1900: A physics genius wandering around Europe

Chapter 416 Celestial Bodies and Atoms! Macro and Micro! One Physics Law Can Apply to All Laws!
The establishment of the International Astronomical Union allowed everyone to see Professor Bruce's love for astronomy.

Dyson even smiled and joked to his colleagues:

"Professor Bruce often goes to the Greenwich Observatory to look at the stars."

"But he can't even tell the most basic constellations apart."

"Every time he wants me to be there and explain it to him in detail."

Dyson's words made the bosses smile knowingly.

It turns out that Professor Bruce has such a cute and innocent side.

Always watching the other party making great strides in the field of physics, everyone had long believed that Professor Bruce was omnipotent.

Haier said, "I heard that Professor Bruce is not good at doing physics experiments."

"Now it seems that he is also not good at astronomical experiments."

"He is a natural theoretical astronomer!"

In this era, there was no division between experimental and theoretical astronomy.

All research must be based on real observational data, including the star's spectrum, position, size, etc.

However, the emergence of general relativity clearly goes beyond the scope of traditional astronomy.

Astronomers have new tools to do some theoretical analysis.

And there was one thing that allowed everyone to roughly guess Professor Bruce's favorite research direction.

After the elections for various positions at the meeting were completed, there was another arrangement, which was for astronomers to give reports.

The content of Eddington's report aroused Li Qiwei's great interest.

Since Eddington proved the bending of starlight, he has become a superstar in the world of astronomy.

But he did not dwell on his past glory, but continued to break through himself.

He turned his research direction to the formation and evolution of stars.

Astronomy can be divided into the following levels according to its research object:

Planetary level, stellar level, galaxy level, universe level.

Hubble's current research direction is at the galaxy and universe level, commonly known as large-scale astronomy.

But this does not mean that large scale is more important than small scale.

As the most common celestial bodies in the universe, stars have extraordinary significance for human beings.

Because without the sun, there would be no basis for human existence.

The earth has been bathed in the sun's rays for hundreds of millions of years.

But humans know almost nothing about the huge fireball above their heads.

Therefore, the study of stars is also the hottest direction in astronomy.

The two most important unsolved mysteries are:
First, where does the energy of stars come from? Why can stars burn for billions of years without extinguishing?

Second, what will be the final fate of a star? Will it turn into dust and dissipate in the vast universe?
Before 1900, these questions were unanswerable.

To put it in professional terms: history has not yet developed to the stage where it can be resolved.

However, with the emergence of theories such as general relativity, quantum theory, and atomic structure.

There may be a breakthrough in the secrets of stars.

Obviously, everyone in later generations knows that a star goes through four stages from birth to death:

The first stage is the birth of stars, also known as the primordial nebula stage.

The huge amount of gas and dust floating around in the universe is gathered together due to the force of gravity.

As the mass gathered grew, the gravitational pull grew stronger, causing the temperature and pressure inside the nebula to begin to rise.

Then it enters the second stage: the mature main sequence star stage (don’t worry about the concept of main sequence star, just understand it as a mature body).

The huge pressure and extremely high temperature inside the nebula make nuclear fusion possible.

The first nuclear fusion to occur is the transformation of hydrogen atoms into helium atoms.

The huge energy generated by nuclear fusion increases the pressure inside the nebula, thereby offsetting the collapse effect of its own gravity.

When the two reach a state of mutual equilibrium, a stable star is officially born and formed.

This is where the energy of stars comes from: nuclear fusion.

However, no matter how big a star is, its mass has a limit.

One day, all the hydrogen atoms in its body will be consumed and turned into helium.

At this point, hydrogen fusion can no longer be sustained.

The evolution of stars has also reached the third stage: the red giant stage.

At this stage, although the hydrogen atoms are gone, fusion is still occurring.

When the temperature reaches 1 million degrees, the helium nuclei undergo complex changes and fuse into oxygen nuclei. This step is called helium combustion.

As the temperature continues to rise, fusion continues to occur.

Elements with low atomic numbers gradually fuse into elements with high atomic numbers.

Until the ultimate limit: iron.

Nuclear fusion inside all stars stops after iron is produced.

