When Are the Intelligent Aliens? | Hacker News Reader

When Are the Intelligent Aliens?

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125 pointsevo_998 comments

Obligatory talking points associated with the Fermi Paradox:

- It takes a very short time in comparison to the age of the galaxy for a single self-replicating probe to result in a descendant probe visit to every star. A few million years. This means that you cannot really argue plausibly that all civilizations fail to do this - it would take trivial effort for just one faction within just one advanced civilization to set this underway. It's quite clearly the case that we will do it when we can.

- There is a proposal I recall reading that suggests all colonization/self-replicated expansion is patchy in a sort of fractal way. You're always going to get sparse frontiers and empty real estate.

- The Great Filter. http://en.wikipedia.org/wiki/Great_Filter

- The Simulation Argument (Bostrom variant). http://en.wikipedia.org/wiki/Simulation_hypothesis

- The Drake Equation http://en.wikipedia.org/wiki/Drake_equation

- Where are the macrostructures? We don't see Dyson spheres or other evident macroscale engineering. Everything we can see so far looks natural. This is more troubling than an absence of detectable communications. There are any number of ways we can think of for interstellar communication networks to exist and yet be undetectable by us at the moment, and then there are no doubt all the ways that we can't think of.

- Agents responsible for the Fermi Paradox through suppression of nascent intelligence are a popular science fiction trope. First one to the top kills off the rest as they turn up. (Berzerkers, Wolves, etc). It makes for good plotting, but in reality this suffers from all the same issues as economic monopolies and monocultures - i.e. without some sustaining outside influence they are fragile and short-lived, prone to defection, being undercut, and out-innovated from a blind spot. So it's not plausible to suppose that we are randomly in a period of suppressive monopoly.

>Where are the macrostructures? We don't see Dyson spheres or other evident macroscale engineering. Everything we can see so far looks natural. This is more troubling than an absence of detectable communications.

Assuming a Dyson sphere was nearby, how would we detect it? What would it look like? If it's able to make use of most of a star's radiation output, wouldn't that make it very difficult to see? It wasn't until recently that we were able to detect black holes and I'd have to guess a Dyson sphere's star would be much less massive and energetic than that.

Even a Dyson sphere can't just swallow the star's radiation. It makes use of a potential gradient, which means it would have to radiate away some energy on the outside. This would probably show up as, say, a brown dwarf. Still, if it's not in our direct neighborhood the chances of us discovering it are even lower.

The Wikipedia article defines a Dyson sphere as a system of orbiting solar-power satellites meant to completely encompass a star and capture most or all of its energy output.

I think there is a misunderstanding here about what that means in practice. Thermodynamics still applies. Energy has to be harnessed across gradients. Even if they wanted to only collect visible light, they'd have to radiate the heat somewhere.

Unless the engineers are concerned about detection and choose somehow to radiate in only one narrow direction, pointed away from any nearby stars.

That's true, and stealth is an interesting proposition. However, there are probably easier methods of preventing detection, such as not building a giant structure in the first place. Also, even if they manage to radiate away most of their waste heat, they'd have to assume eventual detection by an advanced civilization. Sure, with exponential effort you can always get infinitesimally closer to being virtually undetectable, but is that really feasible?

In the end, it's certainly not impossible that a civilization would go to extreme lengths in order to hide its enormous artificial structures. But the real issue is: why would all civilizations hide in this way? And if it turns out they do all have elaborate stealth tech in operation, that means there must be an incomprehensibly huge threat out there - which in itself might be the answer to why nobody is calling us up.

Have you read Revelation Space by Alistair Reynolds? If you haven't, you really need to.

No. why do I need to?

Revelation space is a speculative fiction novel set in the far future during the golden age of space colonization. Spoilers ahead.

Throughout the novel there's alien civilizations that use different kinds of way to cloak constructs and settlements. Examples include devices like artificial moons and holographic, multi-spectral holograms that emulate gas giants to hide stuff inside.

The one I think andrewflnr may be referring to is a device that one race used to cloak entire regions of space to hide their civilization from technologically superior aggressors. Essentially they set up variable-gravity devices at strategic points around their region of space, and had the devices resonate to build 'waves' of gravity that would constructively interfere at a massive scale at the borders of their space, which would essentially tear any intruders apart using the amplified+alternating gravity waves. Several million years in the future, observers/scientists of other races on the outside would dismiss these chaotic space regions as an unexplained anomaly.

Mostly, I was thinking of that whole theme in relation to the "incomprehensibly huge threat" thing Udo mentioned. If you're talking about Shrouders, I don't remember that method of using gravitational waves being mentioned. Did you hear that somewhere else?

So, first you build a Dyson sphere, then you build a system to cool the outer surface of your Dyson sphere to near 3 Kelvin (except some narrow directions in space, where you radiate your excess heat).

Now the interesting question is, is the energy you capture from the star sufficient for running this cooling system of yours. I have no clue.

Let's see if someone in Physics StackExchange could answer this:

http://physics.stackexchange.com/questions/69649/thermodynam...

The black space is at about 3 Kelvin temperature. A Dyson sphere would necessarily (the star inside would heat it) have a much higher temperature than mere 3 K above the absolute zero. Thus it would radiate heat according to whatever its temperature, and be quite distinct compared to the cold back space background.

