chris peck wrote:
Im fairly sure you are attacking a straw man. We can just say that 'now'
races towards the future rather than the opposite without us exerting any
effort, whilst 'here' doesnt really move at all. Especially for a rock. At
least the a priori notions of each spatial dimension dont involve change of
position, but our a priori notion of time at least involves a change of
time. If time has no arrow one way or the other, if there is no succession
of events, then time stops.
I am left wondering whether you know what I mean at all when I say that we
are embeded in time in a way we are not in space. Its more the point that
there is a direction to time rather than whether we characterise the
direction one way or the other, or whether it can be flipped, or whether
backwards in time need be or neednt be represented by positive integers.
One way or the other, time moves on. And if it doesnt, everything stops.
But there's no need to understand this in terms of time "moving", we can
just understand it in terms of our brains having different memories and
anticipations of the future at different points along our worldline.
Relativity poses severe problems for the idea that there is actually a
single "present moment" which is constantly moving towards the future in
some universal, objective sense. In relativity, simultaneity is relative,
meaning that two events which happen at the same time-coordinate in one
reference frame will happen at different time-coordinates in another
reference frame, and relativity says that no reference frame is physically
preferred over any other. I suppose you could still imagine that one
reference frame is "metaphysically preferred" and thus has the "true"
definition of simultaneity, even though there is no experiment you can do to
find out which reference frame this is, but this view seems rather
inelegant.
For more on relativity and why it tends to favor the "block time" view over
the "moving present" view, see this article by Paul Davies:
http://tinyurl.com/dlo3v
Jesse
