I am a Primitive Man
Chapter 840 – The Primitive Version of “Two Kids Arguing About the Sun”
Han Cheng’s affirmation and praise made Shi Tou’s face, already flushed with excitement, turn even redder.
At this moment, he was filled with joy, reminiscent of many years ago when the Divine Child first came to teach them to write and speak Mandarin. Back then, he always did things quickly and well, earning the Divine Child’s praise, and he felt the same happiness now.
Those who had previously grasped some concepts but never fully understood them now, after hearing Shi Tou speak and recalling Han Cheng slowly turning the fruit in the earlier demonstration, suddenly had everything click into place.
Yes—it’s because the Earth rotates from west to east, so the east sees the sun first.
As the Earth continues to rotate, the sun appears to move westward. When the part of the Earth where their tribe lives rotates out of the sunlight, the sun disappears.
Ah! So that’s why we have day and night!
It’s not that the sun moves across the sky—it’s the Earth we live on that rotates!
Many people’s faces showed realization, as if a whole new door to understanding had opened before them.
At the same time, their gaze expanded beyond their familiar small patch of land to a much larger world.
When they thought about the stars and the vast oceans, realizing the secrets behind the Earth they live on, looking back at their settlement seemed almost trivial.
Yet, understanding their own smallness prevented arrogance and fostered humility.
“Can anyone tell me why it’s hottest at noon, but cooler in the evening?”
Han Cheng paused, letting the tribe members ponder the question themselves.
“It’s because the sun is out at noon, but at night, the sunlight doesn’t reach us.”
This was a relatively simple question. As soon as Han Cheng finished speaking, many raised their hands.
He allowed one person to stand up and answer.
“Very good! It’s because at noon the sun reaches us, and at night it doesn’t. It’s like sitting by a fire—the fire warms one side, the other side stays cold.”
Han Cheng nodded approvingly, then looked at the pleased young person and continued: “Now, can you tell me why it’s hottest at noon, yet cooler in the morning and evening? In the morning and evening, the sun is shining just like at noon.”
The person answering was immediately stumped.
Indeed, in the morning and evening, the sun shines too—so why is noon the hottest?
Many others in the large brick-tiled house also struggled to answer, thinking hard.
“Divine Child, I know!”
After a moment, Shi Tou raised his hand, clearly excited.
Han Cheng let the previous speaker sit down and gave Shi Tou the floor.
“It’s because in the morning and evening, the sun is farther away, but at noon it’s closer.
It’s like sitting by a fire—closer is hotter, farther is cooler.”
Shi Tou stood up, explaining and even imitating Han Cheng by using the familiar example of sitting by a fire.
Han Cheng smiled again. Shi Tou really had talent in these areas—he reminded Han Cheng of his younger self.
“But how do you know the sun is closer at noon and farther in the morning and evening?”
Someone asked Shi Tou.
Han Cheng didn’t intervene; instead, smiling at both the questioner and Shi Tou, curious how Shi Tou would respond.
“It’s simple. Not long ago, the Divine Child used a string and a fruit to demonstrate that the sun is farther from the edges of the Earth than from the center. Using the same method, you can figure this out.”
Shi Tou calmly explained the reasoning, recalling Han Cheng’s earlier demonstration.
Han Cheng smiled once more—Shi Tou had actually connected the dots from an earlier experiment about why it gets hotter further south, applying the same logic to this question.
Hearing this, many recalled Han Cheng’s demonstration near the rabbit pen, which connected it to the current situation and made sense.
Shi Tou felt a sense of satisfaction, enjoying a “top student teasing the struggling student” kind of joy.
“But why does the sun look so big in the morning and evening, yet smaller at noon? Isn’t something closer supposed to look bigger?”
Another person asked, sounding puzzled.
Once this was said, even those who had just agreed with Shi Tou became confused.
Being closer to the fire makes it warmer, so at noon the sun is closer—makes sense.
But if you look closer, the sun should appear bigger—but at noon, it looks smaller.
This immediately scrambled everyone’s minds, even Shi Tou’s.
No one could understand why the sun seemed closest at noon but appeared smallest.
Han Cheng wasn’t surprised. This is an age-old problem.
