[extropy-chat] Analyzing the simulation argument

Thu Feb 17 15:10:10 UTC 2005

--- igoddard at umd.edu wrote:

> The hypothesis that the universe could be a computer program 
> is attractive, but Dan may be right that it's unfalsifiable 
> (and thus pseudoscientific). If we and our universe are a 
> computer model (CM), we do not know reality. If we don't 
> know reality, we cannot specify what our universe fails to 
> be in order to establish falsification criteria for a CM 
> hypothesis. In other words, it seems that I cannot say, "If 
> the universe was not a CM, then it would be like x," for 
> what could possibly warrant my knowledge of x? From this it 
> seems to follow that even if the universe is a computer 
> model, we'd never be able to absolutely confirm it because 
> we could not distinguish it from something that we, as 
> artifacts of and within the computer model, do not know.

On the contrary. If this universe were a simulation, then everything
about it would be a product of the physical characteristics of the
originating universe. One problem with this discussion is that many
participants have a very biased view of what a 'simulation' is that is
colored by their experiences with human simulation technology to date.

It is like saying  in the middle ages "this universe is a chessboard".
The pieces are so different from humans that one automatically assumes
that those who play our game must be significant different from us and
their world must operate by much more complex rules than ours. The
problem with this position is in the first conception of what is meant
by 'chessboard'. Computer game players today are so used to having god
powers or using magical spells in the cheap sims we have today that
they automatically assume that the sort of sims we talk about in the SA
are as capable of operating by magical rules. Magic is possible in
current day sims, and not in this 'real' world because magic doesn't
HAVE to follow any physical laws, nor do sims which allow magic have to
follow any consistent internal set of physical laws that explain
everything.

Making a sim that is so internally self consistent as ours is going to
require its own TOE, theory of everything, that is not self
contradictory. Essentially, the set of all possible such universes can
be described in M theory, although fanciful physicists might devise
other TOEs that apply equally well to other possible sets of universes.

Secondly, the whole concept of 'brain in a vat' or 'body in a pod'
participants is similarly infantile, but is all too common among SA
critics. This is the Matrix concept, that our reality is merely a set
of data streaming into minds that have a real existence in the root
universe that spawned this one. This is a rather peruile way of
conceiving such a simulated universe that falls significantly short of
the mark of the kind of technology required to simulate a universe such
as ours.

Rather the sort of universe at a level of complexity that ours is
requires one of two possible methods of simulation: quantum computation
in pocket universes, aor quantum computation through matter ballistic
conversion in gravitational singularities. There may be other methods
to achieve this end, but it is certain that the computational needs of
a universe like ours to exist are far greater than can be done by the
sort of computational technology we are used to conceiving.

Any possible universe described by M theory would require roughly
similar magnitudes of computation.

> 
> Hal Finney wrote: 
> >
> >The simulation argument is not an assumption.  It is an 
> >argument. It is logic, not science.
> 
> 
>  But since the simulation argument makes empirical claims 
> (ie, claims about the apparently real physical universe) it 
> is properly subject to scientific-knowledge criteria such as 
> the necessity of falsifiability. While it may fail there, it 
> could prove to make useful predictions about the universe, 
> but at best that only confirms that the universe behaves 
> like a computer, not that it necessarily is a computer. 
> Things that can't be falsified can't really be known.

Well, if our universe is a simulation, we should be able to communicate
to its sysop/root, but not necessarily would we be able to hear
anything back, even if the root wanted to.

It might be said that (and this explains the Fermi paradox as well) the
first civilization to reach such a level as to figure out how to
communicate to the root triggers the end of the sim, however that is a
tiresomely solipsistic view of things that is contradicted by our
apparently immense unimportance in the universe.

> >The simulation argument can be expressed in the form, 
> >if A and B, then C. The argument's validity depends only 
> >on whether it is true that A and B together imply C.  An 
> >argument is valid if its logic holds.
> >
> >The validity of this kind of argument does not depend on 
> >the truth of C. The argument may be valid even if A or B 
> >were false.  Only if the argument is valid, and A and B 
> >are both true, can we deduce that C is true.
> 
> 
>  But "if A and B, then C" is a conditional statement, not a 
> logical argument schemata. A valid argument is one where if 
> the premises are all true, the conclusion must be true too. 
> So if the premises of a valid argument are not all true, the 
> conclusion is not necessarily true. For example:
> 
> 1. If unicorns do not exist, then Batman exists.
> 2. Batman does not exist. 
> __________________________________
> 3. Ergo, it is not the case that unicorns do not exist 
>   (so by double negation unicorns exist). 
> 
>  That argument schemata (modus tollens) is valid, but the 
> argument is bunk since premise 1 is false. I don't think the 
> SA argument (as you state it below and assuming it's valid) 
> can assure us that all the premises are true and so it might 
> be no better than the valid unicorn argument above.

Sure, but you need to provide a rigorous reason why it is bunk, because
the SA seems to be based on premises which are generally considered
valid, to the limit of our current knowledge. The only real variable is
whether posthuman civs would attempt truly realistic sims, which is
really not that hard a premise to take as a given.

> >In the case of the SA, A = "the human race is unlikely to 
> >go extinct before becoming posthuman"; B = "any posthuman 
> >civilization is likely to run a significant number of 
> >simulations of their evolutionary history (or variations 
> >thereof)"; C = "we are likely to be living in a computer
> >simulation".
> 
> 
>  Obvioulsy we can express that as the argument:
> 
> 1. The human race is unlikely to go extinct before becoming 
> post human.
> 2. Any posthuman civilization is likely to run a significant 
> number of simulations of their evolutionary history (or 
> variations thereof).
> ______________________________________
> 3. Ergo, we are likely to be living in a computer simulation.
> 
> 
>  But we can't really evaluate the logical validity of that 
> argument until it's formalized and the premises do not lend 
> themselves to obvious formalization. But here's a shot:
> 
> 1. Ex(Hx) -> Ex(Px)
> 2. Ex(Px) -> Ex(Sx)
> __________________
> 3. Si
> 
>  Fleshed out in words and adding tense:
> 
> 1. If some things are humans, then some things will be post-
> human.
> 2. If some things will be post-human, then some things will 
> be human simulants.
> _______________________________
> 3. Ergo, I am a human simulant. 
> 
> 
>  Is there a preferable formalization (it's not my argument 
> so I could be missing it's intent and proper logical 
> structure)? This obviously fails to convey the uncertainly 
> expressed in the SA, but if we want to rest the SA on 
> logical validity, there should be a logical formalization.

Because you aren't involving the Bayesian probabilities in your
formalization that describes the leap from 2 to 3 that is inherent. I
would instead say:

2. If some things will be post-human, then some things will tend to be 
be human simulants.

=====
Mike Lorrey
Vice-Chair, 2nd District, Libertarian Party of NH
"Necessity is the plea for every infringement of human freedom.
It is the argument of tyrants; it is the creed of slaves."
                                      -William Pitt (1759-1806) 
Blog: http://www.xanga.com/home.aspx?user=Sadomikeyism

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