Why are scientists so bored as to put forward such sophistry that it is not even an experiment?
To answer this question, we need to know the development history of quantum mechanics.
The concept of quantum originated from Planck. 1900, in order to explain the blackbody radiation, Planck discovered the smallest energy in our universe-6.61510 (-34) j s, and all the energy in the world is transmitted by integer multiples of this minimum energy, which is quantum.
1905, Einstein applied the concept of quantum to the explanation of photoelectric effect, and put forward the concept that light quantum is photon. In 19 16, Einstein formally determined the wave-particle duality of photons. 1924, de Broglie made an amazing analogy between physical particles and photons in his doctoral thesis, and proposed that physical particles also have wave-particle duality.
The concept of "everything is a wave" has shocked the academic community. How can a real substance evaporate?
Inspired by De Broglie's "material wave", Schrodinger began to think: If matter really has its own wave, does it also have a wave equation to describe its nature? Thus, the Schrodinger equation, the first and most famous wave equation of quantum mechanics in 1926, was born. Although Schrodinger created this equation, the physical meaning of its solution is not clear.
Later, born, another founder of quantum mechanics, gave a cognitive subversive probability explanation to Schrodinger equation-the solution of Schrodinger equation is to describe the probability of physical particles appearing. The probability mentioned here is completely different from the probability we say every day. The former is an uncertainty that has never been introduced in physics, while the latter is just a kind of statistics.
Based on this explanation, Born won the 1954 Nobel Prize in Physics, and was finally included in the orthodox "Copenhagen Interpretation" of quantum mechanics.
copenhagen interpretation
1, probability explanation of born wave function: the wave function calculates a probability wave, and its solution represents the probability of finding a particle at a certain position. Observation and measurement can only predict the probability of a certain result, but not what result will be obtained.
2. Heisenberg uncertainty principle: some paired physical quantities have a * * * yoke relationship, and they cannot be accurately measured at the same time. The more certain one is, the more uncertain the other is. Such as speed and position, time and energy. ...
3. Bohr's complementary principle: Some physical objects have seemingly contradictory multiple attributes. In principle, it is impossible to see their multiple attributes in the same way at the same time, and different attributes can only be observed in different ways.
4. Bohr's correspondence principle: the conclusions derived from quantum rules on the micro scale can't go against the macro observation results, and the classical physical rules are still valid on the macro scale. That is to say, with the increase of quantum quantity, the motion of quantum system tends to classical mechanical system, and the laws and equations of quantum physics can be transformed into classical ones.
5. Superposition principle: If A and B are two states of a particle, then A+B is the third state of the particle and has the characteristics of A \ B..
6. Wave function collapse: Between the two measurements of microscopic particles, except the probability wave function, quantum mechanics claims that microscopic particles do not exist, but exist in various possible states. Only after observation or measurement can the "possible" state of microscopic particles collapse into the actual "definite" state.
"Copenhagen Interpretation" originated from Copenhagen School headed by niels bohr, and based the objective reality of the world on great uncertainty, so it is called a "probability theory", while Schrodinger belongs to the traditional "determinism" headed by Einstein.
"Copenhagen Interpretation" is regarded as the orthodox interpretation of quantum mechanics, which mainly breaks the cognition of classical determinism on a relatively reliable basis. This is a breakthrough in understanding the world, but its defect lies in its "hodgepodge" description, which makes people feel that they have not grasped the core of quantum mechanics, and physics has always liked the concise description of hitting the floor. Therefore, Einstein thought that the quantum description of Copenhagen school was incomplete.
The logical loophole of Schrodinger's cat
In order to express his dissatisfaction with probability theory, Schrodinger developed Einstein's immature thought experiment "uncertain bomb" (that is, in a closed box, the bomb detonated by the decay of elements may or may not explode) into a higher-order biological version-Schrodinger's cat.
Cats are so famous that I won't describe them in detail.
Schrodinger's Cat mainly criticizes the Copenhagen school's explanation of "wave function collapse" and "superposition state"
As mentioned in the superposition principle above, the superposition state is a third state that is not A and B, and has the characteristics of A \ B. What can be more story-telling than "life and death superposition"?
But in fact, the "Schrodinger cat" thought experiment is flawed.
First of all, the concept of "life and death" in biology has risen to the macro level and cannot be judged by micro quantum laws. This forced association actually contradicts Bohr's correspondence principle.
