Hints That You're Living in a Simulation; Plus, What Is a Simulation?

See Bostrom's simulation argument for background. From a practical standpoint, you might be suspicious that you live in a simulation if you inhabit a world with the following characteristics:

Hint #1) Limited resolution. A simulation would be computation intensive. It would be useful to have tricks that increase the economy of operations, but in ways that do no compromise the consistency of the simulation to the players. One such trick would be to set an absolute upper limit to resolution (or a lower limit to the size of the elements that make up the "picture") that is below the sensory threshold of the players. These elements could variously be called pixels or quarks. Similarly, it would behoove the simulators to set a maximum time resolution, i.e. maximum frames-per-second, also called Planck times. Furthermore, the simulation's computing power is spared by a statistical method of calculating relationships between entities in the simulation (i.e quantum mechanics) even though it may look, at the scale of the game players or simulated entities, as if the universe maintained quantitative relationships in terms of integers calculated to arbitrary precision. (Related question: is it possible in principle given the physics of our universe for something the size of a bacterium or virus to "be conscious of" this gap in the behavior of the Newtonian and quantum realms, at a very basic sensory level? If not, isn't it interesting that our universe is such that there can be no consciousness operating on scales that would expose the twitching gears behind the scenes?)

Hint #2) There are limitations in what spaces within the game can be occupied by players or sims. In the old Atari 2600 Pole Position game, you couldn't just randomly go off driving off the track and through the crowd even if you didn't care about losing points; the game just wouldn't let you. Similarly, the total space in our apparent universe that we occupy, or directly interact with, or for that matter even get any significant amount of information from, is an infinitesimally small part of the whole. Unless you're in a submarine or in orbit, you don't go more than 200 meters below sea level or 13,000 m above it. (That's a volume of 2.1 x 10^18 m^3 that for all practical purposes the entirety of human history has occurred in; double that figure, and that's the volume that all of evolutionary history has occurred in.)

Hint #3) Beyond the "active game volume" as described above, dab a few pixels here and there in an otherwise almost entirely dark and empty volume. Make them so far away that sims can't possibly interact with them. Reveal additional detail as necessary whenever someone happens to look more closely at them. (And there's another trick: objects in this simulation are only loosely
defined until one of the players interacts with them, "collapsing the wave function". Yeah, that's what the programmers will call it, that's the ticket.)

Hint #4) Even in that limited location, make the active game volume wrap around. That way the simulators get rid of edge-distortion problems, as in Conway's Life. A sphere is the best way to do this. Therefore, work out the physics rules of the simulation to favor spheres.

Hint #5) Make each state of the simulation dependent on previous states of the simulation, but simplify by dramatically limiting the number of inputs with any causal weight. The simulators can limiting computations by having only mass, charge, space and their change over time determine subsequent frames.

Hint #6) If for some reason it is important for the entities in the simulation to remain ignorant to their existence as part of a simulation, the simulators could make sure the entities are accustomed to not only these kinds of stark informational discontinuities but to profound differences in the quality of awareness, both within themselves and each other. That is, the sims will accept not just that the vast majority of the universe (as seen in the sky at night) is interactively off-limits to them, but they'll also accept that their own awareness thereof and ability to connect the dots will dramatically vary over time. That way, if there is any need to interfere and make adjustments (to stop someone from figuring out the game) it won't strike the sims as strange. (Forgetfulness, deja vu, mental illness, drugs, varying intelligence or ability to concentrate on math, death of player-characters before they can learn too much?)

#6 does raise a very important question: why would the simulators give a damn if we knew we were in a simulation. So what? What would we do about it, sue them? If Pac-Man woke up and deduced that he were a video game character, if he still experienced suffering and mortality the same way, why would it matter? By this same view, there's an easy answer to whether we should behave differently if we're actually in a simulation: no. Whether our universe is in reality just World of Warcraft from the sixth dimension, if we simulated beings can suffer (and I know I can), then the moral rules are exactly the same as before.

