1900: A physics genius wandering around Europe

Chapter 498 The Second Fate of Stars! The Mass Limit of White Dwarfs! Neutron Stars! Shocking!

Li Qiwei's theory of stellar evolution deeply shocked everyone present.

Using the theories of atomics and quantum theory, we can actually solve the long-standing mysteries in astronomy.

This is another wonderful guidance from physics to astronomy.

It’s just like how quantum theory perfectly explained the periodic table.

Many astronomy experts sighed silently in their hearts:
“I’m afraid that students majoring in astronomy in the future will have to spend half of their time studying physics.”

"The idea of ​​doing astronomy by observation alone is outdated."

Eddington, Hubble, Yu Qingsong and others all looked at Li Qiwei with great admiration.

Their hearts were truly shocked.

Newton unified heaven and earth with a pen.

The sky is the sun, the stars.

And now, Professor Bruce uses another pen to describe the essence of the sky for everyone.

The charm of physics once again conquered everyone.

At this moment, when Li Qiwei said that stars have a second fate, the venue was boiling.

The concepts of red giants and white dwarfs are already shocking.

There are even many veteran astronomers who have linked white dwarfs to certain celestial bodies discovered previously.

"It seems we have discovered a white dwarf."

In real history, as early as 1844, German astronomers discovered that Sirius had a very dim companion star.

It was later proved that the companion star was actually a white dwarf.

The discovery of unknown celestial bodies and phenomena is very normal in the field of astronomy.

There are many records of astronomical phenomena in ancient times, both in the East and the West.

It was not until later generations, when various astronomical theories had truly matured, that a reasonable explanation for these phenomena could be given.

So, Ridgway was the first person to propose the concept of "white dwarf", but not the first to discover it.

He was only responsible for providing theories, and of course all the dirty work was left to astronomers.

This is what a theoretical physicist should be like!

And now, everyone wants to know what the evolutionary outcome of stars will be.

Amid everyone's expectations, Li Qiwei continued:
"I just said that when a star's hydrogen is exhausted and nuclear fusion stops, it will die."

"It ejects a lot of its outer layers, leaving only the core of the white dwarf."

"The reason why a white dwarf can exist stably is because its own gravity and electron degeneracy pressure are balanced."

"So, now the question is, what if the balance is broken?"

Wow!
Everyone was shocked again!
They didn't understand what Professor Bruce meant.

If the balance is broken, it means that the white dwarf will collapse directly and turn into a dust nebula.

Is there any other ending?

Many people are puzzled.

However, Eddington had an epiphany.

He suddenly connected everything.

“Yes, it must be quality!”

"In Professor Bruce's theory of stellar evolution, the gravity of stars has always played a key role."

"And the gravitational pull of a star depends only on its mass."

"And this ties in with what I said earlier about how massive stars are rare."

"My God!"

"I seem to understand Professor Bruce's way of thinking!"

At this moment, no words could describe the shock in Eddington's heart.

It was like he was picking up shells on the beach and saw someone in front of him. When he looked up, it turned out to be Newton.

And the two of them were holding shells of the same color.

Walk with God!

In the face of everyone's surprise, Li Qiwei revealed the answer:

"According to my theoretical calculations, there is a mass limit for white dwarfs."

"When its mass exceeds 1.44 times the mass of the Sun."

"The strong gravitational force will exceed the electron degeneracy pressure and crush the atoms."

"At this point, the white dwarf will become a completely new type of celestial body!"

Wow!
The whole audience was shocked!

What kind of horrible celestial body was that? Even the atoms that made it up were crushed.

Does it really exist in the universe?

People couldn't even imagine the scene of atoms being crushed.

Some people couldn't believe it and exclaimed:

"Professor Bruce, if even atoms do not exist, what are celestial bodies made of?"

Everyone nodded. This was the question everyone wanted to ask.

Astronomers have proven that the elements on Earth are the same as those in the universe.

So, if the earth is made up of atoms, then other celestial bodies must also be made up of atoms.