Secondly, the observation described by "wave function collapse" does not refer to the observation of human eyes. All macroscopic substances can be regarded as observed, such as the poisonous gas device in Schrodinger's cat box to judge whether the elements decay or not.
Physicists certainly know about these loopholes, but it doesn't prevent them from playing such overbearing jokes. Schrodinger's cat connects the micro-world with the macro-world in people's consciousness, which makes ordinary people feel the abnormality of quantum laws, and at the same time attracts the public's interest. For quantum mechanics, which was just emerging at that time, this is not a master case of quantum science popularization. Just like the 20th century astronomer percival Lorvoire's view of Mars-even if it was wrong later, it inspired the most fanatical upsurge of space exploration in that era and gave birth to a number of sci-fi blockbusters such as Star Wars.
abstract
To do Schrodinger's cat experiment, it is not the technical difficulties to overcome, but the new understanding of the world.
Its essence is not an experiment, but rather an ideological theory between physicists, with experts watching the doorway and laymen watching the excitement. For Schrodinger personally, it just expresses his dissatisfaction with probability theory; For quantum mechanics, this is a master case of classical science popularization.
Finally, the best experiment to test the superposition state of quantum mechanics is not Schrodinger cat, but polarized light experiment. That is, when natural light passes through the polarizer, it can be decomposed into two perpendicular vibration components. The polarization direction of a single photon cannot be confirmed without a polarizer, or it exists in the superposition state of all polarization directions. This is an established fact about photons.
It is the polarizer, not the subjective consciousness, that observes photons here. Although you can also use people's subjective consciousness to understand, this is one of the focuses of most people's debates.
In fact, the ghostly nature of quantum is not the product of human consciousness, but the language about quantum description is indeed the product of human consciousness. We can't experience the micro-world, but we can only describe it by metaphor or analogy, even physicists are no exception, but the way they communicate is mostly mathematical formulas.
Impossible experiment
Schrodinger's Cat is a story that many people are familiar with, and some people can even recite it completely.
However, not many people can really understand the story and its background. If you really want someone to copy this experiment, grab a cat and try it, then you really don't understand.
Schrodinger didn't intend to do this experiment. He didn't even think it would be successful, because he expounded a paradox and used the best thinking experiment method of scientists at that time. There is a strong dissatisfaction with Schrodinger's cat, and we can even feel a little irony.
(Schrodinger's cat)
Collision of schools of quantum mechanics
Erwin Schr?dinger is a great physicist, the founder of probability quantum mechanics-wave mechanics, and one of the main founders of modern quantum mechanics. Schrodinger won the Nobel Prize in physics for his Schrodinger equation.
Schrodinger is a realist. He put forward two basic principles: one is the understandability of nature, and the other is the objectification principle. Schrodinger has always adhered to these two principles in his scientific research. Because of this, Schrodinger and the Copenhagen school of quantum mechanics headed by Bohr collided fiercely.
(Copenhagen School: Bohr, Heisenberg, Pauli)
Let me briefly introduce the Copenhagen School, which was founded in Copenhagen by Bohr, Heisenberg and Bonn and represented by famous scientists such as Pauli and Dirac. They are the ultimate winners of quantum mechanics theory, so the Copenhagen school's view of quantum mechanics was later labeled as "orthodox explanation" (it is said that opponents die first). But at first, Bohr and Heisenberg's "uncertainty principle" caused a great wave of opposition.
The two fiercest opponents are Schrodinger and Einstein. Schrodinger carried out the cat and Einstein moved out of "God".
(Einstein and Schrodinger)
When it comes to Schrodinger, we can't help but mention the famous Schrodinger equation. Although few people in this world can understand it, I still think it is a very respectable thing to post these tall equations:
(Schrodinger equation)
1926, Schrodinger established quantum wave mechanics through second-order linear partial differential equations, and also established himself as one of the leading figures in quantum mechanics.
The "Confrontation" between Schrodinger and Bohr
In September of the same year, Bohr invited Schrodinger to give a speech in Copenhagen, which was originally a pleasant thing, but Schrodinger was not happy. He quarreled with Bohr from the moment he got off the train until Bohr's home, where he lived. They quarrel every day, from getting up in the morning until late at night.
