Optics

The great artwork of Julian Beever using perspective to transform his sidewalk art into 3 dimensions. See images of before and after his paintings are finished and how he does it.

You may not be aware of it, but polarized light is all around you. Do you have an LCD flat screen television, a laptop computer, a calculator, or other liquid crystal display? Well then, you have been exposed to polarized light. Light reflected from non-metallic surfaces such as water, a polished table top, and glass is also partially polarized as is the light scattered by the earth’s atmosphere.

The sky offers a wide variety of stunning optical effects. A source of inspiration for poets and songwriters alike, these atmospheric phenomena include red sunsets, rainbows, mirages, halos, glories, and coronas. These effects are the result of the interaction of light from the sun or moon with the gases in the atmosphere, clouds, ice crystals, smoke, dust and other airborne particulates. Some of these phenomena can be seen almost every day; others occur less frequently. In this issue of CoolStuff we will examine examples of atmospheric optical phenomena and how they may be demonstrated in the classroom.

While doing science in the hallway or other non-traditional settings may seem a bit unorthodox, this form of informal education beckons members of the entire school community to learn just how interesting and enjoyable science can be.

As strange as it may seem, science and Halloween do have something in common: they both exemplify our innate fascination with the mysterious. The concept of a haunted science lab was conceived of over twenty years ago by Creighton University physics professor Tom Zepf. It began as a collection of activities in Light, Color and Lasers, a core-curriculum course he was teaching at Creighton. Gradually the annual Halloween event evolved into laboratory-based experience consisting of over three dozen displays demonstrating a wide range of physical principles, all of which invite interaction.

As we enter the 21st century, perhaps no area of science touches our lives and the lives of our students more directly than optics. We speak on the telephone without realizing that our voices have been converted into digitally-encoded flashes of light that travel over miles of thin optical fibers. Information, whether it be music, images or text, stored digitally on CDs and DVDs is recorded and retrieved optically. At concerts and sporting events, giant screens consisting of thousands of light emitting diodes provide ultra-bright, high-resolution images of figures too small to be seen on the stage or field. State of the art infrared cameras send eerie nighttime images of battles thousands of miles away to our living rooms almost instantaneously. Our understanding of outer space as well as much of the micro-world has been gained through optical exploration.

In the Spring of 2002, Paul Hewitt and Chris Chiaverina teamed up to present one of the most memorable sessions in a long time; The Best Physics Demo Show. Paul Hewitt is the Author of Conceptual Physics and Conceptual Physical Science. Chris Chiaverina is former President of the American Association of Physics Teachers and co-author of Light Science.