There was a sudden silence in the conference room.
Many boys in the audience look at me and I look at you.
At the same time, a tacit smile appeared on the corner of his mouth.
I understand everything.jpg.
Seeing that the scene seemed to be developing into a needlework exchange meeting, Xu Yun quickly coughed, interrupting everyone's thoughts:
"Ahem...Dear students, maybe I am lacking in my expression, so I will restate my statement here."
"The craft work I'm talking about doesn't mean making a gun or holding a stick, it means polishing metal materials by hand."
I don't know if it's an illusion.
Xu Yun always felt that after he finished speaking, there were a few disappointed sighs coming from the audience.
Of which Ralph Ashley's voice seems to be the most obvious?
Then he shook his head and adjusted his breathing.
Correcting his mentality, he continued:
"Dear students, please now return your attention to our original sentence - although light is highly suspected of possessing wave-particle duality, its properties under specific circumstances must be fixed."
"Everyone knows that there are many scenarios that fit this sentence, even the prism dispersion experiment conducted by Sir Newton and Mr. Fat Fish."
Many members in the audience nodded along.
What Xu Yun said is standard common sense in today's era:
The reason why a certain experiment can prove a certain property of light is because light showed corresponding properties in the experiment.
Don't look at the sentence above as it may seem like nonsense.
When a concept approaches logical nonsense, it also means that the concept is universal...or that its coverage has reached a terrifying height.
What Xu Yun has to do next is to completely destroy the 'nonsense logic' constructed by this sentence.
Then he took another blackboard and drew a small dot on it.
Still label the light source.
At the same time, an arrow from left to right is drawn on the right side of the light source, which means that the direction of the light path is from left to right.
Then he turned around, looked at the people in the audience, and asked:
"Dear students, can anyone briefly describe the double-slit interference experiment of light?"
This time there were more hands raised in the audience, about a dozen at a glance.
Xu Yun looked around briefly, casually nodded at one of the balding boys, and said:
"This classmate, please tell me."
The balding boy stood up, bowed slightly to signal to the classmates around him like a gentleman, and then said:
"As we all know, after Sir Isaac Newton proposed the wave-particle duality of light, although the physics community regarded it as truth from a theoretical perspective, there was a dispute over the proportion of wave properties and particle properties."
"Some people believe that the two properties of light are divided in half, and the number of scenes represented should each account for 50%."
"Some people believe that although light has duality, they are not 50/50 split, but are dominated by a certain quality."
"On the basis of this concept, the latter is divided into the wave majority and the particle majority, also called the wave party and the particle party."
Xu Yun nodded slightly.
The ‘preliminary summary’ mentioned by the balding boy is not difficult to understand.
Just like the harem novels of later generations.
Everyone admits the fact that there are multiple female protagonists, but when discussing the role of a certain female protagonist, many fans will often argue about it.
Some people think that everyone should live in harmony.
Some people think that their favorite character is the female lead, and the others are just bed warmers.
This is almost the situation for the Wave Party and the Li Party in this timeline today.
Then the bald boy touched the top of his sparse head and continued:
"Sir Newton himself insisted on the particle theory in the early days, but after receiving the letter from Mr. Fat Fish, his attitude changed to neutral, and he discovered one of the strong evidences of the wave theory - Newton's bright spot."
"When Sir Newton passed away, the wave theory overshadowed the particle theory."
"Then in 1807, a young man named Thomas Young devised an experiment."
"He placed an opaque plate with two slits in front of the light source. The light or particles passed through the slits and finally reached the photosensitive film, and analyzed its physical properties through the film."
"If the film forms interference fringes, it means that waves are interfering."
"If there are two bright lines on the film, it means that the particles pass through the two gaps and hit the photosensitive plate like small balls."
"In the end, interference fringes appeared on the film, which made the wave theory even more popular, and the Wave Party had an absolute advantage."
"Someone even built a coffin for the Granite Party and placed it on the doorstep of Wilkins Joel, a well-known Granite supporter."
"This situation lasted until last year, when the photoelectric effect demonstrated by you, Luo Feng, brought the situation back."
