In this instructional activity, students learn that light travels in a straight line from a light source and that ray diagrams help us understand how an image will be created by a lens. In the accompanying activity, students explore the...

Bill Nye explains why the moon appears smaller when it is higher in the sky, and he presents a Home Demo experiment that proves its an illusion. The experiment requires a bright moon on a clear night, a stiff piece of cardboard, and a...

Provides a long list of physics formulas for easy reference.

Explore the world of central visual pathways. The visual pathway leads from the eye to the primary visual cortex. There is a detailed visual description of this process. Check it out.

A discussion from Georgia State University of different types of mirrors and the images which they create. Discusses different instruments which use mirrors to produce images.

Test your knowledge of the human eye with this interactive labeling exercise.

Structural Isomers are molecules which have the same molecular formula but have different connectivities (The Order They Are Put Together). Alkanes can be very simple examples of this. This pages shows a few examples.

Students learn how laser communication systems are built by observing how sound can be encoded into, and transmitted by a light beam.

United States Naval Observatory is a unique observatory run by the Navy. It does some of the grunt work of astronomy -- keeping accurate time, determining positions of stars (astrometry), etc. They are responsible for publishing the...

Many articles with consumer information about lenses, eyewear, eye problems, and unique eye conditions. Vast content and many links to off-site information.

Students use this tutorial to investigate the refractive ability of converging and diverging lenses.

This resource provides historic information on length measurement in the United Kingdom. Click on the topics on the left toolbar of the article to find out more information.

This site provides a biography of James T. Russell, inventor of the compact disk, and the basic ideas behind the technology.

This is a ten-question quiz pertaining to spherical mirrors.

A brief history covering magnetic disks, developed as efficient random access memory device. Additionally, a discussion on how a disk drive works is provided. The artifacts are on display at the Computer History Museum. This site...

Thorough overview of glaucoma provided for by Intelihealth. Includes information on symptoms, prevention, treatment, and more.

Easy to understand description of the parts of the eye and their functions. Lots of labeled illustrations. At the bottom of the page additional content includes games, quizzes, lesson plans and activities about vision.

Take this little test about the blind spot, then click on the red "explanation" button at the bottom of the page to find out what you just experienced.

In this activity, students can use a Light Sensor to measure reflection values from paper of various colors and compare these values to reflection values of aluminum foil. They will also calculate percent reflectivity.

Working in teams of "engineers", young scholars explore how a periscope works and is used. They design, build, and test a working periscope made from everyday materials that has adjustable mirrors and be able to telescope as well.

A PBS site explores color and the effects of seeing lots of colors at the same time. Try it yourself with their home experiment.

Homepage of Kitt Peak National Observatory (KPNO) which is the one of the premier astronomical observatory used by professional astronomers in the United States. Although the site is mostly geared toward the professional, the Kitt Peak...

This site provides a fairly in depth description of Scanning Probe Microscopes as well as links and images. This site is designed for those with a strong understanding of this field.

Source of information on the subject of weather photography. There are great links, images and tips on equipment to use. For the intermediate to advanced photographer.