Question

Who discovered the concept of photon ?
Max Planck or Einstein ?

Answer 1

The photon in terms of it being a packet of energy was first proposed by Planck but Einstien was the one who explained the photoelectric effect by using Planck's "quanta idea" and applying it to light. He had to "quantize" light (electromagnetic radiation) in order to explain what was happening with black body radiation. He was approached by a company to help improve the efficiency of lightbulds. But he spent many years trying in this area but with no progress. He was attempting to use Newtonian mechanics but it WOULD NOT WORK.

He eventually gave up and tried again and his conclusion, which he hated to accepted, was that the atom was a digital system, the electrons had to within specific paths. Einstien didn't find this as horrible as Planck and accepted the idea of quanta and came up with the idea that light too must be made up of quanta.

Einstein's equation is;-

\[E = hf - w\]

The E energy is equal to Planck's constant h multiplied by the frequency f, after you account for the energy use to liberate the electron. The above equation describes the energy of an electron after it absorbs a photon. To liberate the electron work must be put in to over come the attractive force of the positive nucleus.

Answer 2

The above is good. Einstein did conceive of the photon. But Max Planck was responsible for the quantization not Einstein. He writes that he was desperate for any attempt to explain the spectra of certain elements and he originally thought it was just a mathematical get around, like a cheat and not real. Later on in his life he accepted it as a fact.

Answer 3

yea.. bt you have to agree that Planck only did it to get the math working as you said.. but had no clue why or what h was ..
it was Einstien who first experimentally calculated the value of h.. and gave a physical meaning.. and hence if its a question asked in exam then yes Max Planck.. if you are asking in general.. both are credited.. Both are called the inventors of the quantum mechanicsl!

Answer 4

Who said that it was Einstein? I said Einstein did the photoelectric effect and felt more comfortable about accepting the ideas that Planck uncovered.

Answer 5

It was Einstien who first experimentally calculated the value of planck's constant!