# Plank's Hypothesis

1. Aug 11, 2012

### XtremePhysX

Can you guys please explain to me planks hypothesis? This is what I know. But I need a better understanding:
Planck’s hypothesis was designed to explain the problem of black-body
radiation and the observed ‘ultraviolet catastrophe,’ not reconcilable with
classical physics. Classical physics predicted (via laws of thermodynamics) that
the radiation emitted by a black body was different to that observed in real life.
Classical theory predicted as the wavelength of the black body radiation
decreased, the radiance would increase to an infinite amount (could not be
reconciled with laws of conservation of energy). Thus an explanation had to be
found.
Planck proposed a theory of quantum physics, which stated that all energy is
quantised. As such, all the energy exchanged within the black body exists as
packets.

I need to know the mathematics behind Plank's Hypothesis, how did he come up with his explanation?
Einstein extended the concept of quantised energy to light waves, reasoning
that the energy from light waves may be treated as a stream of discontinuous
quanta, called ‘photons’. This contribution to quantum theory was based upon
Planck’s hypothesis on the quantisation of energy emitted from a black body.
A photon is the smallest amount of radiation energy possible at a particular
frequency. A photon cannot transfer part of its energy: it can only transfer all of
its energy or none of it. The amount of energy carried by a photon is
proportional to its frequency. The intensity of light is proportional to the number
of photons. The energy possessed by a photon is proportional to its frequency
(the shorter the wavelength - the higher the frequency - the greater the total
energy). The energy of photons is given by: E=hf.

So Plank's Hypothesis was limited to energy only, Einstein is the one who extended it to EMR?

2. Aug 11, 2012

### Miscing

Planck saw the introduction of the constant as nothing more than a mathematical trick that reproduced the experimentally observed spectra; he didn't believe that it represented anything physically. Einstein realised it was more than just a mathematical trick, it represented an actual physical phenomenon, and he used this to explain the photoelectric effect.

3. Aug 11, 2012

### XtremePhysX

Wow, thank you, this explains it all.
So Plank just found a mathematical explanation to the bell curve?
Are you aware of the equations he used?

4. Aug 11, 2012