Exploring Light


We move on in session three to learn how light travels in waves. We learn how light arrives on our planet after a speedy trip from the Sun, 149 million km (93 million miles away). Light travels at 186,000 miles (300,000 km) per second, so the light you’re seeing now was still tucked away in the Sun about eight minutes ago. Some light from the sun is visible and some light is not.

We explore the visible light spectrum and conduct experiments with color to determine how light colors mix together different then paint colors. We experiment in a dark room with filtered light. We overlap the primary colors of light: Red, Green and Blue to see the secondary light colors: Yellow, Magenta, and Cyan (YMC). We use our shadows to reveal secondary light colors.

We also experiment with black to see that black is really made of color. We make a black line with a water soluble black maker on water absorbent paper and watch as the color seeps out of the black line when we place the bottom of the paper in water.

prism_rainbowWe use prisms to separate the colors of light and to see how light behaves. We discover how light waves are reflected, absorbed, transmitted, refracted, and diffracted. We learn the parts of a wave and observe how shorter wavelengths are bent more than longer wavelengths, so blue light is bent more than red. That’s why blue is always on the inside of a rainbow and red is on the outside. We count wavelengths to learn differences in wavelengths between colors. We learn how wavelength and frequency of light are closely related. Frequency is the number of wave crests passing by a given point in one second. The higher the frequency, the shorter the wavelength.

Lessons:

ROYGBV Color Wheels:  Made by mounting a 3-4″ wide circle of white paper onto a same size cardboard circle. Use a craft needle to poke two holes through the middle of the paper cardboard circle. Divide the white paper into 6 even pie sections. Color one section of the circle red, the next one orange, then so on with yellow, green, blue and violet. Loop a 20″ piece of string through the holes so that the color wheel is centered on the string then tie the ends of the strings together. Kids loop their finger through each side of the string and then spin the circle around the string to wind it up, then watch the colors blend together as it unwinds.