Chapter 126 "Things about me building a generator in the Song Dynasty and then rubbing a microscope with my hands"
Although in the past day.
Xu Yun has proven that he does have some unique abilities and has very high practical value.
But maybe it’s due to inherent concepts.
Whenever a new word came out of Xu Yun's mouth, Lao Su would always subconsciously think of Xu Yun's identity as an actor.
After all, there is actually not much conflict between the two characters of the actor and the person with ancestral medical skills.
Blood ties are very common these days, and there are many examples of parents being imprisoned and their children being sent to brothels.
Therefore, it is easy for Lao Su to associate some words with male actors.
Who asked Xu Yun to just dictate the pronunciation instead of directly writing the Chinese characters*(ˊˋ*)*
Like a real poke.
For example, stem vein injection.
Another example is this time
"Hand micro-stem?"
Then Lao Su made up the picture in his mind.
Hiss.
Of course.
This disturbing thought went away as quickly as it came.
Lao Su realized in the next second that what Xu Yun was talking about was probably something new.
Although this is the first time I have heard something new from Xu Yun, Lao Su still looks very curious:
"Xiao Wang, I wonder what kind of object is the microscope you are talking about?"
Xu Yun thought for a while and asked:
"Master, have you ever heard of Juji?"
When Lao Su heard this, he was stunned for a moment, and his eyes immediately showed a thoughtful look, with a somewhat sentimental expression:
"I have seen it before. When Wen Zhonggong had eyesight, someone offered this thing.
I heard Duke Wen Zhong praise this thing more than once. Unfortunately, Duke Wen Zhong later contracted an eye disease, and Kui Kui eventually lost its use. ”
Xu Yun nodded understandingly. He had also heard what Lao Su said.
叆叇.
This word may sound a bit awkward to pronounce, but what it refers to is very common, that is, the future generations.
Reading glasses.
That's right.
During the Song Dynasty, reading glasses had already appeared.
For example, there is a clear record in "Dongtian Qinglu" written by Zhao Xihu of the Southern Song Dynasty:
"Hey, the old man doesn't know how to read fine books, so he uses this to hide his eyesight."
In addition, "Xia Di", also from the Song Dynasty, also provides an example:
"Shi Hang broke into prison and took more than ten kinds of water essences to enter. It was not obvious at first. After knowing that the case was hidden, he used the water essence to carry his eyes and saw it."
Water essence is crystal.
Shi Hang was a fellow villager and friend of Su Xun in the Northern Song Dynasty. When he was a law enforcement officer, he suffered from presbyopia, so he used glasses made of crystal to read case files.
However, the shape of the glasses at this time should not be like the framed bifocals we are familiar with today.
According to the relevant description.
Ancient reading glasses should have a single lens and no frame.
It needs to be held by hand when using it, somewhat like using a magnifying glass.
As for the Duke Wenzhong mentioned by Lao Su, he was naturally Ouyang Wenzhong, also known as Ouyang Xiu, one of the eight great masters of the Tang and Song Dynasties.
He was also a good friend of Lao Su. He was deeply affected by visual impairment in his later years and died almost thirty years ago.
By the way.
In ancient times, there was a famous myopic unfortunate named Bai Juyi.
He also wrote a poem about this:
In the early years, I was tired and tired of reading, but in my later years, I was sad and cried a lot.
If you don’t know how to damage your eyes, it’s all your own fault. Only when you become ill can you realize your desires.
At night, it seems that the lights are about to go out, and in the dark, it seems that the mirror has not been polished.
Thousands of medicines and prescriptions cannot cure it, but we should close our eyes and practice Toutuo.
It can be seen from this.
Lao Bai not only suffers from myopia, but also has a high probability of suffering from astigmatism and dry eye
His gaze returned to its original position.
With the ancient reading glasses as an example, it is much easier for Xu Yun to explain the concept of a microscope:
"A microscope, as the name suggests, is a 'mirror' that can show tiny things in the eye.
To say "叆叇" is to enlarge a word several times.
A microscope can magnify small objects dozens, hundreds or even thousands of times.
With the help of a microscope, microorganisms can no longer escape and can be observed. ”
After listening to these words quietly, Lao Su looked thoughtful.
Tell the truth.
There is nothing wrong with Xu Yun's logic, which is to rely on magnification to explore tiny objects.
