A photon (modeled by a bouncing ping-pong ball) is observed from two reference frames and provides the motivation for time dilation.
Video of our demo in action https://youtu.be/c6m6pCROEf8
Assembly of three gas discharge tubes and white light source for spectral analysis with diffraction gratings.
The redshifted spectrum of galaxies and quasars is due to an expanding universe and can be expressed as the ratio of the scale factor of the present Universe to that of the Universe when the light was emitted. You can think of this as the...
A high-pitched alarm on the end of a rope is whirled about the head.
Doppler shift of sound emitted by an object moving in a circular orbit, with the pitch clearly changing as the object move towards, away or perpendicular to the line of the...
Laser and plastic lens with curvature to simulate bending of light by massive object.
Gravitational lensing is caused by the bending of light rays by the gravitational field of an intervening object. The effect is seen with the Sun, but is...
Run towards the blackboard carrying a tuning fork...
Waves emitted from a moving source are Doppler shifted to higher frequencies when moving towards the observer, and shifted to lower frequencies when moving away from the observer. In this...
Orbital motion simulated by ball rolling on wooden potential well.
Motion in a central potential is demonstrated by a ball rolling on a circular 1/r curved surface.
The 1/r potential well simulates the gravitational potential...
Static model of satellite orbits.
Static 3-D model showing the orbital paths of Jupiter's satellites.
The model marks the orbital paths of the Jovian satellites to a scale of 1.5cm = 106 km. This scale allows the orbit of the...
Plastic Wiffle Ball with built-in shriek to throw past (or at) your audience.
Waves emitted from a moving source are Doppler shifted to higher frequencies when moving toward the observer, and shifted to lower frequencies when moving away...
1m diameter rubber sheet acts as curved space for ball bearing masses.
In general relativity, gravity is replaced by a curved space geometry, where the curvature is determined by the presence and distribution of matter. Objects move in...
Globe pivoted so north pole can precess.
Due to the oblateness of the Earth, the gravitational force between the Earth and the Sun sets up a couple which causes the Earth's axis of rotation to precess. An adapted globe shows what is meant by...