This is assuming that the creators of the Dyson sphere haven't also figured out how to absorb the heat energy with extremely high efficiency.

You are assuming they'd have figured out how to break the laws of thermodynamics as we know it.

> break the laws of thermodynamics as we know it

Not a giant leap to imagine for a species that's been able to construct a Dyson Sphere in the first place ;)

I don't understand why any civilization would ever build a Dyson sphere.

The sphere would be dynamically unstable in the gravity field of the star and station-keeping would be expensive and hard to coordinate over the lightspeed delay.

And stars are terrible energy sources--they're huge, diffuse, inefficient, and not portable. It would be much more useful to build fusion generators to order.

If you've got the technology and infrastructure to build a Dyson sphere, is there that much difference between a star and a fusion generator? Maybe the reason we've had so little success with fusion generators is because they have to be built very big to keep them lit.

Considering the vast time scales and the vastness of the galaxy, the most plausible explanation for me is still that we happen to live in a historical dark zone.

But it's fun to speculate since any number or combination of events might be responsible for the absence of fellow civilizations.

There is a Great Filter argument that tries to say that we're really, really, really special or that our civilization-ending event might still be in the future. Since we're speculating, I don't think the biological filter argument is very plausible. Historically, we have always been proven utterly wrong after presuppositions of specialness. On the other hand if the Filter is ahead of us, it would have to happen very soon - good candidates for this remain AI, nano tech, or plain apathy. But then again assuming these would be an issue for every advanced civilization seems a stretch.

The simulation argument only makes a difference if the simulation is specifically targeted and limited to simulating us humans. If it's just a universe in a box, it wouldn't tip the scales either way.

The Drake equation and its cousins are nice, but they contain a lot of unknowns. Still, it's a good tool that shows how easy it would be to have statistical fluctuations resulting in a dark epoch.

I personally like the Agents of Suppression theory as well. It wouldn't even have to be another civilization suppressing everything directly - it could just as well be a completely automated armada of leftover killer robots. In my opinion it's one of the more plausible hostile alien invasion-stories as well: one day, we'll fulfill a set of unknown criteria and are simply tagged for extermination. But again, they would have to come our way pretty soon, like in the next 1000 years (which is not a lot of time). This would require a pangalactic drone network for observation and a fast local strike capability. Not completely unfeasible, but not exactly obvious either.

The absence of large-scale artifacts is also interesting, but we have to ask ourselves if we could even detect, say, a ring world or a Dyson sphere if it was in our direct neighborhood (and chances are, it wouldn't be that close). Also, intelligent civilizations would not necessarily produce them. However it would be enough if a few did build huge structures. Again, I don't think we're advanced enough to detect them (or their absence) with any confidence.

> the most plausible explanation for me is still that we happen to live in a historical dark zone.

I am no expert, but I remember reading somewhere that our Sun is among the first generation of solar systems that were born with enough heavy elements to make life based on carbon, oxygen, nitrogen, occasional iron etc. possible.

That there first needs to be some generations of starts going nova so that the stars have generated the heavier elements, and then the supernova explosions have to spread these around to that then the new interstellar clouds have enough of these element when they collapse to next generation stars and solar systems.

Yes and no. While our solar system is sufficiently metal rich, we're not especially early. There are systems of comparable generation that are younger than ours. This depends more on where you are in the galaxy than when you are.

Another argument I heard, compatible with life being a fairly easy reaction;

A loglinear graph tracing the genetic complexity of life reaches zero about seven billion years. Obviously this implies an extraterrestrial origin of life theory. But it would also say life came into existence half-way into the big bang expansion and has been gaining complexity ever since. We are the result of this. But there's no reason to think there are other lifes that have that much of a head start. Thus it is not surprising that the manifestations of other intelligences haven't appeared.

http://pacojariego.me/2013/04/21/life-before-earth/

It's a logarithmic graph. It doesn't go to zero. It just goes to 10^0 which is 1. And in this case one billion units of whatever. -1 is 100 million etc..

Given that the axis in question represents genome size, I'd guess "bp" stands for "base pairs", not a billion units of something...

I think it is quite likely that after discovering mind uploading technology (assuming such a thing is possible), advanced civilizations lose interest in the "boring" and "dangerous" space-time world. This idea would probably fall into the "Simulation Argument" you mentioned. But in sll honesty, I don't think humanity will ever have a satisfying answer to Fermi's paradox.

Without some sort of technology that renders them truly immune to the "dangerous" space-time world, they won't be able to ignore it, because if their sun burps they all die if their simulators get destroyed. Even if they "all" happily charge into simulated bliss, a residual caretaking system should be visible as it performs the necessary cosmic-scale engineering to ensure that the simulated ones don't get wiped out by a cosmological crisis, such as a supernova. Further, any such society will still end up wanting more and more energy, so we ought to be seeing Dyson shells or something pop up, in the continuing absence of any apparently way of converting mass directly into energy.

We don't see any of these things. And the amount of "space" left in physics for some sort of true escape hatch that might let us escape fully into an impregnable universe of our own devising or something keeps going down and down.

