Schr?dinger’s experiment amplified quantum effects into our daily world. Now the strange properties of quantum are involved in our daily lives, including the question of whether our beloved pet cats are dead or alive. Although this experiment is simple, it is much more spicy than EPR. This time it hurt the Copenhagen pie. They had to step back and swallow the bitter drink: Yes, the cat was neither dead nor alive when we weren't looking.

The Quantum School later had a widely circulated argument:

"When we don't observe, the moon does not exist." This slightly deviates from the original intention. To be precise, because the moon is also composed of uncertain particles, so if we turn our heads away from the moon, a large number of particles will begin to spread out according to the wave function. As a result, the edge of the moon began to look blurry and uncertain. It gradually "melted" and turned into probability waves that spread into the surrounding space. Of course, the probability that such a large moon will completely melt into space will take a long, long time, but the essence of the problem is: if the moon is not observed, it will change from a definite state to a superposition of countless uncertainties. A definite, objective moon does not exist without observing it. As soon as I turned around, a bright moon would hang high in the sky again, as if nothing had happened. In fact, the laws of quantum mechanics limit the wave function of an object with a huge mass like the moon to a microscopic area. Therefore, even if the moon disperses, the degree of dispersion cannot be seen by the human eye.

Explanation of the uncertainty principle: To measure the position and speed of a particle, the method is to shine light on the particle, and part of the light wave is scattered by the particle, thereby indicating its position. It is impossible to determine the position of the particle to such an extent that the distance between the two wave crests of the light is smaller, so it must be measured with light of short wavelength, at least one light quantum. This quantum will disturb the particle and change its speed, and the more accurate the position measurement, the shorter the wavelength required, the greater the energy of a single quantum, and the more severely the particle's speed will be perturbed. The more accurately you measure a particle's position, the less accurate your measurement of its velocity becomes. (The moon does not exist when it is not observed. When the quantum state is observed, the wave function collapses to a certain value due to the interaction of the observation force. The microscopic particles show regularity as a whole, and the observation force has almost no effect on it at the macro scale.) (< /p>

Reference: "A Brief History of Time" by Stephen Hawking)

I have to admit that this sounds very strongly like subjective idealism, but it is actually the same as what we usually understand. There are certain differences between the philosophical theories, but when it comes to this, many people will probably naturally think of the famous saying of Bishop George Berkeley: "To be is to be perceived" (Latin: Esse Est Percipi). If this sentence were slightly changed to say "existence is measured", it would be inseparable from the meaning of the Copenhagen School. Berkeley's position in the history of philosophy is undoubtedly important, and people are usually willing to criticize him. Have our Copenhagen School gone further than him? After all, Berkeley still believes that things exist continuously and objectively, because there is always "God" watching everything constantly. And quantum theory? "Your Majesty, I don't need the assumption of God."

The Eastern representative who complements Berkeley is probably Wang Yangming. He also said a famous saying in "Zhuan Xilu·Part 2": "When you don't look at this flower, this flower will die with you; when you look at this flower, the color of this flower will become clear for a moment..." If Wang Yangming understands quantum theory , he would probably say: "When you did not observe this flower, this flower did not exist in reality, and returned to silence according to the wave function; when you came to observe this flower, the wave function of this flower collapsed, and its color temporarily became a clear reality... …"Measurement is reason, and there is no reason outside measurement.

Schr?dinger’s Cat and Quantum Suicide

Is it necessity or chance that determines the fate of the universe? Or: Does God play dice? This is the biggest controversy between quantum mechanics and relativity. Quantum mechanics claims that the world is determined by uncertain and random events. This uncertainty (the latter is called fluctuation) is actually the contradictory operation advocated by dialectics; while the theory of relativity holds that the world should be governed by fixed and mechanical laws. Behind any seemingly accidental event, there is actually something supporting it.

Many non-mainstream scientists, including Einstein, are skeptical about Schr?dinger's cat. They believe that this reason is caused by "parallel universes" (MWI), that is: when we When looking into the box, the entire world splits into two versions of itself. The two versions are identical in every other respect. The only difference is that in one version, the atom decays and the cat dies; in the other version, the atom does not decay and the cat is still alive. In the quantum many worlds, we choose our own path by participating. In the world we live in, there are no hidden variables, God does not play dice, everything is real. This view also has an even more shocking hypothesis: quantum suicide.

