Pope Sheldon & Brandon Pezzuto
Light Exploration
11-28-07
1. See attached Spectral Lines paper. 2.
Red 0 0 100 0 100 100 100 Green 0 100 0 100 0 100 100 Blue 100 0 0 100 100 0 100 Predicted color blue green red indigo purple maroon black Observed color blue green red teal purple yellow white
3. Object color Green Yellow Blue Red Green filter Green Green Black Black Red filter Black Red Black Red Blue filter Black Black Blue Black Orange filter Forest Green Orange Black Red
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In the visible spectrum of light, and with reference to the color wheel, the colors that have a shorter wavelength (violet, blue and orange) absorb more light whereas colors with longer wavelengths (red, yellow, green) do not absorb light. The two have an inverse relationship towards each other. See attached drawings sheet. The combination of red, green and blue light creates an additive color mixing, the same as if you were to shine three primary colored lights on a white surface. In the combination of red, green and blue paint is defined as color mixing, which is as if you were to pour puddles of three primary colored paints on a surface, they would reveal a black coloration. The line spectrum in the spectroscope for mercury is similar to the emission spectrum on the web. It is the inverse of the absorption of mercury however. The spots where lines are missing on the absorption spectrum, is where on the line spectrum for mercury there are lines. a.) Florescent lamps use electricity to excite argon or neon gas, resulting in visible light. Mercury is the major metal element used in the florescent lamps. After reviewing the emission lines of mercury and comparing it to the vapor discharge tubes I found that mercury had spectral lines that were observed on a wide range of wavelengths from 400 nm to 700nm. Mercury is considered hazardous waste because mercury can be inhaled or secreted through the mucous of membranes an organism resulting in fatality because of the toxicity of the element. b.) The color emitted by florescent light is a white visible light which is an additive mixture of light from the wavelengths corresponding to red, green, blue. Sunlight emits
all the colors in the visible spectrum. Incandescent light also emits all colors in the visible spectrum. c.) Florescent light is more energy efficient as well as cost efficient because florescent light does not use all the light in the spectrum making it uses minimal energy as well as producing strong light. 9. LED lights shine only certain wavelengths which uses less energy to create the light. Incandescent lighting shines more than one color on the visible line spectrum which uses more energy to produce the light. 10. Due to the fact that argon has a larger number of valence electrons it will emit a light with a longer wavelength of light than neon that has a lesser number of electrons in its outer shell. 11. A purple flame would be seen because when red and blue light is emitted, it creates purple. The occurrence of a purple flame is rare because a flame does not usually emit these colors. 12. Strong Sodium emission line: sodium is 600nm Strong potassium emission line: potassium is 691nm = 3.3x 10-19 J = 1.98 x 10-25J
Sheldon Pope Individual Portion 11-28-07 13. a. The sun emits all light colors. Some of the wavelengths are more prevalent than others. Green is the most prevalent along with blue and red. When these colors mix it makes the sun look white or yellow. b. The maximum blackbody curve of the sun is green and the sun is 5800K. Red has a higher wavelength which means less energy. I would approximate that a red giant start was in the temperature range of 3,000-4,000K. c. Blue has a lower wavelength than green meaning higher energy. The temperature of the surface of a blue dwarf would be somewhere in the area of 6,000-7,000K.