptions based on nothing more than wishful thinking. Whereas the alternate possibility; strong filters exist (or have existed until recently), and make intelligent life very rare, matches well with what we know about both about simple replicators and presently known intelligent life.

Both views make assumptions. The strong filter view assumes that we understand all we need to know about physics in order to understand life, the universe, and everything, and that highly evolved forms of life behave like primitive life.

Not really, as we already are von Neumann replicators capable of colonizing the galaxy in a few 10s of millions of years (ie nothing needed more highly evolved than we already are). The only assumption is that we will not inevitably universally transform into a non expansionist type before we start doing it.

Well, maybe the galaxy, but not the universe. And I don't think we could really do even that at our present level of development. We can't even stop fighting amongst ourselves. We scarcely have the money to plink around in the solar system. I think we need to develop our technology and our societies, at least, before we could contemplate colonizing the galaxy. Or did you mean by a few 10s of millions of years that we would first take a thousand years to develop? By that time, we may no longer even be von Neumann replicators, at least out of necessity. Our development is now so non-linear that predictions longer than a few decades are pointless.

[lunarsolarpower]

What about synchronicity and travel distance / time? Traveling from one major centre to another takes as much time as the development cycle of an entire civilisation.

Exactly. This is why there can never be a galactic empire, and why "community standards" are difficult to enforce on an interstellar scale. What if FTL travel is invented? Nothing changes. Just substitute "local group" or "super cluster" for "galaxy". An infinite frontier is the ultimate breeding ground for replicators.

Along these lines do you foresee there always being rivalries between evolved descendants of various groups of space settlers who went off in opposite directions in previous eons? If possible it would seem ideal to postpone deep space colonization until some level of maturity as a species had been developed.