This simulator is an HTML5 model of light traveling in expanding space.

Activate the simulation with the "Play Animation" button in the lower right.

When the light has reached the observer in the simulation, it stops. The simulation can be reset using the Reset option.

The two input parameters for the simulation are: * initial separation - how far apart are the source and observer at the beginning of the simulation, and * expansion rate - the expansion rate of space, given as a percentage per billion years. The equivalent Hubble constant is displayed to the side.

This simulator is an HTML5 model of light traveling in expanding space.

This simulator models the travel of a photon of 400 nanometer light in an expanding universe from a source to an observer, as well as the accompanying redshift of the light as it travels through expanding space. The plots at the top show the separation between the source and observer, distance from the photon to the observer, and the total distance traveled by the photon at any given time.

This simulator is part of the Foothill AstroSims project, which is aiming to develop new simulations for astronomy education and reimplement, 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.