
New books mount aggressive but ultimately unpersuasive defenses of multiverses - fewi
https://blogs.scientificamerican.com/cross-check/multiverse-theories-are-bad-for-science/
======
vstuart
The many worlds interpretation (MWI) as an explanation for nonlocality
("spooky action" ...) avoids more complete interpretations that avoid locality
(spacetime) altogether as fundamental properties of the universe.

In other leading theories (Roger Penrose's twistors| ima Arkani-Hamed's
amplituhedrons; Lee Smolin's causal relations | views; ...) spacetime emerges,
and issues of locality are "irrelevant."

Pushing MWI as the simplest explanation for nonlocality misses the point --
the need for deeper and more rational, unifying theories that better explain
observed phenomena.

I frankly found the idea that any and every quantum collapse spawned a "new
world" to be absurd, regardless of the arguments.

~~~
stevenhuang
> I frankly found the idea that any and every quantum collapse spawned a "new
> world" to be absurd, regardless of the arguments

Appealing to human intuition may not be the best strategy either, as whatever
the truth is need not conform to any ideas of human intuition or aesthetic.

I'd be more surprised if the answer is something we can easily make sense of.

------
mlthoughts2018
> “ The universe supposedly splits, or branches, whenever one quantum particle
> jostles against another, making their wave functions collapse.”

I’m very tired of seeing pop science articles describe this so incorrectly.
It’s a similar mistake as describing quantum computing as simultaneously
trying a bunch of solution states “in parallel.”

The multiverse theory doesn’t imply any “splitting” action and certainly no
such thing as special measurement or collapse.

If you make a measurement that distinguishes one universe from another, then
“you” just discover which Everett branch you happened to have belonged to all
along. It’s no different from observing outcomes of a random variable. Your
mind is ignorant of a certain state of affairs, you measure something, now
you’re slightly less ignorant of the state of affairs.

I am so sick of these articles. Multiverse QM is a settled debate. Move on.

~~~
teilo
> Multiverse QM is a settled debate. Move on.

That's ridiculous. The Copenhagen Interpretation is still the prevailing view,
among MANY others:
[https://en.wikipedia.org/wiki/Interpretations_of_quantum_mec...](https://en.wikipedia.org/wiki/Interpretations_of_quantum_mechanics)

Further, the science is settled, so anyone who disagrees is a denier? Is that
you, Mr. Carroll?

~~~
mlthoughts2018
Why do you think a poll among certain people adds credulity to one or the
other? Many Worlds allows purely unitary wave function evolution while
explaining all known experimental and observational results with no less
fidelity than any alternative. It’s solely a matter of Occam’s Razor that,
until there is experimental evidence to the contrary, MWI is the solely most
parsimonious available explanation.

Wave function collapse is a purely unjustified extraneous detail that violates
the scientific method to believe it without additional evidence.

MWI is by its own definition the choice of belief not requiring attaching
vestigial extra details onto the theory, as far as any currently known
experimental results go.

~~~
teilo
That's just, like, your opinion, man.

It's also a red herring. You stated that the science is settled. It is not.
Not even close. "Settled" means that that there is a scientific consensus by
all but a fringe, that MWI is the correct interpretation of QM. Of course,
that is not the case, as should be blatantly obvious to you.

Besides which, nothing in science is ever "settled." It is always open to new
interpretations when new data presents itself, or when a more persuasive
theory is formulated. So on both counts your "settled" argument fails.

Furthermore, this statement is pretty bold, but let me re-write it, because it
applies better to MWI than to the wave collapse function: "The Many Worlds
conjecture is a purely unjustified extraneous detail that violates the
scientific method to believe it without additional evidence."

The inability of the MWI to distinguish itself from the CI by any experiment,
real or imagined, is the very reason why it has not gained traction.

~~~
mlthoughts2018
> “ Settled" means that that there is a scientific consensus”

no, science is not related to consensus. If it were, then religion would be a
matter pf physics.

Science is unique in that only theories which hold up to the evidence matter,
regardless of how many or few people (or experts) believe them.

In ~1800, the science against creationism was just as settled as it is today,
despite the prevalence of that religious view, even among scientific
authority, at that time.