Li Qiwei smiled slightly and continued:

"According to the proton-neutron model, when a neutron undergoes beta decay, it becomes an electron and a proton."

"Similarly, in some cases the process can go the other way, with electrons and protons combining to form neutrons."

"So, when the white dwarf exceeds the mass limit and the atoms are crushed, the electrons no longer obey the exclusion principle."

"All the electrons were pressed into the nucleus by the strong gravitational force and formed neutrons with the protons."

"That is to say, the celestial body at this moment is a strange celestial body composed purely of neutrons!"

"I call it a [neutron star]."

"According to calculations, the density of a neutron star will far exceed that of a white dwarf, reaching hundreds of millions of tons per cubic centimeter."

"But its diameter is only a few dozen kilometers, which is equivalent to a city on Earth."

boom!
As soon as the neutron star appeared, the whole place fell silent!

All the astronomers present were stunned with shock.

Because this terrifying celestial body has surpassed the current limits of astronomy's cognition.

According to what they learned, everything in the world is made up of atoms.

Even the stars in the universe are no exception.

No matter whether it is big or small, bright or dark, its constituent elements will certainly not change.

But now, Professor Bruce has shattered all of that.

A celestial body composed of neutrons?
What kind of existence is that?
A heated discussion suddenly broke out in the meeting hall.

"Oh my god! Neutron Star is such a powerful name!"

"With such a high density, wouldn't a spoonful of it be equivalent to the weight of the entire Alps?"

“It’s really scary!”

"How could such a compositional structure exist?"

"We have never found matter on Earth that is made up solely of neutrons."

"No, you are wrong. Even the existence of neutrons has not been confirmed yet!"

"This is another theory from Professor Bruce that is at the pinnacle of his thinking."

"He pushed stellar evolution to unimaginable levels."

Haier, Dyson and other bigwigs murmured to themselves:

"This is too exaggerated."

"Does it really exist?"

The neutron star theory deeply shocked traditional astronomy giants like them.

It seemed to have destroyed their three scientific views and brought the big guys into a completely new world of celestial matter.

At this moment, everyone didn't even know what attitude to have towards this speech.

Although they knew very well that Professor Bruce's stellar evolution model was only a pure theory, this theory contained the most cutting-edge physics such as atomics and quantum theory.

In this world, no one except Professor Bruce himself can combine astronomy and physics so deeply.

Therefore, all the bigwigs present regarded the theory of stellar evolution as a treasure.

Even if it is wrong, it is full of immeasurable value.

Besides, could Professor Bruce be wrong?
While everyone was shocked by the neutron star, Li Qiwei's speech had not yet ended.

"Now we can return to the question that Eddington just raised."

"He said that according to his observations and statistics, there are very few massive stars in the universe."

"This is because massive stars are inherently unstable."

"They could easily become white dwarfs or neutron stars."

"When a white dwarf reaches its mass limit of 1.44 times the mass of the sun, the mass of the star that gave birth to it is 8 times the mass of the sun."

"That is to say, any star in the universe with a mass greater than eight times that of the sun has a high probability of becoming a neutron star."

"That's why it's so hard to find these stars."

"Only low-mass stars are stable."

At this point, not many people even cared about Eddington's problem.

Even Eddington himself no longer cared.

He was stunned by the model of the neutron star.

It was beyond his imagination that a star could turn into such a terrifying celestial body in its later years.

Eddington also studied the direction of stars, but compared with Professor Bruce, he felt that his research was in vain.

“This is the astronomy I pursue!”

but!

Eddington's heart suddenly moved.

“Although Professor Bruce explained my problem, he still did not discuss the most critical issue.”

"Which general prophecy is he trying to prove?"

Then he shook his head gently again.

At this point, even though what Professor Bruce said next was unrelated to the general prophecy, everyone felt it was acceptable.

Because the current results alone are enough to shock them.

However, Li Qiwei will not be satisfied with this.

To everyone's shock, he continued:

"Just now I saw Professor Haier, Professor Dyson and others, they seemed to be shaking their heads."

