1900: A physics genius wandering around Europe

Chapter 525 Shocking speech! Thermodynamics and quantum mechanics! The source of probability! The last barrier of classical physics!

1923 10 Month 20 Day.

Amsterdam, The Netherlands.

Li Qiwei's arrival was warmly welcomed by the Dutch officials.

Amsterdam Mayor Job led many Dutch government and academic figures to personally welcome him.

He said: "The arrival of all the physicists makes Amsterdam shine with scientific glory."

“This will surely be a great meeting that will go down in history!”

This quantum mechanics conference was held at the University of Amsterdam in Amsterdam.

Founded in 1632, the university has a very special way of being run.

It is not as highly free as British universities, but is directly managed by the government parliament.

The mayor of Amsterdam serves as the president of the University of Amsterdam.

All professors hired by the school must also be approved by the city council.

This management system was not abolished until decades later.

However, thanks to the progressive style of the Amsterdam City Council, the University of Amsterdam still has a great deal of academic freedom.

So far, four people have won the Nobel Prize.

Two of them won the Nobel Prize in Physics, namely van der Waals and Zeeman.

After the welcome ceremony, Zeeman accompanied Ridgway to visit the University of Amsterdam.

At the sincere invitation of Mayor Jobs and academic leaders, Li Qiwei will give an academic speech here in two days.

It can also be regarded as an appetizer for the upcoming quantum mechanics conference.

Everyone is looking forward to it.

Professor Bruce’s speech is something you cannot miss!
Under Zeeman's introduction, Li Qiwei shook hands with the professors and teachers of the University of Amsterdam one by one.

Among them, Li Qiwei also met VanderWaal's son, VanderWaal Jr.

He sighed:

"The departure of Professor van der Waals is a great loss to the physics community."

Van der Waal passed away in March this year.

He was the first professor of physics in the history of the University of Amsterdam and made important contributions to the fields of thermodynamics and statistical mechanics.

The famous intermolecular force, the van der Waals force, was named after him.

When Li Qiwei became famous all over the world, the old man had already retired.

The other person lives in seclusion in the countryside, taking walks and reading every day.

Therefore, Li Qiwei did not have much interaction with Van der Waals.

Van der Waals Jr. took over his father's position and is now also a professor of physics at the University of Amsterdam.

He was extremely excited when he met the legendary Professor Bruce for the first time.

"Thank you for your comments, Professor Bruce."

"My father spoke of you more than once during his lifetime."

"He said you are a genius rarely seen in the physics world in a few hundred years!"

"You invited him to the meeting several times before, but he refused."

"It's not that my father is arrogant, but he said it himself: It's useless for an old man like me to go."

Little VanderWaal went out of his way to explain the reason as a sign of respect.

After hearing this, Li Qiwei and everyone else were deeply moved.

As a person of the same generation as Maxwell and other big names, van der Waals has seen countless geniuses.

When he was young, he was also admired by others.

Therefore, he did not want to be a useless person in his later years.

Living in an era of drastic changes in physics at the beginning of the 20th century, everyone's choices and mindsets were different.

Across the sea, the hero shows his true colors!
The next day, Lorenz and Ehrenfest arrived one after another, and the latter brought Uhlenbeck and Gudschmidt with him.

Lorenz laughed heartily and said:

"Bruce, you are finally willing to hold the meeting in the Netherlands."

Li Qiwei said helplessly:

"The political situation in Europe has been a bit complicated recently, so I had to choose a neutral country like the Netherlands."

Lorenz was deeply moved when he heard this.

Although this era was a golden age of science, it was also an era full of chaos and no order existed.

But he didn't have too many worries in his heart.

Europe had just experienced a world war, and nothing more serious than that could happen.

The various trends nowadays are nothing more than a dispute of ideas.

It's just like the debate between wave mechanics and matrix mechanics in quantum mechanics.

So, after chatting for a while, the topic returned to academics.

Ehrenfest smiled and asked:

"Professor Bruce, Heisenberg and Schrödinger are both from the Quantum Institute."

“Who will you support?”

Li Qiwei smiled mysteriously, and then said something meaningful:
"It's too early to talk about winning or losing now."

Uhlenbeck and Gudsmit were unaware of the situation.

“Is this what it feels like to be unfathomable?”

