•
•Want
temperature scale with energy proportional to T
–Celsius scale is “arbitrary” (Fahrenheit even more so)
•0o C =
freezing point of water
•100o C = boiling point of water
–By experiment, available energy = 0 at “Absolute
Zero” = –273oC (-459.7oF)
–Define “Kelvin” scale with same step size as Celsius,
but 0K = -273oC = Absolute Zero
–
•Use
Kelvin Scale for most astronomy work
–Available energy is proportional to T, making
equations simple (really!
OK, simpler)
–273K = freezing point of water
–373K = boiling point of water
–300K
approximately room temperature