It's also worth asking for some humility, and asking why we humans always assume that we would be the purpose of any such simulation. We could be merely incidental consciousnesses that are necessary for harboring the populations of simulated bacteria that the simulators are really studying. Or, the simulators could be cryonicists who preserve pets, and the most popular pets in their dimension look like what we call raccoons, and our universe is actually the raccoon heaven in which their beloved masked companions await a cure for the disease that forced the owners to put them on ice. In fact the raccoon-heaven simulation would contain a whole suite of ecosystem, all of them purely simulated (with the exception of raccoons) to keep up the appearance of a full biosphere. So the point of such a simulation would be to fool raccoons - or maybe even mice (again, why would they care about fooling everyone! If the simulators are reading this, just give me more juicy steaks and I won't make problems. It doesn't cost you anything!)

While the raccoon thought experiment is meant to be whimsical, a healthy respect for our own ignorance is always in order for these kinds of speculations. After all, assuming what we have guessed about the rest of (for the sake of argument simulated) universe is accurate, then there might be "aliens" (other non-human intelligences within the simulation) who may very well be much brighter than us. So even if the simulation is somehow arranged around the most intelligent entities within it (as we assume), those entities need not be human. Even if we're simulated, and we have a real brain and body in the "real" universe that's similar to our form in this one, this simulated universe might be designed for Martians (who are brighter than us) and be much less pleasant than our home dimension.

Finally, the very idea of a simulation is poorly defined. Mostly we think of something like almost completely controlled full-world simulation in the Matrix, but let's explore boundary cases. If I wear rose-colored glasses, is that a simulation (or a red world)? What about LSD that causes me to see unidentified animals scurrying past in my peripheral vision? What about DMT that causes a complete dissociation of external stimuli from subjective experience? What if I have some chip implanted that displays blueprints of machinery in my visual field a la the Terminator, is that a simulation? What about a chip that makes me see a tiger following me around that isn't there? (Hypothetical given current limitations.) What if I hear voices telling me to do things that are produced by tissue inside my own skull, by no conscious intent of anyone? (Not at all hypothetical.)

One of the interesting points in the popular movie Inception is the way that external stimuli appear in dreams. This gives us a hint as to what we mean by simulation, and why we care. Most of us have had experiences where the outside world "intruded" into a dream, with the stimulus obvious after we awoke. I once dreamed that a dimensional portal slid open in front of me with an ominous metallic resonance, and I stepped through it, suddenly speeding over the red, rocky surface of Mars. Then I realized it was my father opening his metal closet door in the next room, and I was looking into that room at the red-orange carpeting. Before I was fully awake I had received the sound stimulus but I had built a world out of it that most of us would not regard as real. (The experience of speeding over Mars was quite real, even if most humans would have a more accurate representation of that auditory stimulus.) So, a better way of saying "how do I know 'this' is reality, rather than another dream, or a simulation?" is to ask "how do I know I am perceiving "true" stimuli, without mapping them unnecessarily onto internal stimuli, giving me as accurate and un-contorted a view of the world as possible?"

And indeed in certain ways, we certainly are dreaming, in the sense of injecting internal stimuli and filtering external stimuli through them. (Notably, it is possible to view schizophrenics as people who experience dreams even while awake and filter their perceptions accordingly.) First and most obviously, because our sense organs are limited in what they can detect, we're obtaining only a slice of possible data. Second, the world we knit together is the result of binding of sensory attributes into object/events, as well as pattern recognition. The limitations of our nervous systems, and the associations we are able to make, profoundly influence the representation we build of the world we're perceiving.

Third, and most significantly, a large part of our experience is non-representational: emotions, pleasure and pain do not exist outside of nervous systems, or rather the events to which those experiences correspond are almost entirely contained within nervous systems. Yes, to be precise the experience of light does not exist until the triggering of a cascade of electrochemical events by radiation incident on pigments in retinal cells; but light, which is what is represented in our experience, exists traveling across the universe. Pain and happiness do not. These are internal stimuli that add a non-representational layer to reality, even more certainly than my dream of the Mars overflight.

A good working definition of a simulation as it is commonly understood is when the majority of one's external stimuli are supplied deliberately by another intelligence to produce experiences that do not correlate to physical reality external to the nervous system (or computational equivalent). This avoids taking a position on AI; the sims may or may not be entities separate from the computation. I.e., you might be in sensory deprivation tank like Neo, or you might be a computer program. The question of reality versus dreams or simulations is not one of discrete "levels" as we've come to think of it in popular culture. It is rather a question about how we know our experiences correspond in some consistent way with events separate from our nervous systems.

