Education Lesson: Exploring the Electromagnetic Spectrum

By Erin Mulcahy

This month’s education lesson uses the Space Kit as well as light modules found it our Light It pack. The activities in Michael Wilkinson’s ‘Lessons in Light‘ can be used in or out of the classroom for a unique way to explore the electromagnetic spectrum. littleBits make it easy to explore the properties of light as experimental apparatus can be prototyped in a few minutes and students can begin collecting data immediately. Read more about Michael’s insights on the science of light below:

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What is light?

Light is energy. It is vital to life. It is part of what we call the electromagnetic spectrum (EM). We all know the spectrum of visible light as the rainbow: red, orange, yellow, green, blue and violet. There is so much more to the spectrum beyond what our eyes can perceive. Infrared, radio waves, microwaves, x-rays, gamma rays and ultraviolet are all part of the EM spectrum.

Experimenting with Light

Scientists have been studying the EM spectrum for a long time, trying to understand the nature of light. Sir Isaac Newton performed experiments with light that are easy to replicate with your students. He first used a prism to “split” the so called white light into the familiar rainbow. The question to be answered was, are the colors a result of something imparted by the prism or are they contained within the light itself? By placing a second prism in the blue segment of the rainbow, he found that only blue light was emitted. Try it for yourself. The colors could not be coming from the prism itself, or else he would have seen a second spectrum. Instead the colors must be contained within the light. In fact, white light is the result of combining all colors of light, each at a different wavelength. Unlike pigments, the primary colors of light are red, green, and blue. Our eyes have exactly these three color sensors, or cones, lining the retina. By stimulating the red, green, and blue cones to different intensities, we are able to see every color. Follow the steps in the RGB lab to test this.

If you don’t have enough RGB LEDs,  check out this video on how to create a spectrum using a Bright LED and a CD; the full activity instructions can be found in the Space Kit booklet.

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Beyond the Visible Spectrum

The EM spectra measures the amount of energy carried by a “packet” or wave of photons. The lowest energy waves, the largest wavelengths, are the radio waves. These waves are the length of football fields! Next, come the microwaves, followed by infrared, visible light, ultraviolet, X-rays and the smallest and most energetic gamma waves. At this end of the spectrum, waves are the size of atomic nuclei, and measured in nanometers (billionths of a meter)! Fortunately, for life on the planet, our atmosphere and magnetosphere filter out the most energetic portions of the EM spectrum. For exploring the UV/IR lights and how we can ‘listen’ to light, check out the extensions at the end of the lesson.

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What other experiments and activities can you create with your Space Kit? Share your lessons with us on the education page.


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