Bostrom's Simulation Argument

The only time I've touched on this topic is in the exchange below with Bostrom back in 2002.  I soon learned that the idea I was asking about is called modal realism, which encompasses all of the most interesting philosophical implications of the Simulation Argument.

From more recent reading on quantum physics, I no longer have such a firm intuition that a non-zero Planck Constant makes the universe easier to simulate, especially in light of the hacks and optimizations that Bostrom describes. However, I'm still fond my insight -- perhaps true, perhaps even original -- that classical physics should allow in principle for infinite information density.

As a technologist, I tend to think there isn't an interesting possibility of our sort of physics being able to support a simulation of a universe of our sort of physics. The hacks and optimizations that Bostrom talks about -- monitoring a simulation to see what its inhabitants "notice" -- can be recognized as nigh-impossible by anyone who's tried to debug their own software (let alone the simulated mental operations of minds that nobody programmed).

So I think that element (2) -- simulations won't happen -- of Bostrom's disjunct is the most probable, but as a modal realist I already feel sort of like how I'd feel if I believed we were in a simulation.

-----Original Message-----
From: Brian Holtz [mailto:brian@holtz.org]
Sent: Wednesday, March 13, 2002 2:36 PM
To: nick@nickbostrom.com
Subject: anthropic reasoning re: "why is there something rather than nothing?"

Hi. Two quick questions from someone who's enjoyed for several years your work on anthropic and transhumanist topics:

1. Has anyone ever applied anthropic reasoning to the perennial philosophical question of "why is there something rather than nothing?"?

2. Has anyone ever noticed that Planck's Constant being non-zero (i.e. that our universe is quantum rather than classical) could be construed as evidence that our universe is a simulation?

---------------------------------------------------------------------------------

Some details:

On the latter question, the point would of course be that simulating a classical universe to arbitrary precision would be much more computationally expensive (indeed, perhaps impossible) compared to simulating a quantized universe.

On the former question, I notice of course that it is closely related to anthropic cosmological reasoning like that discussed in Ch. 2 of your upcoming book. I'm just wondering if anyone has ever applied applied anthropic reasoning to the logic-motivated "multiverse" of logically-possible universes, as opposed to the quantum-theory-motivated multiverse of physically parallel "universes".

Here is a relevant excerpt from a book (see http://humanknowledge.net) I'm writing:

A possibly meaningful (but unparsimonious) answer to the Ultimate Why is that the universe exists (more precisely, is perceived to exist) roughly because it is possible. The reasoning would be as follows. Absolute impossibility -- the state of affairs in which nothing is possible -- is itself not possible, because if nothing truly were possible, then absolute impossibility would not be possible, implying that at least something must be possible. But if at least one thing is possible, then it seems the universe we perceive should be no less possible than anything else. Now, assuming that physicalism is right and that qualia and consciousness are epiphenomena, then the phenomenology of a mind and its perfect simulation are identical. So whether the universe we perceive existed or not, it as a merely possible universe would be perceived by its merely possible inhabitants no differently than our actual universe is perceived by its actual inhabitants. By analogy, the thoughts and perceptions of a particular artificial intelligence in a simulated universe would be the same across identical "runs" of the simulation, regardless of whether we bothered to initiate such a "run" once, twice -- or never.

An earlier exploration of this idea is this:

Consider gliders in Conway's game of Life.  Even if nobody ever wrote
down the rules of Life, gliders would still be a logical consequent of
certain possible configurations of the logically possible game of
Life. It has been proven that Life is rich enough to instantiate a
Turing machine, which are of course known to be able to compute
anything computable. So if mind is computable, consider a
configuration of Life that instantiates a Turing machine that
instantiates some mind.

Consider the particular Life configuration in which that mind
eventually comes to ask itself "why is there something instead of
nothing?".  Even if in our universe no such Life configuration is ever
instantiated, that particular configuration would still be logically
possible, and the asking of the Big Why would still be a virtual event
in the logically possible universe of that Life configuration.  The
epiphenomenal quality of that event for that logically possible mind
would surely be the same, regardless of whether our universe ever
actually ran that Life configuration. So the answer to that mind's Big
Why would be: because your existence is logically possible.

So pop up a level, and consider that you are that mind, and that your
universe too is just a (highly complex) logically possible state
machine.  In that case, the answer to your Big Why would be the same.

