Re: Shadows and smeared selves

From: George Levy <>
Date: Sat, 12 Jun 2004 22:49:42 -0700

Hi Jeanne,

Welcome to the group. The idea behind First and Third Person is the
Quantum Suicide experiment which probably had many originators but the
most well known is Max Tegmark professor at the Institute for Advanced
Studies at Princeton. You can find some of Tegmark's references at

and at

Quantum suicide is a completely hypothetical thought experiment which
show that if one assumes the manyworld interpretation then one may be
forced to conclude that at "death" someone's perspective of the world
can be very strange. First person and third person refer respectively to
one who commits quantum suicide and one who observes someone else commit
quantum suicide.

As these articles explain, after a quantum suicide a first person
observes himself or herself living since he only occupies those "rare"
worlds where his/her attempt has not been sucessful. However, a third
person observes that the person who commit suicide dies since in most
worlds the quantum suicide is successful. Some of the underlying and
unstated assumption in this miraculous survival is that consciousness is
unaware of
        1) any substitution of parts or the whole of its physical
implemetation (i.e. body)
        2) its own measure (the size of the subset of worlds in the
manyworld that sustain his or her consciousness)

George Levy

Jeanne Houston wrote:

>I am a quantum physics enthusiast, but merely an amateur who finds the
>discussion threads of this group to be quite interesting. I have never
>before commented because, to be honest, I am rather lost in regard to the
>discussion of first person and third person. I am trying to figure out
>exactly what everyone is talking about, but it would be helpful if someone
>would point me to some source material on which these discussions are based.
>I would like to say however, that I found the idea of shadows and smeared
>selves to be a fascinating concept to think about; a delightful mental
>exercise. I will read with interest the comments that are bound to come
>from those who are the experts in this group.
>----- Original Message -----
>From: "Giu1i0 Pri5c0" <>
>To: <>; <>
>Sent: Saturday, June 12, 2004 11:48 AM
>Subject: Shadows and smeared selves
>>In this note I try to outline my current thoughts on quantum physics,
>>for your comments. I am sending this to a few mailing lists with
>>overlapping memberships, so you may have received this twice or more.
>>I apologise if this is the case and also for the very imprecise
>>language and gross simplifications and analogies that I am using to
>>make my point. While this is really a sketch of a sketch, I wish to
>>discuss the core idea with people who understands these things better
>>than I do, so please let me have your comments (even "go back to your
>>first year textbook and stop wasting my time").
>>I think that, while Everett's Relative State formulation of quantum
>>mechanics makes a lot of sense, its popular interpretation as "Many
>>Worlds"(MWI) should be taken only as a simple pictorial device useful
>>for a first understanding of the theory.
>>As a more accurate interpretation, I propose thinking of perceived
>>realities as shadows of a more complex reality. I suspect this is what
>>some authors, perhaps including Everett himself, were trying to say,
>>and that others may have said it explicitly (perhaps Lockwood), so I
>>would appreciate any pointer to relevant works.
>>I will use poor Schroedinger's cat as an example. Following Everett,
>>the cat is in a superposition of [cat dead] and [cat alive] states
>>before an observer opens the box and looks inside, and stays so after
>>(there is no collapse). After opening the box and looking inside, the
>>observer is in a superposition of [observer who remembers having seen
>>the cat dead] and [observer who remembers having seen the cat alive].
>>The MWI says that after the act of observation (measurement) the
>>universe is split in two branches where the first has [cat dead] and
>>[observer who remembers having seen the cat dead], and the second has
>>[cat alive] and [observer who remembers having seen the cat alive].
>>The difficulty that I have is: on the one hand we are saying that
>>fundamental reality contains no such things as cats dead or alive, but
>>on the other hand we are describing the world(s) with cats dead and
>>cats alive.
>>To clarify the first part of the statement: as we can choose any two
>>directions to form a basis to use for the description of a particle's
>>spin, all
>>choices generating equally valid descriptions, besides [cat dead] and
>>[cat alive] we should be free to use another basis to describe the
>>cat. While any pair of independent linear superpositions of [cat dead]
>>and [cat alive] will do, of course I have no idea of what such a
>>superposition would "look like".
>>Since I cannot remember having ever seen one, I do not know what a
>>superposition of [cat dead] and [cat alive] would look like, so
>>probably I would not recognise one if I saw it. Perhaps this is the
>>reason why I cannot remember having ever seen one.
>>In other words, perhaps since reality is One Big World too complex for
>>our minds to process efficiently, we use a simplified representation
>>as Many (small) Worlds for our processing. This is not so surprising
>>when we remember that our best computer programs use data compression
>>and segmentation techniques, throwing most of the information away, to
>>perform complex tasks such as face recognition efficiently. Perhaps
>>reducing a complex reality to parallel worlds is a successful trick
>>that sentient beings have developed to process reality more
>>I believe thinking of shadows may be a better mental device than
>>thinking of parallel worlds. Using this model the realities that I,
>>and my doubles in other branches of the MWI model, perceive can be
>>thought of as shadows of a more complex reality. Observing a shadow
>>permits saying certain things about its source, like size and overall
>>shape, but not other things like colour and smell. The shadow does not
>>contain such information. Also, much of what we can say about shadows
>>has more to do with illumination and the surface where the shadow is
>>cast than with the actual source.
>>Thinking of multiple worlds as shadows brings us back to Plato's cave,
>>but there are two important differences: First, each of us observes
>>shadows of the *real* world in a very large number of caves in
>>parallel. Second, we are shadows ourselves, our mental computational
>>processes being shadows of other, possibly much more complex,
>>computational processes.
>>In my view of the world, saying "my mental computational processes" is
>>just another way to say "I". So what am I a shadow of? I don't know,
>>but perhaps by observing the shadow I can develop some plausible
>>assumptions on the source.
>>I know that I am a conscious being: though I am not able to put my
>>finger precisely on what consciousness *is*, I know that it is a
>>property that I posses. I also think that consciousness must have
>>something to do with complexity: if a computational process is complex
>>enough, it may become a conscious process.
>>So, since it seems reasonable to think that a source must have a
>>degree of complexity not lower than its shadow, we should consider the
>>possibility that we are shadows cast by conscious sources.
>>Following Greg Egan who outlined something similar in his novel
>>"Quarantine", we can use the term "smeared self" to indicate such a
>>source. Your smeared self is simultaneosly conscious of a very large
>>number of Everett branches, and you, who can only perceive one, are
>>the shadow that your smeared self is casting on this specific branch.
>>The mental activity of your smeared self may well be much more complex
>>than yours, and perhaps the interaction between I who wrote this very
>>speculative and imprecise note, and you who are reading it, is the
>>shadow of a much more complex interaction between our smeared selves.
Received on Sun Jun 13 2004 - 01:56:54 PDT

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