ELECTROMAGNETIC SPECTRUM!
Speed of light c equals
frequency f times wavelength λ.
Total power output is P = σεAT4.
Peak frequency is fpeak =
[1011 Hz/K]T.
The energy density u is the
time-averaged magnitude of the Poynting vector S
divided by the speed of light c. That is, u =
I/c. The momentum p carried by light is the
total energy U divided by c. Don't confuse
the momentum magnitude p with the radiation
pressure, which to avoid confusion is written below as F/A.
As a source of light gets less and
less intense you can see that the light actually consists
of individual particles, called photons.
The first step into a new universe.
William Herschel discovers infrared radiation, in 1800.
Study Guide for Ch. 29
Red Shift (302L)
Feynman on EM radiation
More on Photons
Reflection and Refraction (302L and
317L)
