Some people may disagree, but if you think about it carefully, you will find it incredible. It's like something you can't see or touch, but it does exist. Look at you and change the world on your own initiative. If you go on, you will doubt the truth of this world.
Let me talk about this electronic double-slit interference experiment first. In fact, the original double-slit interference laboratory was made of light: a parallel monochromatic light shone on two parallel narrow slits, and a stripe of light and dark appeared on the back plate. This is the double-slit interference experiment. The double-slit interference experiment of light proves that light is a wave from the side. But later, physicist Jonson had a whim and made a double-slit interference experiment with electrons. It was nothing, but the experimental result was unexpected. Electrons actually show the same characteristics as light! That is to say, electrons are also a kind of wave!
Because of the theory of matter wave put forward by De Broglie, scientists can only think that electrons also have wave-particle duality. This explanation seems perfect, but everyone doesn't know that the real big move is still behind.
At 1974, a university professor became more suspicious of the experiment, so he did it again, installed high-precision monitors on both sides of two slits, and started the experiment again. The result frightened many people: every electron could see clearly, two bright lines appeared on the back plate, and the double-seam interference disappeared. ......
The professor didn't believe this evil, so he turned off the monitor, and then the double-slit interference miraculously appeared again, but when he resumed monitoring, the double-slit interference disappeared again, and only one electron after another could be seen passing through the double slit to form two bright lines. ......
Having said that, everyone can understand why this experiment is so "creepy", because in this experiment, it seems that there is an unknown existence manipulating electrons, that is, people are not allowed to see what happens at the moment when electrons interfere. This influencing factor is human consciousness, which is the last word in physics. The conclusion from the current double-slit experiment of electrons is that when you see the interference pattern, you can think that the electron is a wave, but when you think it is a particle, it is a particle. Maybe the truth is ......
All the answers were long and didn't get to the point.
The question is why it's creepy.
The reason for the horror is that the result of this experiment depends on whether people observe it or not.
That is to say, for example. If you usually put a cup of boiling water, you stare at it for a day, or shoot it with a camera for a day, or just leave it there for a day without observing it or shooting it with a camera. In all three cases, the result of boiling water the next day is the same: it gets cold.
But in the double-slit experiment, the three results are different. It is equivalent to staring at it, and the water will still boil after a day. If you don't look, the water will light up in a day.
This glass of water is like having life and will, knowing that you are watching it.
This is already terrible, right? What's even more frightening is that if you decide to play hide-and-seek with him, it just happens that people walk away and take pictures of it with their cameras, and it seems that it has seen through your little trick and will be boiled water the next day.
In other words, no matter how you observe it, it knows that you are observing it.
Of course, the object of the double-slit experiment is not water and its temperature, but the photon idea. But that's what's terrible about it: the result of the experiment depends on the will.
Thank you for inviting me!
The single-particle double-slit interference experiment is one of the most amazing experimental results in human history, and it is an amazing interpretation of the quantum world, which is completely different from the macroscopic world that conforms to physical intuition. In fact, it shows that the essence of reality may not be material at all.
Let's start with what we are most familiar with:
We can imagine a rubber duck swinging up and down in the water, causing periodic ripples to spread outward. At a distance, the ripple met an obstacle with two cracks in the middle. Most of the water waves were blocked, but they still passed through two gaps. When new ripples begin to overlap, new ripples that interfere with each other are formed. This is because the peak in one notch just collided with the peak in another notch, resulting in a stronger peak; The superposition of two low peaks and valleys also led to more serious settlement. Scientifically, this phenomenon is called "constructive interference"
But when a peak meets another trough, they will cancel each other out and the water surface will be flat-this is "destructive interference". So we get alternating changes of undulating or calm water surface.
Thomas? Yang first observed the double-slit interference of light in 180 1: a beam of light passes through two narrow slits, producing several bright and dark stripes on the receiving screen, and areas of "constructive" and "destructive" interference appear alternately on the screen. As long as there are more than two photons, interference fringes will appear.
Each photon passes through two slits respectively, and then interferes with each other behind the slits to form interference fringes. At this time, we will see one of the most incredible experimental results in all physics: only one photon is emitted at a time, and interference fringes will still appear.
