1900: A physics genius wandering around Europe

Chapter 254: Mercury perihelion precession problem! Space curvature?

When Ridgway said Hubble's interpretation was wrong, most people in the auditorium were shocked.

Many people were talking about it, thinking that Li Qiwei was trying to cheat.

Hubble used the characteristics of space to explain the nature of various inverse square laws.

In the eyes of all the students, this is a very lofty way of thinking.

The perspective is different from that of ordinary people.

"Professor Bruce, you are probably in trouble now. Look at the big guys in front of you. They are all confused and obviously agree with Hubble's explanation."

"I don't think there's anything wrong with it. There's no need to do any calculations, so how could there be any mistakes?"

"But I always felt that things would not be that simple. Hubble's idea was brilliant, but it was just a flash of inspiration."

"Think about it carefully. If I give you a hint, can you come up with this explanation?"

Many people thought silently.

At this moment, the big guys in the front row, such as Michelson, were also thinking about what Li Qiwei said.

From a mathematical perspective, there is absolutely no problem with Hubble's theory.

If you think of it as a purely mathematical problem, there is no such thing as gravity or electrostatic force.

Then it becomes a simple calculus problem.

It is far less complex than Bertrand's theorem.

However, Bruce never talks nonsense. Since he said something wrong, it means there must be something wrong.

Some bigwigs couldn’t figure it out either.

Li Qiwei smiled as he looked at everyone's expressions and reactions. It was obvious that everyone was under his control.

"Before I tell you what's wrong with Hubble's explanation, I want to raise another question."

"Professor Michelson just talked about Bertrand's theorem's explanation of the inverse square law."

"Although this theorem strictly proves mathematically that gravity must conform to the square law."

"But, I need everyone to remember one thing."

"Physics and mathematics are never the same thing!"

“Mathematics cannot replace physics.”

“Mathematics is always a tool for physicists, not their goal.”

“Even if a physical theory has been rigorously proven mathematically, it does not necessarily mean that it is correct.”

"Because physics is the science that studies the true existence of everything in the universe."

“It has to match the physics we observe in practice.”

"Newton's particle theory of light had a very elegant mathematical form, but it turned out to be wrong."

hum!
Li Qiwei's words shocked everyone present.

It turns out that physical theories not only have to satisfy mathematical forms, they also have to conform to objective laws.

Otherwise it is just a beautiful toy, fun but not practical.

"I don't know if anyone listened carefully to Professor Michelson's explanation at the time."

"Bertrand's theorem has a premise, that is, the orbit of the planet must be closed."

"What does it mean?"

At this time, Li Qiwei began to draw on the blackboard.

"Suppose Mars moves around the sun, whether its orbit is circular or elliptical."

"After a cycle, Mars will return to its original position and then start the next cycle, and the cycle will repeat itself."

“This is the closed track.”

"For this situation, Bertrand's theorem is valid."

"Once Mars' orbit is slightly deflected, it will quickly return to its original orbit and will not fly out."

"It's the inverse square law of gravity at work."

"However, a counterexample has emerged in reality."

"In 1859, French astronomer Le Verrier calculated based on the law of universal gravitation and discovered that there is a planet in the solar system that does not have a closed orbit."

"It is the planet closest to the sun: Mercury."

"Mercury's perihelion is always precessing; it's not a perfectly closed orbit."

"What does this mean?"

"Mercury's orbit around the sun is an ellipse."

"The so-called perihelion is the point in Mercury's orbit when it is closest to the sun."

"And what does precession mean?"

"In addition to orbiting the sun, Mercury also rotates on its own axis."

"Mercury, which is spinning, will also rotate on its axis after being pulled by the sun's gravity."

"And the direction of rotation is the same as the direction of rotation, which is called precession."

"To put it simply, an object moves forward as it moves."

"So its orbit is not closed."

"Using his law of universal gravitation, Le Verrier predicted that Mercury's precession should be 5557.63 arc seconds per century."

"However, the actual observed precession of Mercury is 5600.73 arc seconds per century."

"The theoretical value and the actual value differ by 43.10 arc seconds."

"Scientists at the time speculated that this might be the result of the influence of another planet next to Mercury, and named it Vulcan."

“But people didn’t find this planet.”

"Therefore, this problem cannot be explained by the law of universal gravitation."

"According to Bertrand's theorem, Mercury should return to its correct orbit after a small change in its orbit."

"But that's not actually the case. Mercury is always precessing."

"This is enough to prove that the inverse square law of gravity is wrong."

(Note: In fact, all planets in the solar system will precess, but Mercury's precession is the most obvious and can be observed.)
Wow!
Li Qiwei's words instantly stunned the students.

It's almost like listening to a foreign book.

When did classical mechanics become so complicated?

Shouldn't it just be a ball, a slider and a pulley?
What the hell is this?

What is a closed orbit and what is perihelion precession.

Is this still the gravity in the textbook?

My God, how much our learning has been streamlined.

At the same time, everyone realized that there are celestial problems that gravity cannot solve.

Didn’t they say that humans have conquered the universe?
"Oh my God, the law of universal gravitation actually has flaws and is not a perfect physical theory."

"Today's speech completely changed my worldview. I no longer believe in textbooks."

"No wonder they say you need to have a good teacher. If Professor Bruce were my physics teacher, I can't imagine how good I would be."

"It's over, it's over. Hubble must be wrong."

"."

Countless students wailed as they realized they could not defeat Li Qiwei.

The other party's knowledge seemed endless and several levels ahead of them.

Michelson and other big guys in the front row smiled bitterly.

The problem of Mercury's perihelion precession has always been a major concern for classical physicists.

Many experts have tried to explain it, some even used electromagnetic theory, but all have failed.