~~~
teilo
I see little difference between the religious dogma of the 19th century and
the scientific dogma of the MWI. For it to be remotely "settled," there
actually has to be evidence. There is none. It is nothing but a logical model
that one chooses because of their philosophical prejudices.

What you are promoting is not science but philosophical posturing.

~~~
mlthoughts2018
> “ I see little difference between the religious dogma of the 19th century
> and the scientific dogma of the MWI.”

That suggests you badly misunderstand MWI or else have your own dogma in terms
of how you’ll define it. Either way, comparing MWI to religious dogma is
beyond ridiculous.

> “ For it to be remotely "settled," there actually has to be evidence. There
> is none.”

We have nearly a hundred years of quantum mechanical experimental evidence
that supports MWI and doesn’t require no-evidence purely hypothetical extra
things to be attached to the theory, like special collapse.

> “ What you are promoting is not science but philosophical posturing.”

Unless you can support this claim, it seems entirely disingenuous and it’s
like you expect some purely rhetorical flair to make your point. Copenhagen is
closer to your quote than MWI... it’s not even controversial to say so, purely
_definitional_ (as non-controversial as it can get).

~~~
teilo
You have nearly a hundred years of quantum mechanical experimental evidence
that supports CI as equally as MWI. But you have no experimental evidence of
any kind which would allow you to rule out CI, or any of the many other
interpretations, in favor of the MWI.

See, no one disagrees about the evidence itself. That's why there is an "I" in
"MWI." It is one of many possible interpretations of the evidence.

So that puts your whole "settled" nonsense into the category of philosophical
posturing. You have a preference for the the MWI, but you have no scientific
reason for it. That is why your reasons are entirely philosophical.

~~~
mlthoughts2018
> “ You have nearly a hundred years of quantum mechanical experimental
> evidence that supports CI as equally as MWI.”

But you absolutely do not.

“Thing plus totally extraneous, unnecessary additional complicated hypotheses”
is _not_ equally as supported as just “thing”.

Science says let the simplest, most parsimonious explanation that survives
contact with the data prevail.

There can be multiple hypotheses that are all congruent with the same
experimental observations. That does not make each hypothesis equally valid.

Those hypotheses, like anything specifying needless extra collapse physics,
that are not as slimmed down as they could be while maintaining congruence
with the observations must be rejected in favor of those which make fewer
unnecessary assumptions or invoke fewer unnecessary details.

The evidence is always for all theories that are congruent with it. That does
not at all mean science equally supports all those theories.

------
noneqwerty
The implications of a non multiverse universe sort out to some sort of
conscious design. Obviously religious types will jump all over this but
religion X is not the only way to think about a designer.

What people have trouble accepting is we may be in gross error about the
fundamentals of things we think we understand, things like causality, chance
and probability, the nature of consciousness to name a few.

Scientists long to believe they are _this close_ to a full understanding of
the universe and reality. The sad truth is, the _actual_ nature of the
universe may be such that we cannot grasp it with our brains in anyway, the
same way a goldfish can't grasp particle theory.

------
weavejester
There's been some recent experiments[1] that suggest that an observer's
measurements can be subjective, and that different observers can experience
different past facts.

If that's the case, does that suggest that rather than a neat tree of discrete
universes that don't interact after they branch, the universe could be much
fuzzier mess of conflicting realities that can intercommunicate?

[1]:
[https://advances.sciencemag.org/content/5/9/eaaw9832](https://advances.sciencemag.org/content/5/9/eaaw9832)

~~~
aldoushuxley001
I like this take the best.

"Rather than a neat tree of discrete universes that don't interact after they
branch, the universe could be much fuzzier mess of conflicting realities that
can intercommunicate".

Very well said and, in my opinion, this agrees most with my sense of how the
world works.