In fact, many years before Xu Yun appeared, Lao Su had thought about the possibility of using crystals to make amplification equipment.
After all, in "New Yixiang Fa Yao", Lao Su personally drew 14 star maps and recorded 1,464 stars.
This is also the earliest star chart preserved in China among all-sky star charts collected by later generations.
It was not until the Renaissance in the 14th century that Europe expanded the star map to 1,022 stars and recorded some basic stars.
Not only is it more than two hundred years later than Lao Su, but the number is also much smaller than Lao Su.
Of course.
Another Dunhuang star map from the Tang Dynasty contains 1,350 stars, which is earlier than the Su Song star map.
But sadly.
It was stolen by Stein more than a hundred years ago and is now in the British Museum in London, so it is not included in the star maps preserved in China. (This is also a very angry thing. If you are interested, you can learn more about it. I saw some of the documents in the British Museum and I felt extremely complicated.)
As a contemporary person who has looked up at the starry sky, Lao Su has naturally thought about whether he could use the magnification effect of crystals to observe the starry sky.
For example, in Lao Su's study, there was a simple telescope stored at this time.
However, its magnification is only five or six times, the magnification effect is negligible, and it is difficult to see much.
The collection value is actually higher than the practical value.
However, with these objects and past experiences as a foundation, Lao Su became more and more interested after hearing Xu Yun’s introduction:
"Xiao Wang, I can barely understand what you said, and there's not much problem with the inference, but I don't know about microscopes."
Xu Yun blinked and quickly understood what Lao Su was thinking:
"Sir, do you want to ask if a microscope can be made?"
"Of course."
Xu Yun was silent for a moment and continued:
"It is not difficult to make a simple microscope. Rumor has it that within Fengling Yueying Sect, this is an extremely simple technology, as long as you have the skills.
However, like syringes and generators, making a microscope requires some money and effort in terms of materials."
Hearing this, Lao Su quickly asked:
"Xiao Wang, what items are needed?"
Xu Yun thought for a while and gave several names:
“First of all, we need glass, and it’s not just ordinary glass.
One of them needs to be made of ore from the volcanic crater, and the other material needs to use a kind of silver-gray clay unique to Jiangnan West Road
Next are several items such as glue, boards, nails, etc.
By the way, you also need some alcohol that you made before. ”
diy microscope.
This is considered a very simple thing in the technical geek circles of later generations.
Of course.
This refers to optical microscopy.
All students who haven’t been mad at the biology teacher should know this.
The principle of a microscope is actually very simple. To put it bluntly, there are only five words:
Convex lens imaging.
The microscope structure mainly consists of eyepieces, objective lenses, stages and reflectors.
The eyepiece and objective lens are both convex lenses with different focal lengths.
And the focal length of the convex lens of the objective lens is smaller than the focal length of the convex lens of the eyepiece.
The objective lens is equivalent to the lens of a projector. The object passes through the objective lens to form an inverted and magnified real image.
The eyepiece is equivalent to an ordinary magnifying glass, and the real image is transformed into an upright, magnified virtual image through the eyepiece.
Therefore, the objects that pass through the microscope to the human eye are all inverted and magnified virtual images.
Reflectors are used to reflect and illuminate the objects being observed. They generally have two reflective surfaces:
One is a plane mirror, used when the light is strong.
The other is a concave mirror, used when the light is low, to concentrate the light.
As for the magnification of the microscope, it is also very simple. The value of the eyepiece X objective lens is the method multiple.
Nowadays, the maximum magnification of optical microscopes is 1600 times. Those optical microscopes that say they can magnify tens of thousands of times are deceiving people.
The principle of this multiple involves the diffraction limit, that is, a point light source will form a diffraction spot.
At this magnification, whether it is increasing the refractive index of the lens or adding lenses to increase the magnification, it will become meaningless - at least in the context of optical microscopy.
Of course.
Speaking of microscopes, the inventor of this thing must be mentioned.
Like the American cockroach, this man is also a veteran.
That’s right!
This person is
Robert Hooke.
Actually.
According to later research, it was the Johnsons and his sons in 1595 who really thought about the working principle of the microscope and invented the first microscope.
But these two unlucky guys didn't make any important observations with these instruments, and they didn't do anything after they were made.
Therefore, in the history books, the right to invent the microscope became a battleground between the other two people:
Leeuwenhoek and Robert Hooke.
