Chapter 214 The brilliance and dark clouds of classical physics
On July 15, 1909, Gregory and others finally completed the compilation of all the data.
Li Qiwei began a three-day retreat.
He wants to try to connect classical physics and modern physics in a clear line.
The original manuscript cannot be seen by the world, and his speech in October will only be excerpted from it.
Because his manuscript will contain all major physics events in the next twenty or thirty years.
Any one of them is a Nobel Prize-level achievement.
What an ordinary physicist wants in his life may be just an insignificant paragraph in a manuscript.
In a fantasy world, this is the supreme artifact, the Book of Truth.
Looking at the well-organized papers and author research contents compiled by several doctoral students in front of him, Li Qiwei felt emotional.
He finally made it this far.
From a supreme perspective, sort out the history of physics and open up new directions and paths for future generations.
This should be regarded as carrying on the unique knowledge for the saints and creating peace for all generations!
Although at this point in time, there are still many theories and phenomena that have not yet been discovered in physics.
But decades later, Li Qiwei will definitely do something similar again with a noble status.
The history of physics is different from the traditional history of civilization. Without sufficient knowledge of physics, you will definitely not be able to write a logical and self-consistent story.
He put aside his distracting thoughts and began to write.
The 19th century was the most glorious period of classical physics.
Classical physics consists of three major theories, namely: Newtonian mechanics theory, Maxwell's electromagnetic theory, thermodynamics and statistical mechanics theory.
The three major theories govern physical phenomena such as force, light, electricity, magnetism, and heat. They echo and complement each other and can explain the laws of how everything in the world operates.
As for other sound, wave and other phenomena, they are just combinations and extensions of these three theories.
Every theory has its core and landmark moments.
The core of Newton's mechanical theory is Newton's three laws and the law of universal gravitation.
In 1846, physicists successfully predicted the existence of Neptune and found it through the law of universal gravitation.
Neptune is also known as the "Planet on the Tip of the Pen."
This is the most glorious moment of Newtonian mechanics.
Human beings can calculate such great existences as celestial bodies with just a pen, and defeat nature with their weak body.
Newtonian mechanics has since been put on the altar, it is authoritative, sacred and true.
The French physicist Laplace was even more bold. He imagined a Laplace beast.
It can obtain the motion state of all matter in the universe and know the interaction between matter.
Then according to the calculations of Newtonian mechanics, Laprasmon can know the past, present and future of the entire universe.
This view of the universe of absoluteness, continuity, and causality is the philosophical view of Newtonian mechanics.
This idea rules everyone.
Physicists who grew up under this kind of thinking are called classical physicists.
Including Lorentz, Planck, and even Einstein.
This is why Lorenz was only one step away from the theory of relativity, but never dared to take the step forward, because the theory of relativity violated absoluteness.
Why did Planck open the door to quantum theory, but did not dare to go any further? Because quantum theory violates continuity.
Einstein was unwilling to admit the probabilistic interpretation of quantum mechanics until his death, because the probabilistic interpretation violated causality.
As a great figure born in the era of transition between old physics and new physics, Einstein has a kind of contradictory beauty in him.
Despite the opposition of countless people, he insisted on the theory of relativity, but believed that quantum mechanics was wrong.
Of course, these are things for later.
After Newtonian mechanics, there is Maxwellian electromagnetism.
The core of it is Maxwell's equations, and the highlight is the discovery of electromagnetic waves.
The two phenomena of electricity and magnetism have actually been studied by many people long before Newton.
Because they are so common, lightning and magnets exist in nature, and it is difficult not to notice them both.
But it wasn't until the early 19th century that physicists discovered the relationship between the two.
In 1819, Danish physicist Oersted discovered that a compass placed next to a current-carrying wire deflected.
Then, the French physicist Ampère went a step further. He discovered that two current-carrying wires with different current directions can produce an attraction between them.
If the current directions are the same, repulsive force will occur.
This shows that the energized wire actually produces a magnetic field, the so-called electromagnetic phenomenon.
Later, the British physicist Faraday came up with a reverse thinking. Since electricity can generate magnetism, can magnetic energy generate electricity?
He did an experiment, placed a magnet in a spiral coil, and made the magnet move up and down. As expected, an electric current was generated in the coil.
This is the phenomenon of electromagnetic induction.
As a result, physicists began to think about why electricity and magnetism, two seemingly completely unrelated phenomena, have such connections and effects.
Until Maxwell came out and published Maxwell's equations, unifying electricity and magnetism.
He proved that electricity and magnetism are just different manifestations of the phenomenon of electromagnetism.
Furthermore, Maxwell's equations predicted the existence of electromagnetic waves and calculated that its speed was c, which was the same as the speed of light measured at that time.
So, Maxwell believed that light is an electromagnetic wave.
