Time passes silently every second.

The sunlight shines through the window lattice and moves slowly across the ground.

Meng Yi and Hu Hai still couldn’t think of the answer.

Their eyes moved back and forth on the physics book, their brows were furrowed, and their foreheads were covered with fine beads of sweat, but the answer was like a mirage, far away and out of reach.

“Hey……”

Meng Yi let out a long sigh and looked at the open door.

He wished someone would rush in and tell him the answers to these questions right now.

Unfortunately, there was no one outside except the palace maids and eunuchs.

suddenly!

A light suddenly flashed in Meng Yi’s eyes, like a meteor streaking through the darkness, instantly illuminating his thoughts.

“I see!”

Meng Yi stood up suddenly and shouted excitedly, his voice echoing in the empty room.

Hu Hai, who was flipping through a book, was startled by the sudden shout and almost dropped the physics book in his hands.

He raised his head curiously and looked at Meng Yi, his eyes full of surprise and expectation.

“Uncle Meng, have you found the answer?”

Hu Hai’s voice was trembling with excitement. He couldn’t wait to know that the problem that had troubled them for a long time had finally been solved.

Meng Yi shook his head, but still had a smile on his face:

“No, I don’t have an answer.”

Hu Hai’s originally bright eyes dimmed in an instant, like stars covered by dark clouds, full of loss:
“I thought you had found the answer, Uncle Meng. I got so excited for nothing.”

Meng Yi didn’t care about Hu Hai’s little mood at all. He said excitedly:
“Although I haven’t thought of the answer, I have thought of how to find the answer!”

Hu Hai’s eyes lit up again. He quickly moved closer to Meng Yi and asked anxiously:
“Uncle Meng, please tell me how to find the answer?”

Meng Yi took out his cell phone from his pocket with a smile. The cell phone in his hand was like a mysterious magic weapon:

“I sent the questions to Lao Du, Lao Fang and others.”

“They are so smart, they must know the answer!”

As he spoke, Meng Yi carefully picked up his phone and took a picture of the questions he had written down.

In the chat interface named “Group of Intelligent and Talented Ministers”, Meng Yi quickly sent the picture.

Then, he added a series of names, including Du Ruhui, Fang Xuanling, Wei Zheng, Zhangsun Wuji, etc., and finally added:
“Whoever can answer these questions will be rewarded with fifty taels of gold by Master Hu Hai!”

After sending the message, a smug smile appeared on Meng Yi’s face, as if he had already seen the moment when the answer was about to be revealed.

He turned to look at Hu Hai and handed the phone over:

“Master Hu Hai, do you think it’s ok?”

Hu Hai stretched his head, his eyes wide open, and looked carefully at the contents on the mobile phone screen.

He took a quick glance and his first reaction was that there was nothing wrong, but he soon came to his senses, as if he was suddenly enlightened.

“Hey!”

Hu Hai shouted excitedly.

“Uncle Meng, when did I promise to give you fifty taels of gold as a reward if you could solve the problem?”

Seeing Hu Hai so excited, Meng Yi quickly comforted him:
“Don’t get excited, don’t get excited.”

“Master Hu Hai, think about it, although you lost fifty taels of gold, your brother the crown prince received praise from His Majesty.”

“You have nothing to lose!”

Hu Hai was stunned for a moment. He felt something was wrong after hearing these words.

What does it mean that I lost the gold, while my elder brother Fusu was praised by the emperor?

What about yourself?

What did you get?
“Uncle Meng, did you say something wrong?”

Hu Hai asked doubtfully.

“Shouldn’t I be the one to receive the praise from the Emperor?”

“Huh? No! That’s right!”

Meng Yi said with certainty.

Hu Hai’s face was full of doubts, and a series of question marks seemed to appear in his head:
“???”

Meng Yi then said quietly:
“Think about it, if His Royal Highness the Crown Prince is praised by His Majesty, will His Royal Highness the Crown Prince praise you?”

“He was praised by His Majesty, and then he came to praise you.”

“Isn’t that the equivalent of His Majesty praising you?”

Hu Hai frowned. To be honest, he still felt something was wrong, but it also seemed to make sense.

He was very conflicted and for a moment he didn’t know how to refute Meng Yi.

at the same time.

The Tang Dynasty’s imperial palace was brightly lit.

Li Shimin was sitting together with Du Ruhui, Fang Xuanling and other civil servants, drinking and chatting happily about the past and present.

Their faces were filled with relaxed smiles as they enjoyed this rare time together.

Suddenly, Du Ruhui and others’ cell phones all rang with notification sounds.

The crisp sound broke the original silence and everyone was stunned.

