Hi Dan G. and all,
DAN G.
> Since I am familiar with the Mediterranean and the Dead Sea (from maps
> only, I've never been there) I can conceptually agree with you and
> assume you are north of those places and going "down" there
constitutes
> a southward trip. However, from my perspective here in the States you
> are traveling OVER to your ultimate destination.
I think that this misses the point - I was talking about DOWN in terms
of elevation - down being where gravity takes you. We know that things
spontaneously fall, but never spontaneously defy gravity, thus it is not
the same as North vs. South.
I already pointed this out to Dan and we had a short private exchange.
However, I now see that Dan raises a couple of important points.
While I would say that the downward force of gravity represents a
universal experience/value, Dan points out that the way it is perceived
is not completely universal.
DAN G.
> Jonathan's post intrigues me and I will attempt to clarify what I mean
> when I say there are no choices to be made. If we consider initial
> directions such as "up" or "down" as a choice then perhaps we should
> clarify just what those directions refer to. A plane goes up in the
air
> and lands down on the ground from our perspective here on earth.
> However, from a crew orbiting the earth in a space shuttle, the plane
> would fly down below and land down below.
Dan's point is reinforced by something he wrote to me privately:
>An astronaut in [freefall] about the earth may let go
>of an object and it also falls free along with the astronaut, giving
the
>opinion of zero gravity when in fact gravity is just about as strong
>"up" there as it is here on earth.
According to Aristotle, an object needed a "force" just to keep it in
motion.
Not so for Newton - a force was only needed to change the motion e.g. an
object accelerating under gravity.
Not so for Einstein - an object accelerating under gravity is in "free
fall", following the path determined by the curvature of space.
Now that is cleared up, I want to go to the real reason for my post,
again prompted by something Dan wrote:
DAN G.
> For instance, if we make a trip from here ---- to ---- there a
straight
> line seems best. If our course takes us from here /\/\/\/\ to
> /\/\/\/\ there in a zig zag line, it would seem as if the trip would
> take much longer.
The image that comes to mind is the image of a yacht tacking against the
wind, using the force of the wind to defy the force of the wind. As for
gravity, you can't "tack" against it from side to side, but the waterway
lock system Pirsig describes in Lila provides a way of using gravity to
defy gravity: Phaedrus was sailing downwards towards the sea, but
someone sailing in the opposite direction would use the gravity-driven
flow of water into the locks to lift their boat UP.
Both examples show how we can often control and exploit forces to defy
them.
Yet another example of may come from certain martial arts, where one
deftly uses the opponents own strength to overcome him.
DAN G.
>If one ponders this notion long enough it becomes obvious that only the
>destination is important and the method of arriving, or the course we
>take to get there, is not.
Here I disagree - sometimes the method and choices during the journey
actually determine the destination, just as in the nautical examples I
gave.
Thanks for the stimulation Dan .
Jonathan
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