Bang bang bang——
After the balding man finished speaking, Xu Yun took the initiative to applaud.
Mentioned it a long time ago.
Among the top ten physics experiments, one experiment occupies two of them.
This experiment is Young's double-slit interference.
Its design is just like what the bald boy said, relying on the cracks to observe the properties of light.
Simple and easy to use.
Even spending two tons of breakfast money, you can repeat this experiment at home:
Find a laser pointer, a piece of slightly harder paper or a thin plastic sheet - it is recommended to use barbecue tin foil, and then use a razor blade to score two slits with neat edges that are very close together.
Find a white wall, turn off the lights and do it - well, I'm talking about doing an experiment here.
in the original history.
Yang's double-slit interference once pushed the particle theory into a desperate situation and almost lifted the boards of Maverick's coffin.
I don’t know if it’s the inertia of history.
In this timeline where the development of optics has been accelerated, many well-known discoverers of theories or phenomena have been replaced by different individuals.
But Thomas Young, a child prodigy, still designed this experiment just like the original history.
However, since Mavericks has long proposed the wave-particle duality of light, the impact of Young's double-slit interference on optics has been greatly weakened.
This chapter is not over yet, please click on the next page to continue reading! Use an example from a later Internet article to describe it.
It's probably because the work of Fengshen has become an ordinary Wanding.
Then Xu Yun thanked the balding man, motioned for him to sit back, and said:
"Dear students, Yang's double-slit interference experiment is indeed very subtle, but I don't know if you have thought about such a problem."
"Suppose - I mean suppose, suppose we have the ability to debug a beam of light and change it into individual photons..."
"So what will these photons show on the film?"
"Photon?"
Hearing this word coming out of Xu Yun's mouth, Hubert Ally in the audience subconsciously said:
"Since it is a single photon, it must be two bright lines."
Hubert Airy's answer was met with no objection this time.
Everyone, including the boy who had questioned him before, nodded in unison, as if it was a matter of course.
Although Faraday is still coding chapters related to electronics, he has not yet officially released it to the public.
But mentioned earlier.
Since the discovery of elements, the scientific community has gained a certain understanding of atoms.
So in the eyes of many people.
The 'photon' referred to by the particle theory is a particle similar to an atom.
So after Xu Yun mentioned photons, many members at the scene quickly gave the answer:
If it is really possible to separate individual photons and emit them one by one, then what appears on the bottom plate must be two bars - they are said to be single particles. How can there be interference fringes?
Is it interfering with myself?
This is obviously impossible.
Looking at the many members in the audience who had unanimous opinions, Xu Yun suddenly smiled:
"Dear students, if I told you that a photon can pass through two slits at the same time and cause interference to itself, would you believe it?"
As soon as Xu Yun said these words.
The activity room was silent for less than two seconds before a loud noise erupted.
"impossible!"
"Absolutely impossible!"
"Classmate Luo Feng, are you kidding me?"
But maybe it’s because Xu Yun has already said that ether does not exist before.
Although everyone's reaction was violent this time, it was not as rude as the first time.
Overall it remains at a fairly controllable level.
It's a coincidence.
The most excited person this time was none other than Xu Yun’s old acquaintance, Hubert Airy.
Having been exposed to telescopes since he was a child, his knowledge and 'belief' in light far exceeds that of other club members.
"Classmate Luo Feng!"
I saw Hubert Airy's face turned red at this time, his hands on the table, leaning forward, spittle flying:
"Classmate Luo Feng, although I admire you and Mr. Feiyu very much, and I also know that the Feiyu family must have some secrets that are not passed down, but..."
"The possibility you mentioned, I dare say, absolutely, absolutely does not exist!"
Then he looked around and suddenly fixed his gaze on Wheat, pointed at Wheat's waist and said:
"Let's put it this way, classmate Luo Feng, if what you say is true, I will eat that ax on the spot!"
"...."
Xu Yun twitched his lips when he heard this, and couldn't help but feel sympathy for this stupid young man in his heart.
My child, it seems that you are determined to take this ax...
because....
Even if a single photon passes through a double slit, it will still get interference fringes...
