Rotating Relativistic String (2D Top-Down & Regge Trajectory)

String theory's founding insight was that a fundamental particle is not a point but a tiny vibrating string, and each vibrational/rotational state corresponds to a different particle. This 2D canvas simulator renders a real relativistic open string — tension T, proper length L — spinning rigidly about its center with its fold point approaching the speed of light, viewed top-down along the rotation axis, exactly the classical picture that first connected string theory to particle physics. A second pane unfolds the string's transverse standing wave edge-on. Live readouts track the string's mass M = πTL/2, angular momentum J = πTL²/8, and the Regge slope α' = J/M², which stays constant as you change the string's length yet tilts when you change its tension — the defining signature of a Regge trajectory. An excitation-mode slider layers quantized transverse harmonics onto the spinning string, visualizing how the full particle spectrum builds on top of the classical rotation.