On 29 Nov 2017, at 22:57, Bruce Kellett wrote:
On 30/11/2017 5:53 am, Brent Meeker wrote:
On 11/28/2017 11:10 PM, Bruce Kellett wrote:
On 29/11/2017 5:28 pm, Brent Meeker wrote:
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.
Actually, the whole idea that quantum effects in the brain affect
behavioural outcomes is pretty nonsensical. As we know, the brain
is a hot system with decoherence times of the order of
nanoseconds. If random quantum effects affected behaviour,
behaviour would be random and purposeful action would be
impossible.
But some randomness is useful and evolution would not try to drive
it to zero (c.f. Buridan's ass), which is not to say it needs
quantum randomness. There are plenty of of sources of randomness
in the environment.
As you say, not all randomness is quantum randomness.
This is ruled out by experience -- as is the related notion of
superdeterminism.
I don't see that superdeterminism is ruled out, or can be ruled out
by experience. Experience would seem to rule out MWI too, because
like superdeterminism it posits stuff that can't be experienced:
superdeterminism because the don't happen, MWI because they happen
in another "world" to a different "you".
Maybe that is a good reason to disregard such ideas as pure fantasy.
The problem with superdeterminism, as outlined by Tim Maudlin, is
that is would render science and the endeavour to understand the
nature and operation of the world futile -- nothing could ever be
tested because there could be a giant conspiracy to deceive us.
I agree. Superdeterminism is worst than "God" as an explanation. It
looks more like using "Devil" to explain the things. It is not less
wrong, nor more wrong, but it can only be wrong as an *explanation*.
It is self-defeating, like positivism. It sides also with the social
dilution of responsibility or superpaternalism.
With mechanism, like with some marriage of QM and GR, there are "malin
génies" or (arithmetical) Boltzmann Brains, indeed an infinity of
them, but then we can explain why the probability is null that they
influences our normal histories. Thank God :)
Bruno
Bruce
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