[ExI] The multiverse is unscientific nonsense

[Stuart LaForge]

On 2023-11-14 14:54, BillK via extropy-chat wrote:
> The multiverse is unscientific nonsense
> It's all mere speculation
> 
> 13th November 2023
> Jacob Barandes
> Lecturer in Physics, working on the philosophy of physics, at Harvard
> University.
> 
> <https://iai.tv/articles/the-multiverse-is-unscientific-nonsense-auid-2668>
> Quotes:
> Everyone from physicists like Michio Kaku to Marvel superheroes
> propagate the idea of the multiverse - an infinite set of parallel
> universes. But Jacob Barandes argues that any talk of multiverses is
> nothing more than wild speculation, be it in quantum mechanics or
> cosmology, and that physicists and philosophers are not doing the
> public a service by suggesting otherwise.
> 
> Readers may have heard that according to a particular interpretation
> of quantum theory, we’re living in a “quantum multiverse” consisting
> of parallel realities that exist “in superposition.” And according to
> certain lines of research coming out of string theory, our observable
> universe is only a small part of a vast “cosmic multiverse” containing
> other regions of space in which the fundamental laws of physics are
> substantially different.
> 
> These are extraordinary claims, too, but we don’t have extraordinary
> evidence for them – not by a long shot. As such, any talk of
> multiverses – whether the quantum kind or the cosmic kind – is nothing
> more than wild speculation at this point. With all due respect,
> physicists and philosophers are not doing the public a service by
> suggesting otherwise, even when they include caveats.
> -----------------------
> 
> Quite a long article. It goes into a fair amount of detailed 
> discussion.

I don't like how he is purposefully conflating the string theory 
multiverse where different physical laws exist in different universes 
with the quantum multiverse where heads happen in some universes and 
tails in others all consistent with the exact same physical laws. It is 
like he is trying confuse the reader into thinking that they are equally 
"extraordinary" requiring equally extraordinary evidence.

There is no experimental evidence for string theory, but there is pretty 
good experimental evidence for Everett's multiverse. One particularly 
interesting experiment is the Elitzur-Vaidman Bomb Detector where one 
can distinguish live bombs from duds in this universe, by blowing them 
up in another universe. This is a process called Interaction-free 
measurement where you are measuring a system without disrupting it in 
this universe, by disrupting it in another universe. In Copenhagen or 
Q-Bism interpretations of quantum mechanics, it leads to paradoxes 
thinking about how an event that never happened could give you 
information about an object in the real world.

Here is a good paper on the topic
https://arxiv.org/pdf/0804.0523.pdf


Stuart LaForge