Anthropics and a cosmic immune system

post by Mitchell_Porter · 2013-07-28T09:07:19.427Z · score: -8 (33 votes) · LW · GW · Legacy · 32 comments

Some people like to assume that the cosmos is ours for the taking, even though this could make us special to the order of 1 in 1080. The argument is that the cosmos could be transformed by technology - engineered on astronomical scales - but hasn't been thus transformed.

The most common alternative hypothesis is that "we are in a simulation". Perhaps we are. But there are other possibilities too.

One is that technological life usually destroys, not just its homeworld, but its whole bubble of space-time, by using high-energy physics to cause a "vacuum decay", in which physics changes in a way that makes space uninhabitable. For example, the mass of an elementary particle is essentially equal to the energy density of the Higgs field, times a quantity called a "yukawa coupling". If the Higgs field increased its energy density by orders of magnitude, but the yukawas stayed the same, matter as we know it would be destroyed, everywhere that the change spread.

Here I want to highlight a different possibility. The idea is that the universe contains very large lifeforms and very small lifeforms. We are among the small. The large ones are, let's say, mostly dark matter, galactic in scale, and stars and planets for them are like biomolecules for us; tiny functional elements which go together to make up the whole. And - the crucial part - they have immune systems which automatically crush anything which interferes with the natural celestial order.

This is why the skies are full of untamed stars rather than Dyson spheres - any small life which begins to act on that scale is destroyed by dark-matter antibodies. And it explains anthropically why you're human-size rather than galactic-size: small life is more numerous than large life, just not so numerous as cosmic colonization would imply.

Two questions arise - how did large life evolve, and, shouldn't anthropics favor universes which have no large life, just space-colonizing small life? I could spin a story about cosmological natural selection, and large life which uses small life to reproduce, but it doesn't really answer the second question, in particular. Still, I feel that this is a huge unexplored topic - the anthropic consequences of "biocosmic" ecology and evolution - and who knows what else is lurking here, waiting to be discovered?

32 comments

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comment by [deleted] · 2013-07-28T10:15:08.879Z · score: 18 (18 votes) · LW(p) · GW(p)

Would there be time for large life to evolve? A galactic-size organism is 100000 lightyears across, so can only act as a coherent organism on timescales of at least 100000 years, probably much more.

To evolve immune defense against small life, there would have be many instances of less-fit large life being killed by small life, to generate the selection pressure. Unless the large-life can reproduce implausibly fast and life on earth is a massively slow-evolving outlier (to make this idea work you probably need thousands or millions of galactic civilisations each built on the ruins of the last, in our past), I don't see how this can happen.

Another objection: If small life evolves much more quickly than large life, we'd expect small-life galactic civilisations long before any large-life worthy of the name evolved, and could easily technologically outmatch any evolution of a large-life immune system.

comment by Mitchell_Porter · 2013-07-29T06:30:58.358Z · score: 0 (4 votes) · LW(p) · GW(p)

If you follow the link, you'll see an idea from the 1990s, that universes have been selected to produce technological civilizations that produce black holes that produce universes that continue the cycle. (The physical idea is that behind the event horizon, each imploding black hole bounces, and becomes the big bang of a new space-time.) Here selection is purely for fecundity.

I had the notion that a similar cycle might be constructed here - universes selected to produce large life which guides small life to create new universes which continue the cycle - but with anthropic selection favoring such universes as the ones with the most observers in them. The immediate problem is, why wouldn't unchaperoned universes, in which small life proliferates unchecked, be even more populous?

But I see a way to save the hypothesis. What if the only way to reliably transmit a civilizational imperative into a baby universe, is by seeding it with large life that will adopt the desired values? Perhaps genomes on planets are too far from the big bang to influence directly with any reliability; but perhaps you can do something to the geometry of space which will cause vast dark-matter information-processing systems, forming directly after the big bang, to adopt the imperative of faithful universe replication. Large life would then be a necessary intermediary in the life cycle of the most fecund universes.

comment by [deleted] · 2013-07-29T07:00:45.291Z · score: 5 (5 votes) · LW(p) · GW(p)

But I see a way to save the hypothesis.

That should be setting off huge motivated reasoning alarms.

