Chapter 254 The problem of Mercury’s perihelion precession! Space warps?
When Li Qiwei said that Hubble's explanation was wrong, most of the people in the auditorium were shocked.
Many people are talking about it, thinking that Li Qiwei is trying to cheat.
Hubble used the characteristics of space to explain the essence of various inverse square laws.
In the eyes of all students, this is a very high-level thinking.
The perspective is different from ordinary people.
"Professor Bruce, I guess you're in trouble now. Look at the big guys in front of you who are confused. They obviously agree with Hubble's explanation."
"I don't think it's a good idea anyway. What's wrong? There's no need for calculations."
"However, I always feel that things are not that simple. Although Hubble's idea is exquisite, it is a flash of inspiration."
"Think about it carefully. If I gave you a little hint, would you be able to come up with this explanation?"
Many people thought silently.
At this moment, the big guys in the front row, such as Michelson, are also thinking about Li Qiwei’s words.
Hubble's theory has absolutely no problems from a mathematical perspective.
If you think of it as a purely mathematical problem, there is no gravity or electrostatic force.
Then it becomes a simple calculus problem.
Far less complicated than Bertrand's theorem.
However, Bruce never talks nonsense. Since he said something wrong, it means there must be something wrong.
Some of the big guys can’t figure it out either.
Li Qiwei smiled and looked at everyone's expressions and reactions. It was obvious that everyone was manipulated by him.
“Before I say what’s wrong with Hubble’s explanation, I would like to ask another question.”
"Professor Michelson just talked about Bertrand's theorem's explanation of the inverse square ratio."
"Although this theorem strictly proves that gravity must conform to the square law mathematically."
"However, I need everyone to remember one thing."
"Physics and mathematics are never the same thing!"
"Mathematics cannot replace physics."
“Mathematics is always just a tool for physicists, not a goal.”
“Even if a physical theory is rigorously proven mathematically, it does not mean that it is definitely correct.”
“Because physics is a science that studies the true existence of all things in the universe.”
“It must conform to the physical phenomena we observe in practice.”
“Newton’s light particle theory has a very mathematical form Ingenious, but it turned out to be wrong.”
Buzz!
Li Qiwei’s words shocked everyone present.
It turns out that physical theory must not only satisfy mathematical forms, it must also conform to objective laws.
Otherwise it is just a beautiful toy, fun but not practical.
“I don’t know if everyone listened carefully to Professor Michelson’s explanation at that time.”
"Bertrand's theorem has a premise, that is, the orbit of the planet must be closed."
"What does this mean?"
At this time, Ridgway began to draw a picture on the blackboard.
“Assume that Mars moves around the sun, regardless of whether its orbit is circular or elliptical.”
“After a cycle, Mars will return to its original position and then move again The next cycle starts over again.”
"This is a closed orbit."
"For this case, Bertrand's theorem is valid."
"Once Mars' orbit deflects slightly, it will soon return to the original orbit without flying out."
"This is the inverse square law of gravity at work."
"However, there is a counterexample in reality."
"In 1859, French astronomer Le Verrier discovered after calculation based on the law of universal gravitation that there is a planet in the solar system that is not in a closed orbit."
"It is the planet closest to the sun: Mercury."
< br>“Mercury’s perihelion has been precessing, and it is not a perfectly closed orbit.”
“What does this sentence mean?”
“Mercury’s orbit around the sun is a Ellipse.”
"The so-called perihelion is the position of Mercury's closest point to the sun in its orbit."
"And what does precession mean?"
"In addition to orbiting the sun, Mercury also It is also rotating. "
"The rotating axis of Mercury will also rotate after being pulled by the sun's gravity."
"And the direction of rotation is the same as the direction of rotation. This situation is precession.”
"A simple understanding is that an object moves forward while moving."
"So its orbit is not closed."
"Le Verrier used the law of universal gravitation to calculate, and he predicted 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 is different from the actual value. 43.10 arc seconds.”
"Scientists at the time speculated that this might be affected by another planet next to Mercury and named it Vulcan."
"But people did not discover 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."
"However, This is not 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.)< br>
Wow!
Li Qiwei’s words instantly stunned the students.
It’s almost like listening to the Book of Heaven.
When did classical mechanics become so complicated?
Shouldn’t it just be balls, sliders and pulleys?
This is all what and what.
What is a closed orbit and what is perihelion precession.
Is this still the gravity in the textbook?
God, how much the content we learned has been streamlined.
At the same time, everyone realized that there are still celestial problems that cannot be solved by gravity.
Isn’t it said that humans have conquered the universe?
“Oh my god, the law of universal gravitation is really flawed and not a perfect physical theory.”
“Today’s lecture simply refreshed my outlook. I no longer believe in the textbooks. ”
"No wonder they say you need a good teacher. If Professor Bruce were my physics teacher, I can't imagine how strong I would be."
"It's over, it's over, then Hubble will definitely It's wrong."
"."
Countless students wailed, and they found that they could not defeat Li Qiwei no matter what.
The other party's knowledge seems to be endless, and it is several levels ahead of them.
Michelson and the other bosses in the front row gave a wry smile.
The problem of Mercury's perihelion precession has always been a serious problem that has troubled classical physicists.
Many big guys tried to explain it, and some even used electromagnetic theory, but all failed.
