

The Multiverse and you – Is there another version of you somewhere out there? - mparramon
https://medium.com/starts-with-a-bang/ask-ethan-73-the-multiverse-and-you-46c9e3c493e2

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pingou
So if I get it right, there can't be another you because there are too much
particles (and possible interactions between them) in the universe.

Perhaps there isn't a universe where every particle is the same as in ours,
but we could be just concerned about the particles our galaxy for example. I
might be wrong, but I think it might be theoretically possible to have the
same earth in a totally different universe.

What I find somewhat counter intuitive is that, the more particles there are,
the less our chances are that another version of us exist, I would have said
it makes the chances bigger, or at least in our own universe.

~~~
coldtea
> _What I find somewhat counter intuitive is that, the more particles there
> are, the less our chances are that another version of us exist, I would have
> said it makes the chances bigger_

Think of it like this:

If a human ("Joe") was just one particle, then the chances of the same human
being recreated elsewhere would be 100%. As long as that particle is present,
there's Joe.

If Joe was made of 100 particles, then the chances are less, because those 100
particles would have to be aligned/interact in the same way, which is much
less probable.

Or maybe think of it like this: if you throw a dice, to get 6 is quite easy.
You have 1 in 6 chances.

But if you throw 10 dice to get them all six is very very improbable (1/6 _1
/6_1/6*...).

Think of the particles like dice.

~~~
pingou
Yes, the more particles Joe has, the less it is likely that it will be
recreated elsewhere. But here I'm talking about particles not being Joe, the
rest of the universe.

I see it this way, it doesn't matter that I get 10 times a 6 when throwing a
dice, I just want a 6, I'm not concerned about the whole process, just about
the result. Aren't there many ways to get to a point where particles assemble
to form a brain similar to our own?

Also, is it possible to ignore the vast majority of the universe, because is a
dim light from a star so important, or do we have to, because of the butterfly
effect?

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brianfitz
An interesting implication of the multiverse theory is that it provides an
answer for how we ended up with a universe with just the right combinations of
gravity, electromagnetism, strong and weak nuclear forces. It's like the
Goldilocks story -- tweak any of them to any other value and all matter would
either repel into an nearly empty space or attract into one mass that would
collapse under it's own density. There are other reasons for the multiverse
theory, but under a theory of infinite multiverses, you would by definition
create a universe where all the right combination of forces would come
together to form our stars and planets -- including ones that can sustain
life.

~~~
bglusman
You're referring to the Anthropic principle[1] here, I believe? I tend to
think this is not a very satisfying explanation, because it is not
falsifiable[2]. More compelling/satisfying as an explanation to me, though
controversial, is Lee Smolin's theory of cosmological natural selection[3],
because though it may not be true, it at least makes some predictions that can
be analyzed and modeled to study the correspondence to our universe, and so
can be falsified or supported by improved accuracy and predictive utility of
these models vs observations.

[1]
[http://en.wikipedia.org/wiki/Anthropic_principle](http://en.wikipedia.org/wiki/Anthropic_principle)
[2]
[http://en.wikipedia.org/wiki/Karl_Popper#Falsifiability.2Fpr...](http://en.wikipedia.org/wiki/Karl_Popper#Falsifiability.2Fproblem_of_demarcation)
[3]
[http://en.wikipedia.org/wiki/Lee_Smolin#Cosmological_natural...](http://en.wikipedia.org/wiki/Lee_Smolin#Cosmological_natural_selection)

~~~
brianfitz
This is interesting. I had heard of this theory previously (Smolin), but
didn't appreciate the Darwinian nature of it. You still get multiverses that
each adopt their own distinct rules of physics, but natural selection plays in
to how the universes are created. Some amount of information is transferred
from the source universe to the one newly created, but the information is not
lost -- something Susskin put forth some years ago by comparing the event
horizon of a black hole to a hologram.

