The introduction of Uncertainty Principle

      Werner Heisenberg, born in Germany Wurzburg at 1901. When he was in university, he first applied to study under Ferdinand von Lindermann, a math professor. But Ferdinand rejected Heisenberg, so Heisenberg changed his mind and chose to study under Sommerfeld, a physic professor.

      One time, Heisenberg was studied of the model of electron's motion in atom. In order to solving the model Heisenberg created a new operation "Matrix." Well, Heisenberg wasn't the first man using matrix, matrix has been using in math for a long time since Arthur Cayley first created it in 1858. But, Heisenberg didn't notice it, so he created matrix again by himself!

      Because Heisenberg used matrix to solve the problem, there existed a new subject "Matrix Mechanics." But I think the most important result of using matrix is that Heisenberg discovered a new theorem "Uncertainty Principle."

  Werner Heisenberg

(https://zh.wikipedia.org/wiki/File:Heisenberg_10.jpg)

Matter Wave: is electron particle or wave?

      Prince Louis Victor Pierre Raymond de Broglie, a France teenager, got a paper from his brother when he was 19. Because of this paper Louis de Broglie decided to devoted himself in physic, and this decision is going to improve wave to another goal.

Louis de Broglie

(https://upload.wikimedia.org/wikipedia/commons/thumb/d/d2/Broglie_Big.jpg/150px-Broglie_Big.jpg)

      A.D. 1924, Louis de Broglie found that if we consider two equation together, E = mc^2 and E = hμ, than we can get that μ = mc^2/h. This new equation told us that for any particle that has mass, it will exist a wave with it. Louis de Broglie called this wave "phase wave", and explained the act of electron with it. Louis de Broglie got his PHD with this crazy thinking paper, but most of the physicist can't believe with this theorem and told Louis de Broglie unless they saw the diffraction of electron, they won't agree with "phase wave."

 C. J. Davisson and L. H. Germer

(https://upload.wikimedia.org/wikipedia/commons/thumb/9/99/Davisson_and_Germer.jpg/200px-Davisson_and_Germer.jpg)

      A year later, C. J. Davisson and L. H. Germer were going to proved that Louis de Broglie was right by a explosion they made in lab. After the accident, the result of the experiment changed severely and they have no choice but stopped the experiment. 1927, Davisson founded that the reason why the result changed was because of the diffraction of electron!!!

 G.P. Thomson

(https://upload.wikimedia.org/wikipedia/commons/thumb/c/c2/George_Paget_Thomson.jpg/220px-George_Paget_Thomson.jpg)

      At same year, G.P. Thomson made the experiment of electron diffraction successfully and won the Nobel Prize of Physic with Davisson in 1937. What a coincident!! J.J Thomson won the Nobel Prize of Physic by founded a new "particle" called electron, but his son G.P. Thomson won the same prize by proved that electron can act as "wave."

Light act as Particle??

       After Hertz finished his significant experiment we can absolutely say that light is a kind of wave. But, when we observe the feature of light in a very small field, something strange happened! First, I should introduce one scientist, Max Planck, the pioneer of  quantum mechanics.

Max Planck

(https://zh.wikipedia.org/wiki/File:Max_Planck_1933.jpg)

      December 14(Quantum Day), 1900, Planck said to the whole world that energy shouldn't be continuous, there exist a basic amount of energy, called quantum. What did Planck meant? That means in the world, there's no energy equals half quantum, 4/3 quantum, it's like we can never pay with 1/2 NTD. Planck gave out a really crazy theorem and there's a crazy man who knew that how important quantum is to light

Albert Einstein

(https://zh.wikipedia.org/wiki/File:Einstein_1921_by_F_Schmutzer_-_restoration.jpg)

      A.D. 1905, Bern Switzerland, there's a civil servant worked in patent office, the man called "Albert Einstein.".He found out that if we regarded light with quantum, Photoelectric Effect can be easily solved. We can assume light is consisted with some quantum which Einstein called it "light quanta."(1926, G.N.Lewis changed the name to photon) With is rebellious theorem Einstein won the Nobel Prize in Physic in 1921.

    Isn't light a kind of wave?? Why Einstein say that we should assumed there exist photon, isn't this mean that light is particle? NO!! Einstein didn't said that light is particle but said that light act like particle in certain conditions. What a strange theorem???