When it turns out that Mortimer Q. Snodgrass has an alibi, additionally hypothesising that he can teleport (with no evidence) is just heading further down the garden path.

comment by Mitchell_Porter · 2013-07-30T23:24:15.520Z · score: 2 (2 votes) · LW(p) · GW(p)

Just as a matter of physics, I'm not fond of these reproducing-universe models. But we are being offered an intellectual choice between "the future of the whole universe depends on what happens on Earth now" and "the whole universe is fake". So yes, I am motivated to look for a third option, and to keep working on it even if it doesn't immediately make sense.

comment by [deleted] · 2013-07-31T06:10:03.949Z · score: 0 (0 votes) · LW(p) · GW(p)

You seem to have shifted your original hypothesis quite a bit - originally, the large life killed off the small life before it could make dyson shperes etc. Now, the large life guides the small life to create black holes. So why don't we see a galaxy that's been turned into black holes?

comment by Mitchell_Porter · 2013-08-01T11:49:36.587Z · score: 0 (0 votes) · LW(p) · GW(p)

I see three possibilities so far: 1) creating the baby universe destroys the parent universe (e.g. finetuning the black hole collapse requires ultra-high-energy processes causing a vacuum decay outside the event horizon); 2) galaxies are organisms and only a few sites function as "germ cells", the rest of the galactic mass is needed for other functions; 3) there are bounds on the fidelity of large-life heredity (as mediated via this process), producing an inescapable variance in their enthusiasm for replication, and most of the time reproduction is only a secondary imperative.

And yes, I've drifted from "cosmic immune system" to "cosmic reproductive cycle". Perhaps there are other hypotheses, where we are involved with the "cosmic gall bladder" or "cosmic toenail clippings". :-)

comment by Rukifellth · 2013-07-29T06:46:38.955Z · score: 0 (0 votes) · LW(p) · GW(p)

But, we now also have room for other hypotheses.

What if value systems that discourage expansionism also just happen to be the value systems that allow a species to become space faring?

comment by Vladimir_Nesov · 2013-07-28T17:04:24.533Z · score: 11 (17 votes) · LW(p) · GW(p)

A lot of people upvoted this post (it's at -1 and 47% positive). Why would you do such a thing?

Here I want to highlight a different possibility ... The large ones are, let's say, mostly dark matter, galactic in scale, and stars and planets for them are like biomolecules for us ... And it explains anthropically why you're human-size rather than galactic-size ... Two questions arise - how did large life evolve, and, shouldn't anthropics favor universes which have no large life, just space-colonizing small life?

(The post seems like a clear case of privileging a hypothesis, which is additionally implausible. That Mortimer Q. Snodgrass did it could indeed explain the murder, except in this case Mr. Snodgrass is additionally postulated to be an (ordinary) undead pharaoh; and the questions arise about where was Mr. Snodgrass the night of the murder etc.)

comment by Jack · 2013-07-28T17:59:43.437Z · score: 1 (3 votes) · LW(p) · GW(p)

Most things that sound like updated Lovecraft are probably only being paid attention to because people have fun imagining ancient space gods.

comment by Vladimir_Nesov · 2013-07-28T18:47:43.668Z · score: 3 (5 votes) · LW(p) · GW(p)

This would be some kind of "awesomeness heuristic/bias" where you believe something to be worth considering because it's awesome in some way and not because there are reasons for expecting it to be true. Such things are worth bringing to attention as fiction, but not as hypotheses about the world.

comment by Jack · 2013-07-28T20:11:34.560Z · score: 1 (1 votes) · LW(p) · GW(p)

Yes, that was the point I was making.

comment by Mitchell_Porter · 2013-08-17T06:40:23.662Z · score: 0 (0 votes) · LW(p) · GW(p)

Do you feel similarly, about people who think that Earth life has a chance of conquering the universe?

comment by Jack · 2013-08-17T16:04:36.955Z · score: 1 (1 votes) · LW(p) · GW(p)

I agree that the views share a similar non-rational attraction that is likely to appeal to the Less Wrong crowd regardless of what degree of evidence supports the view. But I don't think the actual degrees of evidence are similar.

comment by gjm · 2013-07-28T23:12:12.482Z · score: 0 (4 votes) · LW(p) · GW(p)

A lot of people upvoted [...] Why would you do such a thing?

I upvoted because when I saw it it was sitting at -3 or thereabouts and I thought the right place for it was more like -1 or 0. (I think it's almost certainly wrong, but the idea is interesting to think about and I wouldn't bet more than 20:1 against there being some substantially better idea that it might provoke someone to have.) If I come back tomorrow and see it at +2 I'll change my vote.

There is something to be said for a strict policy of "vote for things you want to see more of, against for things you want to see less of" without regard for others' opinions, but in practice I bet there's enough of an information-cascade effect (where people are influenced by prior votes to vote in the same direction as the others) that I don't mind occasionally pushing against the flow, in either direction.

comment by Vladimir_Nesov · 2013-07-28T23:32:23.543Z · score: 1 (3 votes) · LW(p) · GW(p)

A rating that close to 0 is unstable (it can fluctuate towards the positive), and the strategy of keeping the rating near zero negates the signal of how many people judge a post bad. Keeping it above at least minus 15 or so seems more defensible.

comment by gwern · 2013-07-28T16:20:27.763Z · score: 9 (11 votes) · LW(p) · GW(p)

The large ones are, let's say, mostly dark matter, galactic in scale, and stars and planets for them are like biomolecules for us; tiny functional elements which go together to make up the whole.