That's right.
The ‘weapon’ that Xu Yun used as his trump card was the double-slit interference experiment of electrons!
The electrons here can be replaced by photons, and there is actually no difference between the two - at least in terms of phenomena.
Mentioned above.
Among the top ten experiments in physics, the experiment designed by Thomas Young ranks second.
One of them is the standard Young's double-slit interference experiment, which is a macroscopic physics experiment that everyone can do for a few dollars.
The other is the double-slit interference experiment of electrons.
And this experiment also has another name, called...
One of the most terrifying experiments in the history of physics.
What's so scary about it?
Because it can be said to be the first time in history that humans have officially encountered a "supernatural event" in a scientific experiment.
However, about 50% of the supernatural beings here are real supernatural beings, and the other 50% are artificially added fake supernatural beings.
The idea of this experiment is based on the Thomas Young experiment mentioned above, but it occurred in 1961.
With the development of science and technology, the scientific community at that time already had machine guns that could shoot electrons.
You can keep biubiubiu.
As a result, the final result is the same as Young's double slit experiment:
The two rays of light passing through the double slits vibrate, intersect, and interfere with each other. The intensity between the wave peaks is superimposed, and the positive and negative cancellations between the wave peaks and the wave troughs are cancelled.
Eventually, complex and beautiful zebra crossings, also known as interference fringes, will appear on the screen.
But the Li faction was dissatisfied, so they made another request:
Let’s do another experiment and emit the electrons one by one to see if they will definitely become two bars!
So they switched the electron machine gun to burst mode to ensure that only one electron was fired at a time.
However, the result is still a zebra crossing.
In fact, if electrons... or photons really are waves, then the grain pie has nothing to say, so it is willing to admit defeat.
But the problem is the single electron they emit!
To know.
According to wave theory, zebra lines originate from the interference superposition between two wave sources generated by double slits.
That is to say, the appearance of interference fringes means that it passes through two slits at the same time, rather than passing through the left one second and right the next second.
But in this way, it conflicts with the "single" of a single electron:
A single electron can either pass through the left slit or the right slit, but cannot pass through both slits at the same time.
This is a mystery that remains unsolved to this day.
Of course.
Regarding the double-slit interference experiment of electrons, the more famous thing may be another thing, which is the so-called third experiment:
In order to further observe the truth, the scientists installed two cameras in front of the screen, one on each side and one on the left.
Whichever camera sees the electrons indicates which slit the electrons passed through.
This chapter is not finished yet, please click on the next page to continue reading the exciting content! Similarly, electrons are emitted in burst mode.
The result is this:
Every time either the camera on the left sees an electron, or the camera on the right sees one.
One is just one, and no electron has ever been found to split into half.
But at this moment, something really weird happened:
The researchers suddenly discovered that the pattern on the screen had quietly turned into two bars at some point!
Didn't use the camera to watch.
The result is always a zebra crossing and photons are waves.
Watched it with the camera.
The result is two bars, and the electrons become particles.
Does the experimental result depend on whether you look at the camera?
Does it sound creepier?
However, as a professional popular science work, here is one thing to popularize:
The third experiment...the so-called experiment of installing additional cameras was actually a thought experiment and was not actually completed.
In fact, you know it if you think about it.
Forget about the camera.
Even with other equipment and instruments, if you want to directly see which slit electrons or photons pass through, is this possible?
Therefore, no matter how you search on the Internet, you will not find any professional papers or experimental videos related to camera observation.
be honest.
The double-slit interference experiment of electrons is indeed very scary, and its truth has not yet been cracked.
But the "thriller" seen on the Internet today actually has the added color of secondary creation.
Currently, there are only three double-slit interference experiments of electrons that have been actually completed:
1. Early double-slit interference experiment.
This is a phenomenon that has been experimentally verified in the early days of the establishment of quantum mechanics. The more famous one is Hitachi TV’s electron double-slit interference. (hitachi/rd/portal/research/em/doubleslit.html)
2. Wheeler's delay experiment.
In 1979.
