How We See

1. How We See • There are three different types of cones in our eyes. They are sensitive to different colors of light. There are cones that detect red light, green light, and blue light. • Our brains combine the information from the cones and create all the colors we see. (Color blindness happens when one of the types of cones does not work as well as the others) • An instrument called a spectroscope separates the light that we see so we can see the individual colors again.

2. Spectroscope Assignment • Build your Spectroscope • You will share with the person beside you • Follow the directions written on the spectroscope • Black goes on the inside • Cut on the solid lines • Fold on the dotted lines • The CD goes shiny side up with black tape at the tip • You will be looking at different types of light and recording your results on the results page. • Sunlight • DO NOT LOOK DIRECTLY AT THE SUN! • Reflected off white paper • Reflected off color paper • Classroom lights • Candle light • Flash Light • Computer screen • Play the power point slide show • Compare the color with the white square on the left

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12. Sunlight – White Paper EXAMPLE Flashlight Sunlight – ______ Paper Classroom Light Sunlight – ______ Paper Color Color Color Color Color Color Violet Green Red

13. Computer White (1) Candle Light Computer Blue (4) Computer Red (2) Computer Green (3) LED Black Light Color Color Color Color Color Color

14. Computer Yellow (7) Computer Turquoise (5) Question 6 Computer Black(8) Question 3 Computer Fuchsia (6) Color Color Color Color Color Color

15. Spectrometer Questions • What is the biggest difference between sunlight (off white paper) and the classroom lights? • Does the candle spectrum look more like sunlight or the classroom light? Why is this? (Think about what a candle and the sun have in common) • Make a prediction of how the spectrum of hot glowing metal might look. Draw it on the previous page. • Does the flashlight spectrum look more like sunlight or the classroom light? • What do you think is happening inside the flashlight bulb? • Predict and draw on the previous page what you think the moon spectrum might look like • Does the laptop screen look more like sunlight or classroom light? • What do the laptop screen and class lights have in common? • What happens when you move around the screen with the spectroscope on slide 9?

16. Spectrometer Answers • Sunlight is brighter, and the colors blend, while classroom light has distinct color bands • More like sunlight. Both are hot. • Glowing metal will look like the flashlight, because it is heat generated light. • Flashlight looks more like the sunlight, both are hot. • Flashlight is making metal inside the bulb, hot, making it glow. • It will look like sunlight, since that is where the moon gets its light • It looks more like classroom light. • They have bands of color instead of a continuous spectrum. • The bands should always be there, but they will vary in intensity depending on what color the spectroscope is in front of

17. Paint Follow Up Assignment • Thinking about what you learned from the spectrometer, and about our eyes, what would happen if we mixed red, green, and blue together and shined UV light on it? • You have just discovered some interesting behavior in your painting. Your paint can be applied to any type of surface, and when excited by certain types of energy, glows different colors. Your task is to develop a product that uses this technology.