An orrery was a mechanical device designed to show the position of celestial bodies at different times. In this modern era, we are able to dispense with the “mechanical”, as well as the hopelessly flawed geocentric models of the solar system. The other day I happened to come across a couple of versions of modern day orreries online. In the spirit of old school orreries, the first (from Dynamic Diagrams) allows you to see both a geocentric model and a Copernican heliocentric model.
The second allows you to see a more true Keplerian model.
And, boom, you have wandered through 2000 years of progress in astronomy. And it was pretty.
The Finch and Pea 
3 thoughts on “Orrery”