I have studied quantum mechanics! Urgent!!

Light waves are probabilistic waves, and this experiment proves this conclusion.

I'm a high school student, so let me tell you, light interferes and diffracts.

a.The state of an atom is not cloning.

b.The shape of a piece of matter is not clonable.

c.The state of a photon is not clonable.

d.The weight of a piece of substance cannot be measured rigorously.

Correct answer: Defense: AC

For those who are new to quantum mechanics, they may feel that quantum mechanics is a niche science. Actually, quantum mechanics and the theory of relativity are the two pillars of modern physics. With that said, you will fully understand the importance of quantum mechanics.

We live on a scale of matter that is about centimeters to kilometers, and Newtonian mechanics is very useful at that scale. But when you go deep into the smaller microscopic world, such as the atomic level, Newtonian mechanics completely fails, and quantum mechanics takes over. Newtonian mechanics dominates our macrocosmic and low-velocity world, and quantum mechanics dominates the microscopic world!

The motion of microscopic particles is strange. We've all seen dust in the air! Dust is doing irregular Brownian motion all the time.

The particles on the microscope are actually quite like this kind of motion, don't you know that it will appear in the next second**? But unlike dust motion, as you record the movement of a microscopic particle, you will conclude the probability that it will appear at a certain location.

For example, you have to investigate the rules of Xiao Wang's life. Xiao Wang often goes to parks, libraries, gyms, and Internet cafes in his life. After a year of observation, you will come up with the probability of where Xiao Wang goes.

Since Xiao Wang's going to ** is random, you can't be 100% sure that he will go to the Internet café tomorrow, you can only say how likely it is that he will go to the Internet café tomorrow.

You leave home at 8:00 a.m. and drive to work. If you know the distance between your home and your work, and you know how fast you drive, you can calculate exactly when you will reach your company.

But this is not the case with microscopic particles, where the position and momentum (momentum = velocity mass) cannot be measured at the same time. This means that you can either measure the position of a particle at a certain moment in time or the momentum of a particle at that moment, but you can't have both. Does that mean you can never be precise about where the particle will appear at the next moment?

Quantum entanglement. Two or more particles make up a quantum system. In the case of a system composed of two particles, a change in one particle causes a change in the other particle at the same time.

Even if they are far apart, they will change at the same time. This is one of the basic laws of microscopic particles!

Only in special cases can the information of energy level degeneracy be obtained directly from symmetry analysis...

Equations are usually solved honestly.

Writing this, I found that the first floor has already said...

Besides, have you explained the kind of situation you mentioned? Finally, to explain my point of view, when we say that a Hamiltonian operator and an operator pair are likely to lead to degeneracy, we usually mean that the operator is the operator corresponding to any other mechanical quantity. Therefore, it should not mean anything special to just analyze the cosmic operator.

The Hamiltonian has a certain symmetry, which is not sure to cause the degeneracy of the energy level of the system, but the symmetry of the system has a lot to do with the degeneration. This is somewhat similar to perturbations, where the addition of perturbations destroys the symmetry of the system, resulting in some degeneracies.

The square integration of the amplitude of the wave function gives a 2a 2, which should be equal to 1, so a = root number 2 a

I opened a quantum mechanics course in my junior year, and I admired the name of quantum mechanics for a long time, because of its magic and abstraction, so I like Zaozhou very much, so no matter whether it is difficult or not, I always have an optimistic and positive attitude to learn and think, until the final graduate school entrance examination is also the choice of this professional course, 126, but whether I can do the problem or not, I always feel that quantum mechanics is difficult, because of its abstract and relatively unfamiliar mathematical system, it is difficult for us to analyze a topic like a mechanical problem, It's all about writing Hamiltonian and then solving the equation of the evidence, and when the eigenvalue comes out, the mission is basically completed.

As a beginner, I would like to give you a sentence first, Feynman, one of the most famous physicists in modern America, said: "Some people say that there are only three people in the world who can understand the theory of relativity, so for quantum mechanics, I am sure that no one will understand", this is also what the teacher told us when I began to study quantum mechanics, quantum mechanics is characterized by its abstraction and contradictions. So you have to be mentally prepared, don't see an incomprehensible phenomenon and go for it, but accept it, not to say that it's not okay to be true, but now is not the time, because you haven't fully understood the essence of quantum.

For books, we were learning the concealment of materials at that time, so we used a very simple book, Zhou Shixun's quantum mechanics, a thin book, but the explanation is still relatively clear, recommended. If you want to know more about and experience quantum in depth, I suggest you buy a copy of Fudan Su Rukeng's quantum mechanics, a very informative book, which is also more clear about the places that we are generally confused about, much better than Zeng Jinyan's book, at least more popular.

For the quantum system, I think you should have some experience, the elementary quantum mechanics is the combination of wave dynamics and matrix mechanics, you do nothing more than use these two to solve the problem, in the final all-copper ion system is the same, just add a spin wave function, but the main line is the same, it is for you to find Hamiltonian, column the eigenequation, find the eigenvalue; Secondly, a very important concept is representation, representation is actually a complete set of orthogonal basis of Hilbert space, representation transformation is actually coordinate system transformation, this transformation operation is the meaning of the operator, you must understand this slippery concept and complete the correspondence between physics and mathematics, which will help you understand the problem; You must have mastered the Dirac symbol, this thing is not just a symbol, and later you find that this thing is directly a revolution in the way of thinking, clear and easy to use. As for the rest, I don't think there's a good way to do it, you just have to grasp it one by one. Let's start with that.

Finally, I would like to remind you that doing more questions is not the point, the quantum focus is on experience! Although it is difficult to analyze a problem, we can understand the intention of the topic, and it is necessary to consider sub-memory. For those of us who are average in mathematics, quantum may not be considered pure science.

I can't find the handwriting.

For more information on this question, you can see "The History of Quantum Mechanics" (a lot of literature), which is the best (and most understandable) popular book in my opinion.

Let me explain briefly:

The state of a quantum mechanical system is largely influenced by the observer. This is mainly done by measuring behavior. Therefore, when the measurement behavior is not done, the system is reversible and seems to be called a u-process.

If the measurement occurs, the system immediately undergoes irreversible changes, which seems to be called the r process.

I also know a little bit about it, I hope it will help you.

The result of the measurement is a quantum transition in the system, such as double-slit diffraction of electrons or other microscopic particles, and the electrons hit the position of the stripes on the screen with a certain probability, so it is impossible to determine which stripes will be hit in this process. The screen is a measurement of the position of electrons, once the electrons hit the screen, they will leave a trace, and will no longer appear in space with a certain probability as before, that is, a quantum jump has occurred, and the jump to a certain state.

The term reversible, irreversible is not very good.

"But the gravitational force between two substances observed in nature does not change in proportion to the square of the distance"!

Some are not"!

A large number of scientists are tired and tired every day to find such a "no", and your "no" is ** here?

All the current experiments show that in the experimental accuracy that we can achieve, the gravitational force is precisely in line with the inverse square law, there are no exceptions, and we are constantly improving the experimental intensive reading, improving the experimental method, and trying to find an example of gravitational force that is not inverse square law.

So, there is no scientific explanation, because it was not found.