They were supposed to be guests. Why did the two scientists quarrel? For academics. As mentioned earlier, Schrodinger founded quantum wave mechanics. He firmly believes that quantum mechanics has the nature of wave function and should be continuous. But Bohr thinks that quantum has discontinuous transition, and this transition is unmeasurable because of the existence of "hidden variables". You never know what state it is before you measure it. Once you start measuring it, it will collapse. This is obviously a challenge to the continuity of wave function, which Schrodinger, who holds the view of classical mechanics, can't accept anyway.
(Bohr and his wife)
After quarreling for a few days, Schrodinger fell ill at Bohr's house. Bohr's wife sent him water and medicine, while Bohr kept explaining and trying to convince Schrodinger. Do you think he is going to lecture or brainwash?
After Schrodinger returned to China, perhaps out of gratitude for Bohr's wife's care, he no longer strongly opposed the "uncertainty principle", but he has always been critical of the Copenhagen School's explanation of hidden variables. Schrodinger and Einstein joined forces against Bohr and Heisenberg's Copenhagen School until Schrodinger's cat came into being.
(Schrodinger "degraded" by Bohr)
In the "Schrodinger's Cat" experiment, two elements are assumed: one is an electronic switch and poison controlled by particles released by nuclear decay, and the other is a cat who does not know how to live or die. Schrodinger hopes to use the uncertain conditions in this thought experiment to allude to the uncertainty of the "hidden variables" of Copenhagen School, thus pointing out that this is a paradox. Because the cat in the experiment has a state of "neither dead nor alive" besides "dead" and "alive", because you can never be sure whether it is dead or alive. Quantum phenomena will be in a chaotic state, and you can't predict it, which makes scientists like Schrodinger very angry.
(Schrodinger and his cat)
So did Einstein. The phrase "God can't roll the dice" is Einstein's amazement and anger in the face of the uncertainty of quantum phenomena. He knows quantum theory, but he can't accept this explanation. Einstein liked the Schrodinger equation and the certainty of wave function. He won't recognize a cat that is neither dead nor alive until he dies.
Thinking experiment
Finally, talk about the thought experiment. Unlike today's physicists who rely heavily on the Hadron Collider worth tens of billions of dollars, scientists in the19th and 20th centuries used a lot of thought experiments. They build thinking machines in their minds, drive microscopic particles with precise logic and thinking, use wonderful mathematical calculations and tell people conclusions with simple and beautiful formulas. When Einstein worked as a clerk in the Patent Office in Bern, Switzerland, he had no conditions to measure celestial bodies at all, but he founded special relativity and general relativity through thought experiments. Similarly, Schrodinger established semi-quantum mechanics with his exact equations.
(the great scientist of that era)
Scientists have been exploring science, and what we people who eat melons have to do is not only recognize our work, but also learn to look at science with a scientific attitude. Even if you question, you should put forward your own views and discuss them, just like Schrodinger did.
Questioning is by no means mindless: "You are talking nonsense!" Then spank and leave.
Of course, you need knowledge.
It's not technically difficult, but it's impossible to do the experiment.
Put a cat in a box and set a poisoning device triggered by the decay of matter inside. In a cycle, rotten materials have a half chance of rotting. If it decays, it will trigger the device and the poison will be released to poison the cat. If it doesn't rot, the cat will live. So after the box is closed, is the cat dead or alive? This is Schrodinger's cat experiment.
Schrodinger believes that the cat's life and death can't be determined before the box is opened, so it is neither "dead" nor "alive", but in a state of life and death superposition, but when the box is opened, this superposition state collapses into a state, either dead or alive. How's it going? Does it feel like a detour?
The essence of Schrodinger's cat lies not in this experiment, but in explaining a superposition state of the micro-world through such a hypothesis. Attention is microscopic, and a cat is obviously macroscopic, so this experiment is meaningless even if it is done. Besides, it is impossible to determine the cat's state without observing it, but if you observe it, no matter how you get the real situation inside, the cat's life and death will collapse to a state instantly, so what's the point of this experiment?
Therefore, Schrodinger's cat experiment is destined to become a macro bridge for human beings to understand the micro-world. There is no way to do this experiment. No matter in the past, present or future, there is no way to obtain ideal results through this experiment. After all, this experiment doesn't conform to the existing laws at all, and we can't observe it at all.