A the risk of being a smart-alek, you answer your own question! The
difference between Spatial and Temporal "dimensions" is that the former is
such that movements can occur that are reversible without any involvement
with any kind of "thermodynamic" laws. Temporal movements are strongly
restricted by thermodynamics and causal restraints. Maybe we should be
asking why this is the case!
As to the notion of more than one temporal dimension: we have that exact
situation in the Many Worlds! Each path in the branching "tree" is a
history, having its own notion of "time". The problem is that there does not
exist a preferred basis with which to define such paths in an unambiguous
----- Original Message -----
From: "chris peck" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Monday, July 18, 2005 1:44 PM
Subject: Re: The Time Deniers and the idea of time as a "dimension"
But then, in what way is time asymmetric to space? You have no answer to
There may be operational reasons why time travel is or is not possible -
I don't have any >>comments on the conjecture of time travel - my only
stance being that I state it is and would be >>improper to consider Time
as -not- being dimensional.
May I ask if you are as agnostic with regards to the possibility of
walking north and then south as you are with regards to moving forward and
backward in time? After all, space is a dimensional like time, isn’t it?
If I claimed an ability walk in a circle, would you remain silent about
There are two ways in which time is not like space. I do not wake up to
find myself travelling haplessly north, however I do wake up and find
myself moving haplessly forward in time. Getting older and older by the
plank instant. Secondly, I cannot reverse the flow of time. I can of
course reverse freely my spatial vector.
Consider the manner in which relativistic theories freely interpret
temporal direction. I’m thinking of Feynman diagrams interpreted as
positrons moving forward or electrons moving back in time. Formally these
interpretations are identical. To overcome the apparent absurdity of such
a concept we dutifully imagine space-time as a (3+1) continuum. As Broglie
"Everything for us that constitutes the past, present and the future is
given en bloc. Each observer, as his time passes, discovers so to speak,
new slices of space-time which appear to him as successive aspects of the
material world, though in reality the ensemble of events constituting
space-time exist prior to his knowledge of them."
It’s an ugly piece of writing, with obvious connotations of times within
times not to mention a deeply deterministic conclusion. (I contrast
'deterministic' with 'indeterministic' here, rather than with 'free
I’m increasingly uncomfortable with such a picture. However - and this is
the point I was trying to make last week - I do not think that one can
account for temporal/spatial asymmetry by appealing to token reflexive
statements. Contrary to McTaggart and Dummet, I do not think that a
complete description of the universe can be given without spatial token
reflexives ('here', 'there', 'this', 'that'). Dummet's contention that one
can conceive of space without adopting a perspective must be one of the
most contentious statements in contemporary Philosophy of Time. I can’t do
it, and I suspect that Dummet cannot do it either. Consequently the
obvious difference between temporal and spatial 'dimensions' is not
captured. If one wants to escape the bloc universe view and entertain
something more dynamic, I really think that such an approach falls flat.
No one must be more intuitive. What is true with regards to reflexives, as
I’ve said in a different way, is that no contradiction follows from the
statement 'what was there is now here', whilst paradoxes emerge from
statements like 'what was past is now future'. Whilst it might be formally
correct to allow for directions in time, it must be just conditional on an
ideal rather than actual concept of time.
[c^2] is exactly an expression of the presence of 2 temporal dimensions
orthogonally configured, >>computing against a sheet region not a linear
What then would it mean for two events to occur in temporally