Because iron fusion is a special process, when two iron nuclei fuse, they no longer release energy but absorb energy instead.

This means that the temperature and pressure required for nuclear fusion can no longer be maintained.

Therefore, the formation of iron is a sign that a star is dying.

During this stage, the interior of the star continues to collapse due to gravity, but the outer layer of matter continues to expand and eject various substances.

The star continues to grow in size and eventually becomes a red giant.

At this time, if the original mass of the star is particularly large (tens to hundreds of times the mass of the sun) and exceeds a certain limit, a supernova explosion will occur.

This is one of the most terrifying celestial phenomena in the universe.

The luminosity produced by a supernova explosion is equal to the total luminosity of hundreds of billions of stars in the entire Milky Way.

The energy released in an instant is equivalent to the total energy released by the sun in 100 billion years.

That was the unwilling roar of a star before its death, sublimated to the utmost, sweeping away everything.

This is a true "natural disaster" that cannot be stopped by any means.

An old star with a short lifespan comes with a supernova. Are you afraid?

Finally, only a few dust particles remain where the stars are, which are blown away by the cosmic wind and dissipated forever between heaven and earth.

Of course, most stars in the universe have relatively small masses (several to dozens of times the mass of the sun) and do not experience supernova explosions.

They will have another ending.

This is the fourth stage of stellar evolution: the terminal evolutionary stage.

During this stage, stars generally become three types of celestial bodies.

They are: white dwarf, neutron star, and black hole.

Stars in the fourth stage can no longer undergo nuclear fusion and avoid gravitational collapse.

But its constituent atoms are not so easy to compress.

Because there are electrons inside atoms, and electrons are difficult to compress due to the Pauli exclusion principle.

This resistance is called electron degeneracy pressure.

So, when the star's own gravity and electron degeneracy pressure are balanced, a white dwarf is formed.

But there is an upper mass limit for white dwarfs.

When its mass exceeds 1.44 times the mass of the sun, the gravitational force it produces will be greater than the electron degeneracy pressure.

At this time, the atoms are crushed and the electrons are compressed together with the protons to form neutrons.

There is also neutron degeneracy pressure between neutrons, which makes it impossible for neutrons to be easily compressed.

When gravity and neutron degeneracy pressure balance, a so-called neutron star is formed.

Neutron stars are the densest celestial bodies discovered by humans so far, except for black holes.

A neutron star with a diameter of ten kilometers has a mass comparable to that of the sun. Each cubic centimeter of neutron star matter can weigh up to a billion tons, which is simply terrifying.

However, the evolution is not over yet.

Neutron stars also have an upper mass limit.

When the mass of a neutron star exceeds 2-3 times the mass of the sun, the gravity it generates will crush everything.

At this time, the star will become the ultimate celestial body in the universe: a black hole.

As for whether the black hole will evolve further, the current astronomical community does not know.

The above are the four stages in the evolution of stars.

The specific process is very complicated, and there are many special cases, but the core remains unchanged.

It can be seen that stellar evolution is closely related to the progress of research on atomic structure.

When physicists had not discovered protons and neutrons, it was impossible to understand the internal structure of stars.

The macro and the micro, the greatest celestial body and the smallest atom, are perfectly combined together through physics.

In real history, Rutherford proposed the element transmutation hypothesis and discovered the proton in 1919, and the secrets of the atomic nucleus began to emerge.

The ideas of nuclear fusion and nuclear fission began to emerge.

In 1920, Eddington first proposed that stars were powered by nuclear fusion, but he did not provide any proof.

It wasn't until 1929 that physicists theoretically calculated the possibility of hydrogen fusing into helium at high temperatures.

In 1931, Raman's nephew, Chandrasekhar, proposed an upper limit on the mass of white dwarfs based on the special theory of relativity, which is called the "Chandrasekhar limit".

In 1932, Chadwick discovered the neutron under the guidance of Rutherford.

Immediately afterwards, in 1936, Oppenheimer proposed an upper limit on the mass of neutron stars, which was called the "Oppenheimer limit."

Li Qiwei had had an idea before.

