[ExI] Shadows and the concept of self

[John Clark]

On Sat, Apr 1, 2017 at 2:37 AM, Giulio Prisco <giulioprisco at protonmail.ch>
wrote:


> ​> ​
> thinking of splitting and recombining worlds is a simplified way to
> describe a reality that is much more complex
>

​Splitting is much easier than recombining. Worlds split when they change,
they recombine when they become identical again, if the change is small
then they might become the same again but if the change is large they're
never going to recombine, that's why we see weird stuff at the sub atomic
level but not at the macroscopic level. Or at least that's
the reason if the MWI is correct.   ​


> ​> ​
> Many Minds comes closer, but it's still a simplification - I think the
> many minds are shadows of One Mind. Having now studied Everett's original
> papers and those of DeWitt, Wheeler's etc., I suspect Everett himself
> wouldn't disagree.
>

​I think Everett would disagree. ​The entire advantage of Many Worlds is it
doesn't need to open a can of worms like mind or consciousness or
measurement or observation. There is nothing special about a observer, when
things change he splits just like everything else

​> ​
> I am writing a new essay with thoughts on my interpretation of Everett's
> interpretations, with plenty of links. In the meantime, I recommend reading
> Peter Byrne's biography:
> https://global.oup.com/academic/product/the-many-worlds-of-h
> ugh-everett-iii-9780199552276
>

​I wrote a review of Byrne's book for the list back in 2010, I'll repeat it
here:​



​I​
've just finished this book and its one of the most enjoyable things I've
read in
​
a long time. Being a staple of science fiction and the only interpretation
of quantum
​
mechanics to enter the popular imagination it's a little surprising that
"The Many
​
Worlds of Hugh Everett" by Peter Byrne is the first biography of the
originator of that amazing idea. Everett certainly had an interesting life,
he was a  libertarian and a libertine, became a cold warrior who with his
top secret clearance was comfortable with the idea of megadeath, became
wealthy by started one of the first successful software companies until
alcoholism drove him and his company into the
​g​
round.
​ ​
Everett died of heart failure in 1982 at the age of 51, he was legally
drunk at the time. He requested that his body be cremated and his ashes
thrown into the garbage. And so he was.

Byrne had an advantage other potential biographers did not, the cooperation
of his son Mark, a successful rock musician and composer whose music has
been featured in such big budget movies as American Beauty, Hellboy, Yes
Man, all three of the Shrek movies and many others. Mark gave Byrne full
access to his garage which was full of his father's papers that nobody had
looked at in decades.

Everett was an atheist all his life, after his death Paul Davies, who got
1,000,000 pounds for winning the Templeton religion prize, said that if
true Many Worlds destroyed the anthropic argument for the existence of God.
Everett would have been delighted. Nevertheless Everett ended up going to
Catholic University of America near Washington DC.  Although Byrne doesn't
tell us exactly what was in it, Everett as a freshman devised a logical
proof against the existence of God. Apparently it was good enough that one
of his pious professors became very upset and depressed with "ontological
horror" when he read it. Everett liked the professor and felt so guilty he
decided not to use it on a person of faith again. This story is very
atypical of the man, most of the time Everett seems to care little for the
feelings of others and although quite brilliant wasn't exactly lovable.

Everett wasn't the only one dissatisfied with the Copenhagen Interpretation
which insisted the measuring device had to be outside the wave function,
but he was unlike other dissidents such as Bohm or Cramer in that Everett
saw no need to add new terms to Schrodinger's Equation and thought the
equation meant exactly what it said. The only reason those extra terms were
added was to try to rescue the single universe idea, and there was no
experimental justification for that. Everett was unique in thinking that
quantum mechanics gave a description of nature that was literally true.

John Wheeler, Everett's thesis advisor, made him cut out about half the
stuff in his original 137 page thesis and tone down the language so it
didn't sound like he thought all those other universes were equally real
when in fact he did. For example, Wheeler didn't like the word "split" and
was especially uncomfortable with talk of conscious observers splitting,
most seriously he made him remove the entire chapter on information and
probability which today many consider the best part of the work. His long
thesis was not published until 1973, if that version had been published in
1957 instead of the truncated Bowdlerized version things would have been
different; plenty of people would still have disagreed but he would not
have been ignored for as long as he was.

Byrne writes of Everett's views: "the splitting of observers share an
identity because they stem from a common ancestor, but they also embark on
different fates in different universes. They experience different
lifespans, dissimilar events (such as a nuclear war perhaps) and at some
point are no longer the same person, even though they share certain memory
records." Everett says that when a observer splits it is meaningless to ask
"which of the final observers corresponds to the initial one since each
possess the total memory of the first" he says it is as foolish as asking
which amoeba is the original after it splits into two. Wheeler made him
remove all such talk of
​amoebas​
​
from his published short thesis.

