Date: Thu, 29 Apr 1993 18:22:46 GMT
From: reich@cod.nosc.mil (Ronald S. Reich)
Organization: Division of Applied Sciences, Harvard University
Subject: geometry
WORLD CLASS TEAM TIPS
by
RON REICH
Here are some things to think about for the would be world
class teams. There is a lot of Geometry and Physics that can be
applied to the construction of your routines. When the
principles of these disciplines are properly applied the judges
will be given the illusion that every thing is in its place.
But, if these principles are overlooked or not taken into
consideration it is possible that even though you as a flyer see
the picture you are trying to create, the judges see something
entirely different.
Realizing that some of the important judging factors are
Spacing, Timing, and smoothness and well as straight lines, the
following geometric and physics principles apply:
1. The opposite sides of a parallelogram are equal
length and remain parallel for all interior angles.
CONSIDER THIS WHEN DECIDING WHERE OR NOT TO STAGGER THE LINE
LENGTHS OF THE MEMBERS. EQUAL LENGTH LINES MAY MAKE IT EASIER TO
MAINTAIN SPACING. (ASSUMING THAT YOUR BODIES STAY PUT) There
are tradeoffs that need to be considered with using equal length
lines. i.e. increased chance of buffeting from the kite in
front.
2. Parallel lines in space appear parallel from any
angle of view.
IN THE CASE OF LARGE TEAMS (6 OR MORE), I THE DESIRED
PICTURE IS PARALLEL STRAIGHT LINES THEN ALL KITES IN THE SAME
LINE NEED TO BE ON THE SAME EXACT PATH. i.e. 2 points determine
a line, the 3rd point may or may not be on the line.
3. Any 3 points in space determine a plane. A 4th
point may or may not be on that plane.
THE PLANE FOR THE KITES IS SPHERICAL. i.e. Four kites in
diamond formation fling a large full sky circular pattern may get
distorted if all kites are not on the same plane. Consideration
should be given to line lengths and body positions.
4. Multiple objects equally spaced on a flat planar
surface will appear equally spaced from any angle of view.
PATTERNS WHICH ARE INTENDED TO REPRESENT BOXES OR RECTANGLES
WILL GET DISTORTED AS THE PASS ACROSS THE WIND WINDOW IF ALL
KITES ARE NOT ON THE SAME PLANE. IF THEY ARE ON THE SAME PLANE
THEN THE ONLY CHANGE WILL BE THE APPARENT LENGTH OF THE SIDE OF
THE BOX.
5. Each individual team members kite is on its own
spherical planar surface.
IN ORDER TO STAY ON THE SAME FLAT PLANE AS THE OTHER KITES
THE FLYER WILL NEED TO MOVE AROUND ON THE GROUND TO COMPENSATE
FOR THE CHANGES DUE TO THE SPHERICAL PLANE.
6. The circumference of a circle is directly
proportional to its radius.
TIMING PATTERNS SUCH AS FULL PINWHEELS CAN BE PERFORMED MORE
EASILY IF THE KITE ON THE SHORTER FLYLINES FLYS THE LONGER PATH.
THE KITE ON THE LONGER FLYLINES WILL BE ON A LONGER RADIUS TO THE
FLYER AND WILL THEREFORE BE FLYING ALMOST THE SAME DISTANCE AS
THE KITE ON THE SHORTER LINES BUT THE ILLUSION IS THAT THE KITE
ON THE SHORTER FLYLINES IS FLYING MUCH FARTHER. CONSIDERATION
MUST BE GIVEN TO THE POINT OF VIEW OF THE JUDGES. i.e. The
picture to the flyers may need to be slightly distorted in order
to present an appropriate picture to the position of the judges.
7. Apparent distance traveled is inversely
proportional to the range of observation.
8. Apparent speed is inversely proportional to the
range of observation.
THESE TWO PRETTY MUCH GO TOGETHER AND SHOULD BE CONSIDERED
WHEN DOING TIMING MANEUVERS. IF ONE KITE NEEDS TO PASS IN FRONT
OF ANOTHER, THE ONE ON THE SHORTER FLYLINES CAN GET THERE SOONER.
i.e. The cascade team compulsory is an example where this may be
a consideration that would help. If the first kite to break from
the top is the shorter flylines then it will reach the bottom in
less time than the others to travel that same apparent distance.
Getting to the ground quickly will give it more time to cut
across the bottom in front of the others.
There is more but at this point I don't have a feel for how
much interest there is on the network for these subjects.
Still Learning and Sharing
Ron Reich