Friday, November 29, 2013

living planet

Assume for a moment that our earth's total mass, which would be the sum of its biomass and its abiotic mass, is relatively constant. Assume, too, that the amount of biomass has been increasing (which has certainly been the case with the human population). Will there come a point when the entire planet becomes biomass? If not, why not?* Is there an asymptote somewhere—some threshold that defines just how much earth-matter can sustainably become biomass? Has anyone ever tried to map this out before? What would it be like to live on a planet where every iota of matter is or was alive?

*If you say it's because gravitational pressure will always mean there's a superheated (and thus uninhabitable) core, I'd counterargue that humans may be clever enough to start building their civilizations inward, toward the core, and perhaps all the way through it, possibly even cooling down the superheating along the way.



Surprises Aplenty said...

I'm a little disappointed in you, Hominid. Are you suggesting life will incorporate currently poisonous metals like aluminum, mercury and, well, others? Even if Silicon-based life were found or created, not that much of the Earth's mass could be incorporated into lifeforms.

As for cooling the super heated core, I guess we can imagine that. On the other hand, I know you're a vintage Niven fan and he was concerned with heat pollution from basic human activities only on the surface.

Kevin Kim said...


I'm simply tracking the trends. You may be right: there may be too many elements that can't be incorporated into biotic matter. I'm not a biologist, so I wouldn't know. Meanwhile, the human population continues to increase, and if we keep pursuing our preservationist efforts, the biomass of other species will also increase, probably leading to an overall increase in planetary biomass. That's an upward-trending curve, and what makes me curious is where it might stop.

Your point is interesting, though, in that it suggests a possible way to figure out where the asymptote lies. If we can somehow figure out the rough proportion in which terrestrial elements occur, and can also figure out which elements—and in which proportions—are needed to create life, we can reason our way to the asymptote. Maybe only 10% of the earth's mass will have the potential to come alive. But wouldn't it be cool if that number were closer to 50%? 70% 95%?

Surprises Aplenty said...

You and I are both science fiction people. James Blish wrote a boot with the central premise being 40,000,000,000 humans living on Earth in relative comfort - it is not a dystopia, but the planet's administrators lurch from crisis to crisis to keep it from becoming a dystopia.

I don't know about our work preserving other species but I would say life on a human-dominated Earth cannot get much larger, with a limit of perhaps three or four times more humans -and a huge loss in other species, but larger total mass.

I feel that the way to maximize biomass would be to have a single-celled, or even bacterial dominate Earth.

gordsellar said...

There is a solution to the problem. One must simply pursue a definition of "life" that is broader than commonly accepted. That is: AIs, uploaded minds or otherwise.

Plenty of Singulatarian fiction has explored the idea that the explosion of "life" in the future would take the form of machine civilizations: pretty much everyone who's written about Dyson spheres *after* Olaf Stapledon posits this.

To convert the whole Earth to "biomass" isn't really practicable for a number of reasons. You could convert the whole of the Earth to, say, computronium--material for the construction of some kind of computation hardware--but if you were to leave the Earth intact, there would be limits to this, too. For one, the pressures that develop at the core of the Earth would require immense energies to resist, which defeats any purpose of tunneling inward. For another, there are limits to how much material you could convert while maintaining an Earth-life structure.

I'd wager someone with more scientific background than me would be able to work out just what the limits to conversion would be while maintaining a solid Earth structure, or even just maintaining a mantle on top of the lava. (The survival of which would be hard enough, let's forget the molten iron core.)

But skirting those limits makes little sense. If you're a machine civilization, then unless you're keeping flesh-and-blood life around as pets, the obvious solution would be to take apart the Earth and the rest of the solar system, convert the lot of it to computronium, and build a solar-powered Dyson sphere around the sun to maximize computational capacity. (Economic growth.) Then you have aeons to "live" until you need to figure out whether to emigrate to a younger sun, or adopt a different strategy. (By then you may have access to more exotic energy sources anyway.)

The most interesting novelistic dramatization of this scenario that I know of is Charles Stross's ACCELERANDO. He released under a creative commons license, I think when it was up for a Hugo Award, and it's still free to download and read:

Of course, that scenario I mention is just a portion of the bigger story. It's a makes-your-brain-hurt hard SF epic, in the form of nine short stories. Definitely one of the best SF books of the last decade. Enjoy!

(Oh, and for an earlier example, Ted Sturgeon's unfortunately titled THE COSMIC RAPE might be another example. Not so freely available, but it is an early singularity story, a sort of biological version of Star Trek's Borg civililzation, I suppose. I haven't read it, but it's often held up as an early singularity piece.)

One more thought: Rudy Rucker's Hylozoic (second book in a series, but the first book is free/CC online) is also about a world where "everything is sentient and telepathic":

Given Rucker's interest in the idea of panpsychism, I think that "everything" includes, well, everything: rocks in the earth, lava, silver deposits in the ground, rain, neutrinos, etc. Again, haven't yet read it, but it seems in the ballpark of what you're asking for. But, again, requires a different definition of "life": things are sentient without being "alive" in the traditional, "organic" sense of life.

I don't know if you've ever read Rucker but I think you'd enjoy him. (I can say the Ware Tetralogy is very fun. Or you might check out his webzine Flurb for a taste: he has some of his own stories there. Also, his collected short stories is available online, free to read.)

Happy Thanksgiving by the way, even if you guys do it a month late. ;)

gordsellar said...

Oh, and: the problem you posit in your comment, Kevin, is already solved:

The page shows the best numbers we have for the universe and for Earth as well.

As for how much of it could be integrated into biological life, it depends on your definition of biological and life. For life of the sorts known to us, I'd say the limit probably not set by availability of this or that element, but rather by the maximum stability of a single interdependent ecological system. Climate change would be an example of a limit to technocratic growth; there would, I imagine, be maximal systems to life. I'm no expert but my first question to a biologist would indeed be whether there has been a relative stabilty of biosphere mass over time, and whether that might represent a natural average representative of carrying capacity. (ie. Something we could surpass either at risk, or only with serious conscious tinkering.)

Kevin Kim said...

My blog suddenly became interesting, eh, Gord? heh.