GEOG 1010 Lecture 3: Lecture3
Document Summary
Radiant energy in the form of electromagnetic waves. Emitted at the speed of light by all objects with a temperature above "absolute zero" (-273oc) The higher the temperature of the body, the more potential for energy emission it has. Wavelength: the distance from one wave crest (or trough) to the next. When the wavelength is relatively long, can be described as "long wave" and vice versa for when its short but called "shortwave" Frequency: the number of waves that pass a point per unit of time. Short wave lengths= high frequency (ie. energy is more concentrated) Two important principles govern the emission of electromagnetic radiation. 1: stefan-boltzmann law: hot objects radiate more energy (at all wavelengths) then cooler objects. 2: wien"s law: the hotter the object the shorter the wavelength of peak radiation. These laws apply only to a perfectly radiation surface know as a blackbody.