Without Constraints, How Do Humans Behave?

Cross-posted to my geek blog as well as my politics and economics blog.

Life on Earth evolved in an environment of constraints: resource limitations, disease and predation all put lids on behavior and reproduction. Consequently, the mechanisms to deal with those constraints have no "brakes", because nature provided them. There's no reason to have tight control on over-eating, because such a situation rarely arose. There was no reason to protect reward circuitry in general from overstimulation. But now we're starting to remove those constraints. Solve food scarcity, and we get obesity. Go straight to the reward center (without a real external reward), and we get heroin and video game addiction.

This is the biggest problem we face in any post-scarcity world, or (more broadly) in any world where our behavioral regulation is freed from the constraints that sculpted it for billions of years, whether in reality (because there really is more than enough food) or virtually (because you can just shoot up and feel good). This problem has even been advanced to explain the Fermi paradox, since whatever behavior regulation intelligent aliens evolve, presumably when they solve their own constraints, they will run into the same problems - perhaps with species-destroying consequences. The more complete and effective a representational system is*, the faster and greater the instability it creates in the system.

You might think of a science fiction story where curious and powerful aliens have put humans in a kind of terrarium where the weather is always fair, there's always enough to eat, there's no physical danger, and where there is always another territory to move into, with no loss of security, if you burn too many bridges with the ones in this one. That is to say, someone looks at you the wrong way, or your significant other mildly irritates you - why stick around? The aliens have guaranteed there will be another handsome gentleman/pretty lady waiting for you when you get to the new territory. And when you get there you wonder idly if these are real humans also in the experiment, or were whipped up and memory-programmed by the tissue replicator twenty minutes before you got there; or maybe you were, before your new mate got here. But you're taken care of; does it matter? (You might even call this hypothetical alien terrarium "California"; perhaps this explains my interest in the simulation hypothesis.) In a world of limitless security and resources and even others' company, why ever tolerate the least inconvenience?

A scenario similar to this that happens in the real world is the strange discomfort of working alongside someone who is wealthy independent of their jobs. Why are they even here, people might ask resentfully - and indeed, from anecdotal experience, when these people get annoyed, they quickly leave, because why not? They have security and more territory.

So what happens to people when all the constraints are removed, when they're both wealthy and not subject to censure by broader political forces? That is to say, how do humans behave when all the brakes are off?Predictably. From "The Prince Who Blew Through Billions" by Mark Seal, from Vanity Fair in July 2011:

On the brother of the Sultan of Brunei, Prince Jefri Bolkiah, who has "probably gone through more cash than any other human being on earth.": "The sultan's biggest extravagance turned out to be his love for his youngest brother, Jefri, his constant companion in hedonism. They raced their Ferraris through the streets of Bandar Seri Begawan, the capital, at midnight, sailed the oceans on their fleet of yachts (Jefri named one of his Tits, its tenders Nipple 1 and Nipple 2), and imported planeloads of polo ponies and Argentinean players to indulge their love for that game, which they sometimes played with Prince Charles. They snapped up real estate like Monopoly pieces—hundreds of far-flung properties, a collection of five-star hotels (the Dorchester, in London, the Hôtel Plaza Athénée, in Paris, the New York Palace, and Hotel Bel-Air and the Beverly Hills Hotel, in Los Angeles), and an array of international companies (including Asprey, the London jeweler to the Queen, for which Jefri paid about $385 million in 1995, despite the fact that that was twice Asprey's estimated market value or that Brunei's royal family constituted a healthy portion of its business).

"Back home, the sultan erected a 1,788-room palace on 49 acres, 'which is without equal in the world for offensive and ugly display,' in the words of one British magnate, and celebrated his 50th birthday with a blowout featuring a concert by Michael Jackson, who was reportedly paid $17 million, in a stadium built for the occasion. (When the sultan flew in Whitney Houston for a performance, he is rumored to have given her a blank check and instructed her to fill it in for what she thought she was worth: more than $7 million, it turned out.) The brothers routinely traveled with 100-member entourages and emptied entire inventories of stores such as Armani and Versace, buying 100 suits of the same color at a time. When they partied, they indulged in just about everything forbidden in a Muslim country. Afforded four wives by Islamic law, they left their multiple spouses and scores of children in their palaces while they allegedly sent emissaries to comb the globe for the sexiest women they could find in order to create a harem the likes of which the world had never known."