Until now, it remains an unresolved question.

Many physicists simply adopt an ostrich mentality, believing that it may be an error caused by unknown reasons.

For example, changes in the structure of Mercury itself, what activities are occurring inside the sun, and so on.

Because the error is too small.

In the face of the huge scale of cosmic astronomy, it seems insignificant. But no matter what, this is a defect that the law of universal gravitation cannot solve, which at least shows that it is not perfect.

At this time, Li Qiwei continued: "After talking about the problem of Bertrand's theorem, let's look at Hubble's theory."

"I think everyone should agree now that the inverse square law of gravity is not accurate enough."

"At least it can't explain all the celestial problems."

"Since the law of universal gravitation itself has problems, Hubble's reasoning based on the law is naturally wrong."

"Hubble's theory is more like a pure mathematical model than a physical model."

"In the real world, there are no point sources of gravity or point charges."

"Besides, there is one most important question."

Ridgeway smiled and looked at Hubble and said:

"Hubble, one of the assumptions of your theory is that space is isotropic and homogeneous."

"In other words, you think space is flat."

"But is it possible that space is curved, inhomogeneous, anisotropic?"

boom!
At this moment, not only the students present, but also physicists such as Michelson were shocked.

What a joke!
Is space curved?

Or even anisotropic?

The discontinuity of quantum theory took classical physicists a long time to accept.

Then the space is curved, which will not be accepted by people anyway.

Space is an empty place, how can it be curved?

This situation is impossible to even imagine.

Can anyone imagine what a curved space would be like?

At this time, Hubble stood up, obviously he was also shocked by Li Qiwei's wild imagination.

He thought his theory was brilliant and bold.

But compared with Professor Bruce, there is absolutely no comparison.

One is a child's drawing, and the other is an essay by Van Gogh.

At this moment, he realized the gap between himself and the world's top physicists.

The other party is skeptical about everything in this world.

Even time and space are no exception.

"Professor Bruce, your point of view really amazes me."

"I agree with your first half. My theory is more like a mathematical game than a physical essence."

"But space is curved and even anisotropic. This seems a bit far-fetched."

As soon as Hubble finished speaking, even Millikan spoke up: "Bruce, you haven't made any breakthroughs in general relativity, have you?"

Li Qiwei smiled slightly, looking very mysterious, and said: "It's just that there have been some small breakthroughs recently."

"Do you know why I brought up the question of the law of universal gravitation?"

"Because the flaw of special relativity is that it is incompatible with gravity."

"There is no absolute inertial reference frame in this world."

"So I've been trying to incorporate gravity into relativity."

"There happened to be some breakthroughs recently."

"My general theory of relativity can perfectly explain not only the precession of Mercury, but also Hubble's theory."

"But for the time being it still has a little problem to be solved."

“It will take some time before it is officially released.”

boom!
It was as if an explosion had occurred in the venue.

Everyone was stunned with shock.

Although Ridgway had announced at the first Bruce Conference that general relativity would be published sooner or later.

But to what extent no one knows.

Moreover, everyone is confused about what problems general relativity can solve.

However, today, Li Qiwei finally revealed some secrets.

General relativity can solve the defects of universal gravitation and explain the precession of Mercury's perihelion.

This is a question that has troubled countless physicists for decades.

Planck, Thomson and other great men have studied it but have no clue.

Could Bruce's general theory of relativity solve the problem?

"Oh my God, I didn't expect that I could hear Professor Bruce talk about the general theory of relativity in person. I can't even understand the special theory of relativity."

"Relative space and time is too difficult to understand. I really don't know what's wrong with Professor Bruce's brain."

“I’m really looking forward to the day when general relativity comes out.”

Li Qiwei looked at the shocked expressions of the crowd and felt very satisfied.

This era, because of his arrival.

General relativity will be even more sensational than the original space-time.

The biggest thing in physics right now is Bruce's publication of the theory of general relativity.

Countless people are waiting.

You can still dare to try other aspects of modern physics, and perhaps you will discover some remarkable achievements.

But as for the general theory of relativity, everyone gave up on it right after they came into contact with the special theory of relativity.

That's simply not the physics that humans learn.

Even the special theory of relativity is so obscure and difficult to understand. The people present couldn't imagine how difficult the general theory of relativity would be.

Many people asked themselves: I got A+ in every physics subject, I can’t be unable to understand the paper.

In real history, after Einstein published the theory of general relativity, physicists used this theory to perfectly explain the precession of Mercury's perihelion.

According to the theory of general relativity, when the speed of a massive object changes in a gravitational field, gravitational waves are generated.

Gravitational waves, like electromagnetic radiation, carry away orbital energy.

The planet's orbit will gradually decay over time, eventually falling into the gravity source at the center.

Of course, physicists at the time explained it through the curvature of space-time.

The gravitational wave thing is a bit too advanced.

However, Li Qiwei cannot make all this public for the time being.

He just said pretentiously: "Classical physics is far more complicated than you think."

“We have too many unresolved issues.”

“Although I listed several classic legacy issues at the first blues conference.”

“But that doesn’t mean that’s the whole problem.”

“Maybe after a while, some genius will discover a new problem.”

“Physics advances and develops in constant doubt.”

“Never blindly trust authority. Ask yourself more about concepts that you take for granted: Why must they be this way?”

"Of course, don't trust me. I might be wrong someday."

"But I don't think that day will come."

Everyone laughed, impressed by Li Qiwei's humor and confidence.

Everyone felt Li Qiwei's personal charm.

Knowledgeable, profound, confident, and patient.

At this moment, everyone present changed their views on all Chinese people because of Li Qiwei.

This is the respect that comes with strength.

However, the speech had just begun and the shock went far beyond that.

(End of this chapter)