John Wheeler, who once worked with Einstein, proposed an ideal experiment at a conference in memory of Einstein:
In order to eliminate the interference of observation behavior on the behavior of electrons in electron double-slit interference, observations are made after the electrons pass through the double-slits in some way.
The idea is this:
A photon is emitted from the light source and passes through the semi-reflective mirror 1. The probability of the photon being reflected and transmitted is 50% each.
After that, place a total reflection mirror A and B respectively on the path of the reflected or transmitted photon.
Let the two paths merge at C after reflection.
There are two detectors AB placed at C, which can observe whether there are photons in path A or path B respectively.
Next.
If another half-reflective half-mirror 2 is placed at point C in front of the two detectors, the photons can interfere with themselves.
After appropriately adjusting the optical path difference, the interference light in a certain direction (A or B) can be destructed. The detector in this direction will always be unable to receive the signal.
At the same time, the detector in the other direction must always receive the signal.
The reason why this experiment is called a delayed choice experiment is because we can decide whether to place half mirror 2 after the photon has passed through half mirror 1.
That is to say, after the light has decided whether to be wavelike or particlelike, we can then place the half-reflective half-mirror 2 to observe it.
When the experiment was first proposed, it was a thought experiment, but it was later verified experimentally. This result was once published in Science. (DOI: 10.1126/science.1136303)
The ideal single-photon source has been available as early as 1974. The single-photon source in the Wheeler experiment above utilized the defect of the N-V color center of diamond.
3. The quantum erasure experiment has also been experimentally verified.
The quantum erasure experiment is more complicated to talk about, which is the source of the so-called "the past can be changed within eight nanoseconds". (doi/10.1103/PhysRevA.65.033818)
Well, just these three - there may be other modified experiments, such as C60, but the core principles are the same as these three experiments.
The closest result to the so-called 'camera' at present is probably a report produced by a research team in the Department of Physics at the University of Nebraska-Lincoln in 2011, but it is still far, far away from a real camera. (doi/
10.1088/1367-2630/15/3/033018)
Incidentally.
The so-called ‘camera’ patterns taken by cameras on the Internet are actually electronic interference patterns made by the team led by Akira Sotomura of Neon in 1988. (doi/10.1119/1.16104)
The so-called experiment that can directly observe which slit electrons pass through is still a thought experiment, and no one has been able to do it so far.
What are the ‘observations’ that can really be done now?
An electronic detector is installed between the double slits. This detector cannot display images directly and cannot observe the path of particles. It can only be used as a receiving screen.
When the detector switch is turned on, the light becomes particle-like;
Turn off the detector switch, and the light will appear in a wave state.
It's like when it rains from the sky, you have no way of knowing which cloud it fell from.
But when you reach out your hand, what you receive is rain.
If you don't reach out and see it fall to the ground with your own eyes, what falls is just a flower.
Everything depends on your observation, or interference.
Therefore, the electronic or double-slit interference experiment is actually horrifying from the beginning to the end:
That means liberal arts students can't understand it at all...
Ahem...wrong, wrong.
The scary part is that if you don't measure, it will be one kind of result, but if you measure it, it will be another kind of result - again, the measurement here is not the direct measurement of the camera, but the detector of the receiving screen.
That is, any information that can leak out the path conditions and be recorded will cause quantum collapse.
It's that simple.
We are professionals in dispelling rumors and popularizing science. (laughs)
This is also one of the current research areas of entanglement.
The expression in some dark science fiction novels is almost like "the designed underlying logic can prove that human beings are imprisoned guinea pigs" and so on...
This chapter is not finished yet, please click on the next page to continue reading the exciting content! Real science should not reprocess unknown information into more terrifying rumors to scare people.
Instead, after discovering the unknown, you should try your best to decipher its mystery.
Of course.
At present, Xu Yun does not need to consider such complicated matters. His current pressure mainly comes from the cognitive conflicts among the members:
"Um... Dear students, please be patient."
"I can understand everyone's mood. After all, what I said is indeed contrary to everyone's existing ideas."
"But it doesn't matter. We are still saying what we said before - we can put aside the experimental results first and simply discuss the particularities of the experimental equipment."
