
Two weeks before death, Hawking submitted a paper on parallel universes - aaronbrethorst
https://www.sciencealert.com/stephen-hawking-submitted-a-paper-on-parallel-universes-just-before-he-died
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epaga
Something I've never understood and would greatly appreciate understanding:
could someone ELI"5" how the concept of "parallel universes" will not always
be a metaphysical instead of a scientific question?

If there are truly separate "universes", then by definition wouldn't it be the
case that there would be no way to test (or falsify) whether they exist or
not, so would the question of their existence not be in the realm of
philosophy and metaphysics rather than the sciences? What am I missing (I
assume it has to do with my understanding of the word "universe")?

~~~
hnarn
>If there are truly separate "universes", then by definition wouldn't it be
the case that there would be no way to test (or falsify) whether they exist or
not

This literally contradicts what the first paragraph of the article. It says
that this paper "lays the theoretical groundwork for discovering a parallel
universe". If you've discovered it, you've tested and proved that it exists.

Furthermore, the article states that it's a "mathematical paper which seeks
proof of the 'multiverse' theory". Assume for a second that there is
_mathematical proof_ of the multiverse theory. In order to disprove this, you
now need to disprove the math.

~~~
ajuc
There cannot be a mathematical proof of a physical fact. You can have infinite
number of theories that are all mathematically correct, yet contradict each
other.

You need data from experiments to falsify the wrong ones. And I think that's
why the article means - paper shows what experiment needs to be done to
falsify some theories that assume multiverse.

~~~
adrianN
Technically you might be able to do a proof by exclusion if you can show that
only one of all the possible theories is sound and consistent.

~~~
wallace_f
I can personally assure you that String Theory is mathematically robust, and
the only sound and consistent TOE; and as all other TOEs are excluded,
therefore String Theory must be, and just has, been proven.

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codeulike
Quite a lot of people worrying about the definition of the word 'universe' in
this thread.

~~~
pegasus
And with good reason. "Discovering a parallel universe" is nonsensical in the
common acceptance of those words. Parallel lines never meet and the universe
by definition contains all there is. So people are grasping for alternative
definitions of the words that might make the statement satisifiable.

~~~
Symmetry
At one point "Split an atom" was by definition nonsensical because atoms were
conceived of as the smallest, unsplittable bits of matter. But then we found
out that we could split these pieces of matter we'd mistakenly called "atoms"
and rather than renaming them we just changed the definition of "atom" to
correspond to what we'd always been calling "atoms". In practice I don't think
this was unreasonable and I wouldn't strongly object to doing the same with
what we've been calling "The universe".

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SaturateDK
Until it's published and reviews there isn't much to say. But it's exciting to
me, hope I can read it soon.

~~~
kgwgk
As the article mentions, you can read it already:
[https://arxiv.org/abs/1707.07702v2](https://arxiv.org/abs/1707.07702v2)

~~~
SaturateDK
Oh, I was a bit too quick there it seems. Thanks! :-)

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baytrailcat
Looking forward to more and more discoveries and theories coming up in this
field. Apart from providing a satisfactory answer to the quandary of "fine-
tuned Universe" problem, there has been some observed anomalies for which
multiverse theory provides explanation.

[https://en.wikipedia.org/wiki/CMB_cold_spot](https://en.wikipedia.org/wiki/CMB_cold_spot)

[https://en.wikipedia.org/wiki/Dark_flow](https://en.wikipedia.org/wiki/Dark_flow)

~~~
poelzi
:)

The problem with physics is, that it went into the wrong direction in the last
100 years and as a result, everybody which looks beyond pop science papers
knows, that it does not fucking fit. The fine-tuned Universe is a Problem of
the model and the requirement of dozens of free chose-able variables required
to make the model fit observations should give you a red sign. And even then
it's a bad fit, in very aspect. 10%+ difference in calculations vs
observations is a pretty strong hint that your model is far from reality.

The model I'm following does not have dark matter, because it does not require
it. I have also expansion of the universe, without abstract higher dimensions
etc. But of course, this can not be done without breaking paradigms and this
is the problem.

Physicists have shown to be tho most short sighted and ignorant scientists of
all:

[http://www.pnas.org/content/112/24/7426.full.pdf](http://www.pnas.org/content/112/24/7426.full.pdf)

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codeulike
And then he leaves. Hmmm, suspicious.

~~~
_xgw
Hopefully to a parallel universe. :)

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keithwhor
Imagine the look on Stephen Hawking 1011156B's face when he finds out Stephen
Hawking 7086C published the exact same paper that he did, died two weeks
later, and the combination of those events compelled scientists in that
Universe to eventually master interdimensional travel, when 1011156B only got
laughed at.

~~~
einrealist
How is the Hawking ID generated? Which universe is used for synchronization?
Do we need a new UUID level? Will the NISTs of all universes ever come to an
agreement? So many questions...

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andygates
Multiversally-Unique ID's are going to be so long...

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zaarn
Depends on how many of them there are. If there is infinite, there is no MUID,
if it's finite and below 2^64 then a traditional UUID should be enough to
assign a UUID per universe and then assing a UUID for objects within.

~~~
jfaucett
> If there is infinite, there is no MUID

Formally, you could still have MUIDs even if there are infinite universes so
long as they are countably infinite. Practically, the system would work as
well so long as you could allocate new qbits to boost your information
exponent.

~~~
zaarn
Well, no, as long as you want a finitely long MUID since a finite number of
digits can only express a countable but not infinite number of elements.

~~~
jfaucett
We don't want a finitely long MUID, otherwise we couldn't represent infinite
universes. A quantum bit represents infinite states. The "fiction" part is
that we (currently) need to collapse quantum bits.

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russdpale
Truly amazing. Thank you Professor Hawking! RIP.

~~~
erric
This statement is in the same domain as “thoughts and prayers”, which is the
same as saying, ”I’m wishing at you really hard”.

Rest implies an awaking or movement at some point in the future, but for
Hawking, he didn’t believe in that.

Maybe it’s just something to say, like acknowledging someone sneezing?

~~~
tutts
Or maybe it's a metaphorical expression of sadness over the recent death of a
respected idol?

~~~
erric
Maybe, but I suspect not.

