Although the Zhao Mansion now had enough space to easily accommodate the two of them, Eryang still let the servants settle down elsewhere as usual. The two of them put on narrow-sleeved Songjiang cotton robes and small hats with gauze, and lived alone in the mansion to serve their master.

After Zhao Hao handed the gift to his uncle to store, the two of them served the master lunch and could no longer hold back and asked:

"Master, when do we have class?"

"Anytime." Zhao Hao said with a smile. The two were about to cheer when they saw him stretch and say, "Let's start after my lunch break."

"Master, sleep well..." The two then remembered that Master had the unshakable habit of taking a nap at noon.

They had no choice but to wait patiently for Zhao Hao to get up.

In order to pass the torturous time, the two of them cleaned the main room and study where Zhao Hao lived carefully.

After Eryang had polished the floor and furniture until they were shiny, and they looked at the mirror-like table, they both felt their restless mood finally calm down.

"Brother, doing housework is really a great way to practice."

"Yeah, I haven't done any housework since I came home, and I've become restless..."

Wang Wuyang nodded in agreement, and suddenly heard the door of Zhao Hao's bedroom open.

“Master…”

The two people, who had been calm just now, rushed out of the study one after another.

"Can we start class now?"

This time, Zhao Hao did not refuse. He ordered Gao Wu to carry the large wooden box he had placed in the study and take his two students out of the Zhao Mansion.

He took advantage of the fact that the three of them were diverting the fans' attention and slipped out through the back door in a car. He didn't dare to reunite until he was out of Jubao Gate.

Then the carriage headed south, passed through Nanchenggang, and arrived at the picturesque Yuhuatai.

Yuhuatai is the commanding height in the south of Jinling City, facing the Da Baoen Temple in the distance. The observatory of the Ming Dynasty's Nanjing Imperial Astronomical Observatory was set up here.

The carriage went slowly uphill along the path through the bamboo forest. The forest was full of tranquility. Thousands of green bamboos stood straight and slender. The autumn wind blew, and the bamboos rippled up and down, making people feel as if they were in the waves.

Er Yang couldn't help but get excited and whispered:

"Master is indeed a master. He chooses the place for his lecture so carefully."

"Yes, in the past there was Wang Yangming's 'Teaching the Way on the Sky Bridge' and 'Discussing Flowers in the Mountains', and now there is my teacher's 'Teaching in the Bamboo Forest' and 'Discussing the Way in Rain Flowers', which can be said to complement each other..."

"We must remember Master's every word, action, and move, and write them down when we return. We will also publish a book called 'Chuan Xi Lu' in the future..."

"But Master is younger than me, so I'm afraid we won't be able to see the day when the "Chuan Xi Lu" is published..."

Zhao Hao was listening happily at first, but the two of them kept talking nonsense, so he glared at Er Yang and said:

"Stop talking nonsense!"

"Yes, Master!" Eryang was afraid that he would anger the master and not allow them to attend the class, so he quickly shut his mouth, looked at his nose with his eyes, and his heart with his nose, until the carriage stopped.

The carriage stopped at the top of the hill. The master and his two disciples got off and saw a five-meter-high building standing before them.

On the outer door of the building, there is a mottled wooden sign with the words "Observatory" written on it.

The main door of the observatory was ajar and unattended. Gao Wu pushed the door open and the three of them went in. They saw the yard was full of weeds and the walls were mottled. It had been in disrepair for a long time.

In the 18th year of Yongle, after Emperor Chengzu moved the capital to Beijing, the Nanjing Imperial Observatory existed in name only, and no one had been to the observatory for who knows how long.

The four searched for a long time before they found an old soldier guarding the tower. They stuffed two taels of silver into the old soldier's hand. Without saying a word, the old man opened the tower and sent the four to the top of the tower.

Then, without asking any questions, he went to the tavern under Yuhua Terrace to get some wine.

Gao Wu put down the wooden box on his back, then retreated to the next level to guard it, to prevent anyone from disturbing the lesson between master and apprentice.

