How is light visible? Examine this source to understand what light is and how it travels. Answer discussion questions and practice problems to better recognize light rays and know their functions.

Where can we experience the phenomenon that light taking two paths from two locations to the same point in space can undergo constructive and destructive interference? There are several answers to these questions and they will be...

Students examine the findings of Thomas Young's light experiment, which showed that an interference pattern results when light from two sources meets up while traveling through the same medium.

A very simple electrical resistance thermometer is described that can be built, calibrated and tested in a school laboratory at virtually no cost. With it, flames, focused sunlight and other high temperature sources can be probed. The...

An account of the Delaware Prophet, from 1808 by John M'Cullough. Although M'Cullough never met the Delaware Prophet, his secondhand account sheds some light on the mysterious figure said to have influenced the Pontiac War.

The National Humanities Center presents collections of primary resources compatible with the Common Core State Standards - historical documents, literary texts, and works of art - thematically organized with notes and discussion...

Informative sight detailing the basics of what a scanner is and what it can do.

Compared to incandescent lamps, fluorescent lamps last longer, require less energy and produce less heat, advantages resulting from the different way in which they generate light.

This primary source set explores the development, commercialization, and impact of electricity.

In previous decades, most news with global reach came from several major newspapers and networks with the resources to gather information directly. The speed with which information spreads now, however, has created the ideal conditions...

Deep under the ocean there is no light for plants to perform photosynthesis. This site is a good overview of the alternative energy method, chemosynthesis. Read all about it.

Ants have one of the most complex social organizations in the animal kingdom; they live in structured colonies that contain different types of members who perform specific roles. Deborah M. Gordon explains the way these incredible...