I consider the lack of cosmic-scale engineering to be a much bigger problem than mere inability to detect signals. A lot of it isn't even that "hard" per se, because what's impossible on the year or century scale becomes feasible with only very realistic projections of what self-replicating technology can do if you can put in millions of years of continuous effort. And a lot of this stuff would both be visible, and essentially necessary; if life is so inevitable and intelligent civilizations so likely, quite a few of them will find themselves dangerously close to an incipient supernova on an uncomfortable time frame, and they ought to be doing things about that. Very visible things. It's just too perfectly quiet out there.

The ground assumption in all of this is that we have some comprehension of the technological end-game / plateau. I.e. that a civilization far more advanced than our own will still care about solar energy and EMR communications. Who is going to build a Dyson Sphere for fun? We could be totally wrong about this. We probably are.

The other possibility is that there's not much more technology for us. Can we build self-replicating probes that can operate, without maintenance, for thousands of years? No we can't.

So we have this wacky set of assumptions -- that alien civilizations will be more advanced than us in certain peculiar ways (able to build self-replicating probes and/or Dyson spheres) but not in others (having the primitive needs and side-effects that we do). This is a tiny corner of a very large set of possibilities.

Maybe the aliens simply build new Universes to order and leave their birth universe behind because it's (a) less hospitable than their new "air conditioned" universe, and (b) it's unethical or boring or pointless to colonize a universe full of new potential civilizations.

Folks need to read some less mainstream SF. I like Clifford Simak's "City" where the vast majority of the human race emigrates to Jupiter to live as hunter-gatherers (because Jovian life is so much more pleasant than human life) leaving Earth to the dogs, robots, and ants.

To be clear, "self-replicating probe" includes all technologies that can transport, at a minimum, human genetic material, a record of all human science and technology to date, and creche-building technology to a distant star. So a few grams or kilograms of bootstrap molecular nanotechnology, computing material, shielding, some form of reaction engine, fuel for deceleration, and fired by the hundred from a solar-system-wide array of magnetic accelerators or accelerated by lasers. More likely the human genetic material will be absent in favor of emulated human minds.

Or think about actual humans, something large that we'd recognize as a starship, and a vast amount of antimatter. Much more spectacular, and much less likely, because of the amounts of energy involved in getting the job done - and all that just to ship things that could be build on site.

The point being that even if you say that we'll never build self-replicating technology (which is essentially the same as being a vitalist) then given the time scales involved - if every step in the probe network takes 1,000 to 10,000 years of resting time to build a complete organic human civilization before kicking off the next series of probes - it still requires a short time span to visit all stars in the galaxy in comparison to the age of the galaxy.

You're still making ground assumptions that this kind of technology turns out to ever make sense. If we invent transdimensional warpgates in 50 or 500 years, there may never be a faction left over that wants to play with steam-powered genetic plagues.

The idea that you can seed the universe with civilizations in the manner described is highly dubious. You're assuming someone advanced enough to do this yet primitive enough to want to do it and that "it" works at all. Suppose that the galaxy produces one star system in a thousand with a suitable planet, and the seed has a one in a thousand chance of actually producing a successful replication. (Both of these one in a thousands seem to me to be quite optimistic.) The equations look a lot less deterministic.

This is a good summary. One of the missing pieces is we don't know what the minimum set of combinational factors are to create "advanced" civilization.

The scare quotes for advanced here are that two incompatible definitions for civilization quality compete for the nominative "advanced." In the current context advanced means we've developed machines that carry us into space, we can create habitats to survive in even when our surrounding habitat is inhospitable and we leverage natural resources to create excess food. An alternative context for "advanced" is that your civilization exists in balance with the other processes on the planet, you don't create anything that that wouldn't be created by natural processes inherent in the system, and your resource utilization is at a rate that does not exceed its replenishment rate. Further you explicitly do not use any resource that is not naturally replenished.

In the context of that dichotomy, the question might be "Why didn't the Dinosaurs develop space flight?" They lived on the planet for millions of years before we got here, there is evidence that their cognitive capacity was at least as large as ours, and some species had the ability to manipulate matter at least as well as our paleolithic ancestors did. So why didn't they build giant Dinosaur cities, grow Dinosaur food, and build institutions of higher learning? Depending on your timeline we went from struggling ape to SpaceX in 3 - 5 million years. They had 165 million years to figure it out. Why were they even on the planet when the asteroid hit, and/or why didn't they do something about it before it hit? Using Dinosaur lasers or something.

Depending on how you count we've gone through 5 to 7 nearly total extinctions on this planet. What made this last one special? What is the key set of things that have to be true in order for life to go from being intelligent to manipulating everything around it in its environment to serve the will of that intelligence?

They are complex questions. Great fun to contemplate on camping trips, while under the influence, and when you've run out of other 'safe' conversational starters.

One of the semi serious answers is you need a peculiar and somewhat unusual arrangement of land and sea to create a long series of oscillating ice ages every ten thousand years or so (to one sig fig), which is just the right wavelength to very strongly evolve intelligence and civilization. Without that intense adaptation pressure you don't get growth. With enough of it, you get us.

