If you use one word to describe quantum mechanics, I am afraid that the only word "weird" is used. Even physicists admit that no one really understands quantum mechanics, which shows how terrifying and incredible quantum mechanics really is.
And it is precisely because quantum mechanics is so obscure that some people on the market have also moved their minds, using the cutting-edge technology of quantum mechanics to start the "pit deception" business, declaring what "quantum fluctuation speed reading", using the so-called "quantum entanglement" and the interaction between the human brain to achieve the miraculous effect of instant memory of book content.
Don't say, there are really many people who are deceived. It is no wonder that it is difficult for ordinary people to deeply understand what quantum entanglement is all about, and can only listen to some people "blindly", saying that quantum entanglement is related to human brain telepathy, and even saying that quantum entanglement is closely related to the soul.
Quantum entanglement is indeed a very strange phenomenon in quantum mechanics, and it is also a real phenomenon. Physicists in modern technology can also use the phenomenon of quantum entanglement to serve humanity.
So what exactly is quantum entanglement? Why is it said that quantum entanglement is much faster than the speed of light? Can we use quantum entanglement for teleportation?
First of all, the core idea of quantum mechanics is "uncertainty" (also known as the "uncertainty principle"), of course, the phenomenon of quantum entanglement is also based on this core.
In layman's terms, the so-called uncertainty, that is, we cannot measure the position and velocity (kinetic energy) of microscopic particles at the same time, which is very contrary to our daily cognition.
Let's say a car whistles past you, and of course it's easy to calculate the position and speed of the car at a certain point in time, but it won't work in the quantum world.
The so-called measurement, we can only do it by reflecting light into the eye. For example, if we want to measure the position and velocity of an electron, we must have light reflected from the electron into our eyes, whether we look directly or through high-tech instruments, in short, there must be light reflected into our eyes.
However, due to the small mass of microscopic particles, such as electrons, it is easy to be disturbed by photon irradiation. Theoretically, if we want to measure the precise position of an electron, we need to use a wave with a shorter wavelength. However, a wave with a shorter wavelength carries a larger amount of energy, and the interference with the electron is greater, and it is difficult to measure the speed of the electron.
Similarly, if we want to measure the precise velocity of an electron, we need to use a wave with a longer wavelength, but because of the longer wavelength, the position of the electron is difficult to measure accurately.
This is embarrassing, just like "fish and bear paws cannot have both", in order to obtain the precise position (velocity) of a microscopic particle, we must abandon the accuracy of velocity (position).
But this is not a problem in the real macro world. Take the above car as an example, because the difference between the quality of the car and the photon is too large, the impact of light on the car in both wavelength bands is completely negligible, so it is easy for us to measure the position and speed of the car.
This is uncertainty, and particles in the microscopic world can only be described by probabilities, and there is a proper noun to describe this probability: the wave function. When we observe a particle, the wave function collapses to become a precise particle.
To put it bluntly, when we are not observing, the state of the microscopic particles is very vague, and once the observation is made, the state of the particles is determined. That is, our observations directly affect the state of the particles.
This phenomenon is too weird to put in the macro world. And Einstein also had "When you don't look at the moon, it doesn't exist?" To question the uncertainty of the "Copenhagen School" led by Bohr. Scientists such as Einstein Schrödinger believe that there are more mysteries behind quantum mechanics that are not known to us, and that "uncertainty" cannot be simply used to explain the strangeness of the quantum world.
One of the famous thought experiments, Schrödinger's Cat, is the thought experiment that Schrödinger used to satirize Bohr's theory of uncertainty. Naked sarcasm with a "dead and alive" cat (Schrödinger's cat will not be elaborated here).
Based on the uncertainty principle, the Gobenhago School also proposed a strange quantum entanglement phenomenon, which Einstein called "ghostly hyper-distance action", and the speed of quantum entanglement is far faster than the speed of light, even more than 10,000 times, which obviously contradicts the phenomenon of the speed of light in Einstein's theory of relativity.
Let's take a popular example in reality. There is a pair of gloves in two bags, no matter how far apart the two gloves are, even if they are located at opposite ends of the universe, as long as we open one of the gloves and find that it is a left glove, then the other glove must be a right glove, and we can instantly know the information of the "right glove".
The gloves are like microscopic particles in an entanglement, sensing each other instantaneously. And "convention" well: you are left, I am right.
According to the uncertainty of quantum mechanics, it is difficult to say that before the bag is opened, the state of the two gloves has been in a vague superposition state, that is, a bag may be both a left glove and a right glove. Obviously, this is not possible, after loading the bag, even if we did not observe, the state of the gloves in the bag was determined.
Pol's explanation goes like this: the moment the two gloves are packed into the bag, their state has "collapsed" and determined, and the subsequent opening observations have no effect. He argues that this thought experiment is untenable.
The debate between the two schools, led by Bohr and Einstein, continued for many years. In the 1960s, Bell conducted an experiment to show that entangled photons "communicate with each other" much faster than light, and much faster. Only many scientists have done similar experiments, and the results have proved that quantum entanglement does really exist.
Much faster than the speed of light? Was Einstein's theory of relativity overturned?
Non-also, although the speed of quantum entanglement is much faster than the speed of light, but the entangled particles do not transmit any information between each other, the entangled particles are a whole, showing the whole, measuring one alone will definitely affect the state of the other particle. Since there is no information transmission, of course, we cannot use quantum entanglement to transmit any information, let alone use quantum entanglement phenomenon to carry out teleportation.
The quantum communication we are vigorously developing is actually not "transmitting information faster than the speed of light", but only using quantum entanglement phenomenon for "encryption". Because of the uncertainty of microscopic particles, scientists use entangled particles to generate codes that are random and impossible to crack.
And even if someone tries to crack the code, it will definitely affect the entangled particles, so the entangled particles immediately "collapse", and this change will be immediately monitored: someone tries to crack the code!
So, although quantum entanglement is very strange, this phenomenon does not violate Einstein's theory of relativity, and we cannot use quantum entanglement to do any faster-than-light work.
Quantum mechanics and relativity are the two cornerstones of the edifice of modern physics, and what we usually call "quantum mechanics and relative incongruity" refers to the incompatibility of quantum mechanics with general relativity, the former emphasizing that space-time is not continuous, and the latter being the opposite. And there is no contradiction between quantum mechanics and special relativity!