Gravity Well (6ft Diameter)

The gravity well is a superior teaching tool. It sets up in minutes and require little storage space. The students are completely captured by how well it demonstrates curved space-time and orbital mechanics. Elliptical, circular, hyperbolic can all be demonstrated. Using a 2.5kb barbell weight and a second lighter weight allows binary system orbits and Lagrange points to be illustrated. A good class challenge is to ask them to write down what happens to a stable circular orbiting marble if the star suddenly vanishes? Why does what they predict happens in terms of physics? Then they see the answer when you quickly remove the weight while a marble is in orbit. It takes some practice to optimally release the marbles and place the weights. Using heavier marbles than supplied helps reduce friction loss and gives longer more stable orbits.

no one talks about using these for electric potential & field

We use this demo when discussing *electric* potential and field. We put a rod underneath, pushing up, to represent a location with high potential, and we hang weights to represent decreasing potential. Then students can see that high/low (electric potential) and steep/flat (electric field) are related, but not the same thing. I'm surprised that I never hear anyone talk about using this kind of demo for electricity.

Cool way to demonstrate the Big Bang Theory and Gravity

My students enjoyed being able to visualize how the Big Bang theory states the universe began, as well as how gravity (attraction) is affected by mass and distance.