"Dao Chief, how about we fly to Chang'an?" Xia Hongsheng drank tea leisurely and said to Yuan Tiangang.

Yuan Tiangang also took a sip of tea and sighed with a smile: "The ancient people who flew against the wind and flew to the sky were not seen in the world, and now those who can drink tea in the sky are just Xiahou and the poor road." ”

"Now that this thing has been made, anyone can do it in the future." Xia Hongsheng laughed, and then asked, "What's the matter, Dao Chief, do you dare to fly to Chang'an with me?" ”

Yuan Tiangang couldn't help but smile bitterly and said, "This thing has not been reported to Your Majesty, if it flies to Chang'an...... I'm afraid that it will alarm the people of Chang'an. I can't say it, I'm afraid I'm going to be shot down, and it doesn't have to be ......."

"That's not good, I must fly to Chang'an, and I must fly into the palace." Xia Hongsheng shook his head.

Yuan Tiangang choked on his throat with a sip of tea, coughed, and his face changed color a little.

"Don't think crookedly, Daoist." Xia Hongsheng saw that Yuan Tiangang was frightened, so he quickly waved his hand and said, "I won't hide it from the Dao Chief, can the Dao Chief know why I want to do this?" ”

"I don't know, Xia Hou has never mentioned it, although Poor Dao has been curious a few times, he didn't ask after all." Yuan Tiangang said to Xia Hongsheng: "Xiahou said it, after Xiahou uses this thing, he will give us Taoist ......."

"Rest assured." Xia Hongsheng nodded: "When did I lie to you?" I didn't know anything, I once promised Princess Changle that she would be able to fly over the walls of the palace like a bird, so I made this thing. How can a husband break his promise? The Taoist has to help me in this matter anyway, as if he was the payment for buying this hot air balloon from me. ”

Yuan Tiangang was taken aback at first, then laughed and said, "Hehe, a merry and talented man, a man of temperament." Even if he is an immortal like Xiahou, he can't escape the love of his children? ”

"Don't call me that." Xia Hongsheng was uncomfortable when he heard the word "immortal", it is estimated that Li Taibai was too resentful, and Xia Hong's goosebumps rose across time and space.

"Good! This is a busy poor road helped! Yuan Tiangang said to Xia Hongsheng: "After going down for a while, the poor road will go straight to Chang'an, and report to Your Majesty, saying that there is Taoism with the help of Xiahou to get the immortal magic weapon to offer Your Majesty, so that Your Majesty will wait in the court, and Xiahou will fly away in this hot air balloon." Is that good? ”

Xia Hongsheng's eyes narrowed, looking at Yuan Tiangang, this old god stick is cunning and cunning, and he said that it was a fairy treasure obtained by Taoism and presented to Li Shimin, which was really a triple win. Not only did the people see the hot air balloon, but they all knew that Taoism had a treasure that could fly in the sky, and they believed in Taoism even more. It can also show people of other religions and suppress their limelight -- why don't you fly into the sky if you can? And dedicated to Li Shimin, it is Taoism's initiative to show favor to the imperial power, and the fairy treasures are all taken out to the emperor, so how can the emperor not believe in Taoism and support Taoism?

It is foreseeable that if this is a momentum for Taoism, then this may be sensational.

A hot air balloon that can fly into the sky is enough to achieve the absolute superiority of Taoism in Datang.

"Good! That's it! Xia Hongsheng clapped his hands, raised his glass, touched the two of them, and drank a cup of tea. He didn't care how Yuan Tiangang used this hot air balloon to build momentum, as long as he could use this thing to fly over the palace and fly to Li Lizhen's palace.

It is already sunset, looking at the window, the sunset shines on the world, a piece of golden, the whole Jingyang is in full view, it is a wonderful scene.

Although, let Yuan Tiangang tell the emperor like this. However, Xia Hongsheng knew that the emperor might already know that there was a behemoth in Jingyang Academy that could fly to the sky and take people to the sky.

There are Li Shimin's eyeliner in Jingyang Academy, and there are spies he planted to report unusual things in the academy to him. Xia Hongsheng knows these things.

It is also one of the reasons why Jingyang Academy, as a private school, is so large, but it can be supported by the emperor.

Maybe the guards guarding the door were one of the people placed by Li Shimin. Xia Hongsheng knew in his heart that those guards were all members of Datang Blade, and their loyalty to Li Shimin was beyond doubt.

However, Li Shimin knows that he knows, but Xia Hongsheng doesn't say it, if it is not necessary, he will pretend not to know and will not ask openly. This is one of the tacit understandings between the two.

The hot air balloon fell, and Yuan Tiangang left Jingyang with Daotong without stopping for a moment, and went straight to Chang'an. Thinking about it, as shrewd as he is, and knowing that the emperor has a wide range of ears and eyes, this matter cannot be hidden, so it is better to tell him earlier to dispel his doubts.

Yuan Tiangang was sent away, but the students of the academy were still excited.

Fly to the sky!

What a mysterious thing!

And now it is in front of their eyes, and they have witnessed it with their own eyes.

Just for this, this Jingyang Academy is not in vain!

The conversation among all the students revolved around this hot air balloon, and naturally, some people couldn't help but ask it.

"Sir, how did you come up with the idea of making something like this, which could fly into the sky?" In the evening self-study class, some students asked questions.

If you don't understand, you have to ask, I know to tell you, I don't know, let's discuss together. This is one of the good school spirits of Jingyang Academy.

"Speaking of which, it involves a principle that we haven't talked about yet." Xia Hongsheng said to everyone with a smile: "I don't know if you have noticed, sometimes in winter, we bake the fire, and there seems to be some distortion on the flame, sometimes the paper is thrown into the fire, or the lighter grass ash will rise with the flame and float on the flame." Has anyone noticed this? ”

"Students know!" The student nodded: "When the fire is lit, some small debris will fly. Sometimes when the paper is lit, the confetti will fly. ”

Many students also nodded their heads to indicate that they knew.

"Have you ever wondered why the confetti flies when you burn it?" Xia Hongsheng asked with a smile.

"Because it's too light!" The students replied.

Xia Hongsheng smiled, casually tore off a small piece of paper from the textbook in his hand, put it in his hand, and asked, "This piece of paper is so small, it's very light, right?" Why isn't it flying now? ”

"This ......" The students were speechless for a while.

"As we said before, if an object is to move, there must be a force exerted on it." Xia Hongsheng continued: "The reason why the confetti can fly is because there is an upward force under it, which is greater than the weight of the confetti itself, so it can hold up the confetti and let the confetti float in the air. Think about it, where does this force come from? ”

The students under "From ......" thought for a moment: "Fire? ”

"Hehe, it's really about fire." Xia Hongsheng nodded and said with a smile: "To be exact, this force comes from the air heated by fire. Air, as we said before, is everywhere, and what we inhale and exhale is air. When the air is heated by the fire, the hot air rises above the cold air. Essentially, hot air is lighter than cold air because the mass per unit volume of hot air is smaller......"

Step by step, step by step, Xia Hongsheng explained the principle of why the hot air balloon can fly. (To be continued.) )