Hearing these two words coming out of Xu Yun's mouth.
Lao Fa, Stokes and other professors all felt a strange feeling in their hearts.
The measurement of the speed of light, which is enough to cause shock in today's scientific community, is just an appetizer in Xu Yun's mouth?
Are you kidding?!
Although the word "speed of light" seems very high-level.
But in fact, it is a piece of data that belongs to the physical "substrate" properties.
First, it represents that the movement of light has an upper limit.
In other words, there is an upper limit to the transmission of information and energy.
That is to say, what happens in different areas of the universe will not instantly reach the earth or any planet with life, and living things will not be "swamped" by the massive amount of information.
This way.
Only the macroscopic world can operate normally. From the perspective of future generations, it should be said that only the evolution of life can proceed normally.
Secondly, it is useful in geometric optics. There are a large number of formulas in theory that require the definition of the speed of light.
This definition may not produce straightforward numerical results, but it will form a framework for the theoretical model, and its importance is self-evident.
Therefore, after Lao Fa and others calculated the results, they generally felt very complicated:
They were surprised that Xu Yun was able to finalize the long-debated calculation of the speed of light in the scientific community, and felt disappointed that the efforts of people like them in the rest of their lives could not compare with Feiyu's plan more than a hundred years ago.
I am also delighted that related theories and even human science and technology will achieve a substantial development.
The result was unexpected
This is an ingenious plan that will go down in history, and the person who proposed it will undoubtedly win the Copley Medal.
Tmd is not a staple food yet?
It's like the heroine in the book thinks that the other person has penetrated all the way, but in fact only half of it has penetrated.
This is a very subtle feeling.
Therefore, after learning that more than half of it was not stuffed in, Lao Fa suddenly felt a complex emotion of fear mixed with anticipation.
The appetizer is so exciting, how about the main course?
Lao Fa even touched the inner pocket of his chest, where there were two tablets of nitroglycerin specially provided by the British royal family.
Then he was silent for a moment, took a deep breath, and said to Xu Yun:
"Classmate Luo Feng, what experiments should we do next?"
Xu Yun glanced at Angus Roman not far away, turned to William Whewell and asked:
"Mr. Whewell, have you found all the other equipment I asked you to prepare?"
William Whewell was chatting and laughing with Stokes. Hearing this, he raised his waist pants and said softly:
"Don't worry, it has been prepared for a long time, but there are still a few small modules that are special and have been stored in the laboratory for the time being."
"I have arranged for Mr. Thomson to take someone to pick it up in person. He should be back within ten minutes."
William Whewell's expression was very kind at this time, with an uncontrollable joy in the corners of his eyes.
He had just learned the meaning of the photometry experiment from Stokes, and the current situation had little to do with Angus Roman's doubts.
In other words, no matter whether Xu Yun can produce evidence to refute the wave theory in the future, it will not have much impact on his status as a "descendant of fat fish".
After all, this scheme for calculating the speed of light is so exquisite. Who else but Fatty Fish could have figured it out?
It can't be Luo Feng himself, right?
In the context where the concept of wave-particle duality has been proposed, the importance of this experiment is not necessarily less than the evidence that refutes the wave theory.
This is like someone in later generations solving Goldbach's conjecture, and then proving the Hodge conjecture.
Even if he cannot solve Ge Guess in the end, does that mean he is not a top mathematician?
The answer is obviously no.
Of course.
In the past, Stokes and others made judgments based on existing concepts without understanding Xu Yun's next arrangements.
all in all.
In front of Xu Yun's appetizer.
The fatal combo that Prime unleashed through Angus Roman had actually lost its effect on William Whewell.
This means that he has retained the dignity of the dean of Trinity College and is still eligible to run for the new president at this time.
How could this make him unhappy?
So before Xu Yun spoke.
He arranged for Thomson to go to the laboratory in person in advance and asked him to carry the equipment requested by Xu Yun to the site.
ten minutes later.
Thomson and Xiaomai returned to the clearing with a few boxes.
Bang bang bang bang
soon.
Several parts, metal sheets of unknown material, metal balls, and a wooden load-bearing frame the size of a piano were placed in the open space.
Xu Yun put on latex gloves and began to assemble the equipment himself.
Although rubber gloves would not be invented until 1889, latex gloves doped with basic lead carbonate had been available for 11 years.
In addition, these parts have been debugged in the laboratory, so it is not particularly troublesome to assemble them.
More than ten minutes later.
A simple electrolytic cell appeared on the wooden table where the flashlight had been placed.
The electrolytic cell is about the size of a food delivery box equipped by later generations of food deliverymen. It is wrapped in a black bandage and filled with solution.
The solution is divided into two areas by a thin film in the middle, with a metal plate inserted in each area.
The size and appearance of the metal plates are all the same, and they are obviously pre-arranged specifications.
