Gravitation

F = Gm₁m₂/r² — inverse-square force between two masses.

g(r) ∝ r inside, 1/r² outside — single curve across both regions.

V(r) = −GM/r — well shape with smooth transition at the surface.

v_esc = √(2GM/R) — launch a rocket with various v₀ and see if it escapes.

v_orb = √(GM/r) — satellite at altitude h with period and g(h).

Elliptical orbit with Sun at focus — equal-area sweep demonstrated live.

Launch satellites into orbit, adjust velocities, and observe Kepler's laws in action with stunning visuals.

Three masses; drag a probe and see net F as the vector sum from each.

g points always toward masses — single mass and binary system fields.

Tune altitude until T = 24h — satellite locks above the same point on Earth.