That is to say, even if only one photon is emitted, it will pass through two slits at the same time and interfere with each other separately. The experimenter once installed a detector to observe which gap the photon passed through and obtain its path information, but at this time the interference phenomenon disappeared. If the detector is removed and a single photon is emitted again, interference fringes will appear again.
Until 1987, scientists found in an experiment that the interference phenomenon (pattern) would not disappear completely if only some particle path information was obtained. This is the "quantum erasure experiment" (a variant of the double-slit experiment): as long as the particle motion is not excessively disturbed during the measurement, the interference fringes will be randomly changed or restored.
Another variation of double-slit interference experiment is delayed selection experiment: after photons are projected on the screen, the path information detected by the detector can eliminate or restore the interference image with marked or erased path information. At this time, the difference relation can even extend for a long time in theory. If the path information is marked, the photon only passes through one path; If the path information is erased, the particles will pass through the two gaps again. That is, observing people's current behavior can determine the past, which is contrary to the traditional theory.
Later physicist Veritasium also conducted this double-slit interference experiment. He was surprised to find that the formation of stripes has nothing to do with the energy transfer of each photon. These stripes are the final distribution positions of many unrelated photons. That is to say, each photon doesn't know the position of the previous photon, and it can't predict the falling point of the next photon, but each photon will fall in the edge area and will not fall outside the edge area.
Copenhagen, the pioneer of quantum mechanics at the University of Copenhagen in the 1920s, thought that wave function had no physical essence, but was composed of pure probability. It shows that the particles in the double-slit interference experiment only exist as a possible position wave that eventually contains all paths. Only when a particle is detected can its position be determined.
Copenhagen's explanation calls this transformation between spatial possibility and deterministic nature "wave function collapse". It shows that it is meaningless to try to determine the position or nature of particles before collapse, which means that the universe allows all possibilities to exist at the same time, but nothing will happen until the last moment. What is even more "creepy" is that these different possible paths or different realities will interact and interfere with each other, so that the chances of some paths becoming reality will increase and some will decrease.
If I say that students who have attended high school physics have all heard of this experiment, will there be no objection? But most students think that the double-slit interference experiment is only a proof experiment of light fluctuation. At that time, they didn't realize that this simple experiment turned out to be one of the most classic experiments in the twentieth century.
Before the experiment, people thought that objects were objective, and no matter how they were observed, they were constant and objective.
After the experiment, it is found that the observation of objective objects will actually affect the observation results, that is, human subjective consciousness will affect the expression of objective objects.
Specifically, it is like this:
When two coherent beams meet at the same time and space, they overlap, and the light projected on the whiteboard shows that the light waves in some areas are strengthened and the light waves in some areas are weakened, which is optical interference.
But if the whiteboard is replaced by a measuring device to detect the specific superposition path of each photon, it is impossible, and only two slits can be observed.
The explanation given by Copenhagen is that we can only observe the time and location of photon impact. In the middle, if we detect the position of the photon, the wave function will collapse and the photon coherence phenomenon will disappear, that is, subjective observation will affect the appearance of the phenomenon. This is an unprecedented theory, so it's creepy.
It is highly recommended to read Cao Tianyuan's "Does God Roll Dice?" History of quantum physics.
The author of the book talked about this problem in detail.
Electronic double slit experiment. This simplest experiment is actually the key to solving top-level physical problems. He drove the super brain and finally discovered the field of quantum physics.
It's creepy Yes, quantum physics is so horrible. Science and philosophy have been arguing about matter and consciousness for thousands of years. First of all, they all agree that matter and consciousness are completely different things. Secondly, they argue about who decides who.
Well, quantum physics has been completely subverted.
First, determinism was overthrown. Everyone is a causal theorist who thinks that everything in the world has a cause and effect, because it determines the result, so there will be no result without cause. According to the theory of quantum physics, if you don't observe him, he is in the superposition of life and death. As long as you observe him, he instantly collapses into life and death, which means that the cause and effect are reversed.
