[ExI] Bergson and Einstein are still debating the nature of time and change

[Stuart LaForge]

In his blog @  
https://turingchurch.net/bergson-and-einstein-are-still-debating-the-nature-of-time-and-change-7fae5d92d235


Giulio Prisco writes:

"David Deutsch noted that other times “are just special cases of other  
universes.” So other times are real: Bergson and Einstein are still  
debating the nature of time and change."
----

Indeed and their doppelgangers Ergson and Binstein also are no doubt  
somewhere arguing over renaissance poetry. Space is vast, If it is  
infinite, then so are we. Every permutation of matter and energy is  
manifested somewhere. So we all occur infinite many times in infinite  
many contexts.
---

"Other physicists include decoherence in their own favorite  
interpretations of quantum mechanics and theories of quantum  
measurement with collapse."
---

I don't see decoherence as being any more necessary than collapse in  
Everett's MWI. If one posits the existence of all possible Everett  
branches, all completely superdetermined, the result would be  
indistinguishable from what we observe. With all randomness  
attributable completely to our ignorance of which of the infinite  
Everett branches we reside in. This view also seems to corroborate the  
Wheeler-Dewitt equation which implies that the total energy and  
information of the multiverse as a whole is unchanging and therefore  
cannot be said to experience time at all.
---

"Back to the questions. Is physical reality deterministic? Is physical  
reality reversible? Is information conserved, or do natural processes  
destroy and create information? These questions are, I think, far from  
settled.
I suspect that both views might be valid, with subtly different  
conceptions of time and information."

If MWI is true, then physical reality could be more than simply  
deterministic, it could be superdeterministic for each and every of  
your entangled non-local quantum doppelgangers. With each version of  
you predestined to make the very choices that lead to your observation  
of a given state of the universe, yourself included.

Information is conserved between universes in the multiverse because  
information is by nature non-local. A single qubit (or even classical  
bit) can span multiple Everett branches and connect parts of the  
expanse that are not otherwise causally connected. That is a direct  
consequence of Bell's inequality violations. But most of the time it  
isn't. I think this is because the Bekenstein bound places an upper  
limit on the information density of space-time but no lower limit  
seems to exist. Therefore a one bit degree of freedom like spin-up or  
spin-down can span the observable universe and beyond. This  
non-locality of information is also necessitated by the Universal  
Wave-function itself as posited by Everett. It could not define the  
Everett branches if it could not transcend and connect all of (not  
just causally-connected) space-time.

We are each a spectrum of information patterns, each different from  
one another by the sum total of the different choices we make out of  
all possible choices available to us. But all we ever see is the  
specific spectral line that the particular instance of ourselves that  
we we find ourselves to be makes.

With regards to physical reality being reversible, I suspect that it  
is only reversible for photons (see delayed-choice quantum eraser  
experiment for details), while matter particles are stuck in  
unidirectional time as a consequence of having rest mass.

Information seems to be conserved across Everett branches but not  
necessarily within them. So when one universe loses information, like  
when a hard drive crosses an event horizon or cosmological horizon,  
another universe gains it.

Any way, though-provoking post, Giulio.

Stuart LaForge