What is quantum entanglement?
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Quantum entanglement is a stunning phenomenon in quantum mechanics that describes a special correlation between two or more quantum systems, allowing their states and measurement results to influence each other. This association is long-range, unrestricted by time and space, similar to telepathy.
In quantum mechanics, the wave function is an important concept for describing the state of a quantum system. For two quantum systems A and B, if there is entanglement between them, their wave functions cannot be described separately, but must be described using the joint wave function of A and B. The joint wave function contains all possible states of A and B and their probability amplitudes. This means that the states of A and B are interdependent, and a change in the state of one system can affect the state of another system.
A significant characteristic of quantum entanglement is that when one system is measured, its state immediately collapses, affecting the state of the other system. This impact is instantaneous and not limited by distance or time. Even if A and B are far apart, entanglement between them still exists, and measurements of one system can affect the state of the other system.
This long-range, instantaneous correlation has sparked many reflections on the real world in quantum mechanics. In classical physics, the interactions between objects are believed to be transmitted through physical particles and limited by the speed of light. However, quantum entanglement suggests that in the quantum world, two or more particles can be tightly entangled in some way, even if they are far apart, and can immediately influence each other.
Although the mechanism of quantum entanglement remains an unsolved mystery, it has important applications in quantum communication and quantum computing. The use of quantum entanglement can achieve secure communication and efficient algorithms. For example, quantum key distribution (QKD) utilizes the properties of quantum entanglement to ensure secure key exchange between communicating parties. In addition, quantum entanglement has a wide range of applications in the algorithms and error correction of quantum computers. By utilizing the properties of entangled states, faster and more efficient algorithms can be developed, as well as more accurate error correction in quantum bits.
In summary, quantum entanglement is a stunning quantum mechanical phenomenon that describes the long-range, instantaneous correlations between two or more quantum systems. Although its mechanism remains a mystery, it has important applications in many fields. With the continuous deepening of research on quantum entanglement, we are expected to better understand this mysterious phenomenon and explore its future applications. Whether in communication, computing technology, or basic research, quantum entanglement has the potential to reveal more fascinating phenomena and possibilities for us. By delving into the characteristics and mechanisms of quantum entanglement, we will be able to better apply it to solve practical problems and promote the development of science and technology.
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These groundbreaking experiments not only confirmed the correctness of quantum mechanics, but also opened up the second quantum revolution
This year's Nobel Prize in Physics has been awarded for quantum mechanics.
At 17:45 Beijing time on October 4th, the Nobel Committee announced the 2022 Physics Prize winners: Alan Aspay, John Crowther, and Anton Salinger, in recognition of their achievements in "binding photon experiments, establishing violations of Bell's inequality, and pioneering quantum information science".
2022 Nobel Prize in Physics Winners: Alain Aspe, John Crowther, and Anton Salinger
In recent days, terms such as "Nobel Prize in Physics, Quantum Bonds, and Quantum Mechanics" have also made their way onto the search list. Today, "Quantum Bonds" has even topped the hot search list.
Some netizens are lamenting that they can't understand it at all, while others are trying their best to explain it to everyone.
What exactly is quantum entanglement? What is its relationship with quantum mechanics?
In 2020, China's quantum computer "Nine Chapters" was launched, which can process calculations from the past 600 million years in just 200 seconds, far surpassing Google and becoming the world's first. Its remarkable feature is the construction of a "quantum bond" consisting of 76 light quanta.
In folk stories, there is a Taoist from Laoshan who can pass through walls. Do you think this is a scam? In quantum mechanics, the 'tunneling technique' is actually true, called 'quantum tunneling'.
Behind these bizarre concepts lies quantum mechanics.
As the saying goes, 'If you don't make a decision, quantum mechanics will do it.' Today, from semiconductors to nuclear fusion, from photosynthesis to DNA repair, quantum mechanics is the underlying logic of cutting-edge technology and international operations.
Even financial giant Soros calls his family business a 'quantum fund'. Along with this, from "quantum shaking speed reading" to "quantum fortune telling", from "quantum massage" to "quantum treatment of dysmenorrhea", many "quantum+" scams are also rampant.
Is Quantum International really that magical?