Xu Yun then called Thomson to whisper a few words and asked him to assemble another experimental device first.
After Lao Tang leaves.
Xu Yun nodded towards the many elders around him and said:
"Prince Albert, Mr. Faraday, Dean Whewell, and, by the way, Senior Roman, we can start the next phase of the experiment."
Lao Fa took another step forward and was the first to come to the equipment.
As an electrical expert, he is extremely familiar with electrolytic cells.
I saw him holding his hands behind his back, approaching the electrolytic cell and looking at it for a few times. He even twitched his nose and sniffed, and judged:
"Is this an acid solution?"
Xu Yun nodded and added:
"To be precise, it's a mixed solution of silver chloride and fluorosilicic acid."
Lao Fajian said and looked at the metal plate placed in the solution, his eyes lingering on it for a moment:
"Platinum electrode?"
Xu Yun gave him a thumbs up and praised:
"You have really good eyesight. That's right, it's a platinum electrode."
Laofa ignored Xu Yun's compliment, frowned slightly, and a trace of confusion flashed in his eyes.
Platinum electrodes, silver chloride and fluorosilicic acid, what do these have to do with light?
Looking at Lao Fa who was deep in thought, Xu Yun asked tentatively:
"Professor Faraday, shall I start now?"
Only then did Lao Fa come back to his senses, looked around, and quickly said:
"Okay, let's get started."
Xu Yun informed Prince Albert and others beside him, and took a bright flashlight and an ammeter from Xiaomai's hand.
According to the original timeline.
Weber invented the two-wire ammeter in 1841, and the electric power meter in 1846, which is an important node in the history of electronic components.
These two nodes are neither advanced nor delayed in the current copy, so it is not surprising that Cambridge University can come up with a high-precision ammeter.
Xu Yun then connected the ammeter to the electrolytic cell, turned on the flashlight, calibrated it and stuffed it into Mai's hand:
"Hold on, don't let go."
Xiaomai said innocently and started to be a tool man.
See this situation.
A question mark popped up in Lao Fa’s head:
"?"
What is the operation of using light to illuminate an electrolytic cell without electricity?
However, Xu Yun had done an experiment on measuring the speed of light with a rotating mirror before, so Lao Fa and everyone continued to watch it patiently.
One minute
five minutes
ten minutes
When the time came to the thirteenth minute.
Lao Fa yawned and was about to speak.
But before he spoke, something seemed to be dancing in the corner of his eye.
He subconsciously turned his head and looked.
The moment he saw the situation clearly, Lao Fa's scalp felt numb:
I only see this moment.
The ammeter, which was originally unresponsive, was suddenly beating weakly and tenaciously!
Lao Fa's actions quickly attracted the attention of other professors, and gradually some people followed suit and turned their attention to the ammeter.
"Look at the ammeter!"
"Hallelujah, where does the electromotive force come from?!"
"It's worse than hanging, what is this thing?"
"The ammeter is moving, I won't play anymore, wdnmd!"
finally.
Xiaomai naively answered everyone’s questions:
"It's so strange. Why is there current in the electrolytic cell even though there is no electricity?"
Swish
The next second.
Everyone's eyes were fixed on Xu Yun.
Even William Whewell's eyes were full of curiosity.
Although his knowledge of natural sciences was limited, he knew somewhat about the principles of electrolytic cells.
Electrolytic cell An electrolytic cell cannot function without electricity.
But now Xu Yun just relies on a strong flashlight to restore the current or potential difference in the electrolytic cell?
Looking at the curious baby-like eyes of the elders, Xu Yun raised his head and looked up for a few seconds.
Why.
It's less than 4,000 words, so I can't go on to the next chapter.
So he sighed slightly and said to Lao Fa:
"One morning more than a hundred years ago, the ancestor of Fat Fish immersed two platinum electrodes in the electrolyte solution to adjust the equipment for an electrolysis experiment."
"At that time, someone happened to come to visit, so the ancestor of Feiyu conveniently placed the unpowered electrolytic cell by the window sill."
"As a result, when he finished meeting the guests and returned to his original place, he suddenly discovered that there was a potential difference in the electrolytic cell!"
"So he eliminated external factors one by one by controlling variables, and finally determined one thing."
Talk about this.
Xu Yun paused, looked around, and made the final decision:
"The platinum electrode will generate an electromotive force when it is illuminated by light. There must be some special close relationship between the electrical properties of the material and the light waves!"
Hear this.
The scene suddenly fell into an eerie silence again.
A few seconds passed.
Laofa glanced at Xu Yun with complicated eyes and asked:
"Did Mr. Fat Fish have a name for this phenomenon?"
Xu Yun nodded and explained:
"Yes, the ancestors of Fat Fish called this phenomenon the photovoltaic effect, or photovoltaic effect for short."