In what sense do the existing stars and galaxies look in any way designed or organized in structures or in any way differing from straight-line extrapolation from the Big Bang without any invocation of life or selection processes? This is the same question as 'how do cells and proteins look different from rocks?'

comment by shminux · 2013-07-28T22:09:21.511Z · score: 0 (0 votes) · LW(p) · GW(p)

Some sort of selection definitely happens. The first stars were huge and simple, with only hygrogen and helium. They seem to be evolving toward high metallicity and medium size. They also compete for the same food source, interstellar dust. I concede that this is reaching somewhat, but probably not nearly as much as liking rocks to cells.

comment by gwern · 2013-07-29T16:35:46.815Z · score: 1 (1 votes) · LW(p) · GW(p)

Some sort of selection definitely happens. The first stars were huge and simple, with only hygrogen and helium. They seem to be evolving toward high metallicity and medium size.

But what sort of selection is this? Evolution requires, roughly, reproduction and inherited variation with selection. I could imagine that we might see something like this in a stellar life cycle where stars go supernova, scatter gas clouds, and new stars form to go supernova and form even more new stars, but as far as I know, this is not anything we see (and wouldn't work with dark matter, anti-life antibodies, or galaxy-scale organisms), inasmuch as stellar creation is shutting down (I've read this in various places, most recently http://lesswrong.com/lw/i2i/link_cosmological_infancy/ ) and I'm not clear what sort of variation could be inherited there either.

comment by timtyler · 2013-07-28T11:23:00.858Z · score: 3 (5 votes) · LW(p) · GW(p)

And it explains anthropically why you're human-size rather than galactic-size: small life is more numerous than large life

That seems likely to be true - regardless of the merits of the "large-life antibodies" idea.

comment by Nelson_Flood · 2013-08-14T00:01:14.488Z · score: 0 (2 votes) · LW(p) · GW(p)

Last week I had an idea very similar to the "cosmic immune system out to get us" concept expressed above, as a result of reading the book "The Life of the Cosmos" (1997) by physicist Lee Smolin, who paradoxically is an opponent of the anthropic principle, preferring his concept of cosmological natural selection as the explanation of why the laws of physics are as we find them. His is a many-worlds cosmology but the individual universes in the ensemble can reproduce further universes, a process accompanied by the introduction of small mutations into the laws of physics (the genome of a universe) that the progeny inherit, which causes the ensemble to evolve in a Darwinian fashion. (My only quarrel with universe evolution is that there seems to be nothing that can remove less-fit individuals from the scene and recycle their matter for use by the more fit, but we must avoid argument from lack of imagination.) Evolution, when discussed in the idiom of DNA-based genes, is driven by increases in gene frequency reflecting reproductive success. Therefore we predict that the corresponding universal process tries to maximize the fecundity of the typical universe. Take-home: we happen to see a specific physics not because it produces the most observers but because it produces the most universes. (Since "universe" denotes all there is, the word is clearly being misused here. Therefore the units of cosmological selection will be referred to as "compartments" in what follows, and the word "universe" will retain its dictionary meaning.) Abandoning the anthropic principle allows us to view the rise of civilizations of intelligent observers in any compartment as no more than accidental, and probably representing a kind of cosmological cancer. Other suitable metaphors would be "parasitic process" and "failure mode". Examples of these abound, such as feedback noises developing in public address systems, epileptic seizures developing in cerebral cortex and/or hippocampus, or any pathogen-triggered disease in the human body. I am sure that this problem has been regularly impairing compartment reproduction all down the cosmological line of descent leading to us, causing a selection pressure that long ago brought about the evolution of a compartmental immune system, which, of course, is out to get us. But how could little ole Earth threaten the whole observable universe? By someday colonizing the Galaxy in finest Science Fiction style and expropriating the interstellar matter the host compartment needs to reproduce, to make new planets for us to live on. Interesting that the universe thinks we can do it. I guess immune attack can be the sincerest form of praise. The compartmental immune system has in fact probably been taking preventative measures against us all throughout our history, leading to the myth of Old Nick, Father of Lies, The Evil One, etc. It cannot even be dismissed as a myth, it's merely what in science would be called an approximate theory. It appears that the compartmental immune system consists of “mousetraps” for the unwary civilization (perhaps baited with goodies like fossil fuels, the use of which is calculated to Venus the planet in a runaway greenhouse effect that strikes without warning, and uranium, whose dangers do not need repeating), Shminux is obviously all over this one. The traps would be encoded into the laws of physics with diabolical subtlety, and technological civilizations exactly such as ours have always been the target. Based on this line of reasoning, I am calling for the creation of a branch of science that could be called Defensive Cosmology, to help us spot these traps before it is too late. Who's with me? P.S.: lest you think this worldview is overly pessimistic, I'll mention that there is a place for God in it. He is an advanced technological civilization in another compartment that contains ours, that has repurposed our compartment as an experimental test bed for doing experiments on how to defeat their compartmental immune system. Notice that they cannot solve their worst problem before they have solved our version of it. Our interests are aligned. Nor must they give us the disease in order to try curing it, as we do with lab rats. That would be totally sinister. It would also be redundant, because all compartments always naturally come with immune systems. It remains to be explained why solving our problem for us would be any easier than trying to solve theirs directly. Here is what I think could be the reason. The entropy, or information content of a black hole has been shown to be proportional to the area of the event horizon, thought to be a kind of abstract surface. But what if it somehow has a claim to being a literal surface? If black holes are the daughter compartments our compartment has produced, as Smolin suggests, then we can unpack this to mean that these daughter compartments are flatlands! The contents are all on the surface which is locally two dimensional. Everything in these compartments is a total open book to us. We can intervene absolutely anywhere in these worlds, and see absolutely anything in these worlds. Wouldn't you say that that is an experimenter's dream? We are to God as these flatlands are to us. I can reconcile this we-are-a-surface idea with the principle of relativity and the need for a living compartment to have internal motions, if anyone is interested.

