
Many Lives in Many Worlds - micaeloliveira
http://fermatslibrary.com/s/many-lives-in-many-worlds
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Xcelerate
The interpretation I prefer: the universal quantum state evolves unitarily at
all times, and there are no parallel universes. Problem solved. Parallel
universes are — by definition — unfalsifiable, so the best theory then is the
simplest one, and that is a theory with one universe.

For similar reasoning used in a somewhat different scenario, see also
[http://plato.stanford.edu/entries/spacetime-
holearg/](http://plato.stanford.edu/entries/spacetime-holearg/)

~~~
pjdorrell
In the context of Many Worlds, a "universe" is an approximately classical wave
function, where the degree of approximation is limited by the uncertainty
principle.

Even if you start with an approximately classical wave function, it may evolve
into a state where it is no longer approximately classical. However, it might
now be equal to the sum of _two_ approximately classical wave functions. Ie,
two "universes".

So, the universal wave function hasn't split, but the attempt to represent
that wave function by approximately classical wave functions _has_ split.

~~~
Xcelerate
> but the attempt to represent that wave function by approximately classical
> wave functions _has_ split.

Exactly. The problem is that people keep trying to view quantum physics
through a classical lens.

Decoherence is simply the fact that a quantum state evolves to a point where
it can no longer be _mathematically represented_ as a tensor product state. I
don't lose any sleep over that.

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ZeroGravitas
There's a BBC documentary about this, also created for the 50th anniversary,
starring his son, who happens to be a semi-famous singer-songwriter with the
band Eels:

[http://eelstheband.com/parallel_worlds.php](http://eelstheband.com/parallel_worlds.php)

It's available in full on Vimeo and embedded at the bottom of the above page.

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Houshalter
Truly a terrifying hypothesis. Dearly hope it is not true.

~~~
Moshe_Silnorin
As it predicts quantum immortality we will all find out if we wait long
enough:[https://en.m.wikipedia.org/wiki/Quantum_suicide_and_immortal...](https://en.m.wikipedia.org/wiki/Quantum_suicide_and_immortality)

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ommunist
Ehm. Did someone picked a photo at parallel universe? Never heard of such an
event.

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_AllisonMobley
That text is impossible to read for me. It's all light grey on white and
patchy.

~~~
jimhefferon
Reads fine for me (Firefox under Ubuntu).

