WHAT IS LIGHT? Part 2 Light is a form of energy! Energy-the ability to make something move, happen, or change.

LENSES Alter direction of light Convex- brings to focal point. Concave-spreads out.

ie: corrective glasses. LENSES con’t CONVEX brings image to focal point. image is larger and upside down. ie: eye, microscope, magnifying glass. CONCAVE spreads image out. image is smaller and upright. ie: corrective glasses.

VIDEO Instructional Videos: https://www.youtube.com/watch?v=ifbCsha7Syc - Bending of light | Laser bending demonstration

LIGHT - WHAT WE SEE LIGHT- energy by wavelengths at a level we can see. EM Spectrum- variety of wavelengths and frequency. Light is small band within.

Terms to help understand: WAVELENGTH Anything that causes a disturbance and transmits energy through matter. (ie: ripple on pond) FREQUENCY Number of waves in set time. Decides energy level.

WHAT WE SEE

What We See The Sun, a candle flame, or a flashlight gives off visible light. The Moon and many objects around us reflect light in order to be seen. In order for an object to be visible, it must either give off its own light (be a source of light) or it must reflect light.

What We See The different colors of light are revealed when white light is passed through a prism and separated into the different colors of the rainbow, called spectrum. · These colors are related to the different amounts of energy in white light. · Each color represents a different amount of energy.

VISIBLE LIGHT (part of EM spectrum)

TO SEE COLOR Different colors represent different wavelengths. Blue- smaller wavelengths Red- larger wavelengths Color Order: ROY G BIV red, orange, yellow, green, blue, indigo, violet

COLOR Light, or “white light”, is made up of all colors of light mixed together. If white light is passed through a prism, it can be separated into light of different colors. The colors are red, orange, yellow, green, blue, indigo, and violet. These are the colors seen in a rainbow.

COLOR The prism does not create new colors, but merely separates the colors that are already there.

COLOR

RAINBOWS The rainbow is caused by sunshine (white light) shining on water droplets that are in the air just after a summer shower. Thousands of these water droplets break up the light, just like Sir Isaac Newton's prism. Can you make a rainbow? Of course! Make your own rainbow by turning on the garden hose, which has a nozzle that will make a fine mist, or spray. Make sure the sunlight is coming over your shoulder. You have made a rainbow.

WHITE LIGHT Adding color makes WHITE Deleting color makesBLACK

WHITE LIGHT Mixture of many color/wavelengths All colors reflected. Enters the eye’s retina 3 cones:red, blue & green

COLOR -decided by what absorbed. If object reflects color, that is what we see. All color reflected = white If an object absorbs, then it hides color. All color absorbed = black