Eight years later, the German physicist Hertz actually discovered electromagnetic waves in the laboratory, and measured its speed and found that the results were the same as those calculated by the equation.
At this point, Maxwell has completely become a god, and the electromagnetic theory is perfect, just like Newtonian mechanics.
The last thermodynamics and statistical mechanics, the reason why they are not named before is because their birth is the result of the joint efforts of many physicists.
Unlike Newton and Maxwell, who created a theory completely by themselves.
The core of thermodynamics and statistical mechanics are three laws.
In fact, before 1900, the three laws of thermodynamics had already been established.
Although the third law was only published by Nernst in 1906, that was only the final confirmation process.
The first law of thermodynamics is the law of conservation of energy, proposed by Joule in 1850, and its core parameter is internal energy.
Today all physicists agree that this law is correct.
The first law also proves that the first type of perpetual motion machine (a machine that can continuously do work automatically without consuming any energy) is impossible to exist.
The second law of thermodynamics is the principle of entropy increase.
With the efforts of Clausius, Lord Kelvin, Maxwell, Boltzmann and other big guys, it was perfected.
Clausius was the first to propose the concept of "entropy", and Maxwell was the first to use statistics to describe macroscopic gases.
At that time, the existence of atoms had not yet been proven. Maxwell assumed the existence of atoms, and then used statistics to explain the pressure and temperature of gases.
The boss is really awesome, he is awesome in any field.
Thermodynamics was just something Maxwell enjoyed when he was bored.
Lord Kelvin put forward the standard statement of the second law: it is impossible to absorb heat from a single heat source and turn it completely into useful work without producing other effects.
This law also completely denies the existence of the second type of perpetual motion machine.
Later, Boltzmann inherited Maxwell's ideas, and he linked entropy to the disordered state of the system.
From the perspective of statistical mechanics, the second law of thermodynamics is redefined in terms of probability.
This is why thermodynamics and statistical mechanics are often taught together.
This idea of statistical mechanics also provided inspiration for Einstein later.
Next, Nernst discovered the third law of thermodynamics, completely completing the theory of thermodynamics.
At this point, the three major theories of classical physics are all completed, shining and sacred, ruling the material world.
Any phenomenon in nature can be explained by these three theories.
As big as the movement of celestial bodies, as small as an apple falling to the ground; as fast as electromagnetic waves, as slow as mechanical waves; as hot as the power of the sun, as cold as the power of extreme cold.
The three major theories are unbreakable, like gods, dominating the world.
Therefore, physicists are inflated and think that physics is perfect and there is nothing left to study.
This was the background of Lord Kelvin’s report in April 1900.
He believes that there are only two dark clouds in physics at present.
However, there were actually a few small dark clouds in more distant places, but the physicists at the time did not pay attention to them.
If we say that classical physics is full of great people, the great masters compete on the same stage.
Then in modern physics, genius is like a meteor passing by, extremely bright.
Writing this, Li Qiwei smiled slightly. Next, modern physics with various subversive phenomena appeared.
The first dark cloud is related to Maxwell's electromagnetism, which is the Michelson-Morley experiment. This experiment found that the ether does not exist and the speed of light remains unchanged.
This led to the special theory of relativity published by Ridgway and Einstein.
Next, the general theory of relativity will shock the world. Of course, Li Qiwei is not ready yet.
The second dark cloud is related to thermodynamics, that is, the energy equipartition theorem encounters problems in blackbody radiation.
This led to the quantum theory published by Ridgway and Planck.
In the future, Bohr will apply quantum concepts to atomic structures and propose quantized orbits.
This will be the culmination of old quantum theory.
In real history, Planck, Einstein, and Bohr were the three giants of the old quantum theory.
However, now, the Big Three will become Planck, Li Qiwei, and Bohr.
But even then, quantum theory still has not transformed into quantum mechanics.
It was not until Heisenberg proposed matrix mechanics that quantum mechanics truly became a theory, which was continuously improved thereafter.
The story that happened in the middle involves many physicists.
Li Qiwei slowly recorded it in chronological order.
In addition to the two dark clouds above, there are also several small dark clouds.
The first little dark cloud is the photoelectric effect, which has been solved by the light quantum proposed by Li Qiwei.
In real history, it was solved by Einstein, which is why he is called one of the three giants of old quantum theory.
Because the concept of light quantum is to treat light as individual quanta.
Although Millikan had confirmed the correctness of the theory, many physicists still did not believe that light could be quantum.
Because they can't imagine this picture.
The second little dark cloud is the problem of the spectrum of elements, that is, spectroscopy.
It is a discipline that studies the interaction between electromagnetic waves and matter.
Hundreds of years ago, Newton had used a prism to decompose sunlight and discovered the sun's simple spectrum.
