-Debate on quantum mechanics
Iola 03 10270 of material physics
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* Since the emergence of quantum mechanics, its correctness has been verified by a large number of experiments.
However, there is an important problem in quantum mechanics: whether quantum mechanics is complete and whether the wave function accurately describes the state of a single system.
1. prologue
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* Copenhagen school thinks:
The 1. wave function accurately describes the state of a single system.
2. The wave function provides statistical data, and the uncertainty relation exists because the shape between the particle and the measuring instrument is uncontrollable.
3. The microscopic process in space-time is incompatible with the classical law of causality.
1. prologue
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* Einstein agreed that the physical world without strict causality is unimaginable.
He thinks there may be something wrong with quantum mechanics.
A great debate of the century is about to begin.
1. prologue
2. First, this debate
* The 5th Solvay Conference was held, with the theme of photons and electrons.
A group or faction
* The meeting was divided into three groups:
* Experimental School: Compton Prague
:: Gerben Hagen School: Polben Heisenberg
* Einstein School: Einstein de Broglie Schrodinger
Debate spread
Roy de Broglie said: particles are singularities in the wave field, and waves guide the motion of particles.
Pauli severely criticized this theory and quoted a series of experimental results to refute De Broglie, who was forced to give up his own point of view.
Heisenberg and Bonn said: We believe that quantum mechanics is complete, and its basic physical and mathematical assumptions cannot be further modified. They attacked Schrodinger's electronic cloud.
Schrodinger admits that his calculation is not perfect, but it is nonsense to talk about electronic orbits.
Einstein speaks
Einstein finally spoke, and he proposed a model:
An electron passes through a small hole to get a diffraction image.
Einstein pointed out two views:
1. There are no electrons here, only electron clouds.
2. There is really only one electron, and the wave function is "probability distribution"
Einstein objected to view 2 because:
This randomness shows that the same process produces different results.
That is, many areas of the sensing screen react to electronic observation at the same time.
This seems to imply a kind of action at a distance, which violates the theory of relativity.
Heisenberg's memory
"The discussion soon turned into a duel between Einstein and Bohr."
"We usually meet in the hotel after breakfast, so Einstein described a thinking experiment, from which we can clearly see the inherent contradiction explained by Gerbenhagen."
"Generally speaking, Bohr is fully aware of these ideal experiments at night, and he will analyze them to Einstein when eating. Einstein could not refute these analyses, but in his heart he was unconvinced. "
Einstein's failure
Einstein believed in causality so devoutly that he could never believe Copenhagen's cynical probability explanation.
* "God doesn't roll dice!"
But he lost the first debate. Lost to Bohr's Copenhagen School.
The second debate
* Three years later, in autumn, the 6th Solvay Conference was held in Brussels.
Einstein's abacus
* Einstein knew from his experience with Bohr:
* There is no dispute about the details.
* He must aim at the most critical essence: the principle of uncertainty!
Einstein put forward the experiment of light box.
* There are some photons in the box.
* Open time Δ t, only one photon is released, Δ t is determined.
* So the box is Δ m lighter and can be measured with an ideal ruler.
* Substitute Δ m into e = MC 2, and Δ e is determined.
Δ e and Δ t are both definite, and there is the uncertainty principle.
δeδt & gt； H/2π does not hold.
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* The essence of this experiment is:
When δ t is measured accurately, δ m can also be measured accurately.
δ m can be converted from mass-energy equation to accurate δ e.
Both Δ e and Δ t are accurate, and the uncertainty relation is invalid.
* Bohr was unprepared for this, pale as ash and stupefied.
The next day, Bohr's victory came.
δq
* Bohr pointed out:
* A photon ran away and the box was lighter by Δ m..
* Use the spring scale to set the zero point and set the displacement δ q..
* According to the redshift effect of general relativity, the box moves Δ q in the gravitational field, and Δ t changes Δ t accordingly.
* You can calculate: Δ t > h/Δ mc 2.
* substitute e = MC 2 to get Δ e Δ t > h/2π.
It's Einstein's turn to be speechless this time.
* Einstein's general theory of relativity overthrew himself.
* The Copenhagen School won a great victory.
* Bohr won again.
Einstein was unwilling.
* Einstein had to admit that Copenhagen's explanation was not contradictory, and quantum mechanics depended on probability theory. But he thinks this statistical description is not a complete "image".
* In Einstein's own words, the theory of quantum mechanics is incomplete, and the wave function cannot accurately describe the state of a single system. It involves many systems, just a "lineage".
* The statistical description of Copenhagen School is only an intermediate stage, and a more complete theory should be sought.
Similarly, Bohm's theory holds that:
* At present, quantum mechanics is a statistical theory (explained by Copenhagen School) because there are hidden variables that have not yet been discovered. The laws of individual systems are determined by them.
* If we can find hidden variables, we can accurately determine each measurement result of microscopic phenomena, not just the probability of various possible results.
* That is to say, if hidden variables are found, then the law of causality still exists, "God does not roll the dice".
End of movement
* Einstein left his hometown because of the persecution of Nazi Germany and did not attend the seventh Suwei Conference.
* And the theme of this conference has been changed to atomic physics.
Solvi conference on quantum mechanics has ended.
End of movement
* But it didn't end once.
* 1935, Schrodinger published a paper "The Present Situation of Quantum Mechanics" and put forward the nightmare cat experiment.
* For the second time, the Copenhagen school can only swallow the bitter water and admit that cats are in a ghost state of "mixed life and death".
* Their explanation even involves "consciousness".
End of movement
The Solvay Conference is like a historical stage, which witnessed the development and existence of quantum mechanics.
* Einstein seems to be a "villain", playing a role similar to those who try to overthrow the theory of relativity.
* Bohr has withstood these tests, and the ideas of Copenhagen School are widely circulated.