Electromagnetic spectrum and visible light What is each color made of? Which color carries the most energy? How do you know?

How your eye sees color Photons hit the retina The retina contains two types of cells: rods and cones. Rods process vision in low light - black, white, and shades of grey Cones process color vision and detail When photons collide with these cells chemical reactions occur and an electrical signal is sent along the optic nerve to the brain. The retina contains 100 million rods and 7 million cones.

Reflected Color – color made from photons that reflect from objects Emitted color – photons of different color are made and released Refracted Color – color is made when white light travels through a different medium and refracts Reflected Color – color made from photons that reflect from objects Ideas???

Emitted color Photons with different energies will appear different colors Emitted photons made from: Chemical reactions Stars Red – lower temperature/less energy/ longer wavelength Blue – higher temperature/more energy/ shorter wavelength Binary stars in Cygnus: Albireo A & B (380ly)

Fireworks – which color has the most energy?

Fire – a chemical reaction Which color would have the shorter wavelength? Which color would carry the most energy?

Refracted Color Which color has the highest frequency? How does white light turn into colored light?

Refracted Color Red is slower (lower frequency) with less energy so red refracts or bends at a smaller angle (bends less) Purple or Violet is faster (higher frequency) with more energy so purple refracts or bends at a larger angle (bends more)

Rainbows: reflection & refraction http://eo.ucar.edu/rainbows/

Reflected Color or Why is your shirt red? All white light is made of the following colors (ROYGBV) Red Orange Yellow Green Blue Violet (purple) white light (visible) lands on an object some photons are absorbed by the object some of the photons are reflected by the object. reflected photons are what we see; the energy color of the photons. objects are different colors; because they reflect some colors but absorb other colors. http://www.physicsclassroom.com/class/light/u12l2c.cfm (quiz)

Why is it that color?