Chapter 758 Photoelectric Effect and Lin Kes Equation!
Lin Ke's voice was deafening.
Andrew did tell him before he broke through level 15.
Before he broke through, Emperor Wumian, Ruiwen, Aofu, Lika, etc. all told him how to break through to level 15.
He can be sure that everyone really has his best interests at heart.
It's just that at that time, he made a mistake that he often made in his previous life, which was to trust his elders too much.
In previous lives, whether it was relatives or teachers, they often taught future generations based on their own experiences and judgments based on their own subjective perspectives.
Sometimes they are right because their experience is indeed useful.
But sometimes it is undoubtedly wrong.
After all, you must have your own judgment and practical methods, and you cannot let the words "for your own good" limit your vision and revenge, or directly deny what you see and hear.
Reject empiricism and dogmatism!
At this time, Lin Ke wanted to teach everyone the same thing.
It has to be said that many students are actually quite blindly obedient.
Why do we say blind obedience?
It’s not that they didn’t think during the experiment, but they didn’t have their own thinking.
Others say that this experiment can prove that light is a particle, and then they judge whether the experiment is wrong. If it is correct, then they believe it.
Others said that another experiment could prove that light is a wave, but they judged it and found it to be true.
But they overlooked one point.
Whether light is a particle or a wave, as a [scholar], shouldn't we think about how to observe and judge by ourselves?
The world does not mean that there is only one experiment that can prove that light is a particle or a wave.
As a [scholar], shouldn’t I be inspired after seeing other people’s experiments, and then think about another experimental method that can be proved?
Just like Andrew said at the beginning.
As a strong person on the [Scholar] side, Lin Ke, couldn't he try it out on his own and see how best to break through to level 15?
Someone else's is always someone else's.
Therefore, Lin Ke's words at this time greatly benefited everyone.
"That's it...that's it..."
"The principal's words are indeed so thought-provoking!"
"I...I broke through!"
"Me too!"
"I'm not far away! There are indeed too many doubts about some past experiments..."
"It's so shocking, so admirable, it makes me enlightened!"
Not to mention the students, the teachers, staff, and various visitors all felt suddenly enlightened.
At this time, Lin Ke finally said his last experiment of the day: "...Finally, I will do the last experiment, which is to prove whether light is a particle or a wave."
"But, everyone."
At this point, Lin Ke's tone became slightly more serious: "I did this experiment just to verify what I was thinking. It is not authoritative, nor does it mean that what I made must be the truth!"
"Not only the best, not only books, but only reality!"
"This is the real [scholar]!"
With that said, Lin Ke waved his hand and started researching.
What experiment is he going to do?
Double slit interference experiment!
The instruments behind Lin Ke began to change.
To prove wave-particle duality, the main method is Young's double slit experiment.
That is, a candle is placed in front of a piece of paper with a small hole cut out, thus forming a point source of light.
The light source is emitted from a point, and another piece of paper is placed behind the paper. The difference is that two parallel slits are opened on the second paper.
When the light emitted from the small hole passes through the two slits and is projected onto the screen, it will form a series of alternating light and dark fringes, which are known as double-slit interference fringes.
In the last life, when did scientists discover wave-particle duality?
This is one character that cannot be escaped - Albert Eins!
Albert Einstein used the concept of photons to explain the photoelectric effect, and physicists began to realize that light waves have dual properties of waves and particles.
Later, de Broglie proposed the "matter wave" hypothesis. He advocated that "all matter" has wave-particle duality, that is, it has the dual properties of waves and particles.
According to de Broglie hypothesis, electrons should have wave phenomena such as interference and diffraction.
Then the Davidson-Germer experiment designed and completed by Davidson and Germer successfully confirmed de Broglie's hypothesis.
In other words, light does indeed exhibit two properties.
At this time, watching the experiments of various equipment behind Lin Ke, the people from the two schools below gradually became unable to sit still.
"This...this is impossible!"
"How is this possible? Light is clearly an electromagnetic wave!"
"Why particles?! No! There are also wavelengths..."
"This kind of observation...this kind of observation..."
The students were excited, especially the physics students.
Lin Ke, on the other hand, not only did the double-slit experiment, but was also conducting other experiments at the same time.
Photoelectric effect…matter waves…
As a result, Lin Ke’s explanation voice directly overwhelmed everything:
"...Photons from the upper left collide with the metal surface, driving the electrons out of the metal surface and moving toward the upper right."
"I believe that irradiating a beam of light on a metal surface will cause it to emit electrons. The emitted electrons are called photoelectrons."
"Of course, in order to produce the photoelectric effect, the frequency of light must exceed the characteristic frequency of the metal material, which is the 'floor frequency'.
For example, if a blue beam with very weak irradiance is irradiated on the surface of potassium metal, as long as the frequency is greater than its bottom frequency, it can emit photoelectrons. However, no matter how strong the irradiance is, the red beam will emit photoelectrons once the frequency is less than the frequency of potassium metal.
If the limiting frequency is reached, it will not be able to emit photoelectrons."
“According to the wave theory of light, the irradiance or amplitude of light waves corresponds to the energy carried, so a beam with very strong irradiance must provide more energy to expel electrons. However, the fact is exactly the opposite of what classical theory expected.