Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information....

Which temperature scale to use

You open an astronomy book and encounter the equation

(light emitted) = (constant) T4

for the light emitted by a star as a function of its surface temperature. What temperature scale is implied?

The equation tells us that doubling the temperature results in the emission of 16 times as much light. Such a ratio only makes sense if the Kelvin scale is used.




Last Update: 2009-06-21