Note that, while the Life thought experiment depends on mind being
computable, the logically possible universe (LPU) thought experiment
only assumes that our universe could be considered as a logically
possible sequence of (not necessarily finitely describable)
universe-states.  The LPU hypothesis also depends on the thesis that
physicalism is right and that qualia and consciousness are
epiphenomena. The LPU hypothesis is of course unparsimonious (sort of
like the many-worlds interpretation of quantum theory), but parsimony
is perhaps inconsistent with *any* answer to the Big Why.  The LPU
hypothesis is incompatible with strong free will (which itself may be
incoherent), but is compatible with weak free will (perhaps only if we
assume there are rules governing the transitions among
universe-states).

The idea that the world might be a dream is of course not new.  But I
don't recall ever hearing that the world might be just a logically
possible dream for which no dreamer exists.

-----Original Message-----
From: Nick Bostrom [mailto:nick@nickbostrom.com]
Sent: Wednesday, March 20, 2002 1:26 PM
To: Brian Holtz
Subject: Re: anthropic reasoning re: "why is there something rather than nothing?"

Hi Brian,

Hi. Two quick questions from someone who's enjoyed for several years your work on anthropic and transhumanist topics:

1. Has anyone ever applied anthropic reasoning to the perennial philosophical question of "why is there something rather than nothing?"?

Derek Parfit touched upon this topic in some lectures he gave in London a few years ago. There is also a mailing list, the everything-list, where this topic has been discussed extensively.

2. Has anyone ever noticed that Planck's Constant being non-zero (i.e. that our universe is quantum rather than classical) could be construed as evidence that our universe is a simulation?

Yes (I think Hans Moravec might have been first, but I'm not sure). My view (see the Simulation Argument paper) is that it is not good evidence for that because the apparent ultimate physics of our universe could easily be an illusion if we are living in a simulation. That is, our simulators could create the appearance that our physics is quantum or classical without actually having to go to the trouble of simulating our world down to such find detail.

All best wishes,
Nick

Mark Clark: Libros Virumque Cano

Hi Dr. Clark, I was a student of yours in the University of Southern Mississippi Honors College starting in 1983, and I also took a second year of Latin from you.  You fortified my lifelong love of learning with the way you treated us undergraduates as peers in your intellectual journey.  You literally changed my life walking across campus one day with your casual question about what grad school I was going to attend.  It was only your assumption that I would continue my studies that prompted me to do so.  That resulted in a University of Michigan M.S. degree that launched my software engineering career here in Silicon Valley, where I met my wife and started a wonderful family.

Thank you!

Brian Holtz
Class of 1987

Appropriating Ground Rent Is Aggression

The standard Libertarian dogma on the needy -- let 'em beg -- is simply wrong.  The best libertarian answer to poverty derives from correcting a standard Libertarian misunderstanding of property rights.  That misunderstanding consists in ignoring Locke's insight that excluding people from the commons -- i.e. enclosing unowned land for exclusive ownership -- is naked aggression if that exclusion does not leave "as much and as good" for others.  Land (i.e. space, locations, sites, sections of the Earth's surface) cannot be created or moved or destroyed by anyone's labor, and so is a different category of property than that created by re-arranging matter.  Land (i.e. spacetime) is the coordinate system, and matter (i.e. mass-energy) is what exists in the coordinate system.  Owning a set of spatial coordinates is fundamentally different from owning the matter that currently exists there.  This seemingly academic distinction turns out to be the key to rescuing libertarianism from self-imposed moral bankruptcy.

In the state of nature there are always marginal but productive sites available for use by the destitute, and faithful historical observation of the Lockean proviso (leaving "as much and as good") should have always ensured that this remained the case even to this day.  To the extent that it is no longer the case, excluding people from access to the natural productive opportunities on what used to be the commons is unjust -- i.e. is aggression.  Standard anarcholibertarianism seeks to institutionalize this aggression -- ironically doing so in the name of de-institutionalizing aggression. The aggression that it institutionalizes is a subtle one called the appropriation of ground rent.