That is to guide others to study nuclear fusion, while he himself led China to study nuclear fission.

This is very possible because nuclear fusion has important implications in astronomy.

Research on nuclear fusion started much earlier than research on nuclear fission.

Now, it seems that time has finally arrived.

But Li Qiwei's ideas are a little different from before.

As Eddington shared his research on the internal structure of stars, Ridgway asked several questions.

So this made the bigwigs present think that Professor Bruce was interested in stellar research.

After all, to theoretically analyze the composition and structure of stars, you don’t need to know any constellations, and it doesn’t even matter if you can’t use a telescope.

That's what theoretical physicists are like.

Eddington was very excited when he saw that Ridgway was interested in his research.

This made him feel flattered and like he was being picked by a big shot.

After the founding conference, Eddington, Dyson and others returned with Ridgway.

On the way, Eddington said happily:
"Professor Bruce, I never thought you would be interested in stellar research."

"I thought you were going to continue studying the expansion of the universe."

Li Qiwei casually spread his hands and said jokingly:

"Director Dyson knows that I still don't even know how to use a telescope well."

Several people laughed.

Eddington was at a loss whether to laugh or cry. Boss, you are too casual.

He even suspected that Professor Bruce's so-called research on astronomy might just be something he did in his spare time because he was tired of studying physics.

But Eddington had a strong premonition that even if Professor Bruce conducted casual research, he would publish results that would shock the astronomical world.

After all, that's Professor Bruce, and no one knows his limits.

While chatting with Hubble, he easily solved the problem of catalyst for artificial synthesis of ammonia.

He attended a biology conference and proposed concepts such as gene mutation and gene chain on the spot.

Nowadays, when studying astronomy, it is only natural to publish major results.

At this point, Eddington asked:

"Professor, what specific direction will you study?"

"I also want to make a reference, and I can ask you for advice if I encounter any problems in the future."

Dyson on the side was also very curious.

He absolutely agreed with Li Qiwei's research on astronomy.

The Quantum Research Institute is so close to the Greenwich Observatory, so if Professor Bruce makes any achievements, he will definitely be the one who benefits the most.

Dyson even thought about sending all the people in the observatory to study with Professor Bruce in the future.

In this way, the strength of the Greenwich Observatory will definitely be greatly enhanced.

As for astronomy and physics, they are different disciplines.

Dyson said: "Does it make any difference to Professor Bruce?"

In response to Eddington's question, Li Qiwei smiled slightly.

"I'll probably study the energy problems of stars."

“I think this question is very interesting.”

“Why does the sun burn so long?”

“Where does its energy come from?”

"If we humans master this power, we won't have to worry about energy in the future."

"Also, are there any differences between the various celestial bodies in the universe?"

“For example, why do black holes and stars have different properties?”

"and many more."

"Just treat it as a pastime in your spare time."

"Maybe I'll have to ask you for advice often in the future."

Wow!
Li Qiwei's words immediately made Dyson, Eddington and others stand in awe.

They study astronomy for their own fame and fortune, for their dreams, or for work.

But look at Professor Bruce.

Even when studying astronomy, all I was thinking about was the fate of mankind.

This is the mind of a big boss.

As expected, people are more irritating than others.

Everyone had the utmost respect for Li Qiwei.

"How can there be such a perfect scientist in the world!"

However, Eddington suddenly felt a pain in his chest, as if he had lost something most precious.

He muttered to himself: "It seems that I can't stay up late often recently. I need to pay attention to rest."

Unfortunately, Eddington did not have the opportunity to talk to Professor Lorentz, otherwise the two might have discovered some clues.

Just when Ridgwell made a high-profile appearance in the field of astronomy and proposed the great debate of the century, causing a sensation.

On the other hand, his close friend Rutherford was about to make his voice heard in the atomic field in an equally high-profile manner.

Rutherford and Ridgway are known as the two geniuses who came out of the Cavendish Laboratory.

But in the spotlight of Ridgway, many people have forgotten Rutherford's amazing talent.

The big guy who won the Nobel Prize in Chemistry by accident for his physics achievements has been silent for too long.

This time, he will shine his own light to the fullest.

(End of this chapter)