A Man of Science and Engineering in Troubled Times Wandering in the Late Qing Dynasty

Chapter 256 The Real Purpose
But Planck is a very sensible person. He said: "I myself feel that there are many holes in quantum theory that need to be filled. Why do you just use it as the basic assumption?"

Li Yu said: "The emergence of new theories means that there should be many areas that need to be improved, but I think the word 'loophole' mentioned by the professor is biased. It should be said to be 'supplementary'."

Planck said: "Aren't loopholes meant to be filled?"

"Um, that's what it means, but you can't say that." Li Yu said.

Planck said: "Not only physics, I also recognize your mathematical ability. According to the mathematical deductive method, only completely correct things can be used as axioms to deduce the following theories. Now that quantum itself is a hypothesis, how can you As a basic assumption?"

Li Yu said: "It's just an experiment now. There is no problem in doing experiments after having a basic hypothesis. Isn't this experimental verification?"

Planck felt that what Li Yu said made a little sense. After all, if you think about it carefully, even if it caused an uproar in the academic world, with the volatility theory as the backing, it would be a big deal to use the volatility theory to explain it later.

Because at this time everyone's inherent impression is gone, light should be able to interfere, because it is just a wave.

Li Yu actually had this idea to some extent. It is not easy to see the essence of the experiment.

Although this experiment is sensational now, it may not affect many people in essence. The one that can really affect is the temporary worker Einstein who is now in Switzerland.

——This is Li Yu's purpose.

The experiment was done for Einstein.

At that time, it can be called the combination of two swords when it is explained together with the photoelectric benefits.

Because after the particle nature comes out, in order to match the wave nature, the single-photon double-slit interference experiment is almost what everyone expects.

Otherwise, if a photon does not exhibit wave properties, the "wave-particle duality" has no real meaning.

This is the theoretical and logical closed loop.

Think about it: now there is a wave theory of light, →Einstein's photoelectric effect will reveal that light has particle nature, →single-photon double-slit interference experiment will further prove the wave-particle duality.

It's just that Li Yu slightly reversed the last two steps.

By that time, after Einstein proposed the photoelectric effect, it is estimated that Li Yu will be busy again, and there are still many experiments to be done.

Because in actual history, after Einstein proposed this theory, no one paid attention to it in a short period of time, two or three years.

Must rely on some experiments to continue to confirm.

After all, wave-particle duality is a super new theory that subverts the current physics world.

Li Yu thought to himself, this little clumsy experimenter himself must hurry up and continue polishing.

——This is the case with physics in the microscopic field. After the theory is published, if it is not tested, it will not work, and everyone cannot fully believe it.

Only since then, the status of theoretical physicists has really stood up, not just a vassal of experimental physicists.

Theory can also guide the direction of experiments.

Instead of existing experimental phenomena in the past, the theoretical physics community will seek explanations.

Karl Siemens was listening to the exchange of the two great gods, and he was also a little confused, so he asked: "Photons? I have heard of stones? So, light is like a stone?"

"Although this metaphor is very inappropriate, Mr. Siemens can understand it this way for the time being." Li Yu said.

Carl Siemens said: "If you understand it this way, if you throw stones through the double slits one by one, they will interfere if they don't work?!"

Li Yu said: "They will only form two piles of stones."

Carl Siemens said: "This is in line with common sense! I also agree with what Mr. Planck said, the single-photon experiment you proposed is at most two bright spots."

Carl Siemens put it more plainly, and Planck added: "I still think that if photons really exist, they cannot form interference if they pass through the double slit one by one. Interference requires at least two photons to pass through at the same time."

Li Yu said: "No, just let the photons pass one by one, it will still be an interference pattern."

Planck said: "Could it be that a photon interferes with itself? Illogical!"

Li Yu said with a smile: "You will know when the experiment is done."

Plank said: "Well, I will wait and see."

Li Yu knew that once it was done, it was just the beginning.After that, we still need to do experiments to continue to prove the particle nature of photons, so as to continue to support our own experimental results.

The development of quantum mechanics is like this, it is established step by step.

As for the theory of relativity, basically Einstein figured it out by himself.

Li Yu has already made a lot of preliminary preparations in China, and it will be very fast to continue the experiment at this time.

The key point is that the test equipment provided by Karl Siemens is very complete and advanced. It is worthy of being a German laboratory, rigorous and meticulous.

Seeing Li Yu's appearance, Lu Bicheng didn't dare to say a word, but thought in his heart that when he was serious, he had a strange feeling that he couldn't put it into words.

It takes quite a few days to do the experiment, and Li Yu will definitely be bored in the laboratory during this time.

Lu Bicheng asked cautiously, "Do you need my help?"

