PHYSICAL SIGNIFICANCE II

     OK tonight we are going to go further into the subject of physical
significance and specifically how special relativity threw a monkey
wrench into man's cherised ideas of how space and time work.

     Einstein and Godel were good friends, and working together in their
afternoon walks, eating icecream every day at Princeton after the war,
they did a lot of damage to our common sense view of the world.

     In fact special relativity is relatively special in the theories of
man as it was the first theory to utterly dumbfound his efforts to
integrate the evidence into a coherent physical significance of the
world.

     Just say the words 'Michelson - Morely' to scientists of the day in
1905, and you would see them turn pale just considering the fate of
their feces, I mean theses.

     To this day, when you ask people who know about these things,
"Why?" they just smile and say "Why ask why?"

     Most have given up trying to understand the physical significance
of space and time, and are content to know how to work with it using the
math alone.

     So let's go back and do some simple experiments like we did with
the clock and the cube.

     Special relativistic effects really only come into play at high
speeds.  General relativity deals with WHERE your viewpoint is and how
that affects your perceptions of space and time, but special relativity
deals only with how fast your viewpoint is moving relative to something
else.

     The problem with relative motion, is that it is relative.

     You can't say he is moving and I am not!  Because he is going to
say you are moving and he is not!  Which is right?

     Both views are look likes that then need to be integrated into an
is like.

     The is like is NOT that he is motionless and you are moving nor
visa versa, but how fast you two are moving relative to each other.

     If A and B are moving past each other in space and are separating
at 10 miles per hour, there are many ways a 3rd observer can look at
this.

     One can say A is still and B is moving to the right at 10.

     One can say A is moving to the left at -10 and B is still.

     One can say that A is moving to the left at -5 and B is moving to
the right at 5.  Or A is moving at -3 and B at -7 etc.

     One can even say that A is moving to the right at 10 and B is
moving to the right at 20!

     There are an infinite number of viewpoints moving relative to A and
B that will give different answers as to how fast A and B are 'moving'
relative to the observer, and these form the 'look likes' of the
observer of the situation.

     But no matter how fast the observer is moving relative to A and B,
and thus no matter how fast the observer says A is moving and B is
moving relative to the observer, ALL observers will agree that A and B
are moving at 10 miles per hour relative to EACH OTHER.

     This then becomes the IS LIKE of the situation.

     The is like is an observer free description of the 'what is'.

     When you integrate over all of the look likes of a situation taken
from many different viewpoints by many different observers, the OBSERVER
DROPS OUT OF THE FINAL ANSWER and what you have left is the IS LIKE
describing the OBSERVED situation as if there were no observers at all.

     Thus it is very important to remember that when you are reporting
what an observer saw you are reporting a look like, and when you are
reporting how things actually are, you are reporting an is like and the
observers are all gone and might as well never have been.

     Going back to our Rubik's cube for a moment, the three pictures
taken by the cameras are the observer's report and thus are look likes.
The pictures not only show the cube but also the implied viewpoint,
WHERE THE CUBE WAS LOOKED AT FROM.  Thus the observer's report always
contains data about BOTH the observed and the observer!

     When we integrate the three images to form an idea of what the cube
is like, the final description is about the cube from all possible
angles and viewpoints, and no longer contains any data about which
viewpoints where actually used to take the pictures.

     That's really important, read it again until you get it.

     So integration of evidence taken from many viewpoints about a
viewed object, leaves only data about the object and not about where the
object was viewed from, nor that it was ever viewed at all.

     A look like says:

     "This is how the cube looks to me now."

     An is like says:

     "The cube is this way and not that way" even if no one ever
observed it at all.

     Thus many different sets of observers can take many different
snapshots from many different viewpoints, and end up with an absolutely
identical common description of what was observed, with no hint of where
it was observed from or who observed it, or how many, left in the
description.

     Technically speaking the integration of observations produces an
INVARIANT, that single description of actuality that can be deduced from
the many realities of the observers reporting in about the object under
observation.

      Thus we have the following equalities:

      Reality   = look like = implied viewpoint    = variable
      Actuality = is like   = no implied viewpoint = invariant.