Li Shimin frowned slightly and said with some dissatisfaction:

“Didn’t I say that?”

“We are having dinner together today, so please keep your cell phones on silent to avoid being disturbed by Cheng Yaojin and his other generals.”

This time, Li Shimin specifically invited all the civil officials to dinner. It was not that he did not want to invite the military generals, but many of them were stationed in the border areas and it was difficult for them to get together.

He planned to wait for the next opportunity to gather everyone together and have a good reunion with the generals.

Du Ruhui said apologetically:

“Your Majesty, I forgot. I will mute it now.”

Fang Xuanling scratched his head a little embarrassedly and said:
“Your Majesty, it’s not that I don’t want to mute the phone, but I’m afraid my wife will come to me for something, so I will…”

When everyone heard this, they rolled their eyes at Fang Xuanling.

Everyone still doesn’t know Fang Xuanling?

He is just afraid of his wife, so he doesn’t dare to turn on the mute function and makes an excuse that something happened at home.

Who doesn’t have a wife or anyone else at home?
What could be so important that I have to look for it at this time?

Li Shimin waved his hand and said helplessly:
“Alright, alright, I won’t blame you this time.”

“Now you guys turn on mute.”

Du Ruhui and Fang Xuanling quickly took out their cell phones.

When they opened their phones and saw the message, they were stunned.

It turned out that the news was not from Cheng Yaojin, but from Meng Yi of the Qin Dynasty who “@”ed everyone in the group.

“Your Majesty, this is not a message from Cheng Heizi, but a message from Meng Yi of Daqin.”

Du Ruhui held the phone in front of Li Shimin and said respectfully.

“Ok?”

Li Shimin raised his eyebrows and looked over curiously.

Du Ruhui clicked on the picture and explained:
“Meng Yi asked us these questions, how should we answer them?”

Li Shimin looked at the question written on Meng Yi’s paper and couldn’t help but read it out:

“Where does the north wind come from, and where does it go?”

“Star……”

After Li Shimin finished reading, he frowned and said speechlessly:

“Why is he asking these questions?”

“If Sizi asked these questions, I could understand it, but why did Meng Yi ask these questions?”

Li Shimin really couldn’t understand why Meng Yi suddenly asked these seemingly simple yet confusing questions.

After thinking for a moment, Changsun Wuji said:
“These problems should be physical problems.”

“Although the questions are all about common things in our lives, it is difficult to answer them accurately.”

Fang Xuanling’s eyes lit up and he said:

“Although I can’t answer these questions, I know there is someone who can!”

Everyone looked at him and asked in unison: “Who?”

Fang Xuanling smiled complacently and said:

“Your Highness the Prince of Wei!”

Li Shimin asked doubtfully:

“You mean the bluebird?”

Fang Xuanling nodded and explained:
“Your Majesty, among all the ministers and princes, only His Royal Highness the Prince of Wei has a solid knowledge of physics.”

“I think these problems are easy for him.”

Li Shimin nodded in agreement and said:
“In that case, call Qingque over.”

Soon, a young eunuch received the order and left in a hurry.

After a while, Li Tai, who was slightly fat, came over.

Li Tai lived not far from here, and he came here in a sedan chair.

But even so, when he arrived in front of the palace and got out of the sedan chair and walked for a distance, he was still exhausted and sweating.

“Your Highness has greeted the Emperor and all the uncles.”

As soon as Li Tai entered the door, he bowed respectfully.

He has always been very polite and knows how to respect his elders. He never puts on a condescending attitude towards his ministers just because he is a prince.

Li Shimin nodded and said:

“Li Tai, I have a few questions for you.”

Li Tai quickly bowed and said respectfully:

“Excuse me, Father.”

“I will tell you everything I know.”

Li Shimin nodded with satisfaction, and then asked slowly:
“Where does the north wind come from, and where does it go?”

“The stars are blinking in the cold, why don’t they wear cotton clothes?”

“How dark is the night?”

“Where does the sun come from in the dream?”

“How big is the world?”

“What’s outside the sky?”

After hearing Li Shimin’s question, Li Tai was completely stunned.

He widened his eyes and asked in disbelief:
“Father, is this the question you asked?”

Li Tai originally thought that his father would ask him some questions about state affairs or national events, but he did not expect them to be these strange questions.

Li Shimin shamelessly nodded slightly.

“I heard that you have been doing well in physics and geography recently, so I want to test you.”

“Forehead……”

Li Tai paused and said.

“Father, please wait for me to think about it.”

Li Shimin nodded, signaling him to think slowly.

After nearly half an incense stick of time, Li Tai finally raised his head and said confidently:
“Father, I have already thought of the answers to all the questions.”