Interesting idea, I'd like to know more. Is 'The Ascent of Mind' by William Calvin what you are referring to?

http://www.amazon.com/exec/obidos/ASIN/0595161146/

My apologies, I messed up by not providing things to google for.

There is a hyper specific (perhaps overspecific) theory by a geologist named Matthias Kuhle with many publications from vaguely the 80s thru the 90s. He's probably the most "famous" of the proponents of the whole plate arrangement theory.

The general idea that plate tectonics causes the overall cycle of ice ages doesn't seem very controversial. What the geologist types seem to fight over a lot is Exactly which of numerous causes contributes Exactly what percentage of the positive feedback loop in Exactly which numerical model.

For example Kuhle has a lot of publications about the tibetan plateau being a great place to bootstrap the glacial positive feedback loop. There's others who get all excited about the precise location of the continents affecting the flow of ocean currents pushing warmth up north... The current that pushes warm water to England so its warmer than alaska, the current that used to flow over Panama but can't anymore, the current that used to not exist over the Bearing straits in Alaska but exists now. Then theres the other folks who get all wound up about continents being over a pole (like antarctica) or landlocking a polar ocean (like the other side, the north pole) leading to glaciers. There's something of a minority opinion about "really big continents with mountains in the middle covered in glaciers"... think America's Glacier National Park as visual model, other than its all melting right now.

I don't know anything about the book you linked to, although it's reviews make it look interesting.

That's all very fascinating! Thanks very much for the reply.

Right, we simply don't know the conditions to generate a advanced civilization. We're certainly not it (yet) -- at least in terms of the characteristics we're expecting space-faring extraterrestrials to have.

There might be billions of worlds full of dinosaur analogs running around happily eating and growling till their star burns out...and that might be all that you can expect out of life in the general case when it happens.

"Why didn't the Dinosaurs develop space flight?" Why don't we? Again, in absolute terms of the characteristics we're requiring of an alien civilization, we're not really any closer (in measurable absolute terms) to visiting Vega than a struggling ape is. The furthest distance a human has ever traveled off of the Earth is very slight navigational/rounding error when going to another Star.

I think you don't give us enough credit :-) We have developed enough technology to leave the planet and walk around on our Moon. We are, perhaps within a decade, going to have that capability again but with a much higher level of base technology. While it would be unlikely for Dinosaurian satellites to have remained in orbit for millions of years, anything they left on the moon would still be there.

"There might be billions of worlds full of dinosaur analogs running around happily eating and growling till their star burns out...and that might be all that you can expect out of life in the general case when it happens."

This is the essence of the Fermi paradox I believe. (And I've ordered a copy of the book mentioned below, it looks intriguing) So what hypothesis could support billions of iterations of 'life' evolving into the multicellular form we see today and in our past, and so few evolving technology?

I totally agree it is a somewhat useless question to ponder but I can't help it.

> So what hypothesis could support billions of iterations of 'life' evolving into the multicellular form we see today and in our past, and so few evolving technology?

Probably just a function of environmental input and enough generations optimizing along directions that matter more for species propagation than a large, energy burning cognitive organ. Keep in mind, it appears that Human level intelligence seems to have (so far) only evolved maybe a handful of time maximum in planetary history...and AFAWK only along a fairly specific mammalian family line that happened to live on part of the planet with fairly specific thermal/environmental and energy availability properties.

On a planet slightly warmer than the Earth, the dominant species might be selected to have heat management organs we're not even aware of; or a planet with more landmass vs. ocean, the ability to handle dry climates; or a planet with two moons and higher gravity an efficient metabolism and ambulatory system...some kind of reptilian slug perhaps?

Are savannas necessary to culture space faringness? Or could a planet with no moons, shotgunned with equally dispersed Guam sized islands provide the necessary conditions?

It's useless, but an incredibly fun thought experiment.

I quite like Geoffrey Miller's theory that the human brain is primarily the result of sexual selection rather than natural selection - the hominid equivalent of the peacock's tail.

i find that theory to be unlikely to be true, because its usually not the smart guys but the buff guy that gets the prettiest girls (at least, that is the cultural belief).

Product of our culture more than anything. We'd all be buff if we barely ate and were outdoors/hunting all the time.

I disagree with your characterization of our accomplishments. Getting to the moon isn't just a matter of distance from earth's center, it's a fundamental difference in kind from anything done before by living things on this planet. We could, today, launch a craft in the direction of a star. It would eventually get there, it would just take a long time.

I think the distinction is that getting something going with enough velocity to escape the gravity well of the Sun, and in a vector the points it towards another star's gravity well is different than getting living representatives from a civilization around one star to another.

Philosophically, even an Ark ship, with technology capable of sustaining a population of humans for a million years wouldn't fit the bill since I'd argue that by the time the descendants arrive they:

a) would probably not be the same species anymore, having evolved over thousands of generations for ship life

b) wouldn't be the same civilization anymore, having developed their own micro-civilization in the intervening years -- they'd no longer be representatives from their home civilization...any more than I as an American can be a representative for the European civilizations I am descended from when I travel to Asia

c) their home population and civilization will have evolved and diverged from the Ark's population and civilization regardless of the Ark's conditions. Even if the population on the Ark was put into some kind of suspended animation for the length of the trip (preserving the both the original species and civilization) they'd be representing a species and civilization that no longer existed

Upvote for dinosaur lasers alone.