      In the case of A and B moving relative to EACH OTHER at 10 miles an
hour, that is an invariant because all observers agree on it no matter
how fast the observers themselves are moving when they view A and B.

     It is that invariant that forms the common ground of the universe
that is the same for all observers and allows them to play together.

     If there is NO invariant between observations, then each observer
is in their own Private Idaho, playing with their own private
hallucinations of the world.

     When the world changes COMPLETELY with viewpoint, what common world
is there left to agree on?

     It is the invariant that allows us all to sync with each other so
that our many private worlds can be treated as one common one at least
as far as the invariant is concerned.

     We have to comment here that just because a set of observers are
able to extract an invariant out of their combined observations, doesn't
mean they can easily build a physical significance of how the world
actually works.

     As we shall see, special relativity definitely leaves us with an
invariant, but for most people our concepts of a workable sensible
physical significance to how space and time pulls it all off is left in
shambles.

     Goober: "What the hell is this stuff called spacetime anyhow and
how does it work?"

     Professor Harumphsalot: "Don't know, don't care, its not important,
let's just play the game and hit the ball already."

     So let's go back to the subject of simple physical significance
before we tackle the prime time.

     HORSE AND TRAIN.

     Say A is at a train station back in the old days, and at a specific
moment of time, he reports that he sees a train down the track moving
away from the station at 10 miles per hour.  At the same time A sees a
cowboy on a horse racing neck and neck with the caboose of the train
waving to the passengers inside.

     The horse and train are running in parallel, the train on the
tracks and the horse on the dirt road right next to the tracks.

     That is A's look like.

     Say that B is in the caboose of the train, and at the same moment
of time he looks out the back of the caboose and he feels himself to be
still but sees the station moving away from him at 10 miles an hour, and
looking out the window of the caboose he sees the cowboy on the horse
not moving at all relative to the caboose.  He can even hand the cowboy
a cup of coffee and chat calmly with the cowboy while both he and the
train move down the tracks together.

     In the first report, A feels himself to be still, and both B and
the train and the horse are moving away from the station at 10 miles an
hour.

     In the second report, B feels himself to be still, and so is the
horse, but the station is moving away from both of them in the opposite
direction at 10 miles an hour.

     Which one is 'right?'

     What is the physical significance of these two different reports
(look-likes)?

     In other words let's integrate these two reports and distill an
invariant out of them that both observers will agree on.

     That's pretty simple, the train and the station are moving at 10
miles an hour away from each other, and so are the horse and the
station.  Further the horse and the train are not moving away from each
other at all.

     Since both A and B would agree to that interpretation of the
evidence (integration of viewpoints), and since neither A nor B, as
observers, are mentioned at all in the final description, we have an
invariant that properly describes the actuality of the situation
independent of any observer.

     So that was simple, straight forward and made every day common
sense.

     But, now let's say something else is reported by B.

     At the same moment of time as before, A reports the same thing,
both horse and train are moving away at 10 miles an hour from the
station and are already a ways down the track.  Further A asserts the
train left the station at the same time as the horse.

     B also reports that the station is moving back away from the train
at 10 miles an hour, but that the horse is moving 10 miles an hour ahead
of the train!

     In fact when B tries to hand the cowboy a cup of coffee he can't
because the horse is way down the tracks from the train having been
pulling further ahead of the train from the moment both left the
station.  B claims the horse left the station AFTER the train did, then
caught up with the train, then passed it and is now way down the road
ahead of the train.

     A rejects B's data as hallucinatory and integrates over his own one
and only view and says that the horse and train are moving away from the
station at 10 miles an hour.  A also concludes that B should see the
horse stationary to the train, and the station receeding from both the
train and the horse at 10 miles an hour.

     B rejects A's data as hallucinatory, and integrates over his own
one and only view and says that the train is moving away from the
station at 10 miles per hour, but that the horse is moving ahead of the
train at another 10 miles an hour, and thus the horse is moving head of
the station at 20 miles an hour, and in fact left the station AFTER the
train did!