Then it overthrew the boundary between matter and consciousness. Consciousness can't be touched, seen or smelled, while matter can be seen, touched and smelled. How can it be the same? According to the theory of quantum physics, all substances are made up of elements, elements are made up of atoms, and atoms are made up of electrons. What is it when electrons decompose? It's a string, yes, it's a string curled up in a low latitude space and a high latitude space. To be precise, it's a wave, vibrating. If you don't observe it, it will vibrate. If you observe it, it will collapse into particles. Well, the essence of all matter is wave, vibration and space.
My worldview was shattered by quantum physics.
Thank you for inviting me to read the world.
The double-slit interference effect is precious, and it is not reliable to explain it with the uncertainty principle, which will naturally cause a fuss.
The author believes that the explanation of this topic should analyze the two self-interference effects of photons and electrons together, and the principle is the same.
The so-called self-interference effect: 1 particles have double-slit interference phenomenon. According to quantum theory, 1 particle can pass through two slits simultaneously.
The reason of quantum theory is that the particle motion does not obey the law of causality, has no process trajectory, can be in any position at the same time, and has separation.
This is sacred logic. If the nonlocality theory or Heisenberg's uncertainty principle is not established, how to explain the self-interference effect?
In my opinion, the root cause is that quantum scientists don't know the basic principle that electromagnetic wave is the excitation effect of matter wave.
In addition, the "supersymmetry theory" is needed: the atomic spectrum is the epitaxial part of the unity of opposites of fermions and bosons.
The fine structure of atomic spectrum shows that the electrons outside the nucleus move around the nucleus, and as the harmonic oscillator of eternal oscillation, they excite the field medium in the internal space of the atom and produce the atomic spectrum that radiates outwards.
Atomic spectrum is the product of the excitation medium of electrons and nuclear matter waves, and it is the peripheral component of the whole atom.
Taking hydrogen atom as an example, according to the principle of minimum action, it can be estimated that the ground state electron oscillation speed is basically stable at about V 0 = 2,200,000/s, and the proton oscillation speed is basically stable at about V * = 500 m/s. ..
The kinetic energy of electrons excites electromagnetic waves, including: Ek=? mv？ =hc/λ，λ=hc/Ek，Ek=？ ×0.9 1e-30×(2.2e6)？ That is, Ek=2.2e- 18[J], λ=9e-8[m]=0.9[nm].
Proton kinetic energy excites electromagnetic waves, including: Ek'=? M'v'? =hc/λ'，λ'=hc/Ek '，Ek'=？ × 1.67e-27×500？ Namely: Ek'=2. 1e-22[J], λ'=9.5e-4[m]≈ 1[mm].
A real atom is not a closed system, it will be influenced by other particles. The oscillation speed of electrons outside and inside the nucleus is variable, which leads to the fine distribution of atomic spectrum.
For the atomic spectra of many nucleons, theoretical calculation can be made according to the outer electron matter wave and nuclear matter wave as prominent representatives.
Kopai's quantum theory worries that if electrons move around the nucleus, coulomb force needs to provide centripetal force and constantly release electromagnetic waves, and the coulomb force will soon be exhausted, leading to the absurdity of electrons collapsing to the nucleus.
This kind of worry is unnecessary. Because:
(1) motion is the existing mode of particles; Motion is absolute, otherwise there will be no vortex ball of * * * particles.
② Only when electrons/protons/photons spin at the speed of light can they realize their independent selves and maintain their inherent mass and gravitational potential energy.
(3) Spin produces two poles, which produce axial tilt, axial tilt produces precession, and precession produces oscillation or geodesic cycle.
(4) The atomic spectrum displayed outside the atom is the peripheral component of the atomic system, and subatomic atoms are only the source of moving electromagnetic waves.
There is a special electromagnetic wave source or laser generator, also called "primary source", in which electrons outside the nucleus accelerate to oscillate.
Suppose that the electron oscillates 1 cycle, exciting the nearby field medium and generating 1 photon. This photon is equivalent to a "secondary source" and can be regarded as a "single photon exciton".
This photon plasma, just coming out of the generator, will excite or push all the field media around the exit, producing a large number of N photons distributed on an ultra-thin sphere, that is, the wavefront.
These "n photon excitons" excite the nearby medium, just like the domino effect, forming a coil of photon front, which is called electromagnetic wave.