Where are the macrostructures? We don't see Dyson spheres or other evident macroscale engineering.

This might be a stupid question, but could the Red Square Nebula be considered a candidate? http://en.wikipedia.org/wiki/Red_Square_Nebula

I can't say but whenever I hear about something that 'defies' theory [n] I like to take a moment and. Imagine that the anomaly in question was constructed by unimaginably developed beings. Of plasma, computronium and other unmet exotic concepts. Powered by rainbows of gamma radiation from stars coerced into the bellies of super-massive black holes.

Then I tidily put away the thought because I know it is not even falsifiable, I don't bother assigning probabilities like unlikely. But the short moment (following such news) of delight at contemplating exotic entities so foreign, that words like conscious and alive are inapplicable is a healthy pastime I much enjoy.

[1] http://news.nationalgeographic.com/news/2013/01/130111-quasa...

Well, it is probably natural. But if I was tasked with building a nebula-sized art project, that's what I would do.

Though, I'd also put three planes intersecting the conical surface and showing off the three different conical intersections, then inscribe their equations on a planet orbiting the star at the centre.

Maybe interstellar travel is just really hard even with technology far beyond our own.

Is it possible nearly all advanced species have gone to great lengths to hide their existence ? The more advanced, the better at hiding?

Perhaps gravity is the only radiation they cant hide, so all we could detect of them is 'dark matter'?

My favorite is: We're first. Assuming we make it out of the solar system and so on, then just imagine the practical jokes we get to play on future civilizations: Whoopee cushions crafted out of gas giants, mysterious "ruins" that have no bloody purpose at all, ancient stone tablets that end with "Assuming a spherical cow in a vacuum..."

Some archeologist, 20 millions years hence: "Oh god, not /these/ forerunners again."

It wouldn't be all bad, being first.

I used to wish for this every single Stargate episode. Stargate needed a race of Q's.

Our radio emissions aren't that visible, there is a horizon, so to speak, where your radio signals attenuate to be indistinguishable from background radiation. For our TV transmissions I believe this to be no more than a handful of light years. As tech has been increasing we've been putting less power into our transmissions and thus reducing that horizon. Even high powered military radars aren't typically banging away into the sky in the same way they used to.

Then you've got the fact that the env for coms has been becoming increasingly hostile anyway. Long term quantum computing is pretty much a certainty, and when that happens quantum encryption seems like it's going to be the only workable form of coms for anything you want to keep quiet. Even if you assume that in the West it'll only be places like NSA and GCHQ and so on who have one - China's going to have one too, and do you really think they're not going to use it against commercial systems? People will have to move to quantum encryption - you're just not going to be able to do business without it.

So, I wouldn't expect us to keep using the airwaves very much. I expect the future of airwave use to be primarily relatively short ranged point to point transmissions.

The visibility for radio transmissions, even if humans survive a million years isn't, I think, going to be a million years, I'd expect it to be more like 100. Thus - though I don't know how they calculated their number - I'd make the back of the hand odds that someone examining our planet randomly would pick us out not 1 in 5,000 but, instead, 1 in 50,000,000.

And since we're not going to get 50,000,000 civilisations within the handful of lightyears before our signals have attenuated down to the background... I'd put the odds heavily against anyone seeing us on that basis.

Whether someone will pick up the composition of our atmosphere and aim a more powerful beam in our direction I don't know. But it makes it ... something that the other civilisation would have to decide to do. And then you're dealing with - does it actually make sense to let other civilisations know that you exist? What are your potential gains when balanced against the risk of relativistic weapons and the like?

Kraus's famous classic 'radio astronomy' textbook had some comments about this topic toward the end. If I recall correctly it was a couple light years for analog NTSC. Nice stable transmitter, satellite disciplined carrier freq toward the end, and the doppler as the earth rotates of a zillion signals gives the little green men something interesting to think about. Planetary radar, IF aimed directly at the target, had much better range, but analog NTSC television had much better coverage over the whole sky.

The radio detection of the earth by broadcast analog NTSC TV carriers has already ended. The article author specified it as a million years. We got about fifty instead. If the LGM are watching our analog TV carriers and the SNR is less than 20 dB or so, there is no way they'll see digital as a discrete signal, nor will they likely randomly guess the correct signalling types/codes.

The meta issue is as a species we're really good at thinking our time is special. 100 years ago watching a spectrogram of analog AM video carriers would have been unthinkable futuristic not even rational to discuss, 25 years ago it would have been a pretty good idea, today its ancient nothing but static, no body would do something so anachronistic.

This misbelief in the importance of your time is closely related to one of the funniest atheist arguments, which is so intellectually unthinkable its rarely discussed. Even the slightest gaze on religious history of the species shows that before the birth of a prophet or whatever, people really thought they had it all figured out almost as well as after. Because this mis-design-pattern has repeated itself with pretty much all religions in the past, I'm sure it will happen again in the future, so simply deciding to believe in nothing until the true prophet is born in 100000 years is the most rational decision. In fact over 100000 years we'll probably have about 100 prophets, all of which, however temporarily, being considered the last word in religion... Its sometimes called the patience atheist argument, or a few other things... Why, everyone knows the best and most important and most correct culture to ever exist, in the past, or more importantly in the future, is now, of course.

