1900: A physics genius wandering around Europe

Chapter 548 Integer spin! Bose-Bruce statistics! The fifth state of matter! A sensation in the physics world!

After the probability wave and uncertainty principle were proven, quantum mechanics ushered in a period of rapid development.

Various achievements have sprung up like mushrooms after rain.

For example, Kronig, Uhlenbeck and Goudsmit discovered integer spin through theory and experiment.

That is, the spin number of the particle is no longer ±1/2, but 1.

This means that the particle can rotate around and return to its original position just like a normal ball.

The news shocked the physics community.

Soon after, Pauli, an associate professor at the University of Hamburg, discovered through calculations that particles with integer spin do not conform to the exclusion principle.

The spin number of an electron is ±1/2, and it satisfies the exclusion principle.

Therefore, two electrons with the same energy level cannot be in the same position.

A particle with a spin number of 1 means that many particles can be in the same position at the same time.

This is very strange.

Soon, physics proved that photons are particles with spin of integer 1.

In addition, it has been discovered through theory that spin 2 or even 3 is possible, but no one has been able to find the corresponding physical particles.

In real history, it took more than ten years for the prototype of particle physics to appear.

At that time, physicists discovered many microscopic particles with different properties through particle collisions or cosmic rays.

For a time, the concept of spin became popular again.

Many physicists study the properties of integer spins.

Because particles with non-integer spins are microscopic particles such as electrons and protons, which have been studied sufficiently, everyone assumes that there is no problem.

Department of Physics, University of Dhaka, India.

Bose has been very depressed lately.

He had just submitted his paper to several physics journals, but none of them were accepted.

The editors' comments all indicated that there were obvious errors in the paper.

Although Bose participated in the third Bruce Conference, this did not give him an advantage in publishing his paper.

At the third Bruce Conference, in order to encourage the younger generation, Ridgwell specially selected a group of young physicists as representatives.

For example, Fermi, Dirac and Bose are among them.

But everyone in the physics community knows that those young people were chosen not because of their own abilities.

Science is a field that values ​​results; fame and reputation as a genius cannot make a living.

The reason why people like Pauli and Heisenberg became famous all over the world is not because of their reputation as geniuses, but because of their real academic achievements.

Therefore, Bose never felt proud of being appreciated by Professor Bruce.

Attending the Bruce Conference doesn't mean anything. What's impressive is being able to publish results at the conference that shock the academic world.

But even so, being rejected by several journals is a very uncomfortable thing.

For this purpose, Bose went to the University of Calcutta, which was not far away.

He decided to consult Professor Raman, the banner of today's Indian scientific community.

Raman became famous for discovering the Raman effect.

Although he is not the best in the entire physics community.

Great physicist, top physicist, senior physicist, ordinary physicist, Raman is at most a T4 ordinary physicist.

But in India, he is the absolute boss.

And just this year, Raman was elected a Fellow of the Royal Society of London, becoming the second Indian after Ramanujan.

With so many honors and achievements, Raman's position in the Indian physics community is very independent.

Calcutta University, inside the office.

Raman frowned slightly.

He had been reading the paper that Bose brought for more than half an hour, but still said nothing.

Suddenly, he murmured:
"interesting."

Bose took the opportunity to quickly explain:
"Professor, I think the Maxwell-Boltzmann distribution theorem in statistical mechanics does not hold for integer spin particles like photons."

"According to Professor Pauli's view, particles with integer spin can accommodate an infinite number of particles at a certain energy level."

"For example, photons can be infinitely superimposed at the same location."

"This clearly does not meet the conditions for a Maxwell-Boltzmann distribution."

The so-called Maxwell-Boltzmann distribution is a core theory of statistical mechanics in classical physics.

It is mainly used for microscopic analysis of large numbers of particles.

But the particle system it describes has limitations.

That is: particles have no interaction with each other and do not affect each other, and different particles can be distinguished from each other, and all particles strictly conform to the laws of mechanics.

