This simulator demonstrates how the relative movement between a wave source and an observer affects how those waves are perceived by the observer, a phenomenon known as Doppler shift.

Click the "Start emission" button to start the simulation. Waves will begin emanating from the source (marked "S"). When the waves reach the observer (marked "O"), their intensity is recorded in the timeline above.

Click and drag either the source or the observer to have them follow the mouse (they will move at ⅔ speed of the waves).

This simulator is an HTML5 model of the Doppler Shift phenomenon.

This simulator is part of the Foothill AstroSims project, which is aiming to develop new simulations for astronomy education and re-implement, in HTML5, Flash-based simulations that are used in Foothill Astronomy courses.

Funding for Foothill AstroSims provided by an Equity & Innovation Grant from Foothill College.