Ground rent is the advantage you get from exclusive use of a site compared to the most productive available site that is not in use.  In effect, ground rent is the extra income a site earns because of the exclusivity of its location within the community, as compared to what such a site would earn at the edge of the community.  Technically, ground rent is is the extra income obtained by using a site in its most productive use, compared to the income obtained by applying equivalent inputs of labor and capital at the most productive site where the application doesn't require (additional) payments for use of the site. Thus ground rent doesn't include the income from any labor-based site improvements -- buildings, irrigation, swamp drainage, etc.  Instead, ground rent includes just the benefit a site derives from the surrounding community by forcibly excluding them from it.

Geolibertarians say ground rent should be considered part of the commons (like the atmosphere, EM spectrum, etc.), with each individual having an equal right of access to it.  In practice, the way to undo the aggression of site monopolization is through a land value tax.  This allows a government to finance both rights protection and aid to the indigent, all without any force initiation.   The fundamental principle is that each person has full rights to his body, labor, peaceful production, and voluntary exchanges, but he must compensate those whose access he impairs when he monopolizes, consumes, pollutes, or congests a natural commons.  Details and references are available at http://EcoLibertarian.org.

World Philosophy Day

Yo dude, thanks for the link.  I didn't know it was World Philosophy Day. Your BBC article covers four classic questions, each of which I've written about before.

1. This is called the Trolley Problem, and I use it on fellow libertarians a lot. The crucial consideration is how much freedom you have in choosing who is the one who will be sacrificed to save the many.  If circumstances (or a bad guy) picks the one, then the right answer should be clear. Otherwise, you need to set up a lottery, and you need to weight things according to expected lifespans, objective quality of life, impact of the losses on others, risk of setting precedents, etc.  Luckily, these tragic "lifeboat" scenarios pretty much never happen, and that is why we're not used to making the hard choices involved in them.  The choices would be emotionally hard, but they're not philosophically paradoxical.

2. This is called the problem of Theseus' Ship.  The answer I give in my book is: "A given entity is identified through time with its closest close-enough continuous-enough continuer. A continuer is an entity which is similar to a previous entity and exists because of it. A continuer is close enough if it retains enough of the original entity's properties. A continuer is closest if it retains more of the original entity's properties than any other continuer. A continuer is continuous enough if there is no extraordinary discontinuity in its relationship to the original entity."  This whole topic of identity (including forked and joined identities) is covered in one of the best philosophy books I've ever read: The Metaphysics of Star Trek.  If I haven't bought you a copy before, then you're getting one for Xmas.

3. Yep, there is no absolutely certain synthetic (i.e. empirical) knowledge.  We've known this since Hume.  As I say in my book: "All synthetic propositions (including this one) can only be known from experience and are subject to doubt."  The crucial thing is to understand the level of confidence to assign to synthetic propositions, and to understand the ways in which they might be false.

4. The problem with free will is that people think of their mind/soul as something apart from the universe, rather than as a subset of the universe.  I write: "Free will is either of the doctrines that human choices are a) determined internally rather than externally (volitional free will) or b) not pre-determined at all (indeterminate free will).  Determinism is incompatible with indeterminate free will, but is compatible with volitional free will if agents have internal state that influences (and thus helps determines) their actions."

These are great classic problems.  Another really good mind-twister related to free will is http://en.wikipedia.org/wiki/Newcomb%27s_paradox.  Infinity is also a great mind-bender, such as the way it lurks in http://en.wikipedia.org/wiki/St._Petersburg_paradox.  I bet you would like http://en.wikipedia.org/wiki/Doomsday_argument.

Yes, I've tivo'd Parallel Universes, can't wait to watch it.  I'm a big fan of modal realism -- the theory that possible universes are just as "real" as this one.  It's related to the biggest of all philosophy questions: why is there something instead of nothing?  My answer: "A merely possible universe would be perceived by its merely possible inhabitants no differently than our actual universe is perceived by its actual inhabitants. [Modal Realism says "actual" just means "in this universe", and so is redundant when talking about our universe.] Thus, our universe might merely be the undreamed possible dream of no particular dreamer."

The Market Failure in K-12 Education

The primary market failure I see in K-12 education is that poor minors needing tuition money are not allowed to enter into long-term contracts that surrender a fraction of the alleged increase in earnings that a tuition investment would buy them. If education investments are as wise as we liberals claim, then such contracts should be able to make education for the poor self-financing. In the absence of such contracts, I don't mind the geolibertarian citizen's dividend financing tuition vouchers (or land value tax credits for tuition donations to) for poor families. There is no more need for the government to own and operate schools than to own and operate grocery stores.