On 7/23/2011 3:37 PM, Jason Resch wrote:
On Fri, Jul 22, 2011 at 3:54 PM, Stephen P. King
<[email protected] <mailto:[email protected]>> wrote:
On 7/22/2011 10:46 AM, Jason Resch wrote:
On Fri, Jul 22, 2011 at 3:30 AM, Stephen P. King
<[email protected] <mailto:[email protected]>> wrote:
On 7/22/2011 2:11 AM, Jason Resch wrote:
On Fri, Jul 22, 2011 at 12:44 AM, Stephen P. King
<[email protected] <mailto:[email protected]>> wrote:
On 7/22/2011 1:24 AM, Jason Resch wrote:
All the relevant parts of relativity which imply
block time have been confirmed. The above is like
arguing against gravity because Newton's theory
wasn't compatible with the observations of Mercury's
orbit.
Hi Jason,
Could you be more specific? Exactly which "relevant
parts which imply block time have been confirmed" and how?
Special relativity, time dilation due to speed, non
simultaneity of events reported by observers in different
reference frames, and so on.
And to Brent's point, regarding the conflict between
relativity and QM, that issue is with GR, SR is not in
conflict with QM.
This paper explains it well:
http://philsci-archive.pitt.edu/2408/
Jason
Hi Jason,
I will check that paper, thanks! But here is the thing
about the implications of relativity of simultaneity: Since
it prohibits any form of absolute synchronization of events,
this in turn restricts how the entire space-time manifold can
be considered as parceled up into space-like and time like
regions.
Imagine that spacetime is a 3 dimensional instead of four
dimensional. Now take any object's velocity through that space
time, and consider a plane perpendicular to the direction of that
velocity. The content of that plane is considered the "present"
for that reference frame. This is more clear if you consider
euclidean space time rather than Minkowski space. The only
difference you need to make to convert spacetime to Euclidean is
to imagine that every object's velocity through space time is c.
/Relativity Visualized/ is a good book which explains this view,
but this site also explains it:
http://www.relativitysimplified.com/ . It enables an intuitive
understanding of all the strange effects like time dilation and
length contraction. Since we see only the three dimensional
"shadow" of objects, an object with a different velocity is
rotated in space time. It is like having an umbrella pointed
straight at the sun vs. it being tilted, if it is tilted its
shadow becomes compressed along the direction it is tilted.
In other words, there cannot exist a single Cauchy
hypersurface what acts as the set of initial (or final)
conditions for a GR field equation for the entire universe.
The fact that relativity iplies a unique present for every
reference frame is one of the main arguments for block time. How
can the car driving past you have a present containing different
real objects than yours? Presentism assumes the present is the
set of real objects at a given period of time, but what is real
to you now in this moment is different from what is real to me in
the same moment if we are moving relative to each other (even if
we are at the same location). See:
https://secure.wikimedia.org/wikipedia/en/wiki/Rietdijk%E2%80%93Putnam_argument
The paper I cited also goes on to counter objections made to that
argument.
Thanks,
Jason
--
Hi Jason,
Stephen,
Thanks for your comments. I will not reply to everything you
mentioned, because I think Jesse did a good job of adressing most of
the issues you raised.
None of those papers address the concern of narratability that
I am considering. In fact they all assume narratability. I am
pointing out that thinking of time as a dimension has a big
problem! It only works if all the events in time are
pre-specifiable. This also involves strong determinism which is
ruled out by QM. See
http://plato.stanford.edu/entries/determinism-causal/#StaDetPhyThe
for a general overview and
tph.tuwien.ac.at/~svozil/publ/1994-calude.pdf
<http://tph.tuwien.ac.at/%7Esvozil/publ/1994-calude.pdf> for a
discussion that involves computationalism.
Determinism and locality are only lost in the collapse theories.
Under MWI and similar theories, physics is local and deterministic.
The idea that time is a dimension assumes that the events
making up the points of the dimension are not only isomorphic to
the positive Reals but also somehow can freely borrow the well
order of the reals.
Imagine space time as an apple. Now I ask you the question "Which
seed comes first?" There is no objective answer, the seed that comes
first depends entirely on the angle at which you approach the apple.
The same is true of events in space time, there conclusion of which
event occurred first depends entirely on the angle at which one is
travelling through space time. Time, under Euclidean relativity is
exactly like any spatial dimension, the reason it seems different from
the other dimensions (we can't change direction through it, go
backwards, change our velocity through it) is because there is a
physical law that all objects must always travel at the speed of
light. The dimension of time is merely the one parallel to the
observer's direction at the speed of light. This is why two objects
in relative motion to each other have slightly different
interpretations of what the dimension of time is. It is why in
Feynman diagrams, one can rotate or swap dimensions of space or time
and the physical interaction remains entirely possible. Since length
contraction occurs in the dimension of time, from the perspective of
an observer their dimension of time is 0-length (this is intuitive
because if everything has to move at c one cannot speed up or slow
down to travel freely through the dimension of time).
Please do not think that I am trying to knock Special or General
Relativity, they both represent time in terms of local readings of
clocks and therefore bypass the question that I am considering.
The block universe idea assumes a unique and global ordering of
events, the actual math of SR and GR do not!
In the context of the everything, there exist an infinite number of
different block universes, and an infinite number of them contain you
as you exist in this moment. Just as you can be recreated (and
brought back to life) in a different time or place, using different
material, you may also be "recreated" in these other universes. Thus
from one second to the next, you can travel between these universes,
between vast times, between vast distances. You can never be sure
where you are or where you will be. This is the reason for the
apparent indeterminism in physics. For details, see this paper, which
explains how the simple theory that our universe is infinitely large,
leads directly to the weidness of quantum mechanics:
http://arxiv.org/abs/1008.1066
Jason
--
Hi Jason,
Please see my last response to Jesse.
I like that Aguirre
<http://arxiv.org/find/quant-ph/1/au:+Aguirre_A/0/1/0/all/0/1>, Tegmark
<http://arxiv.org/find/quant-ph/1/au:+Tegmark_M/0/1/0/all/0/1> and
Layzer <http://arxiv.org/find/quant-ph/1/au:+Layzer_D/0/1/0/all/0/1>
paper ! I only take exception to its tacit assumption of spacetime
substantivalism.
http://plato.stanford.edu/entries/spacetime-holearg/#PriSpaSub It
assumes an infinite number of spacetimes instead of just one and so does
not address the problem that I am trying to point out.
I am arguing that spacetime is not a substance what we are somehow
embedded in but something that emerges from the interactions of many QM
systems; it is what their observables have in common. I take QM to be a
theory of observers and GR is a theory of how observations are
organized. A theory is a explanatory model and its concepts should never
be considered as objectively existing 'things'. If there is a one-to-one
correlation between the entities of a theory and entities within our
phenomenal experience then that is the hallmark of a good theory, but
the theory is never the phenomena itself.
Onward!
Stephen
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/everything-list?hl=en.
