Gustav Kirchhoff

1824–1887 · German physicist

Topics: physics

• Heat rays have the same nature as light rays... The invisible heat rays are distinguished from light rays only by the period of vibration or the wave length.

  — Gustav Kirchhoff

• Under these conditions the following law holds : The ratio between the emissive and the absorptive power is the same for all bodies at the same temperature.

  — Gustav Kirchhoff

• All heat rays follow the same laws in their propagation, which are known for light rays.

  — Gustav Kirchhoff

• A perfect mirror, like every diathermanous body, can itself send out no rays; for if it did (confined in an enclosure of like temperature) it would warm this enclosure... and cool itself more and more.

  — Gustav Kirchhoff