Lin Ping set up the experimental equipment, what he wanted to do was a very simple physical experiment - double-slit interference experiment!

This is also a physical experiment that has not been reasonably explained in the physics community so far, and it is also known as the most bizarre physical experiment.

The equipment was simple: a flashlight or a candle, a wooden board with two gaps.

"Come on, close the windows, plunge the classroom into darkness!" Lin Ping said with a smile.

So, the students hurriedly found something to block the small window of the earthen house classroom, and the classroom door was also closed, and the classroom fell into darkness.

"Students, look, there is a wooden board on the table now, and I have opened two gaps in this cardboard!" Lin Ping raised the flashlight, "Now if I shine this wooden board with the flashlight in my hand, guess what will appear on the wall?"

Liu Xiangqian raised his hand: "There must be two light marks!"

Liu Weiguo said: "I think it's a match." ”

"Are you stupid? It's obviously two seams, how can there be only one light mark!" Liu Xiangqian retorted unconvinced.

Liu Weiguo shrugged: "I feel that it may be merged!"

"Okay, students, it's time to witness the miracle!"

Lin Ping turned on the old-fashioned tin flashlight in his hand, and the beam of light passed through the two gaps in the wooden plank, and then the students widened their eyes in surprise and opened their mouths.

The light on the wall is neither one, nor two, but many, or innumerable, from the middle to the sides in a regular and spaced distribution, and gradually darkens from the middle to the sides.

“1...... 2...... 3......”

The students began to count the light stripes on the wall.

"Oh my God, 8 rays of light, why are there so many?" Li Shulin said in surprise.

"No, it's nine, you see there's another one around the corner of the wall, but it's not obvious. Feng said with a smile.

"It's ten! How do I feel that the one in the corner of the wall should be two overlapping together!"

The students began to argue about how many stripes there were on the wall.

"Isn't it amazing?" Lin Ping said with a smile.

"Hmm. The students nodded.

"And then this is not the most amazing place!" Lin Ping said with a smile, "I'll ask you a question now, I said that Liu Xiangqian, this classmate is both a boy and a girl, do you believe it?"

The rest of the students burst out laughing: "I don't believe it!"

Liu Xiangqian pouted and said, "Teacher, I'm a man!"

Lin Ping thought for a while and said, "Then I said that I am both dead and alive, do you believe me?"

The six students below collectively shook their heads.

Liu Qingmei pouted and said cutely: "Teacher, I'm timid, don't scare us!"

Lin Ping laughed twice and said: "In the history of physics, scientists have always debated one thing, that is, whether light is a wave or a particle ......."

Lin Ping then explained the difference between waves and particles on the blackboard for the students.

"In the end, the physics community finally reached a consensus that light has wave-particle duality, which in layman's terms means that it is both wave and light!" Lin Ping said.

The children looked at Lin Ping in surprise: "How is it possible?"

Lin Ping said with a smile: "That's the case, light is both a wave and a particle! It has both wave and particle characteristics! If you have to use an analogy, it means that Liu Xiangqian is both a man and a woman, and he has the dual characteristics of a man and a woman at the same time!"

"Ahh

Liu Xiangqian wailed in protest, and several others laughed.

"Okay, now let's go back to the experiment we just did, this experiment is called the double-slit interference experiment, which proves the wave nature of light, because light is a wave, so it interferes with each other and forms several light stripes on the wall. Lin Ping said.

"But light is also a particle, so the scientists used the device to see how light passed through these two gaps, so they started looking further. What the teacher wants to say here is that not only light has wave-particle duality, but now the physics community believes that all matter has wave-particle duality. It's just that the wave of macroscopic objects is almost negligible, and the elementary particles such as protons and electrons in microscopic objects also have wave-particle duality. To facilitate the experiment, scientists conducted further experiments with electrons. ”

Lin Ping popularized the basic knowledge concepts of protons and electrons on the blackboard.

"So, the scientists decided to let the electrons pass through the double slit one by one, and now we assume that it is not the electrons that pass through the two gaps, but the rice, what do you think will happen? Will there still be such interfering streaks on the wall?" Lin Ping said.

