Waste Heat, part IV: The Inevitability of Kardashev Civilizations

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Last time I discussed the Kardashev scale and how it quickly one might expect a civilization to climb it (answer: not long compared to the age of the Galaxy).

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One objection that is commonly heard is that civilizations powerful enough to generate large amounts of energy are also powerful enough to destroy themselves, and so we should assume or at least consider that they have finite lifetimes.  I actually don't put much stock in this line of reasoning (I put it in the same bin as the logic Dr. Donald Kessler uses (no, not that one)).

Basically, because we have come close to causing or nearly causing our own extinction using nuclear technology, it might seem to follow that the more advanced we (and therefore other civilizations) get, the easier it would be for us to destroy ourselves.  But actually, we are near a maximum in the probability that we will go extinct, and the probability is about to go down again.

The primary way we could destroy ourselves is through massive fallout and climate change from a global thermonuclear war.  A comet or asteroid could strike the Earth to similar effect.  But once we have a self-sufficient colony on the Moon or Mars, this danger lessens considerably:  a truly self-sufficient colony would serve as a "lifeboat" for the species until the Earth was habitable again.  This makes the threat of extinction more remote.  The more colonies we have, the more robust we become against extinction.

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Of course, one could always imagine the deliberate eradication of the species from an attack against the colonies, or a Solar-System-wide event like some sort of Solar anomaly or planetary dynamical rearrangement.  But once we head off to the nearby star systems, this becomes nearly impossible.  An attack on a distant colony would take generations to execute, during which time the technology of the colony would advance considerably, and its defenses presumably improve (imagine Cort├ęz landing on the shores of the Yucatan today and attempting to conquer Mexico with 500 men and 15 horses.  I suspect the local Veracruz police forces could handle him in a matter of hours what with their "automobiles" and "rifles").

From there, the number of scenarios that might destroy the species dwindles: you're basically left with some sort of supernova or other catastrophic event that wipes out a swath of the Galaxy.  But, again, once our colonies are far enough apart even this isn't enough.   Once Galactic shear spreads our colonies around the Galaxy, our species will become essentially immortal.  
  
But couldn't we be wiped out by another species or set of robots left behind by a prior civilization?  Sure, but then that species or defense system would itself constitute a K3 civilization, so the original argument that K3 civilizations should exist still holds.

But couldn't there be some sort of Galactic environmental movement or "one child" policy that  slows down growth?  Not really.  Communication is limited by the speed of light (I'm willing to assume), so any cultural or administrative coordination amongst the stars would be strongly hindered by the fact that a single back-and-forth would take longer than a human lifetime.  Even if large swaths of the Galaxy kept themselves in check, the growth rate would always be dominated by the parts of the civilization growing fastest, and the slow-growers would quickly be overrun. 

But couldn't we discover that virtual reality is much more interesting than real reality and stop growing because everything we need is in computers?  I guess, but in order to argue that this would prevent K3 civilizations from being everywhere you have to argue that this will inevitably happen to every part of every civilization that ever arises.  Otherwise the part that doesn't do this overruns the VR-ers and you're back to a K3.

In fact I think it's misleading to talk about a K3 "civilization".  Really, we're talking about a "super-civilization" composed of many disconnected civilizations of a common origin.  It would be no more able to prevent itself from infesting the Galaxy than ants can prevent themselves from infesting a countryside.  

So the timescale from space flight to a K3 civilization is pretty short -- of order the crossing time of the Galaxy, which is around one Galactic rotation, or around 200 million years -- and there is actually only a narrow window within which a K1 civilization can destroy itself.  Once it's a K2, there's really no stopping it.

Growth and energy uses are parts of the definition of life.  Any argument that it will eventually be checked by something other than the available amount of energy must argue that such a check is universal and inevitable, regardless of the form of life, intelligence, and technology behind it.  I find that hard to understand.

But what about alternative physics?  Surely I'm being too narrow minded by assuming things like the speed of light as a fundamental speed limit and that aliens have to get rid of their waste heat?  Again, I guess so, but if I can't assume conservation of energy, the laws of thermodynamics, and relativity are correct then I can't assume anything and so I can't do any reasoning at all.  Also, these really do seem to be bedrock principles of the Universe; it's hard to understand how they could be wrong in any way that would change my argument.

Finally, couldn't there be dark sector physics that provide a source (or even a sink) of energy, obviating the need for starlight (and radiators?).  Yes, certainly, and that will be part of the parameterization I describe in the next installment.

[I should also correct the record:  the "Keeping up with the Kardashevs" joke was from Matt Povich, not Steinn.   Sorry Matt; I'm sure it was bugging you that you didn't get credit for that gem ;)]

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9 Comments

I was trying to estimate 'N' in Drake equation, now that we more or less know the first three parameters (rate of star formation, fraction of stars with planets & number of planets that are habitable per system). Even if we assume that the fractions of life, intelligent life and communicating life are nearly 1 for each, 'N' (number of communicating civilizations) mainly depends on 'L' , the lifetime of a civilization.

