Picking up various tools, Jian Chen first took a small copper ball and rolled it on the ground at will. Pen | fun | pavilion www. ｂｉｑｕｇｅ。 ｉｎｆｏ

The copper ball slowed down and finally stopped. Then Jian Chen put the ball on the wooden trough that was flat on the ground, and this time the copper ball rolled much farther and the speed was much slower.

"You see, the copper balls can roll very close to the ground, but they can roll very far in a smooth wooden trough. Similarly, if it's icy, it's easy to glide a long distance on the ice with a plow, but if you're on the sand, you'll fall with a dog and chew on mud. Right? ”

"So can we assume that if it is extremely smooth, completely devoid of bumps and friction, is it impossible for this little ball to stop?"

Everyone nodded, this question is obvious, and it is also a question that many people have thought about, otherwise there would be no special sellers of whale oil and castor oil, let alone sleds and climbing plows on snowy days.

"So here's the problem. Assuming that this plane is completely frictionless, the ball will keep moving. So what is the reason for this constant movement? Is there an invisible hand pushing it along? Or, as I suspected, that everything tends to its current state and will not change until it is subjected to an external force? If the former assumption is true, then force is force; In the latter hypothesis, a force is a force, and a force is a force, and a force is what changes the current trend of an object, not what it is doing that year. ”

This is the most difficult question to understand, many people's brains can't turn around, and they can't understand why a small ball that is moving at a uniform speed is not forced, and if it is not forced, then why does it move?

"Based on these two assumptions, we have to prove it experimentally. Because sometimes the world is not what we think, and what we think may not be the truth, which needs to be verified. Before verifying, first of all, I would like to ask you a question, do you say that there is a force that can make objects fall from a high place to a low place? ”

"I think that's beyond doubt. This force, you can imagine you lying on the ground, someone stepping on you and pressing you. If there is an abyss below you, then it is the force that weighs on you that person that falls. ”

"We first have to make it clear that when you stand on the top of a mountain and are stepped on, you stand at the bottom of a mountain and feel the same power. But the question arises, why is the water falling from the heights more powerful, and the water falling from the lower places having less power? That's the crux of the whole issue, which is why I separate force from power. ”

Seeing that everyone had begun to wonder and start thinking, Jian Chen finally raised the wooden plank, glanced at the senior brother who was controlling the water drop timer, and got ready.

"It is now known that when the ball is placed on the ground and placed on a high place, the downward force is the same. So when the ball falls, the velocity is the same? Or is it getting faster? This is something that cannot be visually observed with the naked eye, but it can be tested with this small wooden trough. ”

After the connection was completed, Chen Jian repeated the experiment 20 times with different heights and lengths.

In the end, relying on the water drop timer and the inclined plank, a result was reached that all these people must agree with. Not with his mouth, but with the experiment and the drop timer and the ruler that were repeated twenty times right in front of him.

After writing down the results, distance, and time of each measurement on the board, Chen Jian said: "Now, we can clearly say that the ball is rolling down from the inclined plank faster and faster. And if we remove some of the friction, the air...... As you already know, air is qualitatively invisible, so it can hinder the balls...... So roughly, it can be seen that ......"

Turning back to sort out the relationship between the distance of time, he said: "It can be seen that the distance of the ball rolling from top to bottom in the same time is related to the square of time. Why is it related to the square of time? Let's assume that the velocity of the ball is getting faster and faster, but the velocity increases the same in each tiny amount of time - note that this is the increased velocity and not the velocity itself. ”

After taking out a plaster pen and writing it according to this speculation, there was thunderous applause again, and according to the simple uniform speed increase algorithm, the answer was basically the same as the conclusion proved by the experiment.

"From this, we can infer that if the force has been blessed on an object, if the force remains constant, then the object will continue to accelerate, and the speed of increase will be the same in each tiny period of time."

Then, if this conclusion is correct, it proves that a small ball moving on a smooth plane does not have a force blessing after we let go. Otherwise it will get faster and faster, instead of staying still. On the contrary, the ball will slow down because of friction, which proves my hypothesis that any object has a tendency to remain as it is, whether it is in motion or at rest. If no force is applied to the object, the object will remain forever. In the same way, the force is what changes the object to maintain its status quo, not to maintain its status quo. ”

"We can call this state of maintaining the current status quo inertia, in other words, the force is the inertia of the object."

"So what shape would a stone look like in the air if it wasn't resisted by the air?"

Turning around again, I wrote it out with a quadratic equation in a Cartesian coordinate system.

"Obviously, if it were not resisted by the air, the trajectory of the pebble would be a curve, and the equation would be a simple one-dimensional quadratic equation. As long as we know the speed of the stone and the force of the downward pull, we can know the position of the stone at any time, time distance, and under any conditions. ”

"It's the same with artillery shells, which can make our artillery technology a big improvement compared to Qi State."

