[Asked whether he would like to see an experimental demonstration of conical refraction.] No. I have been teaching it all my life, and I do not want to have my ideas upset.
—
Isaac Todhunter (1820–1910)4.7 Dynamic Illustration of a Point Conic and a
Line Conic
[Asked whether he would like to see an
experimental demonstration of conical refraction.] No. I have been teaching it
all my life, and I do not want to have my ideas upset.
—Isaac Todhunter (1820–1910)
The first diagram is for a point conic. The second diagram is for a line conic.
Drag d to move one
line in the pencil of points with center P to see
the formation of a point conic.
Clear the trace by clicking on the X in the
lower right-hand corner.
Drag centers
points P and
P' to see different conics. It is possible to obtain both hyperbolas and
ellipses; try it.
Observe the points P and P'. How are the centers of the pencils, P and P', related to the point conic?
To reset to the original settings, type the letter "R" on
the keyboard.
Drag the E to see
the envelope that forms a line conic.
Clear the trace by clicking on the X in the
lower right-hand corner.
Drag axes p
and
p' to see different conics. It is possible to obtain both hyperbolas and
ellipses; try it.
Observe the lines p and p'. How are the axes of the pencils, p and p', related to the line conic?
JavaSketchpad,
a World-Wide-Web component of
The Geometer's Sketchpad.
Copyright © 1990-2001 by KCP Technologies, Inc. Licensed only for non-commercial
use.
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© Copyright 2005, 2006 - Timothy Peil |
