In the southeast corner of Beijing, next to the Ciyun Temple and the Rite Tribute Courtyard, there is an institution called the "Armor Factory".

There are many craftsmen there, mainly producing chain mail and iron armor, and the four-hole wire drawing machine hidden in the factory can make iron wire in batches!

Wang Yangming used to work in the Ministry of Industry, and through Uncle Wang's relationship, Wang Yuan took out his own silver to customize a few steel wires, and then wrapped them around the iron rod to form a spring.

"What is this?" Gu Yingxiang asked.

Wang Yuan smiled: "Dynamometer." ”

Gu Yingxiang hung a piece of weighing stone and pulled it up with a dynamometer: "Why is there no scale?" ”

Wang Yuan said: "It needs to be measured slowly. ”

Immediately, the two of them brought a small scale and weighed out thirty bags of fine sand of one or two to three catties respectively. Then hang them separately with a dynamometer, mark 30 scales, and the Ming Dynasty version of the dynamometer is completed.

Gu Yingxiang took the scale as the experimental object, used the dynamometer to make repeated measurements, and came to the conclusion: "If two forces acting on the same scale are equal in magnitude, opposite in direction, and in the same straight line, the two forces cancel each other out and keep the scale still." It is speculated that if the multiple forces acting on the same scale are balanced, the scale will also remain stationary. ”

Wang Yuan smiled and asked, "What if we were doing experiments on a speeding carriage?" ”

Gu Yingxiang thought carefully: "Even if the scale is balanced by force, it is stationary relative to the carriage, but it is moving relative to the ground. ”

Wang Yuan inspired: "Then can we assume that all objects have certain properties, and tentatively named 'inertia'. When there is no external force, or when the external force is in balance, the object must remain at rest or in its original state of motion? ”

"It seems like so," Gu Yingxiang said and shook his head suddenly, "According to your assumption, if I push this scale forward, the force on it above and below is balanced, and the front and rear are only the thrust I exert." So, why does the scale stop when it should keep moving forward? ”

Wang Yuan pressed Gu Yingxiang's hand to the table and pushed it forward: "Where objects meet each other, friction and resistance will inevitably occur. The rougher the contact surface and the wider the contact surface, the greater the resistance! ”

Gu Yingxiang's eyes lit up: "In other words, if the desktop is smooth enough and long enough, I can push the scales to Ruoxu's hometown Guizhou with a gentle push?" ”

"That's how it should be," Wang Yuan said with a smile, "but we also have to consider air resistance." ”

"Air?" Gu Yingxiang didn't quite understand this concept.

Wang Yuan elaborated: "Air is everywhere, and strong winds are air flowing. The wind is strong enough to even uproot trees, and obviously the air has resistance! ”

Gu Yingxiang asked, "How do you prove the existence of air?" ”

Wang Yuan called a bucket of water, took out a thin-mouthed translucent glass bottle, and asked, "Is there something in the bottle?" ”

Gu Yingxiang shook his head and said, "No." ”

Wang Yuan smiled: "Look! ”

Wang Yuan turned the glass bottle upside down and quickly pressed it vertically into the water, and the water in the barrel immediately poured into the mouth of the bottle. But when Wang Yuan pressed all the glass bottles into the water, the water level in the bottle was lower than the water level in the bucket, as if something was preventing the water from pouring in.

"Is there anything?" Wang Yuan asked again.

Gu Yingxiang was a little confused: "It's air inside?" ”

Wang Yuan smiled: "Maybe, I guessed so." Look again. ”

Wang Yuan picked up a piece of straw paper, threw it out casually, and quickly fell after only throwing a foot away. He picked up the straw paper again, crumpled it into a paper ball and threw it out, throwing the paper ball directly out of the door.

Gu Yingxiang suddenly woke up: "This is the resistance of the air!" When the straw paper is unfolded, the contact surface with the air is larger, and the air resistance is greater. ”

Wang Yuan nodded and said, "The hero sees the same thing. ”

Gu Yingxiang played with the dynamometer, pointed to the scale and asked, "How should force be expressed?" Or is it in pounds? ”

"Jin is weight, I think although force is related to weight, but it is definitely not the same thing as weight." Wang Yuan couldn't directly say the gravity coefficient, and without experimental data, he couldn't really convince Gu Yingxiang.

It was already very late, Gu Yingxiang went home with a stomach full of doubts, he didn't even bother to pay the public food, and lay on the bed and tossed and turned over and over to think about the problem of hard work.

Wang Yuan made two single-pendulum devices for gravitational acceleration measurement experiments, so as to derive the gravitational coefficient of the earth.

Everything was ready, and Wang Yuan found that he didn't have a stopwatch...... What a cheat!

In fact, even if Wang Yuan has a stopwatch, due to the poor accuracy of the experiment, most of them will not be able to get the textbook data of 98.

Then don't give any data, just the definitions and laws for the time being, and simply describe them. Newton's "Mathematical Principles of Natural Philosophy" often only gives definitions and laws, and even the experimental process is simply omitted, and only says that it can be known through "precise so-and-so experiments".

Wang Yuan repeatedly recalled various formulas and theorems, and after recording them, he found that they were not systematic with each other, and they had to be explained scientifically in an orderly manner.

Like Newton, Wang Yuan started with "quality", otherwise it would be difficult to explain many things later.

He had to define "mass", explain the relationship between mass, density and volume, and also give a concrete process of argumentation.

Newton was right when he said that he stood on the shoulders of giants, while Wang Yuan did not have the shoulders of giants to stand on. Newton could "get an experiment" because European scientists had done similar experiments, and Wang Yuan had to do the experiments himself.

The density experiment also lacked tools, so Wang Yuan had to get a graduated glass beaker first, otherwise the experiment would be very tedious.

So, Wang Yuan planned to create his own laboratory.

It just so happened that the house in the west of the city had been rebuilt, and only a few illegal details were demolished, and the overall layout had not changed.

"Mr. Wang, please sign and draw." The eunuch in charge of the handover said with a document in his hand.

Wang Yuan signed in three or two clicks, and he officially took over the house. However, the royal property is not under the management of the Ministry of Households, and he has to go to the Yamen to report, and then submit it to the Ministry of Households for approval, and then it will be regarded as a real transfer.

During the Zhengde period, the transaction of real estate and land was not as strict as that of the Hongzhi Dynasty.

Taking the transaction of land and property as an example, the Hongzhi Dynasty needed the local yamen to report to the household department, and then the household department issued the deed and the end of the deed. The deed is an indication that the household department acknowledges the transaction, and the end of the deed is left to the local yamen as a tax payment certificate.

In the Zhengde Dynasty, the household department no longer issued the deed, that is, the control over the land and property transactions, and sank from the household department to the local yamen. The household department only gives the end of the deed, which is equivalent to only caring about the content of the tax, and no longer cares who owns these acres of land. By the time of Jiajing, the household department had not even issued the end of the deed, and land transactions had become more frequent and difficult to control.

Wang Yuan's house and Zhuangtian were both rewarded by the emperor, and they could be directly taken to the household department for sealing, and the approval was quite fast.

In this regard, Wang Yuan has a mansion covering an area of 208 acres in Beijing, and another 1,000 acres of fertile land, a proper landlord! (Liu Jin's house, after repeated calculations by Lao Wang, found that one hundred and eight acres was not enough to build so many palaces, so it was changed to two hundred and eight acres.) ）

When the eunuchs had left, they left behind thirty-three male servants, twenty-six female servants, and ninety-seven tenant farmers attached to the fields.

Before setting up the laboratory, Wang Yuan had to arrange these people.