On 11/28/2017 8:51 PM, Bruce Kellett wrote:
On 29/11/2017 3:22 pm, Brent Meeker wrote:
On 11/28/2017 7:59 PM, Bruce Kellett wrote:
On 29/11/2017 2:29 pm, John Clark wrote:
On Tue, Nov 28, 2017 at 9:05 PM, Brent Meeker
<[email protected]>wrote:
>>
And how is the Eternal Inflation Multiverse fundamentally
different from the String Theory Multiverse?
>
I didn't say they were different from each other; I said they
were different from the mulitple worlds of Everett which all
share the same physics with the same physical constant values.
I see no reason all the Everett worlds have the same physics,
Everettian worlds follow from assuming that the Schrödinger equation
applies everywhere without exception, so that all physical evolution
is unitary. A change in the underlying physics -- such as a change
in the value of fundamental constants, Planck's constant or
Newton's constant for example -- would not be unitary, so cannot
occur in MWI.
The same reasoning applies to the Level I multiverse from eternal
inflation -- same physics everywhere. However, the level ii
multiverse from the string theory landscape has physical constants
and the number of space-time dimensions varying from world to world.
unless it turns out that only one sort of physics can happen. But
lets assume you're right, then the string theory multiverse must be
larger than the many worlds multiverse incorporating everything in
Everett's version and MORE; after all if it contains universes with
radically different laws of physics it must also contain more
modest things like a world where my coin came up heads instead of
tails.
I would suggest that there is no such world. Whether a coin comes up
head or tails on a simple toss is not a quantum event; it is
determined by quite classical laws of physics governing initial
conditions, air currents and the like.
That's not so clear: https://arxiv.org/abs/1212.0953v1
I don't find the arguments in this paper in the least convincing: air
current easily overwhelm Brownian motions, and quantum uncertainties
in times of neural firings are not responsible for the results of coin
tosses, or random digits of pi. We can construct classical coin
tossers, etc. It sounds like they are very close to superdeterminism.
Well I'm pretty sure they're wrong about the coin flipping since Persis
Diaconis trained himself (as magicians do) to flip a coin and catch it
so consistently he can make it heads or tails at will.
Brent
Also, in the Level I multiverse it is quite unlikely that the
initial conditions could differ to an extent such that everything
was identical in the two worlds up to your coin toss. I think
Tegmark is wrong about this. His argument (as outlined in his book)
assumes that worlds are made up at random out of the available
constituents, so every way of filling space-time units is realized
somewhere. But this is wrong. Worlds are not random objects, they
follow the laws of physics, so given some initial conditions, the
future is determined in a deterministic Everettian MW scenario. It
is not the case that everything logically possible happens -- only
those things that follow from the initial conditions by
deterministic evolution happen. So although all possible initial
conditions may be realized somewhere, not everything can follow
deterministically -- the laws of physics cannot be broken.
Right: http://lanl.arxiv.org/abs/quant-ph/0702121v1 The Schrodinger
equation predicts some zeros.
That is more interesting. It is not the case that everything possible
according to some ideas actually can happen in reality.
Bruce
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