“So cool.”

10 month 22 day.

The University of Amsterdam is bustling with people.

Countless Dutch teachers and students came to hear Professor Bruce’s lectures.

It had been exactly ten years since he last gave a speech at Leiden University.

So, this is another rare opportunity.

Surrounded by the crowd, Li Qiwei came to the school's lecture hall.

At this moment, the hall was already crowded with people and all seats were occupied.

As the host, Zeeman first delivered a warm welcome speech.

Under the expectant gazes of everyone, Li Qiwei slowly walked up to the podium.

At this moment, his momentum suppressed the entire audience!

"The topic of my speech today is heat and quantum mechanics."

"Actually, I came up with this topic on the spur of the moment."

“Because when I came to the University of Amsterdam, I thought of the late Professor van der Waals.”

"He played a fundamental role in the development of physics at the University of Amsterdam, and his main research direction was heat science."

"So, naturally, I thought about the history of the development of thermal science."

"With the rapid development of modern physics, many people's enthusiasm for classical physics has greatly decreased."

"And thermodynamics is probably the most neglected field in classical physics."

"Many people here probably think it's natural."

"What's so good about thermodynamics? The four laws of heat and cold are perfect enough."

“But I want to say that you are wrong!”

"Thermodynamics is very, very important. The development of quantum mechanics is closely related to thermodynamics!"

Wow!
As soon as Li Qiwei opened the show, he shocked everyone!
This is Professor Bruce's personal style, seeing the big picture from the small.

He can always discover the most profound truths from the most ordinary and overlooked places.

It makes people feel a sudden enlightenment and awe.

"Ah? Is thermodynamics so amazing? It can even be related to the high-level quantum mechanics?"

“There are very few PhDs studying thermal science these days.”

“Everyone is busy studying relativity and quantum mechanics.”

"."

Everyone was very curious about why thermodynamics, which is just a commonplace subject, became so important in Professor Bruce's words. Young van der Waals was particularly moved, as his own research field was thermodynamics.

Professor Bruce was so interested in thermodynamics that he was even well aware of his father's achievements.

At this time, Li Qiwei continued:

“Hot and cold phenomena are among the earliest natural phenomena observed by humans.”

"But before, people could only sense and utilize this phenomenon but could not study its principles."

"It was not until the early 18th century, with the establishment of thermometry, that thermodynamics, like mechanics, finally embarked on the path of scientific experimentation."

"But the thermal science of this period was focused on elementary basic concepts, such as temperature, work, heat, etc., and no logical deductive system was formed."

"There are two views on the nature of heat: the caloric theory and the kinetic theory."

"The former regards heat as a kind of fluid substance that is neither created nor destroyed. The more heat an object contains, the higher its temperature will be."

"The latter is considered to be a macroscopic manifestation of a form of motion of hot objects."

"It was not until Joule proved the correctness of the mechanical equivalent of heat by precise experiments that the caloric theory was abandoned."

"Physicists realized that the thermodynamic theory was correct, that heat was related to the random motion of large numbers of molecules."

“Thus, thermodynamics has entered the second stage of studying thermal phenomena and their laws, from the stage of studying basic concepts.”

"Depending on the different research methods, the second stage of thermal science is divided into thermodynamics and statistical mechanics."

“Thermodynamics is the study of the thermal properties of objects from a [macroscopic] perspective.”

"The word 'force' is included because thermodynamics, like mechanics, now has mathematical logical deduction and is no longer just a conceptual explanation."

“For example, studying the compression process of a certain volume of gas.”

"Thermodynamics is the study of the three state functions of temperature, internal energy, and entropy during the compression process to describe the system."

"Its basis is the three, no, now I should say four, laws of thermodynamics."

"These four laws, like Newton's laws, make the foundation of thermodynamics unbreakable."

“Since we can study heat from a macroscopic perspective, can we try it from a microscopic perspective?”

“So, statistical mechanics was born.”

“It studies the thermal phenomena of objects from the perspective of [microscopic] molecular motion.”

“Let’s use the same example as above.”

"If we use traditional mechanical methods to study gases, we need to establish mechanical equations for a large number of gas molecules."

“It’s an impossible task.”

"Statistical mechanics uses the method of probability statistics to provide a microscopic explanation for the thermal properties of macroscopic objects composed of a large number of particles."

