Huo Gang's words were like opening a new window for Sun Er, and his whole face was slightly red, not only Sun Er, but all the craftsmen who heard Huo Gang's words here were all red, because they seemed to have heard a lot of great knowledge.

"Huo Zheng." Huo Gang said that he didn't continue here, because a lot of chemical knowledge, in fact, Huo Gang also forgot, or he may remember, but if you ask him to say it systematically, Huo Gang can't do it, but sometimes he can think of saying a little bit, because modern people accept too much knowledge and too much.

A lot of knowledge is hidden deep in the brain, and sometimes it can just pop up.

"The end will be."

Huo Gang took out his personal seal from his arms and threw it to Huo Zheng, and then said: "You go to Wan'er, take this, and tell her that I, bring that set of books on chemistry and physics, and I will use it." ”

Physics and chemistry are not separated, physics and chemistry must be together, since it has been decided to take it out, then Huo Gang will naturally not ignore it.

"Yes. The subordinates went in person. Huo Zheng said very simply, he knew that this set of books was very important.

However, this set of books, Huo Gang has actually printed several sets of them, what he is afraid of is that in case of damage or loss, these things are all given by the spirit of the Jade Gate, if they are lost, let Huo Gang write them again, it will be more difficult.

Huo Gang has never felt that he is a genius, he can only learn this knowledge, but to summarize the laws of nature and form a certain truth, then only Dana can do it.

There must be such people in the world, and Huo Gang believes that there will be many in ancient China, and it is not necessarily the West that will appear as a scientific giant, and now Huo Gang hopes that such a person can appear in his territory.

At the very least, Huo Gang hopes that in the history of this world more than a thousand years from now, many of the names of the laws will be named after the Han people.

Of course, perhaps more than 1,000 years from now, there will be only Han people left in this world, but there will be different ethnic groups with different hair and skin colors among the Han people.

"Now that I've said that for today, I'll tell you a few more things. These things may be needed soon, but let's talk about them together today. Huo Gang thought about it and simply fought from his seat.

"Let's change places, Lu Mu, you go find me some pulleys." Huo Gang said.

The pulley was recorded in the "Book of Ink" as early as the Spring and Autumn Period and the Warring States Period, and the pulley block had been used in the entire industrial city for a long time.

Huo Gang wanted the pulley group for something else, and soon, several pulleys were sent to Huo Gang, and at this moment, Huo Gang's surroundings were already surrounded by a circle of craftsmen, and Anno and they were also on the periphery, but they couldn't grab these craftsmen by grabbing the position.

"Let's talk about a simple, but practical thing today." Huo Gang said as he placed the pulleys side by side on the ground, put a brick on them, and then said to Lu Mu: "You should be familiar with this way of pulling heavy objects, right?" ”

All the craftsmen nodded, of course they were no strangers, it was nothing more than a row of logs side by side in the ground when pulling heavy loads, so that it was often used to transport heavy loads.

"Have you ever thought about how it would be to shrink such a log to the size of a human finger, and then make it a circle side by side, with a log attached to it in the center, and this log is the axle of the carriage, and then the outer circle is the hub that connects the wheels, and these little cylinders in the middle are replaced?" As soon as Huo Gang said this, several carpenters on Lu Mu's side instantly stayed in place.

Not only these carpenters, but Sun Er also understands them, although they are not carpenters, but they have been working together for a long time, and they also know a little about carpenters, not to mention that they don't know the structure of the carriage?

"This ...... This...... The carriage will turn faster and with less effort. General, what you said about this should mean that we can replace these cylinders with steel? Lu Mu said with some excitement.

"Yes, now that we have enough steel, if the bearings and wheels in the middle of the carriage were made of steel, and the steel cylinder in the middle was replaced, and lubricating oil was added, I think the efficiency of the carriage would be much more efficient than it is now, right? Oxen and horses will be more labor-saving when pulling the carriage. Huo Gang said with a smile.

"Yes, yes, yes, with that in mind, the chief...... Is it okay to use steel balls? Lu Mu thought for a moment and asked again.

Huo Gang immediately smiled, look, isn't this coming? "Of course you can, but the quality of our steel now, if we use steel balls, the load-bearing capacity is definitely not as good as that of cylinders, but these need to be experimented with, because horse-drawn carriages can also pull different goods, can't they?"