In a way, reminds me of Rupert Sheldrake's work a bit, atleast in the sense
that his biological work, despite mostly lacking known mechanisms, does seem
to belong more to a universe that's a "fuzzier mess of conflicting realities
that can intercommunicate".

------
charlesism
Shouldn’t the _default_ position be that a multiverse exist? A multiverse is
what logic suggests (starting with “a point in motion is a line” and moving up
to higher dimensions)

~~~
yoz-y
I don't think there should be any _default_ position before we can even think
of an experiment to prove or disprove it.

~~~
charlesism
Why isn’t the Schrödinger's cat thing sufficient? I don’t know much about
quantum physics, but if we find situations where matter has _odds_ of behaving
a certain way, that seems like evidence. How do we explain events not always
having a predictable outcome unless all possible outcomes occur somewhere?

~~~
yoz-y
> How do we explain events not always having a predictable outcome unless all
> possible outcomes occur somewhere?

I think the leap from A to B is unnecessary. "We don't know" is also an
acceptable answer.

------
maroonblazer
From the final paragraph:

>But I’m less entertained by multiverse theories than I once was, for a couple
of reasons. First, science is in a slump, for reasons both internal and
external.

It is?? Does anyone know to what he's referring? From my un-scientific vantage
point it seems to be thriving.

~~~
fourthark
Probably stuff like, we still don’t have any new particles despite spending a
lot of money smashing stuff.

And string theory looks like it may have wasted a lot of people’s time with no
result.

~~~
admax88q
We do have new particles. The Higgs Boson was observed. Unless you don't count
that because it was observed where we predicted it, but then you're just
punishing scientists for being right.

~~~
fourthark
Some people were hoping for more particles.

I’m not sure I agree... was just trying to explain why there is a perception
of progress slowing down.

------
dvduval
From the title of the thread it seems it is best we don't have any more new
books.

------
ganzuul
Can't tell if the author means that, but decoherence doesn't follow MWI.

------
RcouF1uZ4gsC
> Today, physicists still lack evidence of other universes, or even good ideas
> for obtaining evidence.

Until this is no longer true, I will view discussions of the multiverse as
akin to medieval philosophers discussing how many angels can dance on the head
of a pin.

One of the biggest lessons of the scientific revolution is that logic alone is
a poor predictor of reality. We need at some point to go out and test our
ideas in the real world.

~~~
hprotagonist
> I will view discussions of the multiverse as akin to medieval philosophers
> discussing how many angels can dance on the head of a pin.

Interestingly, this is almost certainly anti-catholic protestant agitprop that
lost context.

As such, the question never seems to have been asked; similar questions of
extreme minutae were widely parodied but were probably never a matter of
actual debate or discussion by scholastics.

~~~
bawolff
Similarly, how many actual physicists actually seriously argue about
interpretations of quantum mechanics? I'm not a physicist but i'm pretty sure
its a thing more talked about by philosophers and the popular press than
actual physicists.

Not that there is anything wrong with philosophizing and inquiring into
metaphysical questions.

~~~
archgoon
Sufficiently few that it is beginning to be said by a small number of
physicists that it is a point of embarrassment that the Measurement Problem is
about as unresolved as when it first came up a hundred years ago.

[https://www.nytimes.com/2019/09/07/opinion/sunday/quantum-
ph...](https://www.nytimes.com/2019/09/07/opinion/sunday/quantum-physics.html)

~~~
bawolff
The nytimes article you linked has the quote:

> But what is the wave function? Is it a complete and comprehensive
> representation of the world? Or do we need additional physical quantities to
> fully capture reality, as Albert Einstein and others suspected? Or does the
> wave function have no direct connection with reality at all, merely
> characterizing our personal ignorance about what we will eventually measure
> in our experiments?

Isn't this really just asking about scientific realism? Couldnt you say the
same thing about any scientific concept? Instead of "what is the wave
function", why not "what is an atom". I suspect the main difference is that
earlier physical theories had a direct analogy to real life events. We could
tell a story about the billard ball model of atoms and we can imagine that in
our heads. I have no idea how to imagine a superposition of states. Without
the ability to analogize it, i suspect humans intuitively assume its wrong.
But lack of imagination hardly seems like a logical reason to reject
something.