Yes, it will completely overturn your traditional cognition. Moreover, it is necessary to engage in a continuous flow of time and space to understand true quantum and distinguish false quantum. The following article is a bit thought-provoking, so we have to provide a friendly reminder.
If you don't believe it, please see the comparison between the creator of quantum theory - Planck - before and after discussing quantum, turning a lively and beautiful young man into a messy and disfigured uncle.
01 Ghosts are Coming
Time flows back to 1900. At that time, everything in the world, from the starry sky of the Milky Way to the dust beneath human feet, was conquered by Newton's "universal gravitation" and operated quietly and orderly. The discovery of Neptune in the solar system further solidified the invincibility of Newtonian mechanics. Humans have confidently assumed control of all natural laws such as force, heat, light, electricity, and magnetism. The classic physics empire has entered its heyday. On April 27, 1900, the weather in London was fluctuating between warm and cold. At the Royal Institute on Albemarle Street, the most renowned scientists from around the world gathered together. 76 year old academic guru Baron Kelvin spoke: 'All the principles of international operation have been discovered, physics is useless, and there can never be any breakthrough progress again! But, in the dazzling sky of physics, there are still two dark clouds floating - the' ether problem 'and' blackbody radiation ', which have not been explained.'. ”The atmosphere began to become heavy, and then it was like black clouds pressing down on the city, about to be destroyed. At this moment, Planck appeared. When choosing a major in college, Planck, who had a natural talent for music, said to his mentor Zuli, "Teacher, I want to study physics." The teacher said, "Don't, child, studying physics is not easy to find a job. Its feast is over, there is no space left, why waste time on it?" Planck said, "I am interested." The teacher shook his head and said, "Hey, go ahead. It's a pity that Germany has lost an excellent musician." In 1900, Planck, who had been studying "blackbody radiation" for many years, was already 42 years old. After the age of 40, he had not found the answer yet. Fate began to laugh at him, and the teacher's words came true. It seemed that there was really not much room for Planck's physics future. One day, Planck, who was at a loss for a solution, simply smashed the jar and thought to himself, "Should I not consider the physical principles behind it first, but instead come up with a mathematical formula for 'blackbody radiation'?" So, Planck divided it by two three times and actually managed to mask it! The famous blackbody equation and the magical Planck constant (h). How powerful is the Planck constant? Being able to rank among the top 3 in the entire international number, the other two are Newton's gravitational constant G and the speed of light c in relativity. Planck's most important contribution to thinking was pointing out that "energy is not emitted and absorbed continuously, but in portions". What's so great about this? You just need to know that this concept overturns the continuous claims about all natural phenomena since Galileo and Newton. From then on, a discontinuous and uncertain international perspective was born. And this one by one thing, Planck called it:
Quantum. In December, Planck published his theoretical results, as if opening Pandora's box and releasing the ghost of "quantum" that had been sleeping for billions of years, officially giving birth to "quantum mechanics". A dark cloud in Kelvin's mouth triggered an extremely microscopic revolution. However, at this moment, Planck cannot explain what "part by part" energy means. The one who revealed the secrets of the universe is still a small love student with no way to find a job. Five years later, he wrote "photoelectric effect" with his left hand, explaining Planck's confusion and becoming another pioneer of quantum theory; He wrote "Special Relativity" with his right hand, dispelling another dark cloud of Kelvin and sparking a revolution in the microscopic realm. Surprisingly, quantum thinking is so unconventional that Planck and Einstein will soon become staunch opponents of quantum theory, while innovators themselves become anti innovators! What is even more unexpected is that not recognizing quantum laws will become Einstein's biggest "defeat" in his life.
The greatest scientific debate of the 20th century
Everyone should have read this English poem: "One sand, one world, one flower, one paradise; holding infinite with both hands, an instant is eternal." People marvel at the imagination of this poem. But if you go back to 1913, 28 year old Danish youth Bohr would most likely tell you: One sand, one international, this is true. For example, if the particle of an atom is magnified 10-30 times, it is equivalent to a Milky Way galaxy; An atom, containing the entire world, is a holographic embryo of the world. In that year, Bohr proposed the atomic structure model, declaring the beginning of the "youth" of quantum mechanics. He pioneered the famous "Copenhagen School" and became the academic center of Europe. Bohr, with this achievement, became one of the early "three giants" of the quantum world: Planck, Einstein, and Bohr.