------
amelius
Even though the universe is (probably) infinite, this does of course not mean
that it is infinitely repetitive.

Take for example the function y=x: even though the x-axis is infinite, no
value of y occurs twice.

Also note that the argument can be made in time also. If time is infinite,
events may occur repetitively indefinitely. But they may also not (for
example, if the universe "crunches" and stays that way).

~~~
macspoofing
>Even though the universe is (probably) infinite, this does of course not mean
that it is infinitely repetitive.

If the universe is infinite and consists of matter, I think you can safely say
every feasible combination of particles repeats, infinite number of times.

~~~
mathattack
This isn't necessarily true. The article largely explains it. The interaction
of particles trends to infinity faster than time.

Another way to think of it... Let's say that t is trending to infinity
starting from 0. There are #s that will always be larger than t. Such as
(t+1)^2.

One more way... Time is one dimension. The rest of space-time is 3 (at least).
The size of possibilities is larger to 3 orders of magnitude.

And a last way... If it's feasible that matter can expand forever, then
there's no way for the particles to repeat themselves. They just keep going
and going...

~~~
macspoofing
Stop time right now. You now have an static, unchanging, universe. This
universe is infinite in size, and roughly equally dense with matter and
radiation across this infinity. You really want to make the argument that
there isn't another Earth out there?

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danbruc
To me it seems the article is completely mixing up two multiverse theories -
one is that there are several essentially completely independent universes
separated in space (or time) and the other is that there is no collapse of the
wave function but all the possibilities encoded in the wave function are
actually real and therefore many universes are kind of overlaid at the same
time in the same space and in each universe you observe the wave function
collapsed to a different state. Did I get it wrong or the article?

~~~
grondilu
Max Tegmark, whose talk is summarized in this article if I understand
correctly, describes four different types of Multiverse. This article presents
three of them (levels I, II and III).

See Max Tegmark's webpage for more information and links on the subject:

[http://space.mit.edu/home/tegmark/mathematical.html](http://space.mit.edu/home/tegmark/mathematical.html)

~~~
danbruc
Thanks, that is what I suspected. Maybe I just read the article to quickly but
I completely missed the clear distinction between the different types of
multiverses in the article.

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MichaelGG
I thought the whole implication of MWI is that every possibility does happen
and universes are constantly splitting off. So there's an unlimited number of
copies of you, some essentially identical, others experiencing inconceivable
suffering or pleasure.

~~~
fernly
Many Worlds is one concept; this is another and quite different.

~~~
MichaelGG
But if aiming at the "philosophical" impact and consequences, why focus on the
one that doesn't have some potential for implications?

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vorg
> we have every reason to believe there’s plenty more, and perhaps even
> infinitely more [Universe out there beyond the portion that’s accessible to
> us]

Which order of infinity do you mean when you say "infinitely more [space]"
here? Aleph-One?

> we can extrapolate the Big Bang backwards to an arbitrarily hot, dense,
> expanding state, and what we find is that it didn’t get infinitely hot and
> dense early on

And what order of infinity here for the energy?

> the Universe was filled with energy inherent to space itself: a state that
> causes the Universe to expand at an exponential rate

If the infinity used to measure 2 different entities are of different orders,
then there'd be at least an exponential differential between those entities.
But what if the order of infinities is switched around between energy and
space, could that then mean there's only one instance of inflated space in
existence?

I've never read a discussion of multiverses, whether wrt inflation or quantum
mechanics, where the order of infinity used is mentioned. Specifying what
order of infinity is to be used for each measurement seems to be crucial to
what result is infered.

------
rl3
> _So realistically, we’re talking about at least 10^10^50 Universes that
> started off with initial conditions that might be very similar to our own._

Presumably, what follows from initial conditions is bound by determinism.

By the logic of that assumption, even if we assume an infinite set of initial
conditions, can there really be alternate universes wherein everything is
identical _except_ for one miniscule thing, billions of years after initial
conditions have unfolded?