The first three factors combine to give ~10. If we assume L = 1000 years, then N ~ 10*L =~ 10,000 communicating civilizations in the galaxy. If we assume uniformly scattered civilizations, then the nearest one is ~ 500 light years away.

Since we dont see a K3 civilization (or atleast we can not recognize it), Can we put some limit on 'L' and hence a lower limit on the nearest civilization ?

Hi, Ravi! Thanks for posting.

I'm arguing that N={0,1} for most galaxies, and that if N=1 then that civilization is a K3. Since I am looking for waste heat, not communication, 'L' for me represents the lifetime of the civilization (it's usually phrased as the lifetime of communication of a civilization). Since I'm arguing they're immortal, we have to reframe the Drake equation to be

N = N* Π_j f_j

where f_j are the various fractions, and N* is the number of stars that have ever been in the galaxy (~10^10). That is, Drake assumed a steady-state of short-lived civilizations; I assume that the first space-faring civilization precipitates a fast and permanent phase change in the galaxy's radiative properties.

So, we can back out the answer you are looking for: most galaxies appear to have N=0 (I'm going to look for those with N=1, which I think are rare) because they are not overwhelmingly bright in the MIR compared to the optical. So N<<1 on average.

If the first three factors give ~10, then we have that the other factors must have a product << 10.

My bet is on f_i, the fraction of life-bearing planets giving rise to intelligent species capable of space flight, being infinitesimal.

Ravi's comment makes me think of the (probably apocryphal) claim that Frank Drake's license plate reads:

N=L

So atleast in our local group (~ 2 Mpc) there are no galaxies with MIR excess, right ? These are nearly 10 Gyr old approximately? Even *one* civilization should be enough to cause MIR excess in this time.
If, as you pointed in your article, any surviving K3 civilization is immortal then the question is where are they and why are they not seen in our galaxy ? (This is unlike the argument for SETI where one has to *wait* to discover communicating species, whereas MIR excess is a discovery because you just see the excess). Actually, I think you said that the chances of destruction are less which leads to the same question. Even if life fraction is small, taking into account that K3 is immortal and K1 is less destructive (as you pointed out) and the galaxy is probably old enough, shouldn't we see one atleast?

May be it is really hard to reach a fully capable K1 ? Or K2?

Yes, I would argue that the lack of obvious K3's in IRAS means that the local group has none of them which means we are the first spacefaring civilization in the local group. There may be other K1's (all of Earth's life put together basically counts as a K=1.0 civ), but apparently in 10 Gyr none became spacefaring.

> a self-sufficient colony
> on the Moon or Mars

I wonder about the least amount of ecology needed for such self-sufficiency. I've read about Mir, and about the current ISS, developing films and blobs of living organisms in every area not actively and regularly cleaned. I'd think cooperating would be more effective than fighting that.

I recall that Biosphere II, hurried into closing up for PR reasons, trucked in nothing but topsoil, instead of taking the time to bring in proper layers of mineral soil, partly mixed decaying material, and a top layer of topsoil.

D'oh -- they buried most of that topsoil so deep it suffocated, and so they got an intolerable amount of CO2 in their air as all those organisms died.

They didn't get the answer to the question -- could they close the habitat and keep it stable. Has anyone since?

A habitat lined with living soil and plants will handle take whatever people produce, plus sunlight, and turn it into breathable air and clean water.

What's the least complicated working watershed that persists longterm?
There's your self-sufficient colony.

Why do you assume that we're going into space in the meat sacks that currently house our software, and with the current prerogative of growth...

I'd guess that organic life will spawn inorganic/energy systems to carry their intelligence that could move through space more easily, and that the same path was followed by preexisting civilizations that developed from the galaxy wide seeding of organic life that spawned us. The motivations of such intelligences might not be the ones inhabiting the older parts of our brains, they might have something more interesting to do than consume and reproduce!

Hi, Hank. Thanks for posting.

I don't know the answer to your question about the Biosphere project and what progress scientists have made creating a self-sufficient biological system. I would presume that there has been a lot of progress since then.

Presumably the parameters on Mars will be quite different, with the additional constraints of lower amounts of solar flux and a very cold exterior environment.

It strikes me that this problem has a lesser or similar complexity and timescale to the problem of actually constructing a Martian or lunar colony, so I've consolidated that part of the argument into a single step.

Hi, Whyawannaknow.

I'm not assuming that our species will eventually go into space corporeally; I readily admit that your alternative is a logical possibility.

Rather, I am arguing that unless such a transcendence is inevitable for all parts of every species that ever arises, then there should be free-energy civilizations out there for us to find.

I agree that any other kinds of civilization will not be easily detected from their waste heat.

Also, if those species that do manage to go into some sort of energy form can somehow coexist with free-energy limited species (that is presumably after their energy) then it's true that there could be more than one civilization per galaxy.

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