Re: "Morality" in a Block Multiverse

[scerir]

> Hal
> You can also have a "block universe" in QM with the many-world
> interpretation.  It has a more complicated geometric structure but
> philosophically it is deterministic, with the same issues regarding
> changes, free will, etc.

I'm not an Everettista, anyway let us try. Alice has photon 1, which is in a
certain quantum state, unknown to Alice and unknown to anyone else.
Let us say that this unknown quantum state is
|psi>_1 =  a |0>_1 + b |1>_1
with |a|^2 + |b|^2 = 1
and where |0>_1 and b |1>_1 represent two orthogonal quantum states
and a and b represent complex amplitudes.

Now Alice wants to "transfer" (I say: "transfer") her quantum state to Bob,
which is remote, so she can not directly deliver it to him. But, fortunately,
Alice also has a pair of entangled photons, let us say the photon 2 and the
photon 3, and she already gave the photon 3 to Bob, who still has this particle.
Leaving apart normalization factors we can write that the total state of those 3
photons is
|psi>_1,2,3 =
( |0>_1 |1>_2 - |1>_1 |0>_2 )(- a |0>_3 - b |1>_3 ) +
( |0>_1 |1>_2 + |1>_1 |0>_2 )   (- a |0>_3 + b |1>_3 )  +
( |0>_1 |0>_2 - |1>_1 |1>_2 )( a |1>_3 + b |0>_3 )  +
( |0>_1 |0>_2 + |1>_1 |1>_2 )   ( a |1>_3 - b |0>_3 )

Alice now performs a measurement on photons 1 and 2 and she "projects" her
two photons onto one of these four states below:
( |0>_1 |1>_2 - |1>_1 |0>_2 )
( |0>_1 |1>_2 + |1>_1 |0>_2 )
( |0>_1 |0>_2 - |1>_1 |1>_2 )
( |0>_1 |0>_2 + |1>_1 |1>_2 )

And consequently Bob will found his photon in one of these four states below
(- a |0>_3 - b |1>_3 )
(- a |0>_3 + b |1>_3 )
( a |1>_3 + b |0>_3 )
( a |1>_3 - b |0>_3 )

Now Alice, who wants to "transfer" the unknown quantum state of photon 1 to
Bob, must inform Bob, via a classical channel, about her measurement
("projection")
result (on photons 1 and 2). So Bob can perform (25% of times it is not
required)
the right simple unitary transformation on his photon 3, in order to obtain the
initial
quantum state  |psi>_1 =  a |0>_1 + b |1>_1

Note that Alice does not get any information, from her measurement, about the
quantum state she wants to "transfer" and about the values of those a and b
amplitudes. Note also that during Alice's measurement photon 1 loses his
original quantum state, as required by the no-cloning theorem.

Ok, that was the basic teleportation (= trasportation) of a quantum state from
Alice to Bob.

Now something strange happens in the MWI version. Alice's measurement does not
"project" the superposition of
( |0>_1 |1>_2 - |1>_1 |0>_2 )
( |0>_1 |1>_2 + |1>_1 |0>_2 )
( |0>_1 |0>_2 - |1>_1 |1>_2 )
( |0>_1 |0>_2 + |1>_1 |1>_2 )
onto just one of these quantum states (above). They all exist. And all these
quantum
states (below) also exist
(- a |0>_3 - b |1>_3 )
(- a |0>_3 + b |1>_3 )
( a |1>_3 + b |0>_3 )
( a |1>_3 - b |0>_3 )
and one of them (1 over 4 = 25% of times) is the same quantum state that Alice
wanted to "transfer" to Bob.

Thus it seems that in the MWI of teleportation the quantun state it is not
"teleported" or "trasported" but it is already "there", and it is already
"there", in one of those branches, from the beginning. This stuff reminds me of
the "block universe", at least a bit.

s.

[still not an Everettista] :-)

Pointers to places in vast spaces

[Tim May]

On Wednesday, July 10, 2002, at 07:24  AM, Stephen Paul King wrote:
>

> I can't seem to get the idea out of my head that information can not
> just refer to information itself but merely can encode the "address" of
> where and when it can be found - this is how I think Goedelization 
> works.