The students shook their heads thoughtfully.

"No, teacher, the probability of rice passing through these two gaps is random, and the location where they fall is also random. Liu Qingmei said.

"Yes, what Liu Qingmei said is very right, when we have time, we can also do an experiment on rice passing through two gaps, but after replacing the rice with electrons, one by one electrons hit the wall through the gaps, there are still such interference fringes in the end. We started with a large number of electrons, similar to the light in a flashlight, where each electron interfered with each other to form streaks. ”

Lin Pingjixue said, "However, one by one, interference stripes are still formed, that is to say, they interfere with themselves! Just like Liu Xiangqian originally walked through the front and back doors of our classroom, it was random, he was willing to walk from the front door to the front door, and he was willing to walk through the back door and the back door, but there were still interference stripes on the wall, which means that Liu Xiangqian walked out from the front door and the back door at the same time, and he interfered with himself and formed a stripe. ”

The classmates frowned incredulously.

"Incredible, isn't it?, but that's not the most incredible!" Lin Ping said with a smile.

The students were speechless in amazement.

"The scientists decided to observe how a single electron passed through the gap, is it split into two? Or is the first Liu Xiangqian going through the front door, and the second Liu Xiangqian will automatically go through the back door? So the scientists installed a detector in front of the double slit, similar to a camera, and they decided to take a picture of how this Liu Xiangqian walked, whether it was to go through the front door or the back door, or to split into two and go through the front and back doors!" Lin Ping said humorously.

The classmates laughed, and Liu Xiangqian also touched his head and laughed.

"As a result, something magical happened, when the scientists made observations, the interference streaks on the wall disappeared! Gone! There was only one light streak on the wall! That is to say, Liu Xiangqian did not interfere with himself, he honestly only walked through one door!" Lin Ping said with a pretended surprise of surprise.

And the students opened their mouths in amazement.

"And when the scientist takes the observer, the streaks on the wall come back! It's as if the electron knows you're observing it, so it doesn't tell you how it goes, and when you don't look at it, it starts to get naughty. Lin Ping said.

Wang Yige said at this time: "Teacher, could it be that the observation of scientists has affected electrons?"

"Yes, the scientists also thought about it, so they decided to move the observer from the double slit forward to the double slit back, that is to say, I moved the camera that observed how Liu Xiangqian walked out of the classroom door from the classroom to the outside of the classroom, and when you Liu Xiangqian walked out of the classroom, I suddenly turned on the camera, so that I can always catch you!" Lin Ping said humorously.

This is also called the delay experiment, so the scientists did it. When it became a fact that the electrons passed through the two slits, the scientists turned on the detector instantly, but found that it immediately changed from passing through two slits to passing through one slit, and the interference fringes disappeared, leaving only one light streak on the wall. In other words, the scientist's delayed observation has changed the established facts! The whole causal relationship has been reversed!"

Lin Ping's words made the students immersed in surprise.

However, there is no reasonable explanation for this phenomenon in international physics, and even if the level of observation is constantly improving, it is still impossible to find a reasonable cause for this phenomenon. Lin Ping thought for a while and said, "This is equivalent to when you open your eyes and see that this flower is a flower, and when you close your eyes, it is not a flower, and the moment you open your eyes, it will return to a flower." ”

"Of course, the teacher's knowledge is also very shallow, I hope you can study physics well, and then find a reasonable and convincing answer for this experiment, and then go back to the teacher's answer, okay?" Lin Ping said with a smile.

[System: Your student Wang Yige is now very interested in physics, and his thinking ability has been further improved!]

[System: Your students Liu Weiguo, Liu Qingmei, Feng Xiao, Liu Xiangqian and Li Shulin have developed a great interest in physics, and their enthusiasm for learning physics has been improved. 】

(This chapter is not recommended for non-physics enthusiasts and interested parties, as it is indeed amazing, but it is also controversial.) Delving into the risks of deep study, especially those with rich imagination, are prone to imagine the state of doubting life, which is indeed a bit of a strange physical experiment. However, the microcosm and macrocosm cannot be generalized, and there will be no problem if you don't take the microscopic physics content to the macrocosm. ）