Next, the great debate between Bohr and Einstein was the most remarkable debate in the history of science for centuries. At the end of October 1927, the Solvay Conference was held. You may not have heard of the name 'Solvay', but you must have heard of people like Einstein, Madame Curie, Planck, Bohr, Schr ö dinger, Heisenberg, and they all came. The following photo is known as the most intelligent photo in human history, with 17 out of 29 people winning the Nobel Prize.
In 1927, the Solvay Conference took a group photo and they were divided into three factions: the Copenhagen faction, led by Bohr and supported by Bonn, Heisenberg, Pauli, and others; 2、 Einstein's faction, with supporters such as de Broglie and Schr ö dinger; 3、 Experimental faction, let's skip it for now. A group of 'young players' engaged in a verbal battle over cutting-edge physics problems, going back and forth for a few rounds, but without a conclusion, they didn't buy into each other. So, the comments quickly pointed to the hidden real bigwigs, the showdown between Einstein and Bohr. From then on, this duel lasted for nearly 30 years, several rounds, until both of them passed away. Let's take a look at the three most important martial arts competitions among them.
01 First competition: Einstein invades Heisenberg's uncertainty principle.
Uncertainty is the essence of quantum international. Assuming you stand on the nucleus of an atom and treat electrons as the moon, at this moment, the moon in your eyes will appear in all directions together, and the moon will move at various speeds together. At the microscale level, the 'moon' becomes a cloud and mist, known as a 'quantum superposition state'. The so-called superposition state is like listening to a symphony, hearing several different instrument sounds together in a set of sound waves.
But this concept overturns the concepts of "certainty" and "causality", and challenges Einstein's creed. A messy head of hair cannot conceal Einstein's confidence. Now, he has amplified his skills and used his most proficient technique - 'thinking experiment'. He planned a "single seam test" using tension springs and shading plates, easily negating the uncertainty principle (omitting the proof process). Bohr hastily gathered his comrades from the Copenhagen School, ate together, pondered together, and prepared for the "Battle of L ü bu with the Three Heroes". Suddenly, the table slammed and said, 'Yes, Einstein made a prerequisite mistake.' That is, how can you use the tension spring in the microscopic world to invade the electrons in the microscopic quantum world? Einstein confused two different international operating rules. Einstein lost first.
02 Second martial arts competition: Continuously attacking the "uncertainty principle". Einstein drew on the experience of his previous low-level mistake and planned a "light box experiment" from scratch, demonstrating that it was possible to measure the velocity and mass of photons together, but the uncertainty was still incorrect. This move is steady and spicy. On the way back to the hotel, Einstein had a smile on his face and strode forward with great strides, while Bohr was trembling with fear. He followed the rules and advised, "You can't plan this experiment, otherwise quantum mechanics will be ruined." (See the picture below) Einstein said, "We'll see.
Bohr hastily gathered his teammates from his faction, had dinner together again, and pondered together. After holding back all night, he slapped his thigh and said, "I have it! You need the elasticity of a tension spring to measure weight. According to your general theory of relativity, when a tension spring goes up and down, it means a high degree of uncertainty, that is, an uncertainty in mass, and therefore uncertainty at all times. The uncertainty principle is still correct!" Bohr's move is called "One way, another way." Einstein lost again.
In 1935, Einstein and others proposed the "EPR paradox" in the third martial arts competition: the supernatural effect at a distance. For example, suppose Einstein and Bohr formed a "quantum bond" situation, with opposite emotions - Bohr happy, Einstein must be sad; Bohr is sad, Einstein must be very happy. But they are thousands of miles apart, one in the United States and one in Denmark. If you ask one of them, you can instantly determine the mood of the other person, which is a bit like what people often call "telepathy". Einstein said, "This is impossible, as it violates my theory of relativity. No object (information) can exceed the speed of light unless there is a 'ghostly effect at a distance' in the world." This time, Bohr's thigh was swollen and unable to withstand it. The only thing he could do was to admit that the quantum world is a transcendent existence. Until his death, he still drew experimental diagrams of debates with Einstein. Einstein has temporarily 'won'. Due to decades later, scientists from multiple countries (including China) have repeatedly proven the existence of "ghostly long-range effects" through sophisticated experiments! What the hell. Randomness and long-range effects are two hard facts that quantum mechanics must accept. Einstein had a strict classical international view, insisting on exploring the origin of the international world, believing that 'God does not roll the dice'; And Bohr counterattacked, 'Old love, don't tell God what to do.' The latter is an international view of 'don't ask me where I come from.'. If Nietzsche were to be the judge for the two, he would also declare, 'God is dead.' Einstein, death never closes his eyes! In a mysterious way, the international community seems to be a whole, and any action will immediately affect everything else. The thing that transcends time and spatial perception on the back is called the "wave function". It is interesting that the master who wrote the quantum operation wave function is a "cat tamer", and now the most famous "cute pet" in science is about to make a grand appearance.
