| A | B |
|---|
| electromagnetic radiation | one of the 6 types of transverse waves that transfer energy by radiation |
| photons | Particle-like "bundles" of radiation |
| radio waves | longest wavelength and lowest frequency of EM spectrum |
| infrared radiation (IR) | form of EM given off by warmer objects |
| visible light | only part of the EM spectrum that can be seen |
| ultraviolet radiation (UV) | part of the EM spectrum where frequency is high enough to begin to cause damage |
| x-rays | part of EM that has high enough frequency to travel through some types of matter WITHOUT being absorbed |
| gamma rays | shortest wavelength and highest frequency of the EM; emitted by nuclei of radioactive atoms |
| electron excitation | when an electron gains enough energy to briefly rise to a higher energy level |
| electron emission | light given off by an excited electron when it "falls back" to its original energy level |
| photoluminescence | caused by absorbing existing light energy; ex. glow-in-the-dark paint |
| bioluminescence | caused by chemical reactions INSIDE a living organism; ex. firefly |
| incandescence | caused by heat; ex. traditional light bulb |
| fluorescence | caused by electricity; emission in UV range so requires 2nd step to become visible |
| opaque | material that absorbs and/or reflects all visible light |
| translucent | material that allows SOME visible light to pass through it |
| transparent | material that allows ALL visible light to pass through it |
| photoreceptor | cells in the retina (rods and cones) that convert visible light into nerve impulses |
| rods | distinguish differences in brightness |
| cones | distinguish colors and shapes |
| polarization | process in which a filter is used to isolate one plane of light |
| primary colors of pigment | magenta (absorbs green), cyan (absorbs red), and yellow (absorbs blue) |
| primary colors of light | red, blue, and green |
| color blindness | results when one set of cones fail |
| laser | coherent (in phase) narrow beams of light of one frequency (color) |
| fiber optics | uses total internal reflection in tiny glass tubes to carry light and signals |
| optics | the study of how light behaves |
| index of refraction | ratio of speed of light in a vacuum to its speed in a material; CSI use to identify materials |