This is quite correct in many important respects.

Here's an example.

Consider the space of all strings (DNA, RNA) which make up living 
things, from bacteria to reptiles to humans, and perhaps to other 
organisms, past, present, and future. Even assume that this space 
contains strings for beings which are "possible" (would be living if 
they were instantiated, made, grown) but which have never existed in the 
past and don't exist at present.

I usually draw this on a blackboard or sheet of paper as a 
two-dimensional plot, with the x- and y-axes not explicitly labeled. If 
it helps, consider the x-axis to be something like body size in cc, the 
y-axis to be something like total number of neurons, and so on. Clearly 
these axes are just extreme simplifications.

But what one can reasonably see is that in this space there are places 
where the single-celled organisms live, "islands" for the reptiles and 
birds, islands for the mammals, and some region where homo sapiens is 
found.

Now humans have something like 4 billion base pairs in the genome. I 
don't recall what the conversion is from ATCG sorts of base pairs to 
bytes, but it's within a small factor, so something like 4 GB or 32 
Gbits represents the human genome. Fits on a handful of CD-ROMs, 
uncompressed.

But this is not the full story. This 32 Gbit sequence is effectively a 
_pointer_ into a space of 2^ (32 Gbits) points, the space of all strings 
of the same length as the human genome. (And the space of all living 
things is even larger, as it includes all strings of our length, plus 
all orderings of shorter strings. If we include beings with even longer 
strings, it gets much bigger, of course.)

Where living things in this space can be found depends on many other 
things, including the environment around the living thing (e.g., a 
lizard in a desert which only eats wheat or rice cannot live, and did 
not ever evolve).

In Bennett-type terms, the strings of living things have great logical 
depth. They evolved, changed, got more "complex" (in the logical depth 
sense) as the phenotypes competed, lived, reproduced, etc.

In a sense, the genome is a _pointer_ to a particular address in that 
vast space of all possible living things. (Just as the library call 
number of "War and Peace" is much shorter than the actual text of "War 
and Peace.")

(Completely aside: We even have some ideas about the topology and 
geometry of "life space": we know something about what "nearness" means, 
through single-point mutations and their effects of organism viability, 
and we are learning what rearrangements and insertions of string 
sequences may mean.)

--Tim May
(.sig for Everything list background)
Corralitos, CA. Born in 1951. Retired from Intel in 1986.
Current main interest: category and topos theory, math, quantum reality, 
cosmology.
Background: physics, Intel, crypto, Cypherpunks

Re: "Morality" in a Block Multiverse

[Hal Finney]

Scerir writes:
> The argument that the relativistic space-time named (after H. Weyl) "block
> universe" eliminates the possibility of changes, free will, becoming (etc.)
> has been used to conclude that between relativity (which demands separability
> and determinism) and quamtum mechanics (which demands nonseparability
> and indeterminism) there is no "peaceful coexistence", from a philosophical
> point of view.

You can also have a "block universe" in QM with the many-world
interpretation.  It has a more complicated geometric structure but
philosophically it is deterministic, with the same issues regarding
changes, free will, etc.

I believe QM is generally compatible with special relativity, but I am
not sure of the details.  A no-collapse formulation should be even more
compatible since you don't have messy and non-physical measurements to
worry about.

Hal Finney

Re: Which universe are we in?

[Bruno Marchal]

Hi Stephen,

At 10:24 -0400 10/07/2002, Stephen Paul King wrote:
> Is it the difference between 1-person and 3-person that is implicit
>here?


Yes.


>It seems to me that we have expectations about our 1-person aspect of
>experience that are, at best, unreasonable. On the otherhand, it seems to me
>that we need to provide some explanation for the simultaneouly unique and
>absolute appearence that our 1-person expereinces have - what are we to make
>of the concreteness of "what it is like to be 'me' experiencing 'me'".
> One possibility that I have considered is that these two 'me's are not
>one and the same, they are more like an object and its abstract
>representation.