Li Yu said, "No need, I've made all the preparations."

Lu Bicheng whispered, "Okay."

Li Yu was a little embarrassed to let her stay in the laboratory, so he said, "You can walk around, Berlin is quite beautiful and spectacular."

Lu Bicheng shook his head: "I don't speak German."

Li Yu said: "Germans can speak some English, and you can always meet a few who speak it better."

Lu Bicheng shook his head again: "I don't know anything about Germany, and I don't go anywhere."

Li Yu said: "Okay, to be honest, I don't want you to run around. Now that you don't have a mobile phone or navigation, I can't imagine if something goes wrong."

Lu Bicheng's eyes flashed: "You also want me to stay in the laboratory?"

Li Yu nodded: "This is indeed safe."

"Then I'll stay here!" Lu Bicheng said happily, "Also, what do you mean by 'collecting' and 'daoxing' just now?"

Li Yu explained indiscriminately: "That is - to collect some books written by foreigners, and then show them to you, so that you can improve your literary accomplishment and morality."

Then he went on to say: "I almost forgot, let's go to the bookstore to buy some English versions of Mr. Tolstoy's works, as well as Hans Christian Andersen's fairy tales and Grimm's fairy tales, enough for you to read for a while."

In the 21st century of Li Yu's last life, the penetration rate of English in Europe was not low.Generally speaking, people from all over Europe can speak a little English, and even the very arrogant French have a higher English penetration rate than Italy and Spain.

And the British... seem to only speak English.

But today, the English penetration rate of the general population in European countries is obviously not as high as that of later generations, and those with multilingual ability are all highly educated.

After all, Berlin is a big city, and it didn't take much effort to buy the English versions of the complete works of Toon, Hans Christian Andersen's fairy tales and Grimm's fairy tales.

It's enough for Lu Bicheng to look at it for a long time, but the key point is that she still wants to translate two sets of fairy tale books. This is a big project, and she must be busy.

The laboratory that Carl Siemens gave to Li Yu and Planck was indeed not small, with three floors and many separate bedrooms.

One of them was dedicated to Lu Bicheng.

Lu Bicheng looked at the books in front of him, clapped his hands and said, "I'm upstairs, just call me if you need anything, I can just take care of you, I know you are very busy and tired."

The woman's mind is still very delicate, and she can see that Li Yu doesn't seem to have any intention of playing at all for the time being.

Although he didn't know why he made himself so busy, he didn't ask too much.

Planck, who was also in the laboratory, said with a smile: "I just said you need to take care of him."

Lu Bicheng hurriedly said, "The care I'm talking about is... yes... ah, it's cooking for the two of you."

Planck said: "This is really great! If there is delicious Chinese food, I don't have a problem even if I live here and don't go back to the University of Berlin."

Li Yu said with a smile: "It's a pity that Germany doesn't have too many seasonings, so it can't bring out the true strength of Chinese catering."

"Condiment?" said Plank. "Isn't there enough sauerkraut?"

Li Yu almost fell over, why is it like being in Korea? Hey!
"I mean onion, ginger, garlic, pepper, aniseed, star anise, cinnamon, soy sauce, vinegar, etc."

This time it was Planck's turn to be surprised: "Chinese people need so many things to cook? It's too complicated! Even if you study in school for many years, you may not be able to master it."

Li Yu laughed again and said, "You are really right, there is a special culinary school."

Plank said: "I have decided that I will eat Chinese food here for three meals a day!"

Nowadays, there are not many cultural exports that China can engage in, and catering is indeed a very good pioneer card.

Once settled in, it's time to start experimenting.

In the single-photon double-slit interference experiment, you can tell from the name that the key lies in how to control the emergence of single photons, that is, one photon passes through the double-slit device and reaches the photosensitive screen before another photon is emitted.

It sounds difficult, but the principle is actually not complicated. Simply put, it is to reduce the light intensity.

When the light intensity drops to a very low level, a single photon will appear, and then calculated according to the frequency, it can ensure that only one photon passes through in a unit time.

This light intensity is very weak, almost equivalent to the candlelight of a candle nearly 2 kilometers away.

After a long time exposure on the last photosensitive screen, individual small light spots will appear.

As the points of light increase, the famous light and dark stripes appear.

In fact, the appearance of the light spot itself can be regarded as a slight hint that light has a particle nature.

Experiments need to be done many times in order to get enough photos of the process.

As for the final paper, there is no need to explain too much. Li Yu just borrowed the inspiration from the previous correct derivation of Planck's black body radiation formula, and once again used the quantum theory in it to extend it.

From the feeling point of view, the thesis itself has a little "harmless to humans and animals", so it should not attract too much opposition.

(End of this chapter)