Reflection, and Emission of Electromagnetic Energy
- When radiation
interacts with matter it can be detected in a variety of ways depending
upon the frequency of the energy reflected. Reflected energy is detected
as light waves, emitted energy is detected as heat.
- Incident angle,
wavelength of incident reflection, and properties of the target material
(land, water, heat, etc.) determine how the matter interacts.
- Matter warmer than
0 K (-273.15 degrees celsius) emits electromagnetic energy--the higher
the temperature, more energy is emitted.
- An 'ideal black
body' is a theoretic model that absorbs ALL energy falling upon it and
can later emit all energy.
- An 'ideal reflector
body' is a theoretic model that reflects ALL energy incident to it,
neither absorbing nor emitting any energy.
- Neither of these
'ideal bodies' exist in natural material on Earth. These models are
used as a frame of reference only.
- Emissivity = amount
of energy emitted from a material divided by the amount of energy emitted
by an ideal black body.