"The famous ideal gas state equation pV=nRT is the result of statistical mechanics."

“Most of Professor van der Waals’ work falls into the realm of statistical mechanics.”

“At its core, it’s a probability distribution function.”

“The core work in this area was done by people like Boltzmann and Maxwell.”

Wow!
Li Qiwei's in-depth and easy-to-understand analysis gave the students present a new understanding of thermodynamics.

From phenomenon to concept, and then from concept to theory.

As one of the three major branches of classical physics, this is how the names of thermodynamics and statistical mechanics came about.

"I'm getting better."

“No wonder thermodynamics and statistical mechanics are always discussed together.”

"It turns out that they are both studying the same thing, but with different angles and methods."

When Ehrenfest in the front row heard the name of his mentor, his heart was touched.

He still can't face this terrible tragedy.

At this time, everyone suddenly wondered:

"Professor Bruce talked about the history of the development of thermodynamics, but what does it have to do with quantum mechanics?"

Li Qiwei's majestic eyes swept around, and then said:
"I see doubt in your eyes."

"How do you think the sophisticated quantum mechanics has anything to do with the crude thermodynamics?"

“First, the concept of quantum came from blackbody radiation.”

"And blackbody radiation is the standard thermodynamic model."

“As quantum mechanics became established, I discovered that it had a very deep connection with statistical mechanics.”

"Because statistical mechanics studies the motion of a large number of microscopic particles, while quantum mechanics studies the motion of a single microscopic particle."

"There may be some principles and connections that we don't know about, waiting to be discovered."

"If you pay attention to the latest progress in physics, you will find that there is already a direction called quantum statistics."

“Quantum statistics and statistical mechanics are working in the same direction.”

“But there is a fundamental difference between the two.”

“Quantum statistics holds that microscopic particles follow the laws of quantum mechanics rather than the laws of classical mechanics.”

“So, this can have a lot of unexpected results.”

"As far as I know, the person who has done the best job in this area is Professor Fowler of Cambridge University."

"Dr. Dirac, who worked under him, published several very innovative papers."

“It even refined my theory of stellar evolution.”

“I think this will be a whole new area of ​​combining quantum mechanics and thermal theory.”

"Perhaps one day, the theories and concepts in thermodynamics will in turn help the development of quantum mechanics."

Wow!
Everyone was extremely shocked!

What Professor Bruce said opened their eyes!

"Oh my God! So this is how you can study heat?"

"The gold medal in the International Mathematical Olympiad is really amazing. Dirac actually thought of applying quantum mechanics to statistical mechanics."

"If the research doesn't produce good results, it's because of the people, not the direction."

"Thermal science has great potential!"

Lorentz, Zeeman, Ehrenfest and others were also extremely shocked.

Professor Bruce's perspective was something they had never thought of.

It suddenly occurred to them that the core of statistical mechanics is probability distribution.

"Can probability also be applied to quantum mechanics?"

"how to use?"

Li Qiwei looked at everyone's expressions and smiled slightly.

In real history, great men such as Einstein and Planck attached great importance to thermodynamics.

Because thermodynamics is a self-contained system and is extremely perfect.

The later theory of relativity and quantum mechanics claimed to have overturned everything in classical physics.

But only thermodynamics remains unshakable and can be regarded as the last barrier.

On the contrary, it played a key role in the development of quantum mechanics.

For example, Fermi-Dirac statistics, Bose-Einstein statistics, etc., were all developed on the basis of statistical mechanics.

Even Schrödinger's wave equation and Born's probabilistic interpretation found inspiration in thermodynamics and statistical mechanics.

Later, some physicists tried to use quantum mechanics to quantize heat and form a completely new theory.

However, there have been no significant results so far.

Von Neumann once said: Through probability, thermodynamics and quantum mechanics are connected.

This shows the importance of thermodynamics to quantum mechanics.

Li Qiwei ended his speech amid cheers and applause from the audience.

At this moment, people still don't understand the true value of this speech.

They just thought Professor Bruce's angle was very novel.

The antique field of thermodynamics is unexpectedly combined with quantum mechanics.

But soon, everyone will be shocked and extremely upset.

"Oh my god! Thermodynamics is so important!"

(End of this chapter)