Here's a graphical representation of that radio sphere you talked about: http://www.geekosystem.com/human-radio-broadcasts/

My analysis: the time period in which a civilization goes from "present" to "owning the observable universe, rearranging the stars" is short. The first civilization sees an empty sky. The second sees red-glowing stars tapped for all their negentropy, Shkadov thrusters rearranging them, and probes whizzing from star to star, disassembling them for usable mass and building computronium.

My conclusion is, if you don't see that, you're the first.

And if you did see that, you were damn lucky to be born at just the right time to see it before you get annihilated by the oncoming intelligent matter transformation.

Yeah, because the probability that a random alien would recognize "humans would rather not be reassembled into somebody else's compute substrate" as ethically relevant is slim.

Hybrid Theory: Reconnaissance nanobots are dispatched to the planet which is to be disassembled, soaking up every piece of data imaginable. The planet is then converted into computronium, which as a background thread, runs one or more simulations of that planet's hypothetical future, in order to extract any possible scientific value from the developments of the native species, or just as a simple curiosity.

If this is true, we were likely destroyed a long time ago, and we now live in one of those simulations. Any cosmic activity outside of our solar system is a mere fuzzy approximation, and even if we develop interstellar travel technology, we'll hit some sort of "Truman Show" wall if we try to leave our imaginary sandbox.

Makes you curious to keep watching the Voyager probes, does it not? :)

Considering how many life forms are on this planet, and how few of them who provide decent conversation, what are the chances of discovering Vulcans or Wookies? Most life we eventually discover might be more exciting to entomologists.

> Most life we eventually discover might be more exciting to entomologists.

You say it like it wouldn't be fascinating just by itself. About 70% of Earth's surface is covered by water and more than 90% of the ocean still remains unseen by human eyes. We don't even know what incredible creatures could be living deep in the ocean let alone on another planet!

Oh and by the way, even the fact that we can't have a "decent conversation" with other species doesn't mean they are not intelligent (whatever that means). Most people would considered dolphins stupid but it seems that they could be communicating with each other using some kind of sono-visual language and maintain quite complicated social structures.

Didn't mean to sound condescending - it would be very fascinating, especially if we would find evidence of common ancestry and other similarities. Wouldn't exactly be the cantina in Mos Eisley, though.

However, as you point out, we live in the middle of an enormously rich biota need not stare at the stars to find new life forms. That's quite amazing.

The way I view it, by definition someone has to be first.

We just don't know enough about all the variables, such as noted by others in this discussion the probability of evolving to sentience, to state with any confidence that we can't be the first in our galaxy or the portion of it that we're looking at.

>The way I view it, by definition someone has to be first.

no :). That is the beauty of this Universe - global full order of things on timeline isn't possible. Specifically space-like separated events don't have a preferred order, i.e. given 2 space-like separated events A and B, both statement - A precedes B and B precedes A - have the same validity, basically it is meaningless to talk about their timeline order.

Just because they are space separated events does not mean you cannot give assign them chronological order. Can't you just simply refer to a literal universal chronological reference point (i,e Big Bang) and then achieve successful ordering of events? For example: Civilization A achieved space flight x time units (whatever time units, such as Planck time unit) after Big Bang, and civilization B achieved space flight y time units after Big Bang?

Without getting too deep into this issue of relativity, let me point that that the Milky Way is per Wikipedia "100,000–120,000 light-years in diameter".

Rather than go down to Planck level granularity, if reaching space flight, or better, serious engineering works in space that are visible from afar is a low probability thing, with time scales say in the millions of years, then "first" will I think do for our purposes.

>For example: Civilization A achieved space flight x time units (whatever time units, such as Planck time unit) after Big Bang, and civilization B achieved space flight y time units after Big Bang?

as long as special relativity is applicable, for space-like separated events A and B, there exist frames of reference such that A is at x time units after Big Bang and B is at y in one frame of reference, and A is at y and B is at x in the other frame, ie. in reversed order.

Yes, but for any such reference frame if you know the distance between the observer and A and B, then after observing both A and B you can still deduct the true chronological order. But I get the parent's point now, for our purpose of observation there is no point figuring out this "true chronological" order anyway since a civilization could have achieved space flight 100,000 years after Big Bang but is at a distance so far away from us that the information may NEVER reach us due to universe expanding.

someone has to be first

According to whom? See https://en.wikipedia.org/wiki/Relativity_of_simultaneity

I have no doubt that there is other intelligent life somewhere in the universe. That said, with the vast distances involved, I suspect that we will never encounter them.

Intelligence may not be adaptive from the gene perspective. One can see a large number of plausible reasons this might be the case by observing human society and humanity as a whole. If it is in fact true, appearances of that trait would likely be rare and short lived across the universe.

