1. Aim: How can we explain polarization and dispersion?
Do Now:
Why do athletes wear polarized sunglasses?

2. Incoherent Light
When light waves emitted by a source have no special phase relationship, the light beam spreads and loses intensity quickly

3. Coherent Light
Monochromatic light with most waves in phase, spreads very little and is intense
A laser!!

4. Light coming from the sun or a light bulb emit light waves that are vibrating in every plane
We call this type of light unpolarized

5. Polarized Light
A beam of light that only vibrates in one direction

6. So what happens if we add a 2nd polarizing filter oriented 90° to the 1st?
Demo

7. What’s Happening?

8. Only transverse waves (like light) can be polarized
Can sound waves be polarized?
NO!!!

9. Dispersion
When polychromatic (white) light is passed through a prism, it is separated into its component colors

10. What is Polychromatic Light?

11. Which light bends the least?
Which light bends the most?
red
violet

13. Why? Speed of light inside prism depends on the wavelength of light
v = fλ (f is const!!)
λred = highest
vred = highest
Red has the lowest index of refraction, therefore bends the least
Violet therefore bends the most

14. Dispersive Mediums Prisms Air (rainbows) Glass Thin films of: People?
Water
Bubbles
Oil
Gas
People?

15. Prism Spectrometer Disperses light into component colors
Allows you to determine the elements the stars are made out of when attached to a telescope

16. Gas Tubes