It's a pity, everything else can be there, but they really can't make this rubber thing, it's far away on another continent.

"I immediately set out to improve it, and this thing can be used for many things, such as the bearings of the large power wheels on our machinery." It didn't take long for Rumu to have a new idea.

"Yes, since this gadget has been solved, I will teach you the second thing now, the Han people call it Gewu, let's be simple, from today onwards, we will call it physics, that is, to study the truth between all things in the world, the meaning of the law." Huo Gang smiled and spoke.

"If chemistry is the study of the composition of the different components of everything in the world, and then how these components react with each other, for example, the process of burning wood is the process of reacting with oxygen and releasing heat, which is chemistry."

"Physics, then, is the study of some principles and laws that have always existed around our natural world, and formed by nature."

"For example...... Huo Gang looked left and right, and then picked up two stones from the side, one big and one small, Huo Gang smiled and asked: "If we throw these two stones down from the mountain together, who will land these two stones first?" ”

"Big." Everyone spoke in unison.

"Hehe, practice makes sense, let's just experiment. Let's go to the windmill tower and send someone up with these two things. Huo Gang said with a smile.

Needless to say, about half an hour later, all the craftsmen standing beside Huo Gang were completely stunned, the size of the two stones was very different, but when they fell from a high place to the ground together, everyone saw it, and it did fall to the ground together.

The question is...... Why is that?!

"You see, this is the charm of physics, the force of this kind of object falling, I call it gravity, and gravity should be clear to everyone, when falling from the sky, the speed is getting faster and faster, this acceleration I call gravitational acceleration, and gravitational acceleration has nothing to do with the mass of the object itself."

"Okay, we're going to waste a lot of time when we say this, and what we're going to talk about next has nothing to do with this, I'm just telling you that these truths are universal in nature, and I'm going to tell you about this truth, and the next tool that I'll let you make, I'll call it a hydraulic press." Huo Gang took a deep breath and said seriously.

Hydraulic presses? Three words popped up in everyone's heads, but they didn't ask wisely, but were waiting for Huo Gang's professor, and at this moment, Huo Gang knew everything in their hearts.

Modern people know about hydraulic presses, and many industrial fans of large-scale free-forging hydraulic presses know that it is the important weapon of the country, if modern people hear Huo Gang's words, they will spray him directly, and engage in hydraulic presses in ancient times, isn't this nonsense? After the founding of New China for so long, you can't make a hydraulic press, you can only be controlled by Europe and the United States, you can make it in ancient times? Are you kidding?

As a matter of fact...... I really can.

Because what was lacking after the founding of New China was thousands of tons, tens of thousands of tons of hydraulic presses, and what Huo Gang is making now must not be so perverted.

A few tons, dozens of tons of hydraulic presses are also useful in this era, and the principle of hydraulic presses, not only can make such large machinery, such as hydraulic devices are actually the same as the principle of hydraulic presses.

It is based on Pascal's law, which is a law of hydrostatics, even if it is said that in an incompressible stationary fluid, after any point is increased by external force, the pressure increase is instantaneously transmitted to the points of the stationary fluid.

And there are too many places where this principle can be applied, for example, the brakes of later generations of cars use this principle, the brakes are stepped on in the car, and then the brake fluid push pads in the pipe are braked.

So although the brake has electronic assistance, but in fact, the electronic assistance is even if it takes a little effort, but it itself is a mechanical structure, you can still brake! But once the brake fluid leaks, it will give you a thousand times more power, and your brakes will be completely useless.

For example, if a certain pressure is applied to one piston in a hydraulic system, the same pressure increment will be generated on the other piston. If the area of the second piston is 10 times the area of the first piston, then the force acting on the second piston will increase to 10 times that of the first piston, and the pressure on both pistons will be equal.

To put it in layman's terms, if you use a syringe, the syringe port is connected to a bucket with a pipe, and there is a piston in the bucket, and the two pistons are connected with water, if the bucket is 100 times the liquid surface area of the syringe.

Then you apply 1 N force to the piston of the syringe to push it, and assuming that the connection between the syringe and the bucket is completely sealed, then the force on the piston of the bucket will increase to 100 N!

This is the principle of hydraulic press or hydraulics, which in this era can actually be manufactured.