Then he looked around, spread his hands towards the audience, and said with a hint of temptation in his tone:
"Don't you want to know how to emit photons individually?"
As soon as the words came out of my mouth.
The originally noisy discussion in the audience turned into silence again.
Preparing single photons.
These five short words can arouse the interest of many people in 2022, let alone natural science enthusiasts in 1851.
So it's very fast.
The doubts that were clearly visible on everyone's faces were gradually replaced by hesitation and curiosity.
See this situation.
Xu Yun suddenly felt certain:
Very good, the fish took the bait.
As we all know.
There are many ways to prepare single photons in later generations.
For example, use an ordinary light source to emit light, and then add a strong attenuation to attenuate the light intensity below femtowatts.
In this way, only a few thousand photons are emitted per second, which is basically a single photon emission.
Another example is using a single quantum dot light source.
This thing only contains one luminescent molecule or structure, which can only emit one photon at a time.
Quantum communication, which is mentioned every day, usually uses this kind of light source.
If the above conditions are still difficult to obtain, students can take out the divine light stick and transform into Tiga to prepare photons.
However, Xu Yun was not prepared to use these methods. He was planning to commit an early telecommunications fraud in 1850:
Use electrons instead of photons.
After all, the emission of a single electron is relatively easy - at least easier than that of a single photon, and the accuracy is also higher.
At the same time, electrons...or all microscopic particles have wave-particle duality, and this concept has even been extended to microorganisms:
In 2019, the scientific community has allowed gramicidin with a molecular weight of 1886 to undergo double-slit interference without damaging its biological activity. (doi/10.1038/s41467-020-15280-2Focus to learn more)
Again.
Many of the front-end scientific results have surpassed ordinary people's cognition, and will really make you doubt the world.
Therefore, with only a tiny operation, Xu Yun was able to successfully change photons into electrons.
at the same time.
The emotions of many members in the audience were also aroused by Xu Yun's earlier words. The bald boy raised his hand again:
"Classmate Luo Feng, just now you said that craft work refers to hand-polishing metal materials. Is there anything we need to do?"
"Bingo!"
Xu Yun snapped his fingers with a cheerful expression. It is easy to talk to smart people:
"Yes, due to the difficulty of preparation, this experiment also requires about half a year of preparation."
"In the next time, I need everyone to help me do two things."
Then he raised a finger and said:
"The first thing is that in about a week, we will distribute a nonlinear optical crystal and a carving knife to everyone."
"Each of you must carve slits with a spacing of 1 mm on the crystal according to the requirements."
"Before the experiment finally starts, I will check your 'homework'. The person with the highest accuracy will have priority to observe the experimental results, plus a special small gift."
It is different from Thomas Young's Young's double-slit interference.
The 'double slit' used in electronic double-slit interference is not actually a piece of paper or plastic.
It's a nonlinear optical crystal. (No one discovered this clue when measuring the speed of light. I'm disappointed...)
The crystals used to prepare double slits in later generations are generally made through photolithography technology, which can be accurate to the nanometer level.
However, the early double-slit crystal preparation technology was not very mature, so it could only be done by hand like a single man without a girlfriend.
This polished crystal is called a crystal grating, and it is one of the few devices that has been used from the invention stage to later generations.
Transmission electron microscope...that is, one of the functions of TEM is electron diffraction pattern, which can determine the crystal structure. It is also often used in double-slit interference experiments of electrons.
According to Xu Yun's understanding, the cost of a nonlinear optical crystal these days is about 0.5 pounds.
Everyone at the scene was given ten chances, and the total was only a little over one hundred and fifty pounds. An ATM girl said there was no pressure.
Looking at the members who were getting excited about having the opportunity to participate, Xu Yun lightly knocked on the table and reminded:
"Everyone, please be quiet. The task is not over yet."
After the scene is silenced.
Then Xu Yun raised a second finger, this time with a much more solemn tone:
"Since the accuracy of manually polished crystals is not high, we need to add some equipment to achieve the effect of correction coefficients."
"So in addition to polishing the crystal, everyone has a task to complete."