Obviously, 1 photon can excite n photons, and n photons can excite n? ，n？ ...n？ A photon.
When a large number of photons reach the "two slits", each slit passes at least 1 photon respectively.
Once these two photons come out of the slit, they form two wave fronts, namely 2×(n→n? →n？ ...n？ ) photons.
A large number of photons on the two wave fronts intersect, overlap and vibrate at peaks and valleys, leaving light and dark stripes on the "back screen".
There is an electron generator that meets the photoelectric effect, and the emitted free electrons are used as the motion source, which is the electron matter wave.
This material wave of 1 electron can excite the field medium near it and produce a 1 ultra-thin wavefront composed of n photons.
Then the field medium is excited in turn to produce n? ，n？ ...n？ A photon. The excitation mode is 1 electron →n photons →n? Photons.
Later, the mechanism of double-slit interference is exactly the same as that of single-photon interference.
Atomic spectrum shows that space is full of photons with various frequencies. Atom is the unity of "subatomic atom in inner space" and "light quantum in outer space"-two supersymmetric components.
Single electron/single nucleus/single nucleus (matter wave) can excite a large number of photons, and single photon (plasma) can also excite a large number of photons.
Monochromatic electromagnetic wave is a spherical wave composed of coils on the wave front, not just a sine wave.
The double-slit interference experiment is familiar to everyone. Many people have done this experiment in person when they were in school. Letting a monochromatic light pass through two parallel slits on the hood will form alternating light and dark stripes on the back screen. It is this experiment that proves the fluctuation of light for us! And we can calculate the position of light and dark stripes according to the wavelength of light!
1
But this is such a simple experiment,
So far, there are still many unexplained phenomena. In order to explore the mechanism of double-slit interference, scientists installed a detector on the light shield to observe photons passing through the slit, but the incredible phenomenon appeared and the interference phenomenon disappeared. This time, there are no bright and dark stripes on the screen, and the light only chooses to pass through one of the slits, which means that the fluctuation of the light disappears. But even weirder, when we removed the detector, light and dark stripes appeared on the screen again.
In other words, it is incredible whether we observe the experimental process will affect the experimental results. No matter according to daily experience or scientific inference, it is impossible to give a reasonable explanation. For this phenomenon, the famous scientist Schrodinger once made a famous hypothetical experiment, that is, Schrodinger's cat, which has been teased by us!
Although scientists have given many different explanations for this situation, such as string theory and parallel worlds. So far, all the explanations are just a hypothesis and have not been confirmed by experiments. The special existence form of elementary particles at the microscopic level is really frightening, and it also makes many people's world outlook face collapse. But as Qu Yuan said, the road is long, Xiu Yuan is Xi, and Xiu Yuan is Xi, so I am willing to go up and down for it! I believe that with the deepening of human research on the micro-world, this puzzle that has plagued us for many years will be solved one day!
The innate eight diagrams are the universe diagrams. It's all here. What are you excited about?
I was impatient, didn't play with you, and dodged;
Zhuangzi loathe to give up, come in and go out, stay and see; Confucian children become dogs when they are tired, and monks and nuns fool them.
Muhammad is not free, and Jesus always intervenes in the next room.
It is normal that there are fewer people who do practical things and more people who muddle along. Only when there are fewer people who do practical things can a saint, philosopher and superman be admired and respected, and a few people who are now called "scientists" scratch the surface, scream and be excited.
Let me haha.
Isn't the "binary" computer language yin and yang? You can say 0101; Fuxi Nuwa snake has been buried for thousands of years. It is like a candy showing how human beings reproduce, and you find that it is the left-handed mode of human genetic code-DNA? .. with him, "God created everything". What is this? ! There are monks and nuns. What's the matter? ! (Of course, Buddhists didn't say that people were made by monks and nuns).
Chaos or chaos, or crawling in the mud pond. It's creepy
In the physical world, there is never a shortage of great men who pursue truth.
When it comes to the double-slit interference experiment, the first thing that comes to mind is Thomas? In Yang's double-slit interference experiment, a beam of monochromatic light is diffracted by a single slit and then interfered by a double slit, and there will be alternating light and dark stripes. But physics has long known that mechanical waves will strengthen and weaken when I interfere, so it can be concluded that light is a wave.
