Rolf Bertram

Doppler Effect explained in about 2 minutes, relating to water surface waves, sound waves in air, an

Freestyle driving with jumps and spins. On iPad/iPhone/iPodTouch you have the option to control the

Interactive experiments about kinetic energy.

GRec is for medical research, to record g-force events caused by muscle twitches. It uses the device

Colored 3D Lissajous. Fine tune shape by touch position, and view from all directions by tilt/rotate

36 puzzles in which you move the ball to the target by tilting and even sometimes holding the device

Build simple shapes with transparent cubes, and view from all sides by rotating/tilting device.

Interactive demonstration of superposition, amplitude and frequency modulation. Audio explanation in