The yellow disk is a sun in a solor system. The light blue disk is
a planet and the green disk is a moon. The short pink lines starting
at the each disks are the velocitys. The sun, the planet and the moon
attract each other by universal gravitation.
First, click the start button. These disks start moving. If you drag
the pointer near each disk, you can change the velocity and the position.
Next, click the Strobo button. You can see the orbit line of each disks.
The orbit lines can erase by clicking Start button. If you click the
Reset button, you can set the situation initial.
This simulation is calculated by 4th order
Copyright 1997 KATO Noriyoshi (email@example.com)