How do matter and light interact? This lecture is the first of a

two-part lecture on the physical basis of spectroscopy. Today we will

discuss the Kelvin Absolute Temperature scale, which provides a measure

of the internal energy content of matter, and Kirchoff's empirical Laws

of Spectroscopy, along with the Stefan-Boltzmann Law and the Wein Law to

describe the continuous emission from a blackbody. We will end by

briefly describing the suggestive properties of emission- and

absorption-line spectra, whose explanation in the details of atomic

structure will be the topic of the next lecture. Recorded 2006 Oct 25

in 100 Stillman Hall on the Columbus campus of The Ohio State

University.