In fact, it is equivalent to a large number of microscopic hard balls gathered together.

But for particles with integer spin, such as photons, they can be infinitely contained in the same position.

This is completely unimaginable in classical statistical mechanics.

Therefore, the Maxwell-Boltzmann distribution cannot count particles such as photons.

At this point, Bose continued:
"So, when studying the statistical state of a large number of photons in space, quantum concepts such as probability waves should be used."

"Only statistics based on probability waves can truly characterize the movement of photons."

"To do this, I created a new statistical law that applies to the statistics of microscopic particles with integer spin."

"But based on this theory, I came to an incredible conclusion."

"To put it in a more vivid way, in the macroscopic world, if you toss two coins at the same time, the probability of getting both heads is one in four."

"But if the coin behaves like a photon, then the probability of getting two heads becomes one in three."

"Because at this moment, the positive and negative are the same state."

"In academic terms, two photons of the same energy cannot be distinguished."

"This again conflicts with the conditions of the Maxwell-Boltzmann distribution."

"Because the conventional view is that different particles can be distinguished from each other."

"But not photons."

After Bose finished speaking, he looked at Raman expectantly.

The reason why his paper was rejected was because of the coin example he gave in the paper.

A normal person’s first reaction would be to think this is nonsense.

How could there be two things in this world that are exactly the same and indistinguishable?

Yet it is what it is.

This is because particles have the concept of identicalness.

That is: in quantum mechanics, particles with exactly the same intrinsic properties are indistinguishable, and this indistinguishability is called identity.

This sameness is not only found in photons, but also in electrons and protons.

As long as the particles are in a quantum state, they are all identical.

In a system composed of identical particles, exchanging the states of two particles will not change the microscopic state of the system.

For example, a box is full of electrons. Now take out some of them and then put in another batch of the same number of electrons.

So for the box, there is no change.

It sounds like nonsense, but in the quantum realm, it has important implications.

Raman was a little confused at this moment.

He could roughly understand Bose's theory, but he had no judgment and didn't know whether it was right or wrong.

No wonder the other party’s paper was rejected. This point of view is indeed a bit unbelievable.

Bose was Raman's most valued successor in physics.

Without being sure, he was unwilling to cause any negative interference to Bose's theory.

Most importantly, as the current boss of Indian physics, Raman had to solve problems for everyone.

So he smiled and said:

"Bose, your paper is very innovative."

"I think the editors made a mistake." "I'm not good at theoretical physics, so I can't give you authoritative advice."

"However, I can help you send the paper to Professor Bruce for a look."

"Your idea is based on the uncertainty principle he proposed. Perhaps Professor Bruce will be interested."

"What do you think?"

Wow!
Bose couldn't help but be delighted when he heard this.

In fact, he had already thought of this before he came.

However, firstly, he did not dare to write directly to Professor Bruce; secondly, he was too embarrassed to ask Raman for help.

What if the theory he proposed was rubbish and he rashly sent it to Professor Bruce? That would destroy the impression of the Indian physics community in his mind.

Bose cannot afford such consequences.

After all, he is not Little Thompson and has strong connections.

Raman's suggestion hit Bose's heart exactly.

"Thank you so much, Professor!"

"I believe I won't let you down!"

Raman smiled.

"The field of quantum mechanics is changing rapidly, and everyone is racing against each other."

"To be on the safe side, I will send a telegram directly to Professor Bruce."

"Don't let your theory get lost in the dust!"

Bose felt warm in his heart.

This is the charm of a leader!

Quantum Research Institute.

When Li Qiwei received Raman's telegram, he smiled.

He decided to help the other party.

The reason why he treated Raman and Bose well was to urge Chinese scholars not to be proud. Science in India and the Sakura Country was also developing rapidly.

Li Qiwei hopes that everyone can gradually get rid of their dependence on him and become truly independent.

Even if he really unified the four powers one day in the future, it does not mean that science has come to an end.

Science never ends!

The theory proposed by Bose was later developed into Bose-Einstein statistics.