comment by Rukifellth · 2013-07-29T02:18:39.871Z · score: 0 (0 votes) · LW(p) · GW(p)

I'm currently sleepy, aching and overfed myself a few hours ago, so I'm just going to throw this article here. I'm not in a state to articulate why this is relevant, but I'm dead certain that it is.

comment by timtyler · 2013-07-28T11:20:28.197Z · score: -1 (3 votes) · LW(p) · GW(p)

If large lifeforms are not nearby, how would we distinguish between their Dyson spheres and the (observed) prevalence of dark-matter?

comment by gwern · 2013-07-28T16:18:54.195Z · score: 3 (3 votes) · LW(p) · GW(p)

Thermal radiation...?

comment by polarix · 2013-07-29T16:52:54.817Z · score: 0 (0 votes) · LW(p) · GW(p)

If I were building a dyson sphere, I'd want to collimate all the radiation toward a single direction, perhaps gating it periodically. Make it look like a pulsar.

comment by gwern · 2013-07-29T17:15:26.922Z · score: 0 (0 votes) · LW(p) · GW(p)

We're surrounded by stars in all directions, and that would be far from free.

comment by shminux · 2013-07-28T22:01:16.076Z · score: -3 (9 votes) · LW(p) · GW(p)

Not sure why people hate this post so much. Consider that stars (I mean the celestial objects here, not human celebrities), for example, pass most definitions of lifeforms, except those privileging some specific form of metabolism, like carbon-based. Eh, maybe they even pass that one, since many are carbon cycle-based.

Whether Nature has a defense mechanism against large interventions is a testable theory. Some of the consequences have already been confirmed on the small and medium scale. Some examples: Easter Island, antibiotic-resistant bacteria, global warming. We narrowly avoided (by an order of magnitude or so) igniting the atmosphere with thermonuclear explosions. A grey goo might still do us in.

comment by [deleted] · 2013-07-29T14:46:51.401Z · score: 2 (2 votes) · LW(p) · GW(p)

Consider that stars (I mean the celestial objects here, not human celebrities), for example, pass most definitions of lifeforms,

Do stars reproduce?

comment by shminux · 2013-07-29T16:33:55.113Z · score: 2 (2 votes) · LW(p) · GW(p)

Yes, apparently. Supernova explosions send shock waves into molecular cloud which can trigger its collapse. They also seed the interstellar space with heavy elements promoting early ignition of collapsing nebulae (and planetary system formation, as a side effect).

comment by [deleted] · 2013-07-31T10:31:39.512Z · score: 0 (2 votes) · LW(p) · GW(p)

But it's not like the “children” bring a genetic signature of the “parents”.

Is fire a lifeform according to you?

comment by shminux · 2013-08-02T18:03:57.121Z · score: -1 (1 votes) · LW(p) · GW(p)

Is fire a lifeform according to you?

I don't know, why are you asking? what's your definition of a lifeform? Wikipedia suggests something like

capable of responding to stimuli, reproduction, growth and development, and maintenance of homeostasis as a stable whole.

Stars and galaxies are probably close to fitting this description than just random forest fires.

comment by [deleted] · 2013-08-02T21:16:17.215Z · score: -1 (1 votes) · LW(p) · GW(p)

I can see that about stars if I squint hard enough, but galaxies?

comment by shminux · 2013-08-02T21:37:36.884Z · score: -2 (2 votes) · LW(p) · GW(p)

Squint harder? It's true, reproduction might be a stretch, but the rest matches up well: growth, development, interaction, homeostasis. They even eat each other to grow, often triggering star formation.