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

[Stuart LaForge]

Quoting BillK:


>> It seems to violate the Copernican principle that the moon should
>> dance at the whim of mere monkeys and that seems like a slippery slope
>> to solipsism.
>>
>
> It does indeed! But that's not what QBism claims. :)
> Their description of a fuzzy mass of probabilities only applies to
> quantum states.
> They see the collapse of the wave function as an operator action
> causing a result which updates the operator belief. Not that the
> operator belief caused a specific result.

But multiple quantum systems in their quantum states must somehow sum  
to classical states in aggregate. The messy ignorance and randomness  
of the quantum world must somehow give rise to the clockwork certainty  
and predictability of Newtonian mechanics in the limit of large numbers.

Ontological interpretations have decoherence to help explain how this  
happens. But epistemological theories like QBism can't appeal to  
decoherence because they don't believe the wavefunction is real. Why  
would a bunch of imaginary wavefunctions interact with one another to  
cancel out their wavelike properties? Why is the physics of a singe  
electron more complicated than the physics of the moon?

>> In ontological interpretations of QM, such as MWI however, the moon is
>> always there and in every possible phase and position while it is we
>> precious observers that may or may not be there to witness it.
>
> QBism also believes in the moon.  :)  The idea that the rest of the
> world doesn't exist until I look at it (while tempting) is pretty
> obviously not correct. The universe existed before humans appeared,
> even before life appeared.

It is comforting that QBists profess to believe in the moon even if  
they can't explain how it arises from their physical theories. You  
speak of the universe before life evolved. Where did that universe go?  
If you insist that it is in the same location as our present universe,  
only the present universe is in a different informational state, say a  
different arrangement of atoms, then that is fine.

But then you are forced to admit that nothing precludes a different  
patch of space-time from having a similar arrangement of atoms as our  
past universe. And given the same set of laws of nature everywhere  
throughout infinite space and thus infinite chances for the atoms to  
fill together just right, such a result would seem to be guaranteed.  
And if two arrangements of atoms are identical, then can they not be  
said to be the same arrangement?

> As I read it, QBism is presently only arguing a POV about quantum wave
> function collapse.
> They claim this is better than the Many Worlds interpretation which
> they say is meaningless and no help to quantum theory research.

Meaning is purely subjective, a Bayesian should know that. The same  
alarm call meaning "danger!" to one brain might mean "dinner!" to  
another. The alarm call itself, is blank and meaningless placeholder  
for a subjective attribution; as all such symbols and messages are.  
Which is why the swastikas painted on prehistoric cave walls don't  
mean the same thing swastikas do today. Perhaps rather than  
complaining about MWI, QBists would be better served using their  
Bayesian powers to design an experiment to rule MWI out.

> An
> infinite universe doesn't necessarily mean that every possible past,
> present and future exists somewhere.
> Some infinities are bigger than others!

The model I present is predicated on the laws of physics, apart from  
the values of certain constants, being truly universal and valid  
throughout all of infinite space. General relativity rests on a  
similar postulate. Also, I assume space is a continuum so it is  
aleph-1 at least. That should be plenty of room, especially with the  
whole thing expanding Hilbert Hotel style due to dark energy.

Stuart LaForge