Gravity Well
Safety Warnings
Warning: UV Exposure
Purpose
A stretched neoprene sheet models a 2D gravitational potential well. Students observe how mass creates a depression and how smaller objects orbit, spiral in, or escape depending on launch velocity. Under UV light, a fluorescent ball orbiting a non-fluorescent mass demonstrates detection of unseen companions (exoplanet wobble, dark matter).
Figure 1:
Under UV light, a heavy steel ball creates a central well. The fluorescent ball's spiral orbit decays inward due to friction on the neoprene surface.
Figure 2:
Under UV, only the fluorescent ball is visible. A non-fluorescent mass on the sheet (invisible under UV) causes the visible ball to wobble — modeling exoplanet detection via stellar radial velocity.
Figure 3:
Complete setup: UV spotlight on ring stand, neoprene sheet stretched between bicycle wheel rims on tripod frame, heavy steel ball, green fluorescent ball, and bin of assorted smaller balls.
Equipment
- 1
Demo Apparatus
- 1