"So, what is the approximate force of this downward drag? Approximate how much acceleration can it provide? We don't have an exact clock today, so it's hard to measure, but it can be roughly calculated by geometry. ”

"It's just that before we count, we still need to prepare in advance and determine a concept in advance. This concept, like defining a circle or a straight line, is not provable but is the basis of the whole of geometry. Again, there may be other explanations, but this system needs this foundation. ”

This time, everyone nodded silently, and Jian Chen took a deep breath and started the most difficult step.

He took out three springs and demonstrated the parallelogram law of force, a theory that had been accepted by many people before, and although it was vague about the philosophical concept of force, it understood the existence of the parallelogram law.

Later, he explained the relationship between force and reaction force in layman's terms, which did not use too much mathematical reasoning, but used some common phenomena, and the dualistic philosophical view of the whole group easily accepted the concept of action and reaction, which can be regarded as a good karma hundreds of years ago.

Finally, there is the most important question.

Chen Jian picked up a scale, there was a piece of iron on the weighing pan, and after reading the number, Chen Jian said: "This piece of iron weighs two catties." ”

Then he took out a magnet and placed it on the ground, and placed the weighing pan on the magnet to weigh it.

"Now, this piece of iron weighs three pounds. So, folks, why is that? ”

"Because you put a magnet underneath, and the magnet has a magnet that has a pull on iron."

One person gave the answer directly, and Jian Chen smiled: "Then the question is, assuming that we live on a huge magnet, does it seem to us that iron is heavier than now?" However, this piece of iron has not changed, is the weight inherent in the nature of iron? If it is, then the iron changes when it is placed in a place full of magnets, which proves that the iron is not the iron it was just now. But we all know that iron is still the same iron just now, so can it be said that light and heavy are not inherent and unchanging properties of iron? ”

"For example, why do people have to fall? Could it be that there is a similar power of a magnet, but this magnet not only attracts iron, but can have a kind of suction on any object, so people will fall. So suppose that in this case, that suction increases or decreases, do we change? If we haven't changed, then does that mean our essence hasn't changed either? ”

"Since we are still us, we are still here, and our essence has not changed, is it not just an outward manifestation of a force exerted on us, rather than the essence we have?"

In other words, this essence is part of who we are. Chopped us up, crushed us, roasted and frozen...... This essence is not going to change. This essence is what I call the polymerization of particles. As long as the particles are not recombined or disassembled, this essence will not change. Even if the smallest particles that make up our body are taken out individually, as long as the particles themselves are not broken or recombined, then our essence remains unchanged. ”

Speaking of this, Jian Chen picked up the prepared bowl, smashed it, and said: "You see, the essence of the bowl has not changed, the bowl is no longer a bowl in our eyes, but it is still a bowl from the perspective of particles. If we can reglue the pieces back together, it's still a bowl but it's not the original bowl. The appearance has changed, but some have not changed, so if the appearance is seen as an essence of the bowl, it can be said that the essence of appearance has changed; But the essence of the bowl is not only the appearance, but also the particles, so in terms of the essence of the particles, the bowl has not changed. ”

"Why, because bowls have so many essences. What I'm talking about now is one of the essences. For example, I am dead and burned to ashes, and someone points to my ashes and says this is Jian Chen, then ......"

"So, when I say this essence, it's called quality. is a total collection of particles that have not been recombined or split. ”

"Quality can be expressed in terms of weight, but it is not weight, and we must think about this issue clearly. Just like what I just hypothetical, suppose that the earth we are on has a special magnetic force that can absorb all things not just iron, then we receive this force and express it by weighing. ”

"Let's say I weigh one hundred and sixty pounds, but if I go to another place, the suction power of this place is twice as high as here, and I still haven't changed when I weigh ......"

"It's not hard to understand because the scale is a lever, so I've gotten heavier, and the scale has gotten heavier. But...... A different scale would be completely different, such as a spring. If I use a spring, I am 160 pounds here, but when I get there, it becomes 320 pounds, but I am still me, my essence and my quality have not changed, and it has become the external environment. ”

"So, mass is related to weight, but mass is not weight, but only an expression of mass after being forced. If there is no force, there is no weight, but there is also mass. ”

"This is the most difficult circle to go around, like force and energy, and if you can't accept this concept, I can't explain what happens next. For example, if you don't agree that one plus one equals two, then you won't be able to figure out all the arithmetic problems that follow. There is no why, just a definition, a concept, a foundation. You ask me why one plus one equals two? I can't explain it, but that doesn't mean I can't use it to figure out difficult questions. ”

"Of course, I'm just a hypothesis, so please don't refute it first, but look at my later inferences on the premise of agreeing with my hypothesis."

Chen Jian wiped his sweat, there is only one step between metaphysics and philosophy, the steam engine model at the beginning is really not important, on the contrary, these two definitions are the most difficult and important.

If you can't distinguish between force and energy, between mass and force, and by weight, you can't explain all the problems that follow.

And precisely, these two things are philosophical categories, in a sense similar to theology, giving a definition and then reasoning from that definition.

Mathematics is not a science, and quality is not a science.

That's the problem. In fact, the steam engine can be built by craftsmen without scientists, but Chen Jian had to start from here to define the foundation.

The technique is simple, but the Tao is too difficult.