There are only a few properties of light.
Frequency (f) and wavelength ( 
) are inversely
proportional to one another - one goes up, the other goes down
to keep their product constant.
(higher f)
waves carry more energy.
There is an alternative description for E-M radiation in which the light energy is carried in Photons (like little bullets of light) that have associated energy, wavelength and frequency. We will use these descriptions interchangably.
It turns out that most of you are already familiar with a broad range of E-M waves.
meters can be
detected by the cells in the retina of the eye and we call that ``light''
between 1000 and 0.5 meters
is used to transmit radio and television signals.
meters (microwave) is
absorbed by water molecules (``absorbed'' means the energy of the
E-M radiation is transfered to the water molecules, they heat up
and your leftover burrito gets hot in the microwave oven).
meters (infrared)
can be sensed with your skin (but not eyes).
meters (ultraviolet)
activates pigments in your skin which cause suntans and trigger skin cancer.
Ozone in the upper atmosphere effectively blocks much of the UV radiation
from the Sun.
meters (x-rays)
can penetrate flesh, but not bones.
``kilo'' 
``1000''; ``hertz'' 
