[ExI] New article about the Block Universe

[John Clark]

On Sun, Mar 22, 2026 at 6:36 PM Jason Resch via extropy-chat <
extropy-chat at lists.extropy.org> wrote:




> *>> The Universal Wave Function (also called the Multiverse) is as far as
>> you can get from something that exists in one and only one definite state
>> (a.k.a. Realism) as it is possible to be.   *
>>
>
> *> I don't know why you define real as something being and remaining in
> "one and only one definite state".*
>

*I am using that definition because that's what quantum physicists mean
when they use the word "real". And "unreal" and "nonexistent" are NOT
synonyms to a quantum physicist.  I agree that's not what people usually
mean in everyday conversation when they use those words, but most everyday
conversations are not about quantum mechanics.    *


> *> Under that definition it seems only abstract mathematical objects and
> other universals would foot that bill.*
>

*A coin that you have flipped but not looked at is not an "abstract
mathematical object".*

*> Consider that our observable universe changes about 10^106 times per
> second. Yet who would say the universe isn't real on account of the fact
> that it is constantly changing?*
>

*Yes. But "isn't real" certainly doesn't mean "doesn't exist". Don't get
too hung up over a word.   *

*>>>There is the bird's-eye-view of reality, in which there is one state of
>>> the universal wave function,*
>>>
>>
>> *>> In order to obtain that "bird's-eye-view" it would be necessary to,
>> not just step out of the universe but step out of the Multiverse which by
>> definition contains  EVERYTHING, therefore it is a view from a point that
>> does not and can not exist. That would be true even if you don't take
>> Quantum Mechanics into account which of course you must. *
>>
>
> *>Many views in science are like this (they exist from an abstract,
> non-subjective vantage point, which no observer holds in actuality). We
> think about early times of the universe when there were no observers. We
> think of the insides of stars where there are no observers.*
>

*If Many Worlds is correct then there was NEVER a time or a place where
there were no "observers" (except outside of the multiverse) because there
is always something that could change and that could cause change.*

*>> And a thought experiment that would be impossible to perform even in
>> theory is of no use except to prove that the conditions specified by the
>> thought experiment can not exist; for example when Einstein imagined what a
>> light beam would look like if he was traveling at the speed of light and
>> realized what he saw would violate Maxwell's Equations. To remain
>> compatible with Maxwell he needed to hypothesize that it was impossible for
>> anything that has mass to travel at the speed of light, and that light must
>> always travel at a constant speed.*
>>
>
> *> I'm just stating what the physical equations say. If you believe the
> Shrodinger equation describes something called a wave function, and this
> wave function exists and functions whether or not there are observers
> viewing or thinking about it*
>

*As I said before an "observer" need not have the ability to think or to
view or even to calculate,  it just needs to have the ability to change
and to cause change. *


> *>  then you believe in something physically real (as opposed to a mere
> idea, experience, or calculating device),*
>

*NO! As opposed to something incapable of changing or of causing a change
in something else. If you want to play the game you've got to use the
definition of words that the experts in the field use. *


> *> and if you believe in something real that is realism.*
>

*Obviously. But what an art critic means by the word "realism" is not what
a quantum physicist means by that word, and neither of them means what you
insist  "real" means, which is existing as opposed to non-existing. *

*> If you want to deny realism under QM, you need something like QBism, or
> something that says QM is only about observer knowledge states.*
>

*QBism is part of the Shut Up And Calculate quantum interpretation. It
works, it's not wrong, but it's unfulfilling. *



> *>>Quantum mechanics is inherently crazy, no interpretation is ever going
>> to make it intuitive. If I was betting I'd give Many Worlds about a 70%
>> chance of being largely correct, but if it's wrong then something even
>> crazier is true. *
>>
>
> *> Could you say what you mean by the term realism, and give an example of
> a theory that qualifies?*
>

*Pilot Wave Theory is realistic and deterministic but very non-local.
Objective Wave Collapse (my second favorite quantum interpretation) is
realistic and local but not deterministic, Copenhagen is whatever
particular Copenhagen fan you happen to ask says it is. And **QBism is a
polite name for shut up and calculate. *

*>>> and include FTL violations of relativity when the theory doesn't
>>> demand it.*
>>
>>
>> *>> That sort of non-locality would violate Special Relativity but NOT
>> General Relativity because information still cannot be transmitted faster
>> than light, and General Relativity supersedes Special Relativity.  *
>>
>
> *> I've always found this carve out a lame retreat from what relativity
> made so clear: nothing can travel faster than light through a vacuum.*
>

*That hasn't changed, nothing can travel through space faster than light,
that's why it's impossible to transmit information faster than light, but
according to General Relativity space itself can travel at any speed. And
because space is expanding our telescopes can see galaxies that we could
NEVER reach even if we had a spaceship that could move at the speed of
light, even if we had an infinite number of years at our disposal.  *

*> The illusion of spooky action led some to revise this to "no useful
> information can travel faster than light" but in my view this would still
> represent a violation of relativity. Einstein certainly saw it that way.*
>

*No, Einstein certainly did not see it that way!  Einstein might've said
that in 1905 when all he had was Special Relativity, but he wouldn't have
said that in 1916 after he had developed General Relativity. So when Edwin
Hubble discovered that the universe was expanding in 1929 Einstein
accepted Hubble's results without reservation. *

*>> Nobody thinks the split happens at sub-light speed. And even in theory
>> no experiment can differentiate between the split happening at lightspeed
>> and the split happening instantaneously. Many Worlds is perfectly happy
>> either way. *
>>
>
>
> *> Consider the qubits in a quantum computer. They can be initialized into
> a superposition and then other downstream processes in that computer can
> read these qubits and locally split. But because the quantum computer
> remains isolated from the environment during its computation, the split
> doesn't leave the quantum computer, it takes until the computation finishes
> and then the result is read. Only then does the split continue on beyond
> the confined of the quantum computer. But note, during the computation, the
> split definitely was not going out in all directions at the speed of light.
> If it did it would spoil the results of the computation.*
>

*It's impossible to completely isolate a quantum computer from the outside
world, but you can minimize it enough to make a workable machine. So if
Many Worlds is correct alternate worlds  do split off and the split happens
instantaneously or at the speed of light (take your pick) but thanks to the
very good, but not perfect, isolation of the quantum computer the
difference between those alternate worlds is so small they do not affect
the output of the machine. The only difference between two worlds is that
in one a butterfly in Brazil flaps its wings once and in another two times,
but thousands of miles away two quantum computers produce the same output. *

*John K Clark *
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