The proposal of quantum suicide

In quantum mechanics, quantum suicide is an idea experiment. This creepy and ridiculous experiment was proposed by Hans Moravec, Bruno Marchal and others in the late 1980s. , and was developed and reiterated in 1998 by cosmologist Max Tegmark in his well-known paper promoting MWI in response to the "consciousness monster" in the "wave function collapse" in Copenhagen. Max Tegmark believes that there are multiple universes, and quantum uncertainty is distributed to each universe. From a subjective perspective, not only can a person never complete suicide, but in fact, once he begins to exist, he will never disappear! There are always some quantum effects that prevent a person from aging, and according to MWI, these very low probabilities always correspond to some actual world!

Quantum suicide experiment

In a set of equipment, using atomic decay to control the trigger of a gun, we can observe when a person is killed (if the decay -->shoot) or nothing (no decay). Sooner or later he will be killed, because sooner or later the trigger of the gun will be pulled as the probability of atomic decay increases. But this is not the case at all from the perspective of the parties involved. Because the only thing that makes sense to him is "the world in which he lives." There will always be one of him living in some world! If the parallel universe theory is correct, then for someone to die no matter how much they try to commit suicide! If he wipes his neck with a knife, then because the knife is composed of a group of particles that conform to the wave equation, there is always a very, very small possibility that it can penetrate the person's neck without any damage in some way, thus keeping the person alive. ! Of course, this probability is extremely small, but according to MWI, everything that could happen has actually happened, so this phenomenon will always happen in a certain universe! In fact, no matter what method he chooses to commit suicide, it is the same, whether it is jumping off a building, lying on a train, or hanging himself, there is always some universe that keeps him alive. From the person's own perspective, he can't die no matter what! Of course, in infinite other universes, his relatives and friends would mourn him. This is actually a real-life version of Schr?dinger's Cat. Everyone knows that in the cat experiment, if the atom decays, the cat will be poisoned, otherwise it will survive. The Copenhagen school's explanation for this is: before we observe it, the cat is "dead and alive", but after the observation, the cat's wave function collapses, and the cat is either dead or alive. MWI claims that each experiment must produce a living cat and a dead cat at the same time, but they exist in two parallel worlds.

The universe is divided

In this way, Schr?dinger’s cat no longer has to worry about life and death. It's just that the universe is split into two, one with living cats and one with dead cats. For the universe of living cats, cats are always alive, and there is no problem of superposition of life and death. For the universe of dead cats, the cat is truly dead at the moment of division. Don't wait for people to open the box before it "collapses" to conclude the coffin.

Since the birth of the universe, there have been countless such divisions, and their number has increased geometrically, quickly reaching infinity. The universe we are in now is just one of them. Outside of it, there are many other universes. Some are close to us, having recently branched off on the family tree, while those that diverged from us in ancient times may be very different. Maybe there is a universe where asteroids did not hit the earth and dinosaurs still dominate the world. In some universe, Cleopatra had a slightly shorter nose, which did not make Caesar and Antony's hearts flutter.

Those "nose historians" who oppose historical determinism will certainly be very interested in subsequent developments to see if there really is a historical butterfly effect. In some universe, Grouchy was not late for Waterloo and Hitler did not give the order to stop the attack before Dunkirk. In more universes, because the physical constants are inappropriate, there is no life or planets at all.

It seems that this conclusion can connect the entire quantum mechanics and the theory of relativity, or in other words, replace quantum mechanics with the theory of relativity. However, please note: the parallel universe retains the opposites of contradictions (cats in the same universe will not have life and death superimposed) but dismembers the unity of contradictions (making both parties to the contradictions located in two different universes). The fundamental law of dialectics seems to be To be denied?

Wait a minute! Think about it: every electron jump, every photon diffraction, every character I type on my keyboard, could create a universe? So, how many universes have been created since the Big Bang? The number of universes is growing at an alarming rate every second? This theory seems to be to create a huge universe just to explain the diffraction of a small electron! There is no evidence to support this theory, and we have never discovered that we have the ability to create the universe.

Actually, as I said earlier, Schr?dinger’s cat state has been experimentally confirmed and can be observed. Schr?dinger made a mistake back then: pure observation should actually have no impact on the results of the experiment. If we don't open the box, but use an infrared camera to record the situation inside the box, the kitten we see on the TV screen may really be like the experiment we did with our index finger. There is a "nightmare" Superposition status"! This also explains why scientists can achieve macroscopic quantum superposition states with completely opposite spin directions.

String Theory

It seems that the worry about materialist dialectics being overthrown can be put aside for the time being. Perhaps in the near future, with the establishment of a grand unified theory based on quantum mechanics (Most likely string theory), dialectics will also be raised to an unprecedented peak. The theory based on dialectics has a solid foundation, and this is the fundamental purpose of our study of philosophy and physics.