~~~
Permit
>Presumably, initial conditions are slave to determinism just like anything
else.

Why is everything slave to determinism? Isn't true randomness introduced to
the system via randomness at the quantum level?

~~~
rl3
Unless the quantum level itself stems from initial conditions, and therefore
is deterministic as well.

Also, I rephrased the line you quoted almost immediately after I posted it.
Sorry about that.

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shurcooL
I thought this clip [1] from a game was quite relevant.

[1] [http://i.imgur.com/G5hXQ4C.gifv](http://i.imgur.com/G5hXQ4C.gifv)

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getdavidhiggins
A lot of more of the same 'Peek beyond the veil' of this reality type writing.
Obviously a myopia exists on planet earth. Earth is a little bubble we have
been floating in womb-like for aeons of years, and are aware, sometimes even
at a very basic level that there's more out there. What I find awkward is that
scale is seen as a scary thing. Space is often called a "final frontier", and
the "last bastion of hope" and other scary things like that.

But you have to think of those first sailors who set out to discover the new
worlds - they risked their lives - they were the original space monkeys.
Sadly, ethical red tape won't allow a mass exodus to other stars - as the
stock market would inevitably plunge, and there would be chaos.

The moment we get out of the tired economic model of scarcity, and start
opting for abundance, is the moment we can leap towards other dimensions, and
other worlds. But for now - we have an impotent attempt to understand the
universe through a tired Hubble telescope, and a tired generation of rocket
builders who read science fiction novels in secret and know there's another
way out of this place.

~~~
NhanH
> Sadly, ethical red tape won't allow a mass exodus to other stars - as the
> stock market would inevitably plunge, and there would be chaos.

What ethical red tape are you referring too? Because I can't quite think of
any. And do you mind elaborate on the stock market too?

On the topic of scarcity vs abundance, fundamentally, there might be physical
constraints that will never allow us to really be "abundance": space is big,
really really big.

~~~
senormoll
> space is big, really really big.

And the corollary to that: space is empty, really really empty. The government
could _encourage_ space exodus, even offer each citizen $1 million to leave.
It's still just not possible right now.

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sxcurry
Interesting that this article discusses the Big Bang as happening after
Inflation. I always assumed Inflation was the initial stage of the Big Bang.
Is that just assumed in casual descriptions, but technically not true?

~~~
ugexe
It is theorized that for a tiny fraction of time before the big bang the laws
of physics were not the same as they are now, and if they had been such an
expansion would not have taken place. This is the distinction they are likely
trying to make.

~~~
stingraycharles
Correct me if I'm wrong, since I only got my information from non-academic
sources, but if I recall correctly the problem was that with the inflation,
you would have to apply both the theory of general relativity (the science of
the really big), and quantum theory (the science of the really small). In
which case they totally don't work together and you would get really weird
numbers.

Would a more logical explanation not be that our current theories are likely
to be flawed, just like Newton's theory about gravity was flawed (but
nevertheless incredibly useful) ?

~~~
brianfitz
More at its core is that it means that the expansion exceeded the cosmic speed
limit, the speed of light. Two of the competing theories have been a rapid
expansion (inflation) and another that two branes collided and the big bang
started in an expanded state. As of late, it appears there has been more
confirmation of the former rather than the latter. From what I've read, it is
as another commenter noted -- the universe in it's earliest state did not yet
conform to the rules of physics as we know them today. This early state is
something on the order of the first trillionth of a trillionth of a trillionth
of a second.

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hellbanner
Is there? If you can't reach them, it doesn't matter. Articles that start with
"is"..

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zobzu
this is the kind of stuff where I want to live old enough to see super AI
solve this for us ;-)

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logicallee
if you want to meet another version of you, wait ten minutes. you'll be a
different person thinking about something totally different. big deal.

~~~
shurcooL
This is true. Especially evident if a day, week, or a year passes.