Intelegence is clearly adaptive when you consider humans have the widest habitat range of any multicellular organism on the planet. When you consider people where thriving in Alaska at the end of the last ice age the idea that climate change or industrial pollution is going to do us in is overblown. A full scale nuclear exchange may doom modern civilization but modern civilization showed up fairly quickly after modern humans evolved. The only real man made threat would be some sort of perfect disease designed to kill everyone an even a that is likely to fail.

We clever primates rose to dominance out of the ashes of 75% of the species on the planet. It seems entirely possible that we never would have achieved this sort of reach if not for the K/T event.

65 million years is a long time even on evolutionary terms. Without K/T you would still have the dinosaur to bird transision because it's an useful nich to be able to fly. mammals evolved with dinosaurs and things may have followed a similar path even without K/T. However, Dinosaurs could have easily followed the same path as humans by filling the same ecological notch of squirls, then spider monkeys thus gaining thumbs to efficently climb with increased body weight. After that increased body weight and brain capacity are useful and suddenly your using tools.

PS: Birds have limited brains because of weight issues but their neurons are just as evolved and capable as primate neurons.

The other great apes are quite intelligent and occupy the top spots in their ecological niches. Bottlenose dolphins pass the mirror test for self-awareness and appear to have individual names [1], and are at the top of their ecological niche. Elephants pass the mirror test and are at the top of their ecological niche. Octopuses are surprisingly intelligent for invertebrates, and are among the top predators in their niches. In the blink of an ecological eye, intelligence has started showing up at the top spots of the food chain across a diversity of different niches. Just because we haven't seen it before (e.g., the top dinosaur intelligence, the genus Troodon, only had a brain-to-body mass ratio comparable to modern birds [2]), doesn't mean it isn't adaptive - only that it took a while to evolve. Life existed for a pretty long time on Earth before it started running around on the land, too. Doesn't mean running around on the land is maladaptive.

[1] http://www.wired.com/wiredscience/2013/02/dolphin-names/ [2] http://en.wikipedia.org/wiki/Troodon

What about a captive isolated environment that "forces" adaptation such as, tool use in birds & other animals.

It would suggest cognitive thought or at least, competence is a "mutation" forced upon the life-form by environment(s).

Time would only play a miniscule, but essential part in that process until the life-form figured out time doesn't seem to matter too matter.

I would guess that most civilizations don't use detectible radio communications for very long. Look at us now. Everything is going over the internet. I doubt that these signals travel much from Earth before dissipating to the point of being undetectable.

Perhaps the emergence of life itself is The Great Filter. I hope it is.

The Fermi paradox is useful in that it shows us that something must be wrong with Drake. It is more likely to be something wrong in one or more of the assumptions, than with the empirical facts. I think the problem is with notions of "advanced" and "intelligent". When it comes down to it, that really just means like present humans. There is nothing inevitable nor qualitatively special about technology. It is just one particular evolutionary advantage which has helped one particular species on one particular planet. Dwelling on why there seems to be nobody else out there exactly like us is just narcisistic; a super-sensitive kid pining for their one-true-and-never-met soul-mate, when they are surrounded by potential lovers. These hypothetical advanced aliens seem like the scholastic pinhead angels of this age of reason. Having said that, life in general is utterly amazing. I have no evidence for this, but I imagine that if and when we humans discover extra-terrestrial life, we will find that some living organisms on this earth have already "known" about it for eons.

Maybe I'm projecting too much human behavior on unknowns, but we've pretty much come to the conclusion that we when run into an uncontacted tribe of humans, we try to stay completely hands off.

Perhaps we shouldn't discount the possibility that's a universal evolutionary stage, and that there's just some sort of 'prime directive' type thing keeping any life from contacting us yet?

http://en.wikipedia.org/wiki/Zoo_hypothesis

Or perhaps the best move is to hide. With such a large range of time, almost any species you encounter will be either incredibly primitive (thus not so interesting, and not receptive to your signals), or tremendously advanced, and a serious existential threat. Faced with this choice, it's quite rational to avoid looking for the neighbors.

This doesn't really apply to the self-replication wave, but it is an argument against active SETI.

I think the problem is that we are scouring the radio waves while every really advanced society uses quantum entanglement for communication.

Same old invalid assumption error as is always made, and which underlies thinking the Fermi Paradox is a paradox. A mistake so universally made by humans that it's probably an instinctive cognitive bias - assuming 'intelligent life' implies 'intelligent species' and nothing else.

The truth is, technology is incompatible with species. As soon as a race becomes able to competently engineer genes (or whatever serves to encode their form) suddenly there is no more 100% cohesive 'species', but also a number of self-engineering unique entities. Who's interests typically conflict violently with the remaining original species. When one or more of these entities survive they eventually become space faring individuals, wholly transcended from their original species-derived intellectual nature and physical form. Of course there are many pitfalls, and in some cases the outcome is 'everyone dies'. But in NO case, can a technology wielding species ever do so for more than a very brief period.

Space is full of intelligent life. All of whom are immortal, universe-roaming individuals, none of whom have any kind of species-survival related instinctive thought habits. There are no interstellar empires, no expand and conquer instinct-driven behavioral rubbish. Only Travelers.

