Why so blue? As it turns out, very few things in nature only reflect blue light! A short video from a comprehensive science playlist highlights the beautiful blues of butterflies, birds, and human eyes. The narrator shows how adaptations...

Somewhere over the rainbow ... the sky appears to be darker than below it? Why is that? A video from an interesting physics playlist illustrates the interaction between the visible spectrum and droplets of rain. It also doubles the...

Cloaking devices aren't just for Star Trek and Harry Potter any more! Here's a video that explains how cloaking devices work, or don't work. It details the technology needed to perfect cloaking and offers ideas for where researchers...

Holding a conversation underwater has its challenges. Sound and light waves can travel in different mediums, but it affects their waves. The video explains the process of refraction and diffraction and how it relates to energy waves. 

An exploration of Snell's Law using the example of a beam of light being refracted through a pool of water. [11:25]

Learn about waves and optics by discovering this example of Snell's Law. [10:44]

A video describing refraction with examples.

In this video, Paul Andersen explains how light can be refracted, or bent, as it moves from one medium to another. The amount of refraction is determined by the angle of incidence and the index of refraction. Snell's Law can be used to...

This article from Khan Academy provides information about refraction and Snell's Law. This information is intended for high school physics.

This study resource from Khan Academy for the MCAT explores the topic of "Snell's Law" as it pertains to physical processes.

This video lesson provides an example of the application of Snell's Law. This video lesson was developed in collaboration with the Association of American Medical Colleges and Khan Academy.

This article from Khan Academy provides information about refraction in water. This information is intended for high school physics students.

A science demonstration asking students to explain why the penny disappears when water is poured into a cup sitting on top of the penny. Video allows students to observe, make predictions, and explain. [1:03]

A video with students explaining the definitions of reflection and refraction. Students present the material with a rap song and examples of reflection and refraction. [1:45]