Old Fa turned his attention to the gurgling electrolytic cell and murmured:
"Photovoltaic Conductor"
That's right.
The second experiment Xu Yun demonstrated this time was the photovoltaic effect!
The local photovoltaic effect was discovered in 1839, when Alexander Becquerel saw this phenomenon by accident.
The phenomenon of effect is as demonstrated by Xu Yun:
When two platinum electrodes are placed in the electrolyte and irradiated with light, an electromotive force will appear in the electrolytic cell.
But in this timeline.
Influenced by Mavericks.
The field of electronic components has developed extremely rapidly. Becquerel's father, Anton Cesar Becquerel, participated in the invention of the electric light. Therefore, Alexander Becquerel missed the opportunity to discover the photovoltaic effect.
.(No one discovered this foreshadowing, how sad it is)
Of course.
Now that Alexander Becquerel has been mentioned, another person must be mentioned:
Madame Curie.
1903.
In recognition of the discovery of the element radium, the Nobel Prize organizing committee awarded the Nobel Prize to Becquerel and the Curies.
Among them, Becquerel ranked first, Pierre Curie, Mrs. Curie's husband, ranked second, and Mrs. Curie herself ranked third.
And Madame Curie's name was only added by Becquerel at the strong request of her husband, Pierre.
But actually.
Becquerel's recent wave of awards has a lot of merit, and it can be called one of the earliest examples of mixed works.
The reason why he won the Nobel Prize is simple:
He discovered natural radioactivity in 1896 and led related research.
But actually
Becquerel identified this phenomenon as fluorescence and simply ignored it. The Curies were the ones who contributed the most to the discovery of radium.
In addition, it was later rumored that Pierre and Becquerel collaborated closely, which is also a lie.
Pierre has always hated Becquerel. If the Swedish mathematician Robbie Gallagher had not told Pierre the contents of the nomination letter, Pierre might not have known who was nominated until the time of the award.
As for what happened next, everyone should have heard about it.
1906.
Pierre Curie was hit by a carriage on the road and died on the spot.
After being widowed for several years, Marie Curie got together with her student Lang Zhiwan.
It is human nature to start a new family after the death of the husband, not to mention that Marie Curie's transition was not seamless, and the shortest time it took was more than three years.
But Lang Zhivin was a married man at the time, which caused their love story to be cast in a lot of criticism.
November 7, 1911.
Reuters reports that the Nobel Prize in Chemistry will be awarded to Marie Curie that year.
Result November 23rd.
Madame Langevin published Madame Curie's love letter to Langevin in the newspaper through her brother.
Since then.
Gallic newspapers began to report on Madame Curie's "mysterious love affair" with Langevin, and began to publish a large number of her letters.
Some Gauls also attacked her house and smashed her windows with stones.
A group of Gallic scientists who originally supported Marie Curie also began to change their stance. They jointly wrote a letter asking Marie to leave France.
As a result, Marie Curie was not elected as an academician of the Gallic Academy of Sciences. Instead, she fled to a monastery in Gaul and hid for 14 months before getting over the news.
The insulting term "Polish slut" appeared at that time.
Here’s another rather naughty episode.
After Langevin separated from Madame Curie, his wife agreed that Langevin could openly have a lover other than Madame Curie as a condition to save the failed marriage.
after many years.
In order to support his lover, Langevin shamelessly asked Marie Curie to arrange a position for this female student at the institute (:KXSJ.0.2014-07-019)
There are weird things every year, especially in the early 20th century.
alright.
His gaze returned to its original position.
The photovoltaic effect is not directly related to the wave theory in a strict sense, but it is a step that cannot be ignored.
First of all, this is an ideological transition to prevent these elders from having a heart attack after suddenly seeing certain phenomena, causing a tragedy in the history of human science.
In addition, it is for
Inspire old methods.
do not forget.
The concept of semiconductor was proposed by Lao Fa.
Look at his shaking frequency now, which is similar to that of Wu Laoer. In fantasy novels, is that a proper ‘epiphany’?
Then several professors came to the electrolytic cell one after another and observed the phenomenon again.
Stokes even touched the platinum electrode plate, and then retracted his finger after a pause. (I don’t recommend trying it. It feels a bit like a leaky metal mainframe. Don’t ask me how I know this. Just ask me back then.
head iron)
“It’s really weird”
Touching his sore fingers, Stokes suddenly frowned and said:
"Why does an electric current occur inside the solution when irradiating a platinum electrode with light?"
"According to Mr. Ampere's theory, light causes a closed circuit with a potential difference to appear inside the electrolytic cell?"
Another professor on the side took two steps forward, stretched his head and took a few glances into the electrolytic cell.
This person is called Bart Briggs, who is currently ranked among the top five physics experts at Cambridge University, and is also famous in Europe.
I saw him pondering for a moment and analyzed:
"Is it possible that it is a thin layer of impurities coming from the surface of the wafer? For example, doping with heat source effect?"
Lao Fa quickly shook his head and denied this guess:
"The light from the flashlight should not reach the level that causes changes in the thin layer of impurities. At most, the odorants and iodides will decompose briefly to produce an electrical effect, but it cannot be sustained for a long time."
Then he glanced at the 'well-behaved.JPG' Xu Yun, reached out and picked up a clean platinum electrode from the table.
Curl your slender index finger slightly and tap on it:
"So it is obvious that there must be conditions that can form its own field in a metal plate such as a platinum electrode."
Seeing this, Stokes couldn't help asking:
"Mr. Faraday, did you think of something?"
A trace of hesitation immediately appeared on Lao Fa's face, as if he was having some ideological struggle, and finally he said:
"It's just some speculation."
"I wonder if there is such a possibility. For example, there were some charges originally existing in the platinum electrode. They were originally kept in a relatively balanced closed state, so they did not exhibit charged properties."
"The junction that was excited or balanced under light was interrupted, resulting in a potential difference?"
"But in this way, the actual environment of the stimulation may not be visible to the naked eye."
Seeing Lao Fa talking eloquently, Xu Yun remained silent.
However, the clenched hands showed that his heart was not at peace at the moment.
Let everyone know.
The essence of the photovoltaic phenomenon is attributed to the atomic energy band structure, involving the concepts of valence band and conduction band.
The so-called valence band refers to the region relatively close to the nucleus.
The electrons here are tightly sucked and cannot escape easily.
The conduction band is a region far away from the nucleus, where electrons are unregulated and relatively free.
If an external electric field is applied to cause these electrons to run, the material will conduct electricity.
In addition to these two areas, there is another area above the valence band and below the conduction band.
Electrons are not allowed to exist in this area, which is the forbidden band.
Therefore, in the self-heating world, there are generally two completely different materials:
One kind of forbidden band is very narrow, or there is no forbidden band at all.
At room temperature, its outer electrons in the valence band can easily jump to the conduction band.
This is the conductor.
On the contrary, if the forbidden band of the material is very wide, generally greater than three electron volts, and the electrons stay in the valence band at room temperature, then it cannot conduct electricity.
This is an insulator.
Materials with an energy gap less than 3 eV between the valence band and the conduction band are semiconductors.
These electrons will form something called a PN junction, with the two ends showing different electrical properties, thereby forming an electric field pointing from N to P.
This electric field is formed spontaneously, so it is also called the self-constructed electric field of the conductor.
As for the role of the photovoltaic effect, it is to "tempt" those already paired valence band electrons again.
That is, the electrons in the valence band absorb the energy of light, become higher in energy, and jump to the conduction band.
The holes separated from the electrons will be thrown to both sides under the influence of the self-built electric field, forming an electric field pointing from P to N.
This is the photo-generated electric field, and its direction is opposite to the self-constructed electric field.
At this time, as long as an external loop is connected, current will be generated in the loop due to the existence of potential difference.
This is also the principle of photovoltaic power generation in later generations, but the utilization rate has not been able to increase, so it is still only a developing project.
In 1850, when Lao Fa and others were living, electrons had not even been discovered. At most, Coulomb proposed the concept of electric charge, which was still a long way away from real particles.
However, the old method can rely on phenomena to connect to the inner ‘knot’. How can this not be surprising?
Actually.
This is not the first time Xu Yun has encountered this situation.
Calculation of infinitesimal quantities of calves in the 1665 copy
Lao Jia who derived the curvature in the 1100 copy
Lao Su, who built a self-priming pump based on his primitive knowledge
In front of these scientific giants in human history, Xu Yun could feel his own insignificance every time.
Compared with these real sages, he is just a lucky man who has gained a special halo. He still has a long, long way to go in the future.
Just as Xu Yun was sighing in his heart, Thomson walked over quickly:
"Luo Feng, the other set of equipment you want is ready."
Only then did Xu Yun come back to his senses.
He first glanced at Angus Roman not far away.
Wow, this villain actually stopped talking this time. He is still waiting to be slapped in the face again.
Then he coughed lightly, put aside this boring thought, and said to Lao Fa:
"Mr. Faraday, are you ready?"
At this time, Lao Fa was still thinking about the photovoltaic effect. Hearing this, he subconsciously froze:
"Um, what are you preparing for?"
Xu Yun smiled mysteriously at him and looked into the distance:
"Of course it's preparation"
"Go and overthrow the foundation of the physics building!"
Note:
Yesterday, a classmate asked why there are instrument panels these days. Is it possible that the first train invented in 1804 had an instrument panel?
－－－－－－Digression－－－－－
I woke up at one o'clock in the morning, don't say I didn't update, woo woo woo woo woo