And most certainly, from moral principles deriving from the fundamental nature of information, intelligence and fun, NO passing of significant information to any instances of embryonic planet-borne life forms. No more than you'd consider poking a fetus with a pointy stick. Horrible idea, nothing useful could come of such actions.

Btw, the 'Grays' are open-source gene-ware, manufactured intelligent semi-independent remote manipulator/observer peripheral units of visiting Travelers. They are not 'species', rather a range of production models. When they do interact with humans they lie about their nature and origin, since humans are not supposed to be handed the truth. It would interfere with humans' natural progression towards transcendence (or self annihilation.) The only thing that matters is that the human 'story' remains uninfluenced by exposure to external truth. But there's nothing wrong with you working it out for yourselves.

Here's a little story: http://everist.org/texts/Fermis_Urbex_Paradox.htm

I find the definition of intelligent life, specially as given by astronomers, amusing. Looking for a second carbon-based lifeform, in a planet identical to Earth, beeping out on the radio spectrum, in the same time frame as us? How cute.

Meanwhile, we miss a bigger definition of life right under our noses. Unfortunately reductionism is ingrained in science.

Well, don't keep us in suspense. What definition would you use?

Certainly one that doesn't put lifeforms in a lifeless universe like actors in a stage.

Astronomers should be the first to propose that, since they know how the carbon molecules in them can be traced back to a nebula, just like mitochondria can be traced back to a life form from Earth's early days. The parallel is obvious to me.

The Gaya hypothesis, for instance, gives a saner view of how the biota and biome are the same thing, and still, gets dismissed as New Age stuff. And that's talking just about Earth, mind you. Expand the theory to the entire Universe and you will be ridiculed by Dawkins himself, even though this "hunch" is persistent.

Many past thinkers had a gut feeling about this, with less data than we have today. Read about "Anatta" (Buddha's concept of "not self"). Or read about "Tao" (Lao Zi's concept that has surprisingly parallel to what we now call "Big Bang" and how nature works out of pure probability). This is all surprisingly insightful knowledge, made out of pure intuition.

But because post-illuminism abolished holism, we end up looking for analogous of humans with radio antennas, Dyson spheres, among other increasingly ridiculous things, and that gets called science. Meanwhile, ideas like Universal Darwinism are ignored.

Well, that's why I find that amusing.

We're actually not even clear on what conditions are necessary to generate intelligence capable of interstellar travel (or even interstellar communication)...humans aren't even really capable of it.

There might be billions of rockballs in the galaxy with life and intelligence at some level, maybe even up to the level of say a dolphin or a dog or even a chimpanzee on the high end. This might be the status today, or for the last hundred million years and the next hundred million. But those planets (and other orbs of lifebearing rock) aren't going to be sending spaceships our way anytime soon.

But let's suppose there's a million space capable intelligences spread out equally in the Milky-Way...what's the probability of them giving our particular system any interest whatsoever? The Drake equation is a fine estimate for the number of civilizations, but not for the probability that they'll contact us.

So we are getting close to the possibility of detecting (with some kind of specrometry) an exoplanet with an atmosphere with a chemical composition that is far from thermodynamical equilibrium.

It would be a thrilling feeling to know that there, maybe 20 or 100 light-years away, is such a planet, hosting at least microbial or algal life.

I'm not convinced we know enough to do this. A planet in the right temperature with a high-oxygen atmosphere might just be low-carbon and high pH, such that the entire surface is oxidized and glassy and the liquid water carries a pH in the 12s.

What's great is, we're about to get a whole lot more data with which to do astrochemistry.

Aside from the catchy title and the mention of recent planet-finding successes, this article doesn't say anything that hasn't been said by literally hundreds of other people. (And actually, I'd be amazed if this author is the first to come up with the clever "When are..." formulation.)

Spectrum is finite. We're using ours more efficiently now by chopping it up into smaller and smaller sections of the Earth, and by digitally encoding, compressing, and in some cases encrypting our signal.

As a result we're sending a lot less stray analog RF out into the universe. And the stuff we are sending looks a lot more like noise.

Nevermind life outside our planet, why isn't there other non-related life on our planet (independant biogenesis)? From what I gather, evidence at the molecular level (things like molecular chirality in various cellular structures) point to all life being related.

Because DNA has a few billion years head start, and brutally out-competes any upstart life forms.

Probably: our relatives ate them all! There's basically no corner of our planet, from the hottest volcanic ocean vent to the coldest ice at the poles, to the highest clouds in the air, where our relatives don't live.

Of course, it has taken us about 1/4 the lifetime of the entire universe to get this far, so YMMV. :D

The reason I don't buy that line of reasoning is: The Lions eat the Gazelles, yet there are still Gazelles out there. Also, Gazelles and Zebras share the same land, and one hasn't starved the other of resources. And I don't think that is is just because they came from the same single-celled ancestors that make them able to share the same space. In the same way, I would expect other independent biogenesis lifeforms to still be represented (or new ones popping up periodically).

If you were an ultra advanced entity capable of interstellar travel, what would you do with earth? Or if there were many of you? Could you spend time here without bothering the wildlife, like civilized tourists? :)

https://www.youtube.com/watch?v=HPl10L40pBM

> Life seems to have been an easy chemistry experiment.

What an absurd idea!

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