1. Light
Waves Photons
Wavelength Changes
Energy per photon changes
E = hf
Radio Waves vs. X-rays
Color
small  = blue
big  = red
Amplitude Changes
# of photons changes
many = bright
few = dim
CCD Devices, High speed film
small = dim
Brightness
big = bright

2. Einstein’s Photon theory predicts:
Photon energy = work function + Kinetic energy of electron
hf =  + Ekmax
Ekmax = hf - 
Photon Theory predicts:
Ekmax rises with frequency
Intensity of light ejects more
Wave Theory predicts:
Ekmax rises with Amplitude (Intensity)
Frequency should not matter
Survey says
Millikan does the experiment
1915 conclusion
1930 conclusion