The degree of confusion between these two people is so high that even the Biology book published by the People's Education Press contains errors.
First, let’s make a definition from the point of time:
Robert Hooke's invention of the microscope preceded Leeuwenhoek's by twenty years.
However, the microscope invented by Hooke only had a magnification of 20 times, while Hooke's magnification was as high as 270 times.
Therefore, the real statement should be that Hooke invented the microscope, and Hooke invented or improved the high-power microscope.
In addition, in terms of biological contributions, although Hooke discovered cells, he observed slices of cork.
After Hooke zoomed in, he discovered small spaces one by one, and named them after the English cell.
But actually.
What he observed were dead cells; all he saw were the remaining plant cell walls.
Leeuwenhoek observed living microbial bacteria, so he is considered the founder of microbiology.
This is like Hook and Hook both tinkering with time and space machines. Hook traveled to 4 million years ago and discovered the skeleton of a creature. He named the creature a dinosaur.
Hook's technology is better than Hook's. He traveled to 65 million years ago and saw real, living dinosaurs.
The discovery of the latter is obviously more complete, but because the former was one step ahead, the discoverer of dinosaurs can only be attributed to the former.
all in all.
Hooke discovered the cell wall and named the cell.
Hooke discovered bacteria and observed the complete cell structure, thus defining microorganisms.
At the same time the former invented the microscope.
The latter invented the high-power microscope.
This is the historical truth that cannot be explained in biology books.
His gaze returned to its original position.
According to Xu Yun’s design, there are two key points in the entire microscope DIY process:
The first is to ensure that the objective lens is imaged at the objective focus of the eyepiece. Specifically, it can be calculated using f′(x)=$\frac{1}{3}$.
The second is the issue of multiples.
The first person in the world to discover the limiting magnification of an optical microscope was Ernst Abbe, who invented the 1500-magnification optical microscope in 1874.
The resolution is about 200 nanometers, which is half the shortest wavelength of visible light.
Therefore, if you want to build an optical microscope by hand, you don't actually need much assistance from modern process equipment.
As a technical geek who has used a double-digit microscope, Xu Yun naturally knows one thing very well:
In ancient society, there were two types of materials that could achieve the perfect combination of refractive index and dispersion rate.
That is, crown glass and flint glass.
In the 21st century, crown glass is essentially bundled with Zeiss glasses.
But actually.
It is a type of glass with an Abbe number greater than 50, that is, lanthanide glass.
Local lanthanum mining sites are mainly in Inner Mongolia and Jiangxi, namely Jiangnan West Road in the Tang Dynasty and Jiangnan West Road in the Song Dynasty. In later generations, pepper water will flow when you open the tap.
In addition, the lanthanide series rare earths have distinct characteristics, so it is not difficult to find them with Lao Su's ability.
As for volcanic glass, it’s even simpler.
As the name suggests.
This is a type of mineral derivative that can be found in volcanic craters.
Although there is a troublesome thing about the above two, it is that if they are not handled properly, scary radioactive elements such as thorium may remain.
But with the right process, these can be easily avoided.
After the raw materials are gathered, excellent achromatic lenses can be prepared through a series of techniques such as stirring the glass solution and plano-convex lenses.
Let’s not talk about the ultimate magnification of the finished product by then. It is not difficult to achieve at least 900 times magnification.
During the observation process under the microscope, red blood cells can be seen more clearly with a low-magnification lens of 100x and 400x.
As for seeing the detailed structure of bacteria, you need a 1000x lens. Its field of view is very small, and you need medicine to expand the field of view.
In addition, staining is required, otherwise the shadow of bacteria cannot be seen.
Therefore, a 900x microscope is already a very practical instrument.
Say something not nice.
Lao Su might not have discovered all the uses of a microscope with this kind of magnification until the day he burped.
Of course.
Considering that the raw materials of microscopes are relatively special, even simple transportation is troublesome.
Xu Yun conservatively estimated that it would be rare for the materials to be ready within a week.
Therefore, the specific hand-rubbing matter must be postponed for the time being and discussed later.
What's more.
There is one more thing that needs to be prioritized right now.
That is.
Wang Yue’s intravenous injection.
After all, if he didn't inject allicin solvent, it was hard to say when Lao Su would burp. I'm afraid this Lord Zhonghou is really feeling cold.
(End of chapter)