Yes, but once you postulate comp you are willing to identify yourself
with a ... somehow abstract representation, or certainly with something
immaterial. For exemple, in a well developed comp civilisation, you could
choose each morning the body which you feel more suitable for the day.
And each evening you will do some backup of yourself, i.e. of your immaterial
relative abstract/concrete (it's a number) representation.
Now you will argue that you still need a concrete universe with physical
resource for making manifest your incarnation during the day.
But here I refer you to the uda reasoning which shows that if you can survive
such a backup then you loose all possible criteria for distinguishing if,
from one instant to some next one, you are still manifested by some
"physical" universe, or if you are manifest by some purely arithmetical
version of the
running of a program which approximates (perhaps perfectly, perhaps not) some
portion of that "universe", so that, with or without a physical universe, your
expectation must be given by a measure on all computations (living 
immaterialy in
numberland), which are going through your actual state.
The slogan is that there is no need to run the UD. There is no need to imagine
we are living through the working of a screen saver of a computer in some other
universe (like Tim said), because the "apparantly singular universe" emerge
from all possible running which exists atemporaly in the "block arithmetical
truth". That's useful because that suppress the need for an infinite regress.
I don't know for sure if comp is true, and so you may be right 
invoking "natural
resource", but at this stage you would just be stepping outside my working
hypothesis ;)


> Bruno, I still don't understand how your theory dispenses with the
>necessity of physical resources.


Honestly the necessity of apparent resource is what we must explain (if comp).
Now, either you mean some materialist concrete and singular decomposable
aristotelian stuff, and *I* ask you what do you mean by that. Or you accept
the idea that physical resources (including its necessity-like feature)
emerge from some inside view (first person plural) for collection of
machines (necessarily sparsely distributed in the deployement of the UD),
in which case it is clear that I don't dispense with those resources at all.
I just don't believe they are fundamental or primary. The primeness op 17 is
more primary (I think, or, by definition with comp).



>Another way of posing my question is
>perhaps: How can a Platonic Comp perform a computation without some analogue
>of persistence of memory or duration.


I have an explanation of persistence of memory with the Z1 logics, and it
can be related with JL Bell quantum logic. But that looks like an authoritative
answer isn'it? Roughly speaking you can bet we are embedded in a
deep (= +/- necessarily long computation, cf Bennett) computation 
which dovetails
on some big (like the continuum) sets (the reals, the complex numbers
perhaps, perhaps the quaternions, why not the octonions ...), so that our type
of story is terribly rare, but our singular computations (with that similar
type) is terribly multiplied. (A little like our genome btw: your precise
DNA is unique on earth, but similar DNA code is numerous and kept to be
multiplied; It is also not unlike quantum states. (And this is related
with the very interesting notion of quantum depth, by David Deutsch)).
Now Platonic Comp don't *perform* any computation. All computations
are there, and notion like "performance" emerge, from our multiplied point of
views of finite being necessarily ignorant (but yet betting) on
(never completable) realities in which we are embedded.


> I can't seem to get the idea out of my head that information can not
>just refer to information itself but merely can encode the "address" of
>where and when it can be found - this is how I think Goedelization works.


I don't think there is an absolute "where" and "when" in arithmetic, but
the analogy between godelisation and programmation helps to figure out what
you intend to say I think. Information does not need to refer to 
itself, though.
Only UTMs will makes reference relatively to emerging patterns, which are
emerging and stable relatively to their (the UTM) m

Re: "Morality" in a Block Multiverse

[scerir]

>By the term "block multiverse" I mean a reality in which everything
>MUST happen, in some "timeline" or "universe."  This sounds a lot like
>predestination to me.
>Scott W. Somerville, Esq.

The argument that the relativistic space-time named (after H. Weyl) "block
universe" eliminates the possibility of changes, free will, becoming (etc.)
has been used to conclude that between relativity (which demands separability
and determinism) and quamtum mechanics (which demands nonseparability
and indeterminism) there is no "peaceful coexistence", from a philosophical
point of view.

But the issue is not so simple as N. Maxwell (Are Probabilism and Special
Relativity Incompatible?, Philosophy of Science, 52, 23-43. 1985)
and H. Stein (On Relativity Theory and Openness of the Future, Philosophy of
Science, 58, 147-167, 1991) have pointed out. [But I did not remember
what they wrote, since I've read these papers 30 years ago].

s.

