Yes, guys, it was me all around. Funny that it took you so long to find out. I kickstarted this big simulation as a weekend hack and let it evolve for a month, so I could come and play as Warren Beatty.

Can we now, as a universe, move on?

 * * *

Now, I'm not protesting that we talk this. It's fascinating stuff. It's funny to recognize in this thread some of the same crazy ideas that would get people shuffling away from me at parties, like 'what if our whole known universe is but an atom inside other universe, which in turn [...]?'

Re: worlds simulated inside worlds, aka the Matrix, aka Plato's cavern- when I did work on a MMOG we had this conversation once or twice that if we gave our non-player characters ability to learn and communicate for an arbitrary length of time, eventually they'd come up with theories like "Every object in the universe has an unique ID, which is a 64-bit integer". And they'd wake up after a downtime and comment things like "gee, finally capacitor recharging is fixed!", and then stop and wonder about the deep meaning of that.

Re: internet and cybernetic consciousness: when I first learned about the internet, one of my first thoughts is that the interconnected computers would create a new consciousness, or an ecosystem of competing consciousnesses. Not that it would be pursued, but that it would happen spontaneously, just like life evolved out of the primordial soup.

Then I thought that something similar would happen as a result of connecting so many people. Now, it's been always like that to some extent (cultures, memes, ideologies, etc. can be thought of as supraindividual consciousnesses), but the instant communication would make it more ostensible and powerful. Just like oxidation and explosion are instances of combustion, yet the difference in speed makes it counterintuitive for us to recognize any sameness between them.

Fast-forward to 2007: for about a year, the global hivemind has been thinking intensely about cats with captions. Who knows what deep intentions hide behind this?

Some people are reported to have survived with only one hemisphere of the brain. It's not a huge stretch to imagine that you could transplant into yourself all needed duplicates or artificial replacements for vital organs, then split yourself in two so both halves survive, with one of the brain hemispheres each.

Then, there are two new independent yous there, neither of them being quite like the old you, neither of them feeling the other you as yourself anymore, but both of them independently feeling themselves as you. Stop and imagine this situation. How do you think you'd feel? How do you feel now, thinking about it?

Now let's leap a bit from the medical to the philosophical: let's abstract the fact that parts of the brain are specialized. Assume that we could do other partitions but left-right, or suppose that brains will rewire to make up for lost functionality. Imagine it's actually true that 90% of our mental power usually goes to waste, and that we could lose half of the brain and somehow mostly make up for it. Or imagine that it's possible to make a perfect copy of yourself, as proposed elsewhere in this thread. The result is the same: there is another you out there, virtually identical, with the same past, but which you don't feel as you anymore.

How do you feel about that other you?

Interesting thought experiment nonetheless.

I think where it's easy to believe the simulation theories is where they're so in line with what our brains do on an everyday basis. We simulate reality when we're getting ready for the day and deciding what to wear. Or when our stomach rumbles for lunch and we mentally compare General Tso's finest masterpiece against the toasty cheese of Quizno's. Indeed, I'd argue that the human brain is at it's best as a simulation engine - predicting the future and understanding the present based on past experiences

Don't fall for the 90% myth. We can't be sure where it came from, but it simply isn't true. The brain is a simple organ only in the sense that if you don't use it, you lose it.

Consider: You were born with 10x the number of cells you end up needing. The ones that survived are ones that found connections and strengthened them with their neighbors.

Indeed, that's what makes "mind transplants" so difficult to pull off. Your mind is a unique product of your development.

Now, neural implants for boosting abilities and restoring function after damage....

An interesting property of a simulated brain is the simulation can take an arbitrarily long amount of time. You can update in virtual "Planck timesteps", even if in real time this takes a million years. Any simulated brain won't be able to tell, because it doesn't get any updates in between these steps. Time becomes a property of the system you're simulating... Just like in reality.

It might take until the Sun goes Red Giant to run your single lifetime simulation.

The speed of light is a convenience for updating the simulation in discrete steps. Particle/wave duality "deciding" upon observation is just lazy evaluation, like in Haskell. Quantum entanglement is no mystery when distance is virtual. A Universe where the speed of light is a hard limit can still contain a simulated Universe where it isn't.

Why do we want virtual worlds? Properly implemented and convincing, we can do away with suffering altogether. We can "live" in a world that seems fully real, but in which no-one is actually suffering because everyone else is simulated. All our needs are met and all our desires are fulfilled.

The mistake we keep making is that in order to create convincing AIs to inhabit the world with us, they actually become as sentient and conscious as we are; being virtual is no barrier to feelings or emotions! [1]

Thus our creations want to create a simulation to live in themselves, so they won't suffer, either, and so it goes like a perpetual zoom on a fractal set.

[1] To convince yourself of this, consider a matter replicator that copies every single atom in your body. You'd create a clone. It would be thinking and feeling just as you do. Now consider a computer simulation of a single atom; if that can be done, then by extension, it would be possible to simulate anything made of atoms. A simulated clone of you would also behave the same. The neurological activity that occurs in your "real" brain when you feel or think would also occur across the virtual atoms in the brain of your virtual clone. In fact, that would involve real electrical activity taking place among real atoms making up the RAM chips and CPUs "containing" the simulation of the virtual clone. Thus any simulation at the same scope or nesting level as yourself is as real as you are and therefore its feelings are just as valid. [2]

[2] By further extension, if your simulations are as real as you are, then your simulation's simulations are as real as it is, and thus a simulation at any nesting level is as real as one at any other -- a simulation inside a simulation is still running on real atoms with real electricity!