It is a statistical law that describes particles with integer spin.

For convenience, the physics community collectively refers to various particles with integer spin as "bosons."

So, photons are a type of boson.

In real history, after Bose's submission failed, he wrote a letter to Einstein, hoping to get his evaluation.

Einstein saw the great value of Bose's theory at a glance and personally submitted the paper to the then famous "German Physical Journal" for publication.

Moreover, based on Bose, he extended the concept of bosons to atoms and proposed a new phenomenon.

He believed that a group of high-density bosons would form a new state of matter under ultra-low temperature conditions close to absolute zero, namely: Bose-Einstein condensate.

This state is a gaseous, superfluid state.

After Einstein proposed this hypothesis, it was not until 1995 that it was finally confirmed by experiments.

Physicists used gaseous rubidium atoms at a low temperature of 1.7×10^-7K to obtain the Bose-Einstein condensate for the first time.

So what exactly is this so-called Bose-Einstein condensate good for?
One of its important functions is to reduce the speed of light to a few meters per second.

It can even go a step further and "freeze" light and then release it again.

In short, Bose-Einstein condensate is an extremely important theory in quantum mechanics and condensed matter physics.

And its basis is the statistical law proposed by Bose.

However, in this life, it is estimated that it will be renamed Bose-Bruce statistics and Bose-Bruce condensate.

Li Qiwei wrote a letter with great fanfare, giving a very high evaluation.

A few days later.

Raman gets the reward and looks excited.

"Bose, you are so lucky!"

"Professor Bruce is very optimistic about your theory."

"He thinks this is another important breakthrough in the field of quantum mechanics."

"Nature will accept your paper and publish it on the cover."

"Moreover, Professor Bruce has invited you to give a report in Europe to publicize your theoretical achievements."

Wow!
Bose couldn't believe his ears.

He actually received such high praise from Professor Bruce and was even able to give lectures in Europe.

For a moment, he was so excited that he couldn't speak.

Raman was genuinely happy for Bose.

The other party not only made an academic breakthrough, but also in the most difficult field of theoretical physics.

How difficult it is!

I'm afraid this is why Professor Bruce values ​​Bose so much.

Raman felt grateful that he finally didn't have to bear such great pressure alone.

“India’s physics community has a new generation of leaders!”

1924 5 Month 1 Day.

Bose's statistical theory was published in the journal Nature.

As soon as the paper came out, it caused a sensation in the physics community!

This is another important theoretical achievement.

"No wonder Professor Bruce keeps talking about the quantum world."

“This is the real great world!”

"Previously, the theory of relativity was almost monopolized by Professor Bruce alone."

"Quantum mechanics is different. Anyone has the opportunity to participate in it. Maybe they can become a blockbuster like Bose!"

In addition, Bose's conclusion also triggered a wave of research on the identical nature of particles.

In real history, this concept gradually became a consensus and was accepted by physicists with the development of quantum mechanics.

Then, when the story of Bose and Ridgwell spread, it caused another round of exclamations, and everyone was envious.

"This is a great example of a big boss helping the younger generation!"

Just ten days later, Li Qiwei published another powerful article.

Based on the Bose statistical law, he proposed the condensed matter hypothesis.

When the paper came out, the physics community was shocked!

This is the fifth form of matter after gas, liquid, solid and plasma!
"My goodness!"

"Professor Bruce has taken Bose's theory to a higher level!"

"He actually theoretically derived a completely new form of matter!"

"It's absolutely terrifying!"

Bose was shocked after reading the paper.

His theory is for particles like photons, but it can be extended to the atomic level?
This was something he had never thought of.

"Professor Bruce's thoughts are as vast as the starry sky."

Thanks to Bose and Ridgway's contributions to new statistical laws.

The physics community calls this new statistical theory Bose-Bruce statistics.

The corresponding condensed state is called Bose-Bruce condensate.

For a time, research on quantum mechanics was like adding fuel to the fire.

(End of this chapter)