1. Light Inquiry Stations (7 mins)
Name the property you are observing.
Describe what you are seeing.
How does this apply to light specifically?
How might this property change with different wavelengths of light?
Where do you see this property in everyday life?

2. Light

3. Why Should We Care?
Without light and it’s ability to rapidly transfer energy the universe would likely not exist. Sight is pretty cool. Most of what we know about space is thanks to light. Spectrophotometers, mass spectrometers, Fourier-Transformation Infrared Spectrometers, and loads of other fancy scientific instruments.

4. Wave-like Properties of Light
It looks like light always travels in a straight line, but it doesn’t, shadows have fuzzy edges due to diffusion.

5. Wave-like Properties of Light
Wavelength, frequency, amplitude, speed.
Transverse electromagnetic wave.
Effects what it travels through in a perpendicular manner.
Made of photons, both a wave and a particle.

6. Speed = Wavelength * Frequency
The Speed of Light
c = 300,000,000 m/s = 186,000 miles/s
Around the Earth 7.5 times in one second!
It takes light from the sun 8 minutes to arrive.
The next nearest star is 4 light-years away
It takes that light 4 years to reach us
Speed = Wavelength * Frequency

7. The Speed of Light

8. Light Stations

9. Light Intensity Power is in Watts (W) Area is in square meters (m2)
Usually a sphere
What units does Intensity have?

10. Light Intensity Power is in Watts (W) Area is in square meters (m2)
Usually a sphere
What units does Intensity have?

11. Transparency Materials block specific wavelengths of light
Why does your car get hot in the sun if only visible light can get through the windows?

12. Transparency
Why does your car get hot in the sun if only visible light can get through the windows? Visible light goes in and reflects off the interior, releasing infrared light (heat rays) that can‘t escape.

13. Reflection Path of light is traced with ‘rays’
Angle of incidence (incoming light) = angle of reflection (outgoing light)

14. Color Primary colors are RED, GREEN, & BLUE
Different from primary pigment colors, no yellow
RED has lowest λ, BLUE has highest

15. Refraction c changes slightly in different materials
Fastest in a vacuum, slower in everything else
Index of refraction
Vacuum = 1.00
Everything else = More than 1.00

16. Refraction
Snell’s Law

17. Shadows
Umbra
Dark
Penumbra
Lighter

18. Polarization Unpolarized light has photons at all angles
Polarizers act as a grating to filter out all but one angle
3D movies

19. Review Why Should We Care? Wave-like Properties of Light
The Speed of Light
Light Intensity
Transparency
Reflection
Color
Shadows
Refraction
Polarization