EM Waves: Structures of EM Waves


What is the most obscure, interesting, provocative bit of learning you've come across in our conversations of the EM Spectrum (so far!)


LEARNING TARGET: I will be able to describe how light waves propogate during today's class


  • propagation: How light waves move
  • hertz (Hz): a measure of wave frequency in waves/second
  • electromagnetic waves (light waves from radio - gamma)
  • quantum jump
  • energy levels
  • excited (electron) = ("electrons 'jolted' into a higher energy level")
  • rest state (electron) = ("electrons existing on the lowest energy level")


h = Plank's Constant = (6.63 x 10-34 m2kg/s)

c=λυ: The speed of light (c) = wavelength (λ "lamda") x frequency "nu")

E = hυ (The energy in a photon of light is given by Plank's Constant times the frequency of that light


Let's take a gander at TFAD (notice I've added the teaching schedule there too... please make sure you've added a topic. Also, please be specific in your topic ("Next Generation Night Vision Goggles" is AWESOME, "Infra-red Light" is much too broad)



    • VERY generally speaking, how many different frequencies are available for radio broadcasting in the US?

    • Determine the wavelength, frequency and energy of the light broadcast as 107.7 FM (The End) radio in Seattle.

    • What do you recollect about CMBR?

    • Why is it impossible to see through walls using an IR camera (despite what we see on TV)
    • Why is it illegal for teenagers to tan in a commercial tanning facility without a doctor's prescription?


New stuff:

Please work with your group to sketch an actual electro-magnetic wave



Did your sketch look something like this?

Howzabout an animated gif:


Please take a few moments and research what we mean by the term "polarized" light....


With that in mind... let's get someone up here to lead us in a conversation of why this pair of sunglasses reflects light to observers, but allows light in to the user: