Honors 210 -- Evolution of Scientific Thought
This page contains two programs of mine that demonstrate epicycle motion, one (EP_INNER.EXE) for Mercury and Venus, the other (EP_OUTER.EXE) for Mars, Jupiter, and Saturn. They are a bit crude, but they do work! The difference between them, of course, is how they show the position of the sun.
To try them, click on either one below. Depending on how your browser is configured, it will give you the option to open it or save it. First try opening it--it worked on my browser just now. Not many people have used it this way, though, so I'm not sure that it will work from the browser in all cases. Let me know what happens.
If it works, you will get a full screen (It's actually a Dos screen) image showing the earth at the center, a deferent, an epicycle mounted on the deferent, and a planet mounted on the epicycle. There will also be a line that represents the location of the sun. Press any key (repeatedly) to see the planet rotate on the epicycle as the epicycle rotates on the deferent. Note the retrograde loop that the planet describes. Press Q or q to quit running the program.
Note that for Mars, Jupiter, and Saturn, the planet is in opposition when it goes through the retrograde loop.
If that doesn't work (or even if it does), you can also download either program by choosing Save instead of Open, and then running it on your (Windows) computer in a Dos shell.