Until now, it remains an open question.
Many physicists simply adopt an ostrich mentality and think that it may be an error caused by unknown reasons.
For example, the structure of Mercury itself has changed, what activities have occurred inside the sun, etc.
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 flaw that cannot be solved by the law of universal gravitation, which at least shows that it is not perfect.
At this time, Ridgway 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 of the law of universal gravitation is not accurate enough."
"At least it cannot explain all celestial problems."
"Since even the law of universal gravitation itself There are problems, so Hubble’s law-based reasoning 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-like gravitational sources or point charges."
"In addition, there is the most important question."
Li Qiwei looked at Hubble with a smile and said:
"Hubble, your theory has an assumption, that is, space is unidirectional. Homogeneous and uniform. "
"In other words, you think space is straight."
"But is it possible that space is curved, non-uniform, and anisotropic? What about?”
boom!
At this moment, not only the students present, but also physicists such as Michelson were shocked.
What a joke!
Is space curved?
Even anisotropic?
If we talk about the discontinuity of quantum theory, it took a long time for classical physicists to reluctantly accept it.
Then space is curved, and it will not be accepted by people anyway.
Space is a place of nothingness. How can it be curved?
This situation cannot even be imagined.
Can anyone imagine what a curved space looks like?
At this time, Hubble stood up, obviously shocked by Li Qiwei's wild imagination.
He thought that the theory he proposed was very exciting and bold.
But compared with Professor Bruce, there is simply no comparison.
One is a child's painting, and the other is Van Gogh's essay.
At this moment, he discovered the gap between himself and the world's top physicists.
The other party is suspicious of everything in this world.
Even time and space are no exception.
"Professor Bruce, your views really amaze me."
"I admit the first half of your point. My theory is indeed more like a mathematical game than a physical essence."< br>
“But space is curved, even anisotropic, which feels a bit fantasy.”
As soon as Hubble finished speaking, even Millikan also spoke: "Bruce, you have not made any breakthrough in general relativity."
Ridgway smiled slightly, looking very enigmatic, and said: "It's just that There have been some small breakthroughs recently.”
“Do you know why I raise the question of the law of gravity?”
“Because the flaw of special relativity is that it is incompatible with gravity.”
< br>“There is no absolute inertial reference system in this world.”
“So I have been trying to incorporate gravity into the theory of relativity.”
“There happened to be some breakthroughs recently.”
“My general theory of relativity can not only perfectly explain the precession of Mercury, It can also explain Hubble's theory."
"But there are still some small problems that need to be solved for the time being."
"It will be some time before it is officially published."
boom!
It seemed as if there was an explosion in the venue.
Everyone was stunned for a moment.
Although Li Qiwei had announced at the first Bruce Conference that the general theory of relativity would be published sooner or later.
But no one knows to what extent.
Moreover, everyone is still confused about what problems general relativity can solve.
However, today, Li Qiwei finally revealed something.
General relativity can solve the defect of universal gravitation and explain the precession of Mercury's perihelion.
This is a problem that has troubled countless physicists for decades.
Planck, Thomson and other big guys have studied it and have no clue.
Can Bruce’s general theory of relativity solve it?
“Oh my God, I didn’t expect that I could hear Professor Bruce talk about general relativity in person. I can’t even understand special relativity.”
“Relative space and time are too difficult to understand. I really don’t know how long Professor Bruce’s brain is.”
“I really look forward to the day when the general theory of relativity comes out.”
Li Qiwei looked at the shocked expressions in his heart. satisfy.
This era is because of his arrival.
General relativity will be more sensational than the original space and time.
The number one event in physics now is Bruce’s publication of the general theory of relativity.
Countless people are waiting.
If you dare to try other aspects of modern physics, you may be able to discover some remarkable achievements.
But for the general theory of relativity, everyone gave up directly after coming into contact with the special theory of relativity.
That is simply not human physics.
Even the special theory of relativity is already so obscure and difficult to understand. People present could not imagine how difficult the general theory of relativity would be.
Many people ask in their mind: My physics is A+, how can I not even understand the paper?
In real history, after Einstein published the general theory of relativity, physicists used this theory to perfectly explain the problem of Mercury's perihelion precession.
According to the theory of general relativity, gravitational waves will be generated when the speed of a mass object changes in the gravitational field.
Gravitational waves, like electromagnetic radiation, will take away orbital energy.
The orbit of the planet will gradually decay over time, and finally fall into the center of the gravitational source.
Of course, physicists at the time explained it through the curvature of space and time.
Gravitational waves are a bit too advanced.
However, Li Qiwei cannot make all this public yet.
I saw him saying pretentiously: "Classical physics is far more complicated than you think."
"We have too many problems that have not been solved."
"Although I listed several classic legacy problems at the first blues conference."
"But that does not mean that they are all the problems."
"Maybe after a while, some genius will discover a new problem."
"Physics advances and develops in constant doubt."
"Never be superstitious about authority. Ask yourself more about those concepts that you are accustomed to, why must they be like this? "
"Of course, don't be superstitious about me, maybe I will be wrong one day."
"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.
Erudacious, profound, confident, and persuasive.
At this moment, because of Li Qiwei alone, the people present changed their views on all Chinese.
This is the respect that strength brings.
But the speech had just begun, and the shock was far more than that.
(End of this chapter)