Zhao Hao opened the wooden box, revealing a folding blackboard inside. He unfolded the blackboard, placed it on a rusty armillary sphere, and then used chalk made of lime to write five words on it neatly: "Open your eyes and see the world"!

"Open your eyes and see the world!"

Wang Wuyang and Hua Shuyang read out the question in unison.

Zhao Hao’s first lesson in the first year of the Ming Dynasty’s Longqing reign finally began.

In the shining afternoon sun, Wang Wuyang and Hua Shuyang looked at Zhao Hao standing with his back to the light, and felt that their master was covered with a layer of sacred light and shadow.

"Do you remember what strange things happened on the day when Shuyang became my disciple?" Zhao Hao asked.

"I remember that after the rain that day, a rainbow appeared!" Hua Shuyang immediately replied excitedly: "It can be seen that my disciple's apprenticeship is in accordance with the will of heaven!"

“Nonsense, rainbow is a bad omen…” Wang Wuyang curled his lips. He had no sense of celestial phenomena when he became a disciple, so naturally he was unhappy.

"Don't talk nonsense!" Zhao Hao glared at the two of them and said, "Let's start with the rainbow that day."

After a pause, he asked, "Do you know what Hong is?"

"Everyone says that the rainbow is a dragon sucking water." Wang Wuyang replied, and Hua Shuyang nodded. This was also the general perception of the public at that time.

"Really?" Zhao Hao smiled faintly, picked up the bamboo cup, took a sip of water, and spit out a spit of mist with his back to the setting sun.

Eryang then saw a colorful rainbow faintly visible in the mist.

Wang Wuyang couldn't help but exclaimed: "Is there a dragon inside Master?"

“Nonsense.”

Zhao Hao rolled his eyes and sprayed out another puff of mist. In the mist, the rainbow appeared again.

Hua Shuyang suddenly slapped his thigh and said excitedly: "I remember now. Mengxi Bitan said that rainbow is the reflection of the sun on the water. It happens when the sun shines on the rain. It turns out that Shen Kuo was right."

"Shen Kuo is Shen Kuo after all, his knowledge is far beyond the world." Zhao Hao sighed and said in a deep voice: "The second half of his sentence is right. But the first half is not right. The rainbow is not the reflection of the water, but the reflection of the sun."

"Sun Shadow?" Er Yang said in unison.

Zhao Hao picked up the blackboard and placed it in front of the small window. The tower suddenly became dark, with only a beam of sunlight shining in through the hole reserved on the blackboard.

Zhao Hao took out a prism made of East China Sea crystal from the box. The sunlight hit the mirror and refracted onto the wall.

Wang Wuyang and Hua Shuyang were stunned to see a colorful band as bright as a rainbow appear on the opposite wall!

"Red, orange, yellow, green, blue, indigo, purple..." Hua Shuyang read out the order of the seven colors of light and exclaimed loudly: "This shadow of the sun is exactly the same as the order of the rainbow!"

"Master, what's going on?" Wang Wuyang asked in confusion, "Why does a rainbow appear when the sun shines on the mist and this three-sided crystal?"

"Because sunlight is originally composed of these seven colors." Then Zhao Hao answered in a deep voice: "So anything that can diffuse light can produce a rainbow."

"Then why do we usually only see white light?" Er Yang asked in unison.

"Because the seven colors are mixed together." Zhao Hao tried his best to use language that the two could understand, and answered slowly: "But the properties of these seven lights are different. Once refracted, they will disperse and become the rainbow you see."

Zhao Hao said as he took out another equilateral prism and placed it upside down on the line that the previous prism had projected. After a slight adjustment, the colorful light gathered together again and projected white light on the wall...

"Master is right, the sunlight is indeed colorful!" Eryang slapped his thigh suddenly, feeling that he was led into the door of a new world by his master!

It’s true that you open your eyes and look at the world!

But this first lesson has just begun...

ps. The tenth update, 1300 votes and more updates, please give me monthly votes and recommendation votes!!!