Re: Which universe are we in?

[Bruno Marchal]

At 22:46 -0700 8/07/2002, Hal Finney wrote:
>
>If my mind, as a physical or computational system, is instantiated
>in multiple places, whether multiple universes, multiple branches of a
>many-worlds interpretation (MWI), or even multiple places and times in one
>universe, the question is how that appears to me from the first-person
>perspective.  I am adopting a position that from my point of view, it
>is indeterminate which of those instantiations I am now experiencing.
>There is no "fact of the matter" as to which one is me, now.
>
>The alternative is to say that although all of these instantiations
>are in some sense indistinguishable, nevertheless the instances of
>consciousness produced by these systems are all distinct.  That is, for
>each instance of consciousness, there is a single physical system which
>creates that consciousness.  All of the physical systems are similar, or
>even locally identical, so that the consciousness instances produced are
>all structurally the same.  But nevertheless we would not say that there
>is one consciousness which spans all the implementations; rather, there
>are multiple consciousnesses which merely "look alike from the inside".
>
>Anyway, that is the opposite of the view I am taking for the purposes
>of this discussion.  I am assuming the former position, that my present
>consciousness is being instantiated widely throughout the multiverse
>and I can with equal justification think that I am experiencing any
>of those instantiations.

Or even, perhaps, that "I am experiencing" all instantiations at once.
Eventually it will be the relative proportion of differentiating
(or bifurcating) history-instantiations which should count.


>My consciousness, in that sense, spans many
>parts of the multiverse, and the question of "which universe am I in"
>has no unique answer.


I would even say that the question is meaningless. It is not clear that
all "my" possible experiences can be associate with "well defined universe".

I think I agree with Hal Finney. Hal, do you defend this position or was it
only for the purpose of the discussion. Have you a definite opinion?


==
Wei, I hope my way of talking yesterday didn't seem too rude. I am really
trying hard to understand what you don't understand about the necessity
to take into account the comp 1-indeterminacy in TOE, once comp is postulated
(comp = Church thesis + minimal amount of arithmetical realism + there is
a level of self-description such that my private experience doesn't change
for functional substitutions made at that level).

Bruno

the short program

[Juergen Schmidhuber]

Tim May wrote:
> One thing that Tegmark got right, I think, is the notion that a lot of
> branches of mathematics and a lot of mathematical structures probably go
> into making up the nature of reality.
>
> This is at first glance dramatically apposite the ideas of Fredkin,
> Toffoli, Wheeler1970, and Wolfram on the generation of reality from
> simple, local rules. Wolfram has made a claim in interviews, and perhaps
> somewhere in his new book, that he thinks the Universe may be generated
> by a 6-line Mathematica program!
 
I'd like to point out that it was Konrad Zuse himself ("inventor of the
computer": http://www.idsia.ch/~juergen/zuse.html ) who was the first to
propose that the physical universe is running on a grid of simple
computers, each communicating with its neighbors: a cellular automaton.
He called this "Rechnender Raum," which means "Computing Space." As
always, Zuse was way ahead of his time. Perhaps the best reference is:
 
  Zuse, Konrad: Rechnender Raum, Schriften zur Datenverarbeitung,
   Band 1.  Friedrich Vieweg & Sohn, Braunschweig (1969).
 
And here is the simple method for computing all universes, including
ours, if it is computable indeed (adapted from page 1 of the 97 paper
http://www.idsia.ch/~juergen/everything/html.html ):
 
  Order all programs lexicographically. The first
  is run for one instruction every second step, the next for one
  instruction every second of the remaining steps, and so on.
 
As a by-product, this program also outputs descriptions of all formally
describable mathematical systems, and all proofs of all their theorems.
 
A bit of thought shows that the method even has the optimal order of
complexity. For example, it outputs our universe history as quickly as
the history's fastest program, save for a (possibly huge) constant that
does not depend on output size.
 
Juergen Schmidhuber  http://www.idsia.ch/~juergen/