"In the coming time, each member will also need to regularly complete the manual processing and polishing of carbon blocks, tungsten wires, and aluminum tubes. The specific schematics will be distributed to everyone in due course."
Then the corners of his mouth raised slightly, revealing a bright smile:
"If we're going to do it this time, let's just do it to the big guy and fight him until death!"
........
Half an hour later.
The party is dismissed.
Lao Tang still had some matters to deal with at the Federation of Students, so Xu Yun took Aveline and Xiaomai to leave first.
After leaving the activity room.
The silhouettes of the three of them stretched very long under the street lamp, and the winter air also carried a chill.
After walking for a while, Xu Yun turned around and looked at Aveline and said:
"By the way, classmate Aveline, I have something to trouble you about."
"What's the matter? Tell me."
Xu Yun nodded, took out a small note from his body, and handed it to her:
"I would like to trouble you to find a steel factory with qualified technology... It would be better to be an instrument factory to produce these things."
Aveline took the note, glanced it up and down, and whispered:
"A beryllium tube...a hollow solenoid containing zinc-doped ferrite...a cone of pure molybdenum..."
As we all know.
The discoverer of the element beryllium was Vauquelin, who first discovered the element beryllium from beryl in 1798.
In 1828, Vauquelin obtained metallic beryllium by reducing beryllium oxide and beryllium chloride with metallic calcium and potassium respectively.
The preparation process of zinc-doped ferrite appeared in 1813, and now it has become a common solid waste-based magnetic pole material.
Molybdenum was obtained by Elm in Sweden in 1782 by burning a mixture of charcoal and molybdic acid mixed with linseed oil in a sealed manner.
Therefore, the materials given by Xu Yun are in line with the understanding of the chemical industry in 1850, but they are relatively rare in ordinary times.
Aveline's eyes quickly glanced over these names, and after reading, she folded it and put it in her pocket:
"No problem, leave it to me. I'll write a letter tonight to ask the manufacturer to start the furnace."
"That's good...uh, wait!"
Xu Yun nodded a few times subconsciously, but soon discovered that something seemed wrong:
"Classmate Aveline, you said you wrote to the manufacturer to start the furnace...Do you mean you have an instrument factory?"
"Hmm? What's so weird about this?"
Aveline raised her eyelids and glanced at him, then said matter-of-factly:
"Ancestor Newton's research on optics was extremely in-depth. At that time, the equipment produced by many instrument workshops did not meet his requirements, so he opened an instrument manufacturing workshop of his own."
"More than a hundred years later, this workshop has developed into one of the top instrument manufacturers in Europe."
"And I am the sole heir of Newton's ancestors, so now this factory naturally belongs to me."
"Besides, don't worry, I give those workers very good treatment. If you don't believe me, you can go to London and ask..."
"...."
Xu Yun opened his mouth, trying to make a sound, but in the end he remained silent.
Then he suddenly thought of something and quickly looked around.
After confirming that there was no one around, he said to Aveline:
"Um...Classmate Aveline, how much assets do you have in your name now?"
"Assets?"
Aveline stopped and counted on her fingers:
"The annual dividend of tomato sauce is about more than one million pounds, and there is also an instrument manufacturing factory, a steel factory, two shipyards, four horse and carriage shops, plus more than a thousand acres of farms..."
"Prince Albert asked me before if I wanted to take a share in the Firearms Bureau. I didn't like war very much, so I declined."
"If the dividend deposits and industrial assets are all converted into cash... it will be about 70 to 80 million pounds?"
Xu Yun and Wheat:
"??!!"
Damn it, why did you discover this rich woman’s identity just now?
The 70 to 80 million today is really worth tens of billions in future generations...
No wonder this girl turned a blind eye to her IOU at the beginning. She really didn't take the hundreds of thousands of pounds into her eyes...
While Xu Yun was shaking in his heart, Aveline's question rang in his ears again:
"Luo Feng, it's not difficult to produce these devices, but what are you going to use them for?"
Only then did Xu Yun come back to his senses and glanced at the rich woman.
After a moment of silence, two words popped out of his mouth: