Into Unscientific

Xu Yun, who does not have the perspective of God, is not clear.

Mai Mai's sudden "Ah Lie Lie" not only made history stagger, but also took two steps forward.

It also allowed a little boy thousands of kilometers away to experience the feeling of a tauren when he was five years old.

At this time, Xu Yun put on a novel look in his formal attire, and stood aside with Riemann like a mascot, acting as the atmosphere group for the big guys.

I saw Gauss continued to observe the rays for half a minute, and suddenly thought of something, adjusted his glasses, and scanned the light source and vase several times.

Weber is still very familiar with the abilities of his good friend, and he couldn't help asking:

"Friedrich, have you found anything?"

Gauss frowned, nodded solemnly, pointed to the anode and said:

"Look, Edward, the light source of the ray is the anode inside the vacuum tube, so when the light penetrates the outer wall of the vacuum tube, there will be a special contact surface."

"The left side of this contact surface is the inside of the vacuum tube, which has a very high degree of vacuum, and the outside is normal air, which is the standard air pressure."

"So when the light passes through this part of the contact surface, some of the air will be ionized, which allows us to observe the light in the anode area with the naked eye."

"but."

Speaking of this, Gauss pointed to the air between the anode and the vase, and a straight line was drawn in the void.

Then he came to the table, picked up a piece of black paper, and directly blocked the light path.

To the surprise of Faraday and Webb, however.

No spots of light appeared on the black paper, but the fluorescent spots on the vase remained unaffected.

Then Gauss took back the black paper, took a deep breath, and said to Faraday and others:

"You see, the rays in the light path are invisible, but since this is the case"

"Why does the light spot on the vase show?"

Generally speaking.

If a ray of light can be seen by the naked eye, then if a occluder is placed in the middle, even if the occluder is passed by the light, theoretically a spot of light should be visible on the surface.

The simplest example is a flashlight shining through a window in the dark. When the light is seen indoors, a spot of light will appear on the window.

But there is nothing on the black paper right now, which clearly shows one thing:

Where the light falls, there must be something that makes it manifest!

Faraday had worked as an assistant to the chemist Humphrey David when he entered the industry, and his knowledge of chemistry was much higher than that of mathematics, so he quickly judged the problem:

"Friedrich, could it be because of the paint on the vase?"

Gauss nodded silently and walked to the side of the vase.

Then I turned it around with the neck of the bottle, and changed its position facing the light path to a smooth surface without paint.

And this time.

Fluorescence is gone.

See this situation.

Gauss couldn't help touching the paint on the vase, and pushed it a few times with the tip of his nails, muttering:

"It seems that this special ray will have some imaging linkage with barium cyanide platinate."

"Barium cyanide platinate?"

Faraday froze for a moment, then blurted out:

"Wouldn't it also be developed on film?"

Gauss nodded slowly:

"bingo."

Barium Cyanide Platinate.

This is what was mentioned in the previous chapter and also the biggest contributor to Roentgen's ability to discover X-rays.

This is a substance used exclusively for the exposure of paints and negatives, and was especially common in the 19th century.

Of course.

When many students see the word 'cyanide' at the beginning, they will subconsciously think that it is a highly toxic substance.

But in fact it is not the case.

The English name of cyanide is cyanides. Like Bariming in the Internet, it often plays a role in various detective dramas-especially in the comics of a certain elementary school student of death.

Basically, seeing the deceased who drank the drink, and smelling the "bitter almond smell" in his mouth, it can be confirmed that the person died of cyanide.

But students who have taken cyanide in their previous life should know it.

The description "cyanide smells like bitter almonds" is true, but the smell of cyanide is not that obvious.

Most ordinary people can hardly smell cyanide because they do not have the corresponding odor receptors for cyanide.

Even in life, many people don't even know what bitter almond is.

Cashew?

Walnut flavor?

Or almond flavor?

neither.

The real taste of bitter almonds is actually somewhat similar to the towels brought back from the swimming pool, that is, with a little chlorine-containing disinfectant, and it really tastes a little bit astringent.

At the same time.

The real reason why cyanide is harmful is the cyanide ion it contains.

This thing can combine with iron ions in the human body, and the iron ions will not work properly after being combined with cyanide.

In turn, respiratory enzymes are inhibited, causing suffocation in tissues and cells.

The central nervous cells are very sensitive to hypoxia, so the dead usually die from paralysis of the respiratory center.

This is the toxicology of highly toxic cyanide death.

in popular concepts.

The so-called toxic cyanide actually mainly refers to three substances.

That is, sodium cyanide, potassium cyanide, and hydrocyanic acid.

Like barium cyanide platinate, it is difficult to dissociate cyanide ions, so its toxicity is relatively small.

So this thing is indeed a substance with no obvious hazards, not like poisonous substances such as lead plates, which have been used for a long time without knowing it.

Then Gauss glanced at Faraday again, and Faraday immediately understood his thoughts, turned around and said to Kirchhoff:

"Gustav, go to the laboratory next door and get some camera negatives, hurry up."

Kirchhoff nodded and said respectfully:

"clear."

After speaking, he walked out of the house.

A few minutes passed.

Kirchhoff went back and forth.

I saw him walking quickly to Faraday, and handed a cowhide bag in his hand to Faraday:

"Mr. Faraday, I brought back the negatives."

"Thank you, Gustav."

Faraday took the leather bag and took out a palm-sized camera negative from it.

The X-ray negative films of later generations are generally PET films, coated with a layer of emulsion, which is thick and hard.

After exposure to X-rays.

The silver halide crystals in the emulsion layer chemically react and coalesce with adjacent silver halide crystals that are also exposed to light and deposit on the film, leaving an image.

The more light the emulsion layer receives, the more crystals coalesce together.

The less the amount of light, the less the crystals will change and coalesce.

Without light falling on the emulsion, there is naturally no crystal change and coalescence.

Thus, different images can be obtained.

But there were no X-ray films these days, and camera negatives showed positive images, using the daguerreotype method invented by Louis Daguerre.

Its setting agent is edible salt, and its photosensitive speed is very slow, and it takes an average of ten minutes to produce results.

It is also for this reason.

Originally, when Roentgen was studying X-rays in history, he would expose his wife to X-rays for fifteen minutes.

It's a good thing that Roentgen didn't live in 2022, otherwise all the hats with talent but no virtue and the Tianma Meteor Fist would probably have come.

Other than that.

The biggest difference between these negatives in Faraday’s hands and those of later generations is their color—they are colors between light yellow and light green, that is, the color mixed by the developing agent mercury and barium cyanide platinate.

If Xu Yun traveled a few years earlier, he could still see the negatives of the glass substrate.

Faraday then fixed the negative to a shelf and placed it where the vase's light spot appeared.

Then went on to open the first vacuum tube.

soon.

Under the irradiation of X-rays, green fluorescence slowly appeared in the center of the film.

Faraday returned to the operating table and moved the original thermocouple and electroscope to the negative.

It's a coincidence.

Xu Yun happened to write about thermocouples when he was writing novels in his previous life, and the readings happened to be five decimal places.

So, at that time, some readers questioned the question of the degree of the thermocouple:

There were no electron tubes in the 19th century, and thermocouples could not be displayed to five decimal places.

In fact, Xu Yun was a little confused at that time - the value displayed by the thermocouple has nothing to do with the electron tube, okay?

Electron tubes are parts used in electrical instruments, that is, secondary instruments. They just make the values ​​displayed on the screen more intuitive.

In the era when there was no screen display, the scientific community was able to achieve accuracy to six decimal places as early as 1830 through mercury display and pyroelectric effect.

This principle is actually somewhat similar to the Cavendish torsion balance experiment, through multiple delicate stages to achieve the effect of measuring the big with the small.

The screen display just optimizes the steps so that the data can be displayed quickly, not that the data cannot be read and displayed without the screen display.

Alright, let's go back to where we started.

After exposure to unknown rays, a temperature rise is quickly shown on the thermocouple:

0.763.

In the field of optics, this is a rather large value, which means that the energy of this ray is very large.

The greater the energy, the shorter the wavelength and the higher the frequency.

Think here.

Faraday walked back to the operating table and took out a prism and a nonlinear optical crystal—the same thing that Xu Yun used when he demonstrated the photoelectric effect.

Then he put on his gloves, placed the prism on the exit point at the end of the anode, and looked up at Gauss.

Gauss observed the negatives for a while, then shook his head at him:

"The position of the spot has not changed."

Faraday snorted heavily, hesitated for a moment, and replaced the nonlinear optical crystal again.

After a few seconds.

Gauss still shook his head, with a strong incomprehension in his tone:

"The spot. There is still no obvious change."

Faraday stood up, evened his breath, touched his chin with his thumb, and said:

"Strange, why is the refractive index of this ray so low?"

Gauss and Weber on the side also frowned tightly and did not speak.

It's like being unprepared for the appearance of this unknown ray.

Faraday and the others never thought of it anyway, they just did a routine verification step of light refraction

An extremely strange phenomenon appeared in front of them extremely abruptly.

Precisely.

This is a phenomenon strong enough to shake the foundations of the physical system.

mentioned above.

From the readings shown by the thermocouple, it can be determined that this light is very energetic, that is, very high in frequency.

And the higher the frequency, the larger the theoretical refractive index should be—this is the truth verified by Descartes and Newton.

But according to Faraday's experiment at this time, the light hardly refracts after passing through the crystal!

What's going on here?

Seeing Faraday with a dignified face, Xu Yun couldn't help but sigh in his heart.

He could probably guess Farah's third person's doubts, but all he could do was sigh slightly in his heart.

X-ray wavelength is short, but its refractive index is close to 1, which is a very, very esoteric problem.

It's called anomalous dispersion.

It usually occurs near the absorption peak of the material, and when the wavelength is very short, the refractive index may be very close to 1.

This is what happens with X-rays.

And when it happens, another situation arises:

When entering the medium from a vacuum, the electromagnetic wave may be totally reflected, and the propagation speed of X-rays in the medium is greater than the speed of light in vacuum.

Of course.

The propagation velocity here refers to the phase velocity in the electromagnetic medium, and does not represent the propagation velocity of signals or energy.

It is the velocity expressed by the wavefront or wave shape along the longitudinal direction of the guided wave system, and the group velocity represents the energy or signal propagation velocity.

The electromagnetic medium is only an inference of quantum electrodynamics, and there will be some distortion when compared with real physics.

So the theory of relativity still holds.

The reasons for this are complex and involve space-time vibrations in electric and magnetic fields.

The time vibration is represented by the circular frequency ω=2πf, the space vibration is described by the wavelength λ, and the product of the two is the light speed c.

The problem is that the current also excites the magnetic field, which changes the coupling of the electric and magnetic fields.

under normal circumstances.

The electric field drives the electrons in the medium to form a current with the same frequency, so this current does not affect the frequency of the electromagnetic wave, but changes the space period of the electromagnetic wave.

That is, λ becomes λ1, which causes the change of the speed of light.

Roughly speaking, the refractive index is a measure of the change in the speed of light in a medium.

It is very simple to explain and very easy to understand.

However, the physical system in 1850 was still unable to combine the oscillator model with Maxwell’s equations—not to mention, the guy who derived Maxwell’s equations was still standing by the door and responsible for the switch.

So for today's physics community.

In the next period of time, I am afraid that there will be an extra dark cloud overhead.

After all, the higher the frequency, the greater the reflectivity. In a sense, it is one of the cornerstones of classical physics.

Although not a particularly large stone, it is still a cornerstone.

Of course.

This is a question that needs to be considered in the future. What Faraday and the others have to do now is to continue the research on this ray.