[ExI] The Many Dimensional Sculpture, or dont' bother about runtime

[Bryan Bishop]

On Tuesday 11 March 2008, Lee Corbin wrote:
> In an intriguing essay, Rafal discusses "identical copies" and
> whether their runtime, calculated separately and summed, is
> meaningful or important.
>
> One ultimate purpose of philosophy, and I argue the most important,
> is be prescriptive. Philosophy most vitally---for me and for many
> others---should instrucs us about what actions to take and what
> decisions to make.
>
> I don't have time to digress on modal reality, and the way that I
> think that it's subsumed by the Many Worlds Interpretation of quantum
> mechanics. In short, MWI so far as I can tell, provides a complete
> model for modal reality. The Wikipedia articles on "modal reality"
> and "ultimate ensemble" are very clear, and good. If someone wants to
> start a new thread about that, fine. I could stand to be corrected
> here.

I would not have expected an implicit connection between MWI and modal 
realism per Rafal's message. However, I took this opportunity to go 
look at the Wikipedia article and I see what you mean:

> Modal realism is the view, notably propounded by David Lewis, that
> possible worlds are as real as the actual world. It is based on the 
> following notions: that possible worlds exist; possible worlds are not 
> different in kind to the actual world; possible worlds are irreducible 
> entities; the term "actual" in "actual world" is indexical.    

Hrm. I really would like to add some Leibniz in on this. How could 
possibilities be as real as actualities? Let me reform my question. Is 
he saying that possibilities exist in the sense of mental constructs, 
such that one's lack of knowledge of the world essentially makes the 
world both the 'real' and the 'possible' as you recursively explore it 
and make your own representation? A vague, fuzzy set of what the world 
may or may not be, allowing subjective agents to explore it without 
messing up too much. Or is he saying that, metaphysically, the 
possibilities are as real as anything else? Charles S. Peirce would 
have something to say about this use of the word 'possibility' since, 
naturally, it is more tied to the human mind, and he really, really 
disliked anybody saying something was 'possible' when they did not have 
the true source code to the universe to figure out the likelihood of 
something occuring or whether or not something was truly valid given 
whatever underlying laws of the universe there exist (whether a 
cellular automata rule or not, just so I can get in my mention of 
Wolfram and von Neumann etc.). 

Is Lewis saying that possibilities exist (in the sense that a mental 
agent can rationalize that something might be 'possible' given his 
limited understanding of the greater world), or that if we allow 
such 'possibilities' we automatically must acknowledge their full and 
total existence? 

I like to use Leibniz's optimism and his definitions from time to time:
1) real - necessarily existent
2) impossible - necessarily nonexistent
3) possible - unnecessarily nonexistent
And a few others. I realize now that I cannot recall a link that 
explains this terminology, but I do think it is still useful here since 
it ties possibilities/reality/actuality back to terms re: necessity and 
coherency.

> > This form of self-correlation may be the necessary (although
> > perhaps not sufficient) condition for  conscious experience. So you
> > could say that consciousness is a property of self-correlated
> > structures, existing timelessly as parts of the larger branching
> > chains of world-states.
>
> I presume that these are the SAS (self aware structures) described by
> Tegmark.

Why would SASes be needed? If anything it should be more like an 
observer bias to calculate out due to the anthropic principles and so 
on, since all subjective agents would present a slightly different bias 
in consciousness or awareness; in more hard scifi terms, I'd argue that 
consciousness may not even exist, despite my experience and my mind, 
it's not a magical sauce. :)

> > Like a GLUT (Giant Look-Up Table) of you? And this is the only
> > you, the one and unique representation and the time/place of your
> > consciousness?
>
> Of course, as you know, this is at extreme variance with our
> normal usages of the words "you" and the time/places of your
> consciousness. For example, either under modal realism or the
> MWI, something extremely similar to me (under the conventional
> meanings of words) actually received a phone call a few minutes
> ago, and so is not typing this. It's a "possible world" under
> modal realism, and equally real under the MWI. Below, you use
> "versions of you" to talk about, for example, those Rafals who
> get to live forever, or those Lees who got a phone call.

I was not expecting this diversion. Given the distinctions I made above, 
if we discuss them some more, and it turns out that Lewis and his modal 
realism is more about subjective agents and their GLUTs, rathe than a 
metaphysical ensemble, then I think that you would have to drop your 
MWI tie-ins. On my first passing of Rafal's email, it seemed to me that 
the ensemble that he was describing was merely explanatory, and not 
necessitating MWI or even itself -- merely as a way to describe data 
structs in the world that we experience on a more abstract level.

> (Now I am actually very sympathetic to a definition of "you" that
> states that "you are a fuzzy sphere in the space of all algorithms",
> and that (a version of) you traces out some particular path over
> time. This moving point may leave the sphere so far behind that
> "you become someone else".)

That's interesting; perhaps we are tracers running through paths in 
design space, computing the shortest and longest paths all in the name 
of computer science, graph theory, topology, etc.

> Now on your usage of words, he and I and all the Lee's who
> were/are fighting in the Second World War, are simply a part
> of the great Tree of Me. An immediate difficulty you might want
> to address is, "Does the tree of Lee overlap with the tree of
> Rafal?"  If not, why not?  My own "fuzzy spheres" do allow
> for overlap at their extreme edges.

Are not all things, somehow related, if not physically then at least in 
our minds? Somebody might reply to this saying "try to find a 
correlation between X and Y" and that would only serve to show that 
somebody has in fact made that correlation, and the more that people 
read that email, the more 'real' it is becoming (I do not mean to say 
that popular approval increases the realness, merely that the content 
is diffused over the surface area of the local reality, so it is 
becoming more than the 'nothing' that the original emailer was hoping 
to select for).

> > Since every thought and desire correlates with the shape of the
> > tree throughout its extent, I see my thoughts, desires and actions
> > as a form of sculpture. It is as if time existed, and my decision
> > to write this post changed the shape of some branches of my tree of
> > life....
>
> Yes.  We both know enough not to be distracted by the apparent
> but false connection to Free Will vs. Determinism.

Re: Free Will vs. Determinism. They do not seem to be at ends with each 
other. The best solution is to assume you have free will. Maybe we can 
start another thread for this, if we haven't come to this conclusion 
before.


> > A million brains running exactly the same thought, down to the
> > quantum level or below, is only one brain. A million brains that
> > are similar enough to produce the same macroscopic-level
> > thoughts, words and actions but differing at the quantum scale
> > may represent true copies but personally I don't care about them
> > - they do not differ in the higher-order correlations I mentioned
> > above as necessary for consciousness.
>
> Bryan exploded at this point: "What? A million brains doing the

Indeed. :)

> [exact] same thing is really the same thing? I do not see how
> that can be true."  Rafal, who never mentions measure, just
> makes the logical point that the "Tree of Rafal" has no new
> distinct branches when copies are made that are so exact
> that they do not make different thoughts.

I suppose. But he also mentions that this is impossible when he 
says "you can't copy me," so I guess he resolved that scenario on his 
own.

- Bryan
________________________________________
Bryan Bishop
http://heybryan.org/