Who is Schr ö dinger? He is an Austrian who participated in World War I, studied physics, and pioneered modern biochemistry. His love life is as mysterious as a cat, with promiscuous behavior and constant rumors. It is incredible that during a 5-month extramarital affair from 1925 to 1926, he created the "Schr ö dinger Swinging Equation". How powerful is this equation? In quantum mechanics, its status is equivalent to that of Newton's laws in classical mechanics, known as the 'great burst of desire'.
The place where Schr ö dinger created the shaking equation - the Hervig Villa, origin: "Does God Roll Dice?" One day, Schr ö dinger was "rolling a cat" at home and unexpectedly conducted the most fun thought experiment in the history of science: assuming a cat and a quantum device were locked in a box. There is a radioactive atom and a poison bottle in the device. If an atom decays, it will break the poison bottle and poison the cat to death; If it doesn't decay, the poison bottle won't break and the cat will keep meowing.
Origin: Before opening the box of the science popularization film "The Untold Mysteries of International Exploration", due to the superposition of decaying and non decaying atoms, the cat is also in the superposition of dead and living cats. It should be noted that 'both dead and alive' is only one situation, not two. How is this possible? That's right, Schr ö dinger also thinks it's impossible. He originally used cats to oppose the Bohr faction, which amplified the quantum effects of the microscopic international to the microscopic international. The contradiction arises naturally, because how could cats in the microscopic world be "both dead and alive"? After seeing this experiment, Einstein was very happy and wrote a letter to Schr ö dinger, saying, "The cat... refuted the Copenhagen interpretation in the most elegant way." This time, Bohr was deeply moved. The tragedy is that decades later, scientific experiments have proven the existence of things like Schr ö dinger's cat in the quantum world! So, the Copenhagen School is still the mainstream. Einstein, once again unable to close his eyes in death. Is a cat dead or alive? Open the box and 'measure' to find out. The moment you open the box, the state of "both dead and alive" disappears, becoming a situation where everything returns to normal, possibly dead or alive. This process is called "wave function collapse". Is this concept a bit familiar? That's right, the Chinese philosopher Wang Yangming once said, 'When you haven't seen this flower, it and your heart return to silence. When you come to see this flower, its color becomes clear for a moment.' It seems that our old king has also touched quantum mechanics. Now, Schr ö dinger's cat has skyrocketed in popularity among the masses, becoming synonymous with "omnipotent", flirting "artifact", and quantum mechanics. It is also known as one of the "Seven Great Beasts of Science" along with Zeno's turtle, Pavlov's dog, Shakespeare's monkey, Lorentz's butterfly, Laplace's beast, and Maxwell's demon.
Many fun concepts in modern science and even science fiction can start from "Schr ö dinger's Cat". For example, parallel international. Explanation of the theory of "parallel international": At the moment of opening the box, the international split into two different nations. In one of the international markets, you saw a live cat; Another you in another world, hunting and killing cats. Two options, maybe five or five. Many of you live in many parallel worlds, experiencing different lives.
It is incredible that parallel international is not a guess, it has rigorous mathematical proof to hold true! For example, in quantum computers, we know that the basic logic of traditional computers is binary, either 0 or 1. However, in the quantum world, what are the advantages of making photons into "Schr ö dinger cat states" and transforming them into various superposition states such as "both 0 and 1"? For example, now Lu Xun wants to decipher Zhuge Wolong's "Eight Formation Diagram". If he tries each of the eight gates of "Xiu, Sheng, Shang, Du, Jing, Death, Jing, and Kai" one by one, he will need to be fascinated for a long time to solve it. But if he were like Sun Wukong, taking care of both aspects and stacking them together, sending someone to take care of every fork in the road, he would only need to find the exit once, and Mr. Wolong would not be able to resist it at all. This is called "parallel" computing of quantum superposition states, greatly improving campaign efficiency. So China's "Nine Chapters" can shorten the calculation of 600 million years to 200 seconds. Quantum is reconstructing the underlying logic of international operations.