Not true. Consider the anthropic principle, which says that we must be in a universe that has parameters such that we could come into existence in the first place if we are here asking this question. In other words, we couldn't ask the question unless our universe had the "right" parameters to begin with.

Far better explanations of the Anthropic Principle are available at: http://www.anthropic-principle.com/ http://en.wikipedia.org/wiki/Anthropic_principle

Impractical to do on current computers - we'd need at the very least quantum computers (I'm guessing that's what the article means by "Some computer experts have projected, based on trends in processing power, that we will have such a computer by the middle of this century").

But you still run into physical limitations. Could one atom in a quantum computer be used to simulate more than one "virtual" atom at a time? More than O(n) virtual atoms? Do you run out of atoms eventually? Can you actually get infinite recursion that way? I certainly don't know, and I'm not sure whether the best quantum computing researchers can answer today.

Failing that, we'd need something more advanced than quantum computers - so really, at that point we're simply guessing.

Very fun philosophical subject, but I wouldn't go as far as saying it's "almost a mathematical certainty" yet, given our current knowledge...

That's the beauty of it: "at a time" can be arbitrarily long in real time. [1]

You don't even need to simulate every particle in the Universe -- if the simulation is run for you, you only need to simulate enough to convince your brain. Like when you dream and are convinced something's real, yet upon waking, you realize your criteria were extremely lax. For all we know, what we think of as being awake is actually a very hazy simulation presented to our "real" brains, which are actually much sharper and have been induced into a less-discerning state.

Something very interesting at Body Worlds 3 here at OMSI was the brain slices, which showed (according to the placards) that the part we "think with" is just the edges, and the interior is interconnections (grey matter vs. white matter). Compare the darker grey around the folds to the lighter grey filling up the rest:

http://www.med.harvard.edu/AANLIB/cases/caseB/054t_2.gif

So the actual storage needed for a brain's total memory may fit onto a hard drive today, at current estimates (possibly less than a terabyte). Working memory is much, much less. Communication (the interconnections) can take as long as needed.

[1] Another "cheat" would be to put the simulator on a spacecraft travelling at relativistic speeds in a tight orbit around a processing unit; when the simulator sends the processor packets of data to crunch, time dilation would give it extra CPU time.

Let's assume it's true that I can make a logically equivalent copy of myself somehow, and put it in a world where it won't suffer. How does that help the original instance of me, in this world?

Just knowing that it feels is not enough. I believe that this guy that stuffs himself with drugs and does Kate Moss feels (and probably feels quite good, much of the time). But when I suffer, thinking that other people are having fun is only of marginal consolation.

Finally, you can't say a simulation is real without emptying the word 'virtual' of meaning- and by extension, the word 'real' itself. By the same token, our imagination consists of systems in the electrochemical and topological mess that are our brains, so everything we imagine is 'real' too. If we allow this, how is the concept 'real' different from that of 'everything'?

Cf. The Matrix. Except with enough processing power, instead of sharing a simulation, you have it all to yourself -- so you can always be the #1 Most Important Person in the world, if you wish. Everything will work out the way you want it to, whatever your particular ethos; you'll set things to rights. AIs will be programmed to seem like fully convincing humans, but secretly they'll be on virtual happy pills so they'll never suffer.

It would be easier, as the article suggests, to just stimulate the spots in the brain responsible for pleasure. If the point is artificial happiness, why all this simulation stuff at all?

If you only want to stimulate pleasure centers, no need for expensive equipment -- just use poppies. If addiction is a problem, then presumably there is more to life and hence a reason to simulate after all.

What a ridiculous conclusion. It seems to me, the logical way to handle this is to simulate an entire universe, galaxies to atoms.

That might sound like it requires an impractical amount of processing power... but only to us _inside_ this universe. If you think about it, it's obviously impractical to simulate an entire universe within the universe itself.

In our parent universe, this wouldn't be an issue. Their speed of light must be faster, their atoms smaller. Moore's Law continues apace for them, and they can build computers that seem unthinkably powerful to us.

And the weirdness of quantum physics shows the kind of hacks they've made to get it to run.

I'm thinking about writing a short story where a guy implements a universe in 7 days...

Nick Bostrom is an influential transhumanist philosopher. http://en.wikipedia.org/wiki/Transhumanism

"This article seems like a dumbed down version of stoned CS majors ramblings... bah"

Non "dumbed down" version of the ramblings: http://www.simulation-argument.com

But to see something like this published in the NYT...that was a bit surprising. Interesting, though.

Yeah. Normally it's the stuff of 2AM dorm room bull sessions.

Another somewhat related short story - "The Last Question" by Asimov:

http://www.multivax.com/last_question.html

He also has some other cool stuff, like this "Letter From Utopia": http://nickbostrom.com/utopia.html

I then usually eat a sandwich

What's the definition of computer, exactly? Even without any magical circular reasoning, the computer built on atoms and physics that we're being simulated in is just as deterministic as the computer I'm using, so I'm not sure I even see a difference.