Byrne says Everett did not think there were just an astronomically large
number of other universes but rather an infinite number of them, not only
that he thought there were a non-denumerable infinite number of other
worlds. This means that the number of them was larger than the infinite set
of integers, but Byrne does not make it clear if this means they are as
numerous as the number of points on a line, or as numerous as an even
larger infinite set like
​the set of all possible curves.
Neill Graham tried to reformulate the theory so you'd only need a countably
infinite number of branches and Everett at first liked the idea but later
rejected it and concluded you couldn't derive probability by counting
universes. Eventually even Graham seems to have agreed and abandoned the
idea that the number of universes was so small you could count them.

Taken as a whole Everett's multiverse, where all things happen, probability
is not a useful concept and everything is deterministic. However for
observers like us trapped in a single branch of the multiverse, observers
who do not have access to the entire wave function and all the information
it contains but only a small sliver of it, probability is the best we can
do. That probability we see is not part of the thing itself but is just a
subjective measure of our ignorance.

Infinity can cause problems in figuring out probability
​,​
but Everett said his theory could calculate what the probability
​ ​
any event could be observed in any branch of the multiverse
​ is​
, and it turns out to be the Born Rule (discovered by Max Born, grandfather
of Olivia Newton John) which means the probability of finding a particle at
a point is the squaring of the amplitude of the Schrodinger Wave function
at that point. The Born Rule has been shown experimentally to be true but
the Copenhagen Interpretation just postulates it, Everett said he could
derive it from his theory it "emerges naturally as a measure of probability
for observers confined to a single branch (like our branch)". He proved the
mathematical consistency of this idea by adding up all the probabilities in
all the branches of the event happening and getting exactly 100%. Dieter
Zeh said Everett may not have rigorously derived the Born Rule but did
justify it and showed it "as being the only reasonable choice for a
probability measure if objective reality is represented by the universal
wave function [Schrodinger's wave equation]". Rigorous proof or not that's
more than any other quantum interpretation has managed to do.

Everett wrote to his friend Max Jammer:
"None of these physicists had grasped what I consider to be the major
accomplishment of the theory- the "rigorous" deduction of the probability
interpretation of Quantum Mechanics from wave mechanics alone. This
deduction is just as "rigorous" as any deductions of classical statistical
mechanics. [...] What is unique about the choice of measure and why it is
forced upon one is that in both cases it is the only measure that satisfies
the law of conservation of probability through the equations of motion.
Thus logically in both classical statistical mechanics and in quantum
mechanics, the only possible statistical statements depend upon the
existence of a unique measure which obeys this conservation principle."

Nevertheless some complained that Everett did not use enough rigor in his
derivation. David Deutsch has helped close that rigor gap. He showed that
the number of
​ ​
Everett-worlds after a branching is proportional to the conventional
probability density. He then used Game Theory to show that all these are
all equally likely to be observed. Everett would likely have been delighted
as he used Game Theory extensively in his other life as a cold warrior.
Professor Deutsch gave one of the best quotations in the entire book,
talking about many worlds as a interpretation of Quantum Mechanics "is like
talking about dinosaurs as an interpretation of the fossil record".

Everett was disappointed at the poor reception his doctoral dissertation
received and never published anything on quantum mechanics again for the
rest of his life; instead he became a Dr. Strangelove type character making
computer nuclear war games and doing grim operational research for the
pentagon about Armageddon. He was one of the first to point out that any
defense against intercontinental ballistic missiles would be ineffectual
and building an anti-ballistic missile system could not be justified except
for "political or psychological grounds". Byrne makes the case that
​ ​
Everett was the first one to convince high military leaders through
mathematics and no nonsense non sentimental reasoning that a nuclear war
could not be won, "after an attack by either superpower on the other, the
majority of the attacked population that survived the initial blasts would
be sterilized and gradually succumb to leukemia. Livestock would die
quickly and survivors would be forced to rely on eating grains potatoes and
vegetables. Unfortunately the produce would be seething with radioactive
Strontium 90 which seeps into human bone marrow and causes cancer". Linus
Pauling credited Evert by name and quoted from his pessimistic report in
his Nobel acceptance speech for receiving the 1962 Nobel Peace prize.

Despite his knowledge of the horrors of a nuclear war Everett, like most of
his fellow cold warrior colleagues in the 50's and 60's, thought the
probability of it happening was very high and would probably happen very
soon. Byrne speculates in a footnote that Everett may have privately used
anthropic reasoning and thought that the fact we live in a world where such
a war has not happened (at least not yet) was more confirmation that his
Many Worlds idea was right. Incidentally this is one of those rare books
where the footnotes are almost as much fun to read as the main text.

Hugh's daughter Liz Everett killed herself a few years after her father's
death, in her suicide note she said "Funeral requests: I prefer no church
stuff. Please burn be and DON'T FILE ME. Please sprinkle me in some nice
body of water or the garbage, maybe that way I'll end up in the correct
parallel universe to meet up with Daddy". And so she was.

​John K Clark​
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.extropy.org/pipermail/extropy-chat/attachments/20170402/b54e5a3b/attachment.html>