If civilization is destroyed, what should humanity leave behind?
Is the cat alive or dead? This is a problem. Is it here or there after death? This is also a problem. Heisenberg, a quantum scientist on the same level as Schr ö dinger, wrote this epitaph: "I sleep here, but I am elsewhere." This is quantum theory, and the world is full of uncertainty. In the second half of the 20th century, Feynman, a leading figure in modern quantum mechanics, posed a bolder question: If civilization were to be annihilated, what words should humanity leave behind? This sentence should be as concise as possible and contain as much information as possible, so that later generations can rebuild civilization. Feynman said that this sentence should be 'All things are made up of atoms'. How to understand it? In 1986, David Copperfield came to Beijing to play the role of crossing the Great Wall. With the help of a curtain, he crawled from one side of the Great Wall to the other, performing a real-life version of the "Laoshan Taoist", but this was only a magic of projection principles and visual blind spots, not quantum mechanics.
In practice, when you answer your phone in an elevator, the call is easily disconnected, perhaps only with a weak signal. This is because the electromagnetic wave signals are shielded around the elevator, but this shielding is not complete, and signals are still "thrown" in, which is the "wall penetrating technique" of electromagnetic waves. Enter Quantum International. Now, two positively charged atomic nuclei have formed an invisible "wall" between them due to repulsive force. Originally, only under strong collision can the "wall" be broken and nuclear fusion occur; In fact, due to the "quantum tunneling" effect, in the absence of kinetic energy, low temperature, and extremely low probability, atomic nuclei can perform "tunneling" and nuclear fusion can also occur.
So, the sun shines and heats up, nurturing all things in the world. From the formation of water, to photosynthesis, to the birth of life, an increasing number of natural phenomena, delving deeper, will inevitably lead to quantum mechanics.
Can that person actually pass through a wall? According to the Schr ö dinger equation, theoretically it is possible to "tunnel through", but the probability is extremely low, extremely low, extremely low. He needs to constantly collide with walls, collide, collide, collide. From the beginning of the International Big Bang to 2022, it is also difficult to achieve miracles. The ultimate question is, what is the international source? Similarly, quantum mechanics is indispensable. Sitting in a wheelchair, 'Einstein' - Hawking said that before the beginning of the international era, there was a 'quantum superposition state' that could evolve into many forms of history. Suddenly, the international 'wave function collapsed', and the moment began with inflation. The international community we are in is just one of many possible ones. The mainstream international "inflation theory" holds that in a vast vacuum, an occasional tunneling of quantum fluctuations causes the international community to experience a super violent inflation at its inception.
The distribution map of "international microwave background radiation" observed by COBE satellite is called "wrinkles on the face of God". This discovery won the Nobel Prize in Physics in 2006, proving the validity of the international Big Bang theory. Quantum mechanics can generate something out of nothing. But why can't we see quantum phenomena in our daily lives? Scientific experiments have found that 'Schr ö dinger's cat' really has superposition states, and humans also have superposition states, only producing extremely fast 'decoherence'. What you see is particle characteristics, and the shaking characteristics disappear. So the key step in the microscopic use of quantum computers like the "Nine Chapters" is to avoid "decoherence" and to "preserve" them in a harsh environment. Perhaps many of the strange behaviors in the quantum world are real daily life, and we do indeed live in an uncertain world. Einstein said, 'Theory determines what you can observe.'. The frightening thing is that there are over a dozen interpretations of quantum mechanics, and if there is only one fundamental aspect in the world, are there still many fundamental aspects? Every sentence in this article may not be the same. Fortunately, through this "quantum" journey, the next time you see any tricks like "quantum shaking speed reading" on the market, you won't find them so surreal or high-end. This is simply insulting to intelligence, and Schr ö dinger's cat will also die in peace!