     At the exact moment of observation, where A sees the horse and
train running neck and neck with each other, B sees the horse way up the
track.

     Holy Michalson - Morely Batman, how can this be?

     Two completely different look likes compute back to two completely
different is likes.

     Like the old lady said in the Burger King hamburger commercial
"Where's the invariant?"

     Are A and B in their own private Idaho?  Or is there someway we can
salvage this situation and maintain some sensibility in the nature of
things?

     OK, let's consider one really truly implausible possibility that
might account for the discrepancy.

     This one is so far out in left field we aren't even sure it's in
the same ball park any more.

     Let's say that somehow, under some circumstances, A can see into
the past.

     When A sees into the past A thinks he is seeing present time, but
if A could see a clock in the object he is viewing, the clock would read
a few minutes ago!

     So here are the rules to seeing into the past, I am not saying
anyone can do this, I am just saying that if these rules applied we
might be able to salvage the two minority reports and produce an
invariant out of them.

     A can only see into the past if an object is moving away from A,
and the faster the object is moving away from A, the further into that
object's past A can see.

     Now the first thing we need to notice is that the speed of light is
finite, about 1 foot per nanosecond.  So even when things are still
relative to A, the further they are away from him, the more into the
past A will be seeing them, because of the delay of the light coming
from the object back to A.

     So if A is looking at something 30 feet away, what he is seeing now
is light that left that object 30 nanoseconds ago.

     And if A is looking at the train when it is a mile away, the image
A sees now is of the train 5280 nanoseconds ago because there are 5280
feet per mile.

     We are NOT talking about this delay here when we are talking about
seeing into the past.

     For that train one mile up ahead we are talking about seeing an
image that comes from MORE than 5280 nanoseconds ago.  We are seeing
truly into the oject's *PAST*.

     This means that if two objects are moving away from you, like the
horse and the train, but the horse is moving faster than the train, at
the exact moment that the horse and the train are neck and neck, you
will be seeing MORE into the horse's past than the train's, thus the
horse will look like it is behind the train still trying to catch up!

     Let's also say that the further AWAY from A a moving object is from
A, the more A can see into its past as long as it is still moving.

     Ridiculous right?

     But let's see if it works.

     Both horse and train are moving away from A, thus whatever A sees
of horse and train, A is not seeing their true present position along
the tracks, but their position a small time in the past.

     The further the horse and train get away from A, the greater the
discrepancy between their true position in present time, and the
position that A sees them in which actually happened some time before.

     Notice also that the horse is moving faster than the train, as from
B's viewpoint the horse is racing out ahead of the train.

     So from A's point of view, A's perception of the horse is always
MORE into the horse's past than the train's past because the horse is
running faster than the train.

     So in general A has a deeper view of the horse's past both because
the horse is moving faster than the train from A, and because the horse
is further away than the train (after the horse passes the train.)

     We then consider that where ever the train has been on the track,
the horse has been there a short while before.

     Say the train is 1 mile down the track and the horse is 1.5 miles
down the track.  At some earlier time in the horse's past it was also at
1 mile down the track.

     It is apparent that at some point in time A might actually see both
the horse and the train at the 1 mile mark at the same time, even though
the horse was 'really' at the 1.5 mile mark because A's view of the
horse's past is deeper than A's view of the train's past.

     Thus A's report that they are in the same place contradicts B's
report that the horse is ahead of the train, because each is looking
into a different part of the moving object's past.

     And a moment later, A WILL see the horse ahead of the train, but B
will be seeing the horse much further head, because A still has a deeper
view of the horse's past than B does, due to the horse's greater speed
and distance from A.

     But how can you look into an object's past?

     And if you can look into an object's past, can you look into it's
future too?

      To be continued...

      Homer

------------------------------------------------------------------------
Homer Wilson Smith     The Paths of Lovers    Art Matrix - Lightlink
(607) 277-0959 KC2ITF        Cross            Internet Access, Ithaca NY
homer@lightlink.com    In the Line of Duty    http://www.lightlink.com
Sun Feb  8 00:37:53 EST 2009