On the other hand, the question of how/when/why (non-metaphysically) a
superposition collapses into a single state, seem much more scientific, and
that part of the measurement problem seems like a worthy target of scientific
investigation.

Disclaimer: iana physicist nor really know anything beyond basics about quatum
mechanics.

------
vincent-toups
This guy doesn't come across as all that literate about the interpretation of
quantum mechanics.

------
cygx
I agree that the multiverse is a bit over-hyped. However, some of the author's
statements just rub me the wrong way:

 _Science cannot resolve the existence of either God or the multiverse, making
agnosticism the only sensible position._

Science also can't refute me being a brain in the vat, or the universe having
been created last thursday with the appearance of age. It's not only ok to
commit to beliefs that cannot be proven scientifically, it is necessary.

 _Moreover, at a time when our world, the real world, faces serious problems,
dwelling on multiverses strikes me as escapism—akin to billionaires
fantasizing about colonizing Mars. Shouldn’t scientists do something more
productive with their time?_

Why stop at the natural sciences? Let's get rid of all the useless parts of
mathematics - or art and music, for that matter...

If you restricted human endeavours to the utilitarian, the world would be
poorer for it.

~~~
elfexec
> Moreover, at a time when our world, the real world, faces serious problems,
> dwelling on multiverses strikes me as escapism—akin to billionaires
> fantasizing about colonizing Mars. Shouldn’t scientists do something more
> productive with their time?

Couldn't you say the same about the author of the article himself? Why is he
whining about scientists investigating the multiverse theory rather than doing
something more productive with his time? What real world problem was solved
with his article? If multiverse theory is escapism, then what the author is
doing is a worse form of escapism.

------
Koshkin
What does the idea of the multiverse bring to the table?

~~~
dx87
If they discovered that there are infinite universes similar to our own, and
they figured out a way to communicate between them, they could do distributed
research and experimentation like the way we do distributed computing. Instead
of one team spending years doing trial and error, they could divide the
experiment among however many universes they can communicate with, and whoever
gets the solution shares it with everyone else. It wouldn't work for iterative
experiments, but if they have a lot of potential solutions and just need time
to try each solution, things could get done much quicker.

I know nothing at all about multiverses beyond what I read in articles though,
so I don't know if my idea would even be possible.

------
dvduval
If only I could place articles I don't like outside of my event horizon.

As light or matter approaches a Black Hole's event horizon, to the outside
observer it takes an infinite amount of time to actually enter the black hole,
but aside from being ripped apart on the way in, it seems we don't know what
happens after that.

Within this event horizon, this time we can call "now" exists forever to the
outside observer, as we add matter to the black hole we continue to add it to
"now". So in essence the size of the inside of black hole grows inside as we
add matter from the outside, but the inside has "always" had this amount of
matter, yes?

The big bang is often thought to be an explosion, but as you read about it,
there really was no center, rather there was a rapid expansion of space, not
matter. It is the space between the matter that "exploded".

It seems to me there may be the potential for our known universe to be the
result of a massive blackhole that took "forever" to create, so lots of time
to create what we, being inside, see as a massive universe.

Because there may be material still be added from outside the blackhole, our
space-time may be distorted with expansion and dark matter, but that part is
hard to grasp. I suppose there could be blackholes inside of blackholes. If
new material was added inside a blackhole, would we be able to observe that?
Probably not now.

Our observations do indicate some uniformity to the known universe, the way
galaxies are spread out relatively evenly, indicating some sort of law or
tendency.

Continuing to keep in mind there is no center to the big bang, and matter may
be continuing to be added, this may be a possibility of why our universe is is
in a sort of continuous expansion, and in it exists dark matter.

Interesting stuff, but of course no way to know right now, unless of course
now is forever, in which case I either forever don't know, or at some point
will have always known.