Confucius once encountered two kids arguing about the sun and was left speechless, even mocked by them.
It was normal that the tribe’s members were confused by this “timeless riddle.”
Even Han Cheng himself didn’t fully grasp it until high school geography.
“Divine Child, is it closer in the morning or at noon?”
Shi Tou, still dazed, finally asked.
He had been confident in his answer, but now wavered.
Everyone looked to Han Cheng, seeking a definitive explanation.
“Of course, the sun is closest at noon, farther in the morning and evening.”
This was a geography question that would stump Confucius but not Han Cheng. He gave a clear, direct answer.
The tribe still wanted to know why the sun looks bigger in the morning and evening despite being farther.
“The morning sun is slanted and refracted by the atmosphere, which magnifies it. At noon, the sun shines directly, showing its true size, so it looks smaller.”
The tribe, of course, didn’t fully grasp this explanation, not even Shi Tou.
Han Cheng then fetched a piece of ice from a basin outside, shaping it like a convex lens and placing it in front of one eye.
The tribe was astonished—Han Cheng’s eye appeared much larger.
Moving the ice away restored its standard size.
“See? The atmosphere works like this ice, magnifying the sun in the morning, but not at noon.”
He repeated with a flat ice piece, showing that the effect was absent.
This simple experiment helped many understand the concept. Han Cheng let them handle the ice themselves afterward.
“Divine Child, the Earth is a big sphere and rotates—why don’t we get thrown off?”
Shaman finally asked, having thought about it for a while.
Han Cheng explained:
“The Earth has gravity, which holds us down. Everything on it is attracted. This invisible force keeps us from being flung off as it rotates.”
The tribe fell silent, some amazed, some puzzled, some thinking.
“But birds fly, and I can jump!”
“Birds eventually land, and your jump is brief. Without gravity, you wouldn’t fall back—you’d float or keep going up. Gravity keeps us grounded.”
Everyone paused, realizing this made sense.
Han Cheng smiled—his “Newton’s apple” lesson was a success.
He reflected: the first discoveries and inventions are always hard; once someone explains them, future generations find it easier.
Today, he taught natural science, including gravity, in a way understandable to the tribe. Though the tribe’s members were ordinary, this knowledge could guide the tribe’s future.
Over time, the tribe would advance, building on the achievements of their predecessors and producing new talents.
Science is indeed the primary driving force, and foundational knowledge like natural science is crucial.
Gravity leads to discoveries, breakthroughs, and technological growth.
Han Cheng planned to teach tribe members more of this knowledge, recording complex topics for future generations to understand when the tribe reached a more advanced stage.
Lying on the kang (heated bed), he felt confident about his ideas. Guns and money change hands, but truth, especially scientific truth, remains.
Though his plans were ambitious, even more difficult than cultivating crops, he saw hope in planting seeds today for future growth.
In the following days, the weather fluctuated—sunny, cloudy, with occasional light snow.
Leaves turned yellow and fell under the cold wind, signaling the end of Green Sparrow’s eleventh autumn.
Yet tribe activities continued—burning charcoal, transporting manure, plowing land, and Han Cheng continued teaching geography.
He used the question-and-answer method, explaining seasons, Earth’s orbit, perihelion, aphelion, and tropics.
Some struggled to understand, but Han Cheng’s patience and repeated explanations allowed them to grasp it gradually.
Even those who initially failed to understand retained the knowledge in their hearts, which would later allow them to apply it naturally.
For ordinary people, memorization comes first, then application. For gifted individuals like Shi Tou, this step was unnecessary.
Han Cheng reflected: Knowing your limits is crucial; don’t overestimate or underestimate yourself.
As night fell, the tribe rested.
Shi Tou peeked through a corner of the window, seeing two bright stars, his eyes shining like them. Recalling Han Cheng’s teachings, he felt exhilarated.
He realized the seemingly ordinary world around him had deep reasons behind everything.
Han Cheng also lay on the kang, reflecting. As a time traveler in prehistory, his knowledge was invaluable.
He could build and guide the tribe without interference, spreading science and laying a foundation for future generations.
Though implementing it fully now was unrealistic, planting the seeds today could yield a plentiful harvest tomorrow.
He drifted into sleep, thinking of possibilities.