Blackbody Radiation

temperature Kelvin

5000

Blackbody radiation is the maximum amount of energy an object can emit. This Demonstration shows how Max Planck was able to close the gap between the explanation of classical physics and the observed experimental data. His formula was derived by assuming that oscillating molecules emit energy as quantized discrete values. His findings and Einstein's later discovery of photons led to the basis for quantum mechanics.

Rayleigh–Jeans law (classical model):

I

λ

=(2ckT)/

4

λ

Planck's law:

I

λ

=(2

2

c

hπ)/((-1+

(ch)/(kTλ)

E

)

5

λ

)

where

I

λ

= spectral irradiance: emitted radiation intensity/wavelength

(W

3

m

)

c

= speed of light

h

= Planck's constant

k

= Boltzmann constant

λ

= wavelength (m)

T

= temperature (K)