This reads like an account of what each of us would do if we found out tomorrow we were in a simulation, with power over said simulation. This is what happens when the brakes are off. If you object that this is an exception or an extreme example - I guarantee that this behavior happens more among the fabulously wealthy and powerful. Well of course, you again object, other people can't behave that way! But then if the tendency wasn't there, why should it happen at all? And (more to the point) do you seriously think you would be any better-behaved? Of course you would; you're biologically and/or morally superior to these folks and would never let that kind of thing happen. (Also note that lottery winners, with a sudden random infusion of karma or whatever you call the points in our game - that's right, "money" - are known for going off the rails, and being more miserable and more likely to go bankrupt than the general population. Also, see "athletes from poor backgrounds suddenly signed up to multi-million dollar contracts in pro sports".)

An astute observer will say, "So what if people descend into depravity? If you're in a simulation or the aliens' zoo or you're royalty and don't hurt anyone, if you're happy with harems and Ferraris, fine!" That would be fine. But the problem is these people often seem not to be happy. Here it's hard to get data, but they are not invariably happier than other humans and in fact often have considerably troubled emotional lives. Again, they're using nervous systems built for an environment of resource and social constraints. It should not be surprising that they experience boredom, restlessness, and emptiness. In fact in the developed world it's not just the ultra-wealthy that experience these things. That said, it's sure better than starving or being eaten by tigers, but it seems those are our two alternatives: obese or at best bored, versus running from predators, starvation, and stronger neighbors. Yes, I fully recognize the pessimism of this position.

So, there's an addition to Malthus here. Malthus merely pointed out that when all constraints are relaxed but one, that constraint will limit (and his rule concerned, specifically, energy input as the unrelaxed constraint, but you can imagine for example a dense population of well-fed non-preyed-upon humans being periodically cut down by plagues). The addition is that when all constraints are relaxed, the system becomes unstable, whether that system is a cell (cancer) or an individual. The more powerful the system - which can be approximated by how fast it can change - the faster it will become unstable.

*The first representational system to evolve on Earth was the gene: the proteins it codes for are indirect mirrors of a DNA strand's environment - and as the environment changes, the genes change. As life became more complex, systems appeared that became able to more and more rapidly and/or accurately reflect parts of the environment beyond the replicator: the cytochrome P450 system which is a remarkably non-specific but effective metabolism system (which is how most drugs are broken down even though life on Earth has never seen these molecules before) and the immune system, which produces high-affinity molecules with a process of directed by limited somatic mutation. The ultimate such system however is the development of large numbers of cells signalling with ion channels, which can represent much more information much faster, and in humans has expanded to allow the assignment of arbitrary symbols to novel relationships (language). While we still can't assume that our language-enhanced nervous systems can represent every possible state external to themselves (any more than the immune system can do so), it's still by far the fastest-acting system and the one most likely to spell its own demise. As an aside, it's probably no surprise that plants that have begun to evolve "behavior" of a sort - the carnivorous plants - also use ion channels. Assuming causality is unidirectional, what happens first matters, and therefore so does speed.

Leapfrogging the Failures of C. elegans Connectomics

An argument against the present utility of trying to do brain emulations is that we cannot predict or simulate the behavior of Caenorhabditis elegans, despite having a complete connectome map of its simple nervous system. So why do we think replicating the much more complex human connectome computationally would be any more useful? These criticisms have not stopped some groups from forging ahead. Theodore Wong and team at IBM has now published preliminaries on the most ambitious brain simulation to date, with 10^14 synapses.

Certainly simulating a human nervous system is the end goal of all this, but it seems a lot of money and work is going toward projects when there is a very glaring failure at an earlier level of the same enterprise. As long as your project is being funded by a large institution with deep pockets, you probably don't have to address this question; at least not yet. But if a counterargument exists to "simulating C. elegans doesn't give us anything useful so simulating H. sapiens is also unlikely to do so", I haven't yet seen it.