After Planck proposed the energy quantum hypothesis, Einstein put forward the concept of photon.
Surely everyone knows Einstein's photoelectric effect? Simply put, a beam of light will excite electrons on a metal plate, thus generating an electric current. But for a metal plate, not all light can make it overflow electrons, but light with a frequency greater than or equal to a certain value.
Then the problem is coming. Electrons overflow because they absorb the energy of light. If so, all the light should make the metal plate overflow with electrons, which is only a matter of time. This cannot be explained by classical mechanics.
Don't worry, Einstein will explain. Einstein thought that light is discontinuous when transmitting energy (Planck once suggested that energy transmission is discontinuous), and he put forward the concept of photon, that is, light is a particle, and the energy of each photon can only be absorbed by one electron, and the energy of photon is determined by the frequency of light. Well, his explanation, needless to say, is really smooth. So what does this experiment tell Uncle Ai? Yes, light is a particle.
Then the problem comes again. Young's interference experiment shows that light is a wave, and photoelectric effect experiment shows that light is a particle. What is light? Yes, light is both a wave and a particle, which is called wave-particle duality in physics.
Then I will wait for my question (finally). Why is the electronic double interference experiment horrible?
Don't worry, there is one more person to mention. This man's name is de Broglie. This guy thinks that this kind of thing, light, non-physical particles, has volatility and particle nature, so I guess that physical particles also have volatility. Don't tell me, he really guessed. The experiment of electron double-slit interference perfectly explains that physical particles also fluctuate. It gives me the willies to think about it. When you walk on the road, the forward and backward movement is transmitted in the form of waves (I can't seem to imagine this picture), but it does exist. Therefore, in order to commemorate him, later generations called the wave of physical particle movement De Broglie wave or matter wave.
Electronic double-slit interference first comes from photon double-slit interference. It is proved that light is a kind of "wave" because only waves can "interfere" with each other. Later, De Broglie put forward a theory that any substance is a "wave" and has fluctuations. Later, the experiment of electronic double-slit interference proved this point.
The reason why it is "creepy" is that both photon double-slit and electron double-slit interference have proved the "uncertainty" principle in the quantum field.
Didn't Einstein work out the photoelectric effect? So what is "light"? Why is the unknown board charged under the illumination of a specific frequency? The light energy calculation company is △E=hv, and the light energy is related to the frequency of light. Since light has a frequency, it is a wave? Yes, in a sense, he is a wave, and everything can be said to be a wave. Radio, infrared ray, gamma ray, ultraviolet ray and visible light are all one thing, all electromagnetic waves, but with different frequencies. The higher the frequency v, the greater the energy. What the atomic bomb exploded in Hiroshima was gamma rays. There is no essential difference with sunlight, mobile phone light and WIFI signal, but the frequency is extremely high.
But the photoelectric effect formula also says that it is useless for you to shine for a long time, unless it is light with a specific frequency. Photons with a specific frequency are enough to excite electrons ... Wait, didn't you say that light is a special electromagnetic wave? What is a photon? Einstein explained at that time that light waves can only be absorbed discontinuously, just like energy photons, so it is called "light quantum".
But this is not the final explanation. The final explanation is a terrible devil who subverts everything.
Have we done the double-slit interference experiment? Since we can all interfere, light must be a wave. This needs no explanation. It shows that interference is actually the propagation of vibration in a medium (of course, this statement is not correct in the end, and light does not need a medium). Waves are not bullets moving in a straight line. When the bullet hits the wall, it can't continue to fly, but the wave can bypass it. This is called "diffraction". When two different waves meet, there will be interference. For example, if you throw two stones into the water, there will be two waves. When the peaks meet, they will overlap and ripple higher. When the peaks and valleys meet, the ripples will weaken. This is interference.
Well, that's it. This junior high school physics also has it.
Let's talk about the interference of light first. If you put two flashlights together casually, you won't see the interference fringes. Only two coherent light sources with the same frequency, constant phase difference and consistent vibration direction can produce optical interference. The light emitted by two ordinary independent light sources cannot have the same frequency, let alone a fixed phase difference, so they cannot interfere.