Later, physicists used more advanced optical instruments such as gratings to analyze the wavelength distribution of a beam of electromagnetic waves.
This image of electromagnetic waves of various wavelengths arranged on the panel is the so-called spectrum.
In the 19th century, Germany was the center of optical research, and the issue of blackbody radiation was first raised and studied in Germany.
Around 1850, German physicist Kirchhoff discovered the radiation spectrum of elements.
At that time, people did not know whether atoms existed.
What the so-called chemist can do is to measure the weight change before and after the reaction, or to burn the elements on the fire.
Hey, don’t tell me, this burning will produce a major result.
Chemists have discovered that each element has its own specific color when burned by fire.
For example, potassium is purple, sodium is yellow, and calcium is red.
Later generations know that these are flame reactions, caused by electronic transitions.
But scientists at the time didn't know that.
Later, when Kirchhoff learned about this phenomenon, he was very interested.
He built a spectrometer to analyze the spectra emitted by these elements when they were burned.
He discovered that the emission spectra of elements were separated lines, like barcodes, rather than a continuous spectrum.
Then he conducted experiments and recorded the radiation spectra of all elements known at that time.
In the future, if you get a lump of unknown substance, you just need to put it on a fire and analyze its spectrum to know the constituent elements of the substance.
Later, Kirchhoff claimed that he knew the composition of the sun.
This immediately caused an uproar in the scientific community and was extremely shocking.
Everyone found it incredible, but when they understood Kirchhoff's theory, they found that they seemed to know the composition of the sun.
Because we only need to analyze the emission spectrum of the sun.
But after the excitement wore off, physicists had questions.
How is the emission spectrum of elements formed?
Why are these spectra separate lines and not continuous?
Why is the emission spectrum of each element different?
In real history, these problems will be solved by Bohr in the future.
The third little dark cloud is the arrangement of the periodic table of elements.
Although the great god Mendeleev created the periodic table of elements that shocked the world, he arranged various elements according to their atomic weight.
For example, the atomic weight of the hydrogen element is the smallest, which is set to 1.
Other elements are compared with it in order of weight, and different atomic weights are ranked in different positions.
However, as Rutherford discovered the nature of radioactive phenomena.
People have discovered many new elements. These elements have exactly the same chemical properties as some elements, but their atomic weights are different.
So where should these new elements be placed in the elemental cycle?
In real history, this problem was solved perfectly after Soddy proposed the concept of isotopes.
Almost all of Soddy's results were based on Rutherford's experiments.
It can be seen how humble chemists are compared to physicists in this era.
In the eyes of the world, chemists are alchemists and have no theory at all.
Physicists casually miss some points, which is enough for chemists to digest for a while.
It is no wonder that the essence of chemistry is physics.
As for the fourth little dark cloud, Li Qiwei put the "field" up.
Electric fields, magnetic fields, etc. Physicists at this time were not unfamiliar with the concept of fields at all.
Use it to solve problems easily.
However, the scene is invisible and intangible, but it is real, like a ghost.
No one knows what the nature of the field is.
Later, Dirac combined fields with quantum mechanics and created quantum field theory, which deeply influenced later generations of physics.
Li Qiwei stopped writing when he wrote this.
He finally sorted out the most important problems encountered in classical physics.
Next, there are more problems discovered by experimental physicists.
For example, Roentgen's X-rays, Marie Curie's radioactivity, Thomson's atomic structure research, etc.
These are all contents of modern physics.
This was also the main research content of physicists from 1900 to 1909.
Coupled with the theory of relativity and quantum theory, the old and new physics are clearly distinct.
These new theories and phenomena can truly open the door to physics and allow mankind to have a glimpse of the truth.
The classical physics building that once made all physicists proud has begun to falter.
The new building has just laid its foundation and has not yet shown its bright side.
This is the best of times. The old gods have fallen and the new gods have not yet returned.
This is also the worst of times. The development of physics has gradually surpassed human imagination, and the nature of the world has even become blurred.
Even the true God is sometimes blinded.
Li Qiwei suddenly became very passionate.
As the co-founder of the theory of relativity and quantum mechanics, he naturally knows how exciting the future will be.
Every exciting theory and discovery will be inseparable from him.
He wants to surpass the gods and become the God of the gods!
This may be the only update today, but the number of words actually counts as 2 updates.
The next plot is still difficult to write, and the author needs to check the information carefully.
The key is to write comfortably and correctly, wow wow, it’s too difficult.
And for the convenience of readers, I have to popularize a lot of science content. This makes the content a little more cumbersome, I hope you don't mind.
Because if you don’t write it clearly, people may not know what’s so cool about it.
You can’t just say, wow, this theory is awesome and everyone admires it.
Everyone only knows:? ? ? Black question mark face.
(End of this chapter)