"I'm afraid these big guys don't like the theories of us young people."

Li Qiwei's timely humorous words made everyone smile knowingly and their mood gradually calmed down.

"But my neutron star theory is more than just a conjecture."

“It also has its own evolution.”

"Everyone please look at the screen."

"For stars with masses greater than eight times that of our sun, their gravitational pull is very large."

"When the hydrogen and helium elements in the core area have been fused, nuclear fusion has not stopped."

"The strong pressure and temperature caused carbon, oxygen, silicon, sulfur and other elements to begin fusing until iron was produced."

"At this point, iron will no longer fuse because it is a very special element."

"When iron fuses, it doesn't emit heat, it absorbs heat."

"So, to make iron fuse, you need extreme conditions."

“And the evolution process is different from that of white dwarfs.”

"At this point the star will have expanded to become many times larger than a red giant."

"Therefore, I call this state a "red supergiant"."

"The biggest difference between red supergiants and red giants is that nuclear fusion is still taking place in the outer layers of the core region of the former."

"Although there is no hydrogen in the core of a red supergiant star, there is still a lot of hydrogen in its outer layer."

"Under its huge pressure, these hydrogen can still undergo nuclear fusion and be continuously attracted into the core area."

"So, at this moment, the core region of the red supergiant is like an onion."

"Nuclear fusion is happening on every layer of it."

"From the outer layer to the core, the numbers of the fusion elements are getting larger and larger: hydrogen, helium, carbon, oxygen, silicon iron."

Wow!
Everyone was amazed!

The evolution of neutron stars is completely different from that of white dwarfs.

To put it in a more vivid way, it is bigger.

From red giant to red supergiant, the mass of a star determines its fate!

In this case, Eddington's theory became crucial.

Because it can more conveniently and accurately measure the mass of stars.

No one expected that Professor Bruce's theory would also benefit Eddington.

But at this moment, Eddington's face was not excited, but full of confusion.

He couldn't help but ask:

"Professor Bruce, if iron cannot fuse, doesn't that mean the core is still in an atomic state, not a neutron state?"

"Then how can a neutron star be formed?"

Everyone was shocked!
Eddington's analysis makes sense.

At this point, Professor Bruce's theory of neutron star evolution seems to be contradictory.

Since iron has terminated nuclear fusion, how can it become a neutron star?

Li Qiwei smiled slightly and said:

"very good."

"It seems that Eddington likes my theory very much and can always keep up with my ideas."

"But I saw Hubble just looked confused, so I guess he didn't understand."

"This is the consequence of using a telescope every day and not having time to think quietly."

Everyone laughed again.

Hubble scratched his head awkwardly when he heard this; it was indeed difficult for him to listen to.

However, he is already very good.

Most people are worse off than him.

Ridgway's theoretical model was full of calculations and conjectures, which made these astronomers feel overwhelmed.

Their mathematical level is far behind that of physicists.

Therefore, when faced with such purely theoretical things, we can only have the will but not the ability to do anything about it.

After the joke, Li Qiwei became serious and wanted to answer Eddington's questions.

"That's right. At this moment, red supergiants cannot directly form neutron stars."

“It still needs one more crucial step.”

"That is to crush all the atoms in the core area."

"Since iron can no longer fuse under normal conditions, more and more iron will accumulate in the core area."

"The mass of iron is far greater than that of the various elements in the outer layer."

"The huge amount of iron in the core will produce a very strong gravitational force, which will begin to attract more outer matter to fall rapidly into the core."

"The kinetic energy of the outer material is converted into heat energy, and the gravitational pull becomes greater and stronger."

"The temperature and pressure in the core area have reached an unimaginable level, a limit value."

"Finally, under these extreme conditions, even iron has begun to initiate nuclear fusion."

Suddenly, Li Qiwei raised his voice with an excited tone, which startled everyone.

"And at this moment, the Red Supergiant will undergo an extremely terrifying transformation!"

"It is the most terrifying phenomenon in the universe!"

boom!
The whole audience was shocked!

(End of this chapter)