“Write it down now?”

Li Shimin shook his head and said:

“No, just talk to the phone.”

After saying that, Li Shimin gently pressed the button to send the voice message on WeChat. Everyone’s eyes were focused on Li Tai, waiting for him to reveal the answer.

Li Tai nodded and said:

“Father, the first question is: where does the north wind come from, and where does it go?”

“From a geographical point of view, the north wind usually blows from high latitudes to low latitudes.”

“In the Northern Hemisphere, cold air in the Arctic flows southwards due to the pressure difference, forming northerly winds.”

“From a physical point of view, the movement of air is due to the existence of pressure gradient force. Cold air has a large density and high pressure, and it will flow to the warm air area with low pressure.”

“The north wind will eventually interact with the warm air along the way and gradually lose energy. Its direction will be affected by many factors, such as terrain, other air currents, etc., and it will mix with the surrounding air after reaching a certain area.”

Li Shimin and others pretended to nod.

I don’t understand, I don’t understand at all.

But you can’t act like you don’t understand.

Li Tai continued:
“The second question is: the stars are blinking in the cold, why don’t they wear cotton clothes?”

“First, the stars ‘blink’ not because of the cold, but because of the refraction of the atmosphere.”

“When starlight passes through the Earth’s atmosphere, the density of the atmosphere is uneven and constantly changing, causing the direction of light propagation to change, making us see the position of the stars appear to be constantly changing, just like blinking.”

“Stars are distant celestial bodies, very far away from the Earth. They generate energy and heat through nuclear fusion and other methods. There is no need to wear cotton clothes to keep warm.”

Li Shimin and others could understand this explanation.

They had long learned from Ye Jiangnan that the stars in the sky were very distant celestial bodies.

The reason for blinking is that the positions of stars are changing.

Li Tai coughed lightly and said:

“Question 3: How dark is the night?”

“Well…how dark the night is depends on several factors.”

“We see from a geographical perspective that places away from urban light pollution will be darker.”

“In the absence of moonlight and clear weather, there are only faint starlight in the sky.”

“From a physical point of view, darkness occurs because there is not enough visible light reaching our eyes.”

“At night, the sun’s rays cannot directly reach the area where we are, and there is little light reflected from surrounding objects, so it feels very dark.”

“Generally speaking, in a completely dark environment, the illumination may be only a few tenths of a lux or even lower.”

Li Tai was halfway through his speech when he picked up the Coke that the eunuch next to him had prepared long ago and took a sip.

“Cool!”

Li Tai took a sip and felt that the heat in his body was much less.

After drinking the Coke, Li Tai said:
“Fourth question: Where does the sun in the dream come from?”

“The sun in the dream does not come from the physical world in reality, but is constructed by the brain during sleep.”

“When we fall asleep, especially during REM sleep, our brain’s neurons remain active.”

“The brain integrates and processes past memories, experiences, emotions, and various subconscious information.”

“If a person has seen the sun while awake and has memories of the sun’s vision and sensation, then in a dream, the brain may extract these memory fragments and construct an image of the sun, forming the sun in the dream.”

“In addition, dreams may also be affected by a variety of factors such as a person’s psychological state, emotions, and recent experiences. For example, if a person has a strong desire for warmth and light recently, the brain may create the image of the sun in a dream to meet this psychological need.”

Li Shimin and others nodded again.

They also know this.

The things in dreams are not real, nor are they a sign of what will happen in the future.

Ye Jiangnan also told them.

Li Tai continued:
“Question 5: How big is the world?”

“From a geographical perspective, the Earth’s surface area is approximately 5.1 million square kilometers, including land and ocean.”

“But if we look at it from a cosmic perspective, there is currently no definite boundary to the size of the world (the universe).”

“The immortal’s book never mentioned the specific value.”

“So, this question depends on whether you are asking about the Earth or the boundaries beyond the Earth.”

Li Shimin and others also knew this problem.

No matter how big it is, they just need to look at the map they exchanged from the immortal.

Li Tai paused and said

“Question 6: What’s outside the sky?”

“From the Earth’s atmosphere upwards, outside the sky is the Earth’s atmosphere, including the troposphere, stratosphere, mesosphere, thermosphere and exosphere, etc.”

“Beyond that is the vast universe, with various celestial bodies, such as the moon, planets, stars, nebulae, galaxies, etc., as well as interstellar matter, such as gas and dust.”

“In addition, there are various physical fields in the universe, such as gravitational fields and electromagnetic fields, as well as dark matter, dark energy and other forms of matter and energy that are not yet fully understood by humans.”

“This is what’s outside the sky.” (End of this chapter)