Even if Biluo didn't say it, Fei Cai knew that she had understood Newton's first law.

Because just now, a line of text appeared in front of his eyes:

"Congratulations on completing the first phase of the task, the task rewards will be distributed after the end of the task, and the second phase of the task is now released, please pay attention to read it. ”

Immediately afterwards, the introduction of the second phase of the mission appeared in front of Fei Cai's eyes.

"Quest World: I Am a Confucian (Nightmare difficulty)

Quest Phase 2 Name: Capture those shrine maidens.

The goal of the second phase of the mission: unify the Wicans and become the leader of the Wicans.

Time Limit: Unlimited.

Number of attempts: 1 time.

Completion reward: 4,000 points.

Nightmare difficulty mission description: Due to the distorted worldline, you will not be able to kill the protagonist Wen Ren in any way until you complete the second stage of the mission. After you complete the second phase of the task, the third stage task will be automatically published. ”

Catch those witches...... Fei Cai looked at the name, and suddenly had a feeling of "there are too many complaints but I don't know where to complain".

Could it be that the name of the third stage is: Catch all the shrine maidens?

The fourth stage of the task is called: What is that, what are all the shrine maidens?

......

Fei Cai felt that his brain hole could not continue, so it was better to hurry up and get down to business.

The task of the first stage was completed so uneventfully, because Fei Cai had already guessed the mechanism of the source of the witch's power, and now he had no sense of accomplishment at all.

The content of the second stage of the task is the same, basically as he expected, this is indeed a farming mission. On the one hand, he couldn't kill Wen Ren before ruling the Wu Clan, and on the other hand, when he finally ruled the Wu Clan, Wen Ren is estimated to have grown into a super boss...... When the time comes, it will be difficult to say who will live and who will die.

Since it's useless to think about killing Wen Ren now, I just don't want to think about it. Fei Cai turned his attention back to the witch girl in front of him and said, "I'll show you the third oracle of the Great Witch God first. ”

The reason why it is not the second is because Newton's second law is actually about the derivative of momentum versus time, which requires a certain knowledge of calculus to really understand, which already belongs to the category of advanced mathematics and cannot be learned in a day or two. Fei Cai still vividly remembers the fear of being dominated by advanced mathematics in his freshman year......

However, he has already thought of a plan, first let Biluo get a preliminary idea of what Newton's second law is about, which is the most common process of approximating uniform acceleration in linear motion, that is, free fall.

When the time comes, it should be exciting to free fall from a height of thousands of meters......

"The action and reaction forces between the two interacting particles are always equal in magnitude, opposite in direction, and in the same straight line. ”

As Fei Cai spoke, his palm was lifted upward, and he and Biluo suddenly floated.

Newton's third law is the most intuitive one, and Fei Cai's demonstration method is also very simple, he stretched out his palm and said to Biluo: "Push me." ”

Biluo hesitated slightly, but the folk customs of the Wu clan are more open than the Central Plains after all, and it is not a big deal for a woman to touch a man, not to mention, in Biluo's opinion, Fei Cai is not a mortal at all, he is a "divine messenger".

After only hesitating for a second, she reached out and pressed her hand against Fei Cai's palm and gently pushed it.

The two drifted in opposite directions.

"I see. Biluo said.

She stretched out her hand to Fei Cai and recited softly: "The force and reaction force between two interacting particles are always equal in magnitude, opposite in direction, and in the same straight line. ”

Fei Cai suddenly felt his body stagnate, and then slowly stopped retreating, and Biluo's side was the same, as if an invisible rope had pulled the two of them.

"Looks like you understand. He nodded. "Next, let me explain to you another very important oracle of the Great Witch God, called the 'Oracle of Gravity', which is the real reason why objects fall to the ground......"

Fei Cai let the two of them return to the ground, walked to Biluo's side, and began to talk about the law of gravitation, in which concepts such as "square" and "inverse ratio" require a certain mathematical foundation, but now he does not require Biluo to be able to calculate the exact value of gravity, but only qualitatively allows her to understand gravity.

