Seriously, who would simulate me?
From time to time I run across something that just shocks me, not because of the thing itself, but because the thing is so completely something I should have known about and yet have somehow missed. How does a philosophy argument about things that interest me greatly go on for years without my hearing about it?
Today’s example of this is Nick Bostrom’s Simulation Argument.
How could I have missed this? It’s so completely in my wheelhouse, and it’s been around forever in Internet time1, and yet it’s something that I’ve just encountered for the first time this week.
You can follow the link over to the Simulation Argument page for the original paper, a myriad of related information, and some commentary.
The argument essentially says that if you assume that our society has a decent chance of surviving to the “posthuman” stage, and that you assume that posthuman civilizations (or at least some small number of members thereof) would be interested in running a significant number of simulations of their evolutionary history, then it follows that the odds are very good that you are actually living in a simulation. (Actually, he kind of makes the reverse argument that if you don’t think it’s likely that we’re in a simulation, then you must believe that either we won’t make it to posthuman, or that no posthumans would be interested in doing simulations, but the forward case will work for starting a discussion.)
The logic is pretty inexorable: a posthuman civilization has access to adequate processing power to run a very, very large number of simulations very easily, even if only one individual is doing it (and obviously, a larger effort at the simulations would mean a correspondingly larger number of them being run). The number of simulations rapidly outnumbers the number of actual people, and suddenly it’s more likely that any given experience is that of a simulation than an actual ancestor.
In the source paper, Bostrom goes into some detail on this, but if you don’t want the whole paper, but can take a two page summary to make this clearer, Bostrom has provided one.
I don’t know how I missed this: probability theory, the old “brain in the vat” thing, posthuman/post-Singularity speculations, etc. It’s right up my alley. Hell, you could argue that it’s tangentially related to Russell’s travels through phenomenalism.
Oh, and my favourite bit of the original paper?
It may be possible for simulated civilizations to become posthuman. They may then run their own ancestor-simulations on powerful computers they build in their simulated universe. Such computers would be “virtual machines”, a familiar concept in computer science. (Java script web-applets, for instance, run on a virtual machine – a simulated computer – inside your desktop.) Virtual machines can be stacked: it’s possible to simulate a machine simulating another machine, and so on, in arbitrarily many steps of iteration. If we do go on to create our own ancestor-simulations, this would be strong evidence against (1) and (2), and we would therefore have to conclude that we live in a simulation. Moreover, we would have to suspect that the posthumans running our simulation are themselves simulated beings; and their creators, in turn, may also be simulated beings.
That’s like a PKD short story in one paragraph.
I’m definitely going to have to chew through the rest of Bostrom’s stuff now.
- This means “since 2003″ in this case.(back)
George
Kira
March 23rd, 2008 at 4:42 pm
The flaw is in assuming that a posthuman civilization would necessarily be interested in running such simulations. Odds, I would argue, are not good - they are by definition smart enough and knowledgeable enough that their need for such a thing would be unlikely at best.
March 23rd, 2008 at 5:10 pm
Well, it’s not a “flaw” per se, since the argument is of the form “if 1 & 2 then necessarily 3″, not an assertion of 1 & 2.
But, he has pretty convincing argument in the original paper about just that point–essentially you need to think not “the societies as a whole would not be interested in doing this”, but rather “not a single entity would be interested in doing so”. Here’s the bit:
May 8th, 2008 at 12:26 am
[...] Nick Bostrom? And remember the Drake [...]