In order to keep the light intensity distribution of the composite wave field stable in a time interval Δ t, it is required that: ① the frequency v (and thus the wavelength λ) of each component wave is the same; ② The difference between the initial phases of any two component waves remains constant within Δ t ... If you don't understand it here, you can skip it, which means that ordinary light sources can't do this experiment, but lasers in high schools and university laboratories perfectly solve the problem of phase difference.
The actual situation is like this-
This can only prove one problem, that is, wide is a wave with small wavelength and large frequency. But why did you say the devil appeared? It's time to witness the miracle. If you are given a perfect darkroom without interference from other light sources, do this experiment with a light source that can emit a single photon, and the photons will be hit one by one (there is no doubt that this experimental condition exists on the earth and has been successful).
So if we start with ten photons at random, we will find that photons are scattered all over the background wall, with no regularity at all. But if we start with 3 million photons and look at the results, we will find that so many spots like fine sand pile up into a ripple of light? As follows-
Damn it, what's the problem? The problem is-we emit photons one by one, just like shooting. The latter photon is not an intelligent creature, so it is impossible to know the whereabouts of the previous photon. How did they discuss the foothold? Can they communicate with each other? There are no other photons in the darkroom. Who will a single photon interfere with? With yourself? Fuck yourself? There must be a ghost.
In fact, when a photon passes through a double hole, we don't know which hole it passes through. It may be left or right. He can't go through two holes at the same time. He's not the Monkey King. Common sense tells us that the choice of the universe is certain, but common sense is wrong. If we plug one of the gaps, something terrible will happen and the interference fringes will disappear. So Schrodinger wrote the great Schrodinger probability wave equation.
He said that quantum state is a kind of probability wave, which has two states, which can disperse and collapse, similar to the divergence and convergence of functions. You can review the "Young's Double-slit Interference" in high school. A single photon continuously passes through the double slit to form interference fringes, but you can't know which slit the photon passes through. Knowing this, you can't form a fluctuating interference fringe-the observer changes the world-which is a bit idealistic, but it is the truth proved by experiments. A single photon is a probability cloud. At the moment it passed, it collapsed and chose an exit. Later, De Broglie carried forward and extended wave-particle duality to all substances. It is also proved in lattice experiments that electrons can also produce interference fringes similar to Apollo. Look, brothers, you too, Bo.
Heisenberg put forward the "uncertainty principle", that is, the position and momentum of particles cannot be determined at the same time, and the uncertainty of position and momentum obeys inequality.
H is a simplified Planck constant. Heisenberg believes that the action of measurement inevitably disturbs the motion state of the measured particles, resulting in uncertainty. In other words, the observer will affect the outcome of the event. In the field of quantum mechanics, measurement is not a process involving only experimental observers, but an interaction between classical objects and quantum objects, whether or not observers participate in this process. To put it more ideally, it is "wind, fluttering, or monk's heart?"
Heisenberg, the initiator of the non-mainstream view of quantum mechanics, used poisson bracket to do matrix multiplication and got a meaningless physical quantity-that is, the multiplication of position and momentum, which no one could understand. Later, a group of Americans who studied computers carried it forward, denied Schrodinger equation and probability wave, and said that "dispersion" and "collapse" were all nonsense. They put forward the "multi-world theory"-note that this is not nonsense, this is the theoretical basis of quantum computers! The "multi-world" is not the "parallel universe" that everyone imagined-in fact, they think that there is only one universe, and the "multi-world" is the projection of the universe in different dimensions. So it's not that uncertain events have definite results, but that they happen in different worlds, and observers only see the results in a projected world. What they mean is that photons are not probability waves, but bullets. When it passes through the double seam, our world is divided. Plain A sees photons passing through the hole on the left, and Plain B sees photons passing through the hole on the right, and the two worlds continue to develop.
For example, "Schrodinger's Cat", after the box is opened, the cat is either "alive" or "dead", which seems to collapse from two states to one state, and the function converges to a constant value, but the "multi-world" theory school thinks that the world is divided rather than collapsed. You see the cat dying in one world and you are in another. That's all.