Unconsciously, the sun had begun to tilt to the west, and Fei Cai finally gave Biluo a general understanding of the content of gravity, but there was still some distance to understand.

When he answered Biluo's questions one by one, the last barrier focused on two issues.

"Not only the earth is to all things, but there is also a mutual attraction between all things?"

"The land we live on is not a flat earth, but a ball?"

The shrine girl frowned slightly, she believed in the oracle taught by the divine envoy, and she could barely imagine it, but no matter how she imagined it, deep down in her heart, she could not really understand these two questions.

Fei Cai understands Biluo's feelings, these two facts are indeed contrary to people's consciousness.

If the mass does not reach a certain level, the gravitational force is too weak, and the gravitational force between the objects around people is so weak that it is not felt at all.

Compared with the human beings of this era, the earth is too big, and people can only see the flat earth, how can they imagine that they live on a sphere? If they live on a sphere, why don't they fall into the universe?

Therefore, these two questions can be answered together.

Fei Cai stretched out his hand, lifted a huge water ball with a diameter of two meters from the river, and said: "We live on a planet, you can understand it as a huge spherical stone. In other words, it is not very different in nature from the stone under our feet. We are attracted to the ground only because the mass of this big stone is too great, so the force that attracts us is greater, and as for these small stones under our feet, their mass is too small, so the force that attracts us is too small, so small that we can't feel it at all. ”

Saying this, Biluo finally understood a little more, she thought about it, and asked, "Then why do we see that the ground around us is flat?"

"Because the planet is too big, and we're not standing tall enough. Fei Cai smiled. With his other hand, he hooked his fingers and lifted an ant on the ground and placed it on the surface of the giant water balloon.

Due to the surface tension of the water, the ant is "sucked" on the surface of the water balloon and can neither sink nor leave the water, it struggles in vain, and looks very funny.

"Just like this ant, if you look at it from its point of view, it must feel like it is on a flat, endless surface of water. What's more, compared to this planet, we are much smaller than ants. Fei Cai said.

"Hmm......" Biluo nodded thoughtfully.

After a while, she suddenly asked, "But if this ant stands tall enough, it can make the curved outline of this water ball, right?"

At this moment, Fei Cai was a little surprised, this is exactly what he wanted to tell Biluo, but he didn't expect her to think of it herself.

"That's right! You're smart. He nodded.

"So, if we also stand tall enough, will we be able to see the arc of the planet?"

Fei Cai smiled when he heard this: "You guessed right, the planet is so big, why don't you go to a high place to see it?!"

With that, he raised his hand and made both of them float. But this time, they no longer just floated at a height of one meter, the two of them kept going up, and in the blink of an eye, they had risen dozens of meters.

Then, they rose to a height of several hundred meters.

They continue to rise......

"Don't be afraid. Fei Cai said loudly. At this altitude, the wind was already a little strong, whining in the ears.

Biluo was a little scared, but she looked at Fei Cai and smiled, "I'm not afraid." ”

"Let's go a little higher. After Fei Cai finished speaking, he waved his arm and arranged a spherical force field around him, isolating the two from the outside world.

The wind suddenly disappeared.

"I used the force field to isolate us from the outside, and the temperature in the force field didn't drop too quickly, but further up, it was still cold, so be mentally prepared. Fei Cai said to Biluo.

"Hmm!" Biluo nodded, although she didn't understand very well.

They continue upwards.

1,000 ......

2,000 ......

10,000 meters......

20,000 meters......

The earth was getting farther and farther away, the clouds were trampled under their feet, the color of the sky was getting closer and closer to black, Biluo raised her head, and in the sky, she saw the stars that should have appeared at night.

When the altitude reaches 30,000 meters, Fei stops rising, and this altitude breaks through the troposphere of the atmosphere, where the surface of the Earth's arc can already be seen.

He stood beside Biluo and stretched out his hand to point into the distance: "Look!