Chapter 1: Heliocentrism

I was transmigrated into a female-oriented romance fantasy novel.
For me, a STEM professor and science YouTuber in my thirties, a romance fantasy was just absurd.
I mean, why would a thirty-something man read a novel about ‘a female lead receiving unconditional love and protection from two alpha males at an academy, agonizing over who to choose in a love triangle’?
Reading this kind of novel in the first place felt strange.
As expected, it wasn’t fun, so I only read a little before quitting.
My fingers, which had turned the pages out of curiosity, soon slammed it shut in annoyance.
But why did I end up getting transmigrated into a novel like this?
This was a phenomenon that couldn’t be explained by any scientific reason.
And to be transmigrated as an extra who appears in just one scene, confessing to the female lead after being smitten by her beauty, only to be rejected.
Like the science YouTuber I was, I went to the academy library to find out how such a phenomenon was possible.
After flipping through musty-smelling pages under a flickering candle, I reached one conclusion after my investigation.
This world was like Earth, but its level of science was far too poor.
Science was, quite literally, wandering in darkness.
They believed in the ancient cosmological view of geocentrism and didn’t even know the law of gravity.
Their level was just barely past the ancient times when they believed the Earth was flat; it was so pathetic I couldn’t bear to watch.
I should let the kids have their romance full of love and excitement.
An adult like me should try to enlighten this world with science.

The day dawned in the dormitory.
Warm sunlight poured in through the window.
The sound of bells echoed gently from the academy’s spire, announcing the arrival of morning.
The crowing of a rooster could also be heard faintly in the distance.
I stretched as I woke up, then dragged my sluggish body to the washroom.
After hastily brushing my teeth, I looked in the mirror and saw a handsome, black-haired teenage boy staring back at me with languid eyes.
However, the mirrors in this world were nothing more than well-polished iron plates, so the reflection was hazy and murky, as if covered in fog.
The people of this world didn’t even understand the basic principles of a mirror.
Smooth objects have specular reflection, reflecting light in a single, uniform direction.
Rough-surfaced objects like paper or wood cause diffuse reflection, scattering light in many directions.
Only when light is reflected orderly through specular reflection can we see a clear image.
By applying this principle and coating a smooth metal onto transparent glass, you get a perfect modern mirror.
Since they don’t know the principle and just go by the empirical knowledge that ‘doing this reflects a person’, they end up using things like iron plate mirrors.
This is all a regrettable consequence of their lack of science.
I sighed, put the kindling they called textbooks into my bag, quickly got ready, and headed to the academy.
“Aren.”
A low, deep voice called my name from behind me.
When I turned around, a tall, muscular, handsome man with cold eyes was standing there.
No, he was beyond just handsome.
His looks were truly unrealistic, befitting a male lead in a romance fantasy.
He was, in fact, one of the two male leads.
Albrecht von Wallenstein.
The eldest son of the ducal house of Wallenstein and a genius of swordsmanship.
He had countless titles, such as being called the next Knight Commander.
His character was also striving for maturity, a cheat character that couldn’t exist in reality.
In this romance fantasy, he was one of the two alpha males who liked the female lead, forming a love triangle.
“What is it, Albrecht?”
I had a rough idea why he had called me.
“Can I have a word with you for a moment?”
“Sure. Go ahead.”
“I’m not trying to scold you. I just wanted to say something on her behalf.”
“About what?”
“It’s about what you said to Lilia a few days ago.”
I, the character named Aren, had a record of confessing to the romance fantasy’s female lead, Lilia.
Of course, this was before I was transmigrated.
Albrecht pierced me with his sharp, arrowhead-like green eyes.
“Even if you have feelings for Lilia, confessing so abruptly like that will likely make her uncomfortable.”
From what I read in the novel, Albrecht was supposed to be quite angry with me right now.
Because Albrecht had fallen for Lilia at first sight, and I had confessed to her in front of everyone, embarrassing her.
Fortunately, for a romance fantasy male lead, he was a decent young man, so he was only advising me in a reasoning tone.
“I suppose so.”
I agreed calmly.
Albrecht looked quite surprised.
Because the extra named Aren in the novel was supposed to be a character who couldn’t grasp his place, persistently chasing Lilia and confessing, only to whimper and back down after a cold word from Albrecht.
I had just shown a completely different reaction from the Aren that Albrecht was used to seeing.
“Then you won’t embarrass Lilia with such actions in the future, will you, Aren?”
“Of course. I’ve completely given up on Lilia. What can I do if she won’t accept my confession?”
“It’s good that we can talk this out. I didn’t expect this from you.”
“Well, you know now, so that’s that. Keep up the good work, I’ll be going.”
I patted Albrecht’s shoulder and turned away.
At that, Albrecht tilted his head in confusion.
I raised one corner of my mouth.
‘Love squabbles should be left to the kids.’
Why would I get involved in something like that?
I’ll be busy enough with science.

When a tiny human looks up at the vast sky, it appears as if the heavens revolve around the Earth.
That was the limit of their small eyes, and ancient scientists took this optical illusion as truth, concluding that the Earth was the center of the universe.
Ancient scientists drew on papyrus that all celestial bodies revolved around the Earth, writing that they orbited it like puppets moved by an unseen hand.
This is ‘geocentrism’.
This foolish theory dominated human thought, reigning for a thousand years until the heliocentric model, with the sun at its center, appeared in the late Middle Ages.
I sat in the lecture hall with my chin propped on my hand, chuckling softly.
Because the words coming from the astronomy professor’s mouth were absurd.
“By placing the Earth at the center of the universe, we’ve become able to explain the movements of the stars. Perhaps there’s nothing more for us to discover about the heavens.”
If I told the professor lecturing now that the Earth wasn’t the center of the universe, would she be able to understand?
The fact that even the sun is in a remote corner of the universe, and that the universe has been continuously expanding since the Big Bang.
Of course, she wouldn’t know what any of that is.
The professor standing at the podium was an elf.
Her ears were pointed, and her figure was slender.
A genius elf who had lived for a staggering one hundred and forty years, dedicating her life to scientific research.
Her name was Nihir, and she appeared to be in her twenties.
I had high hopes since the person said to be the smartest at the academy—no, in the world—was teaching astronomy.
But as expected, she was trapped by the limitations of her era and couldn’t escape them.
“Professor. Isn’t the world really flat? I just don’t get it. When I look out the window, the ground looks flat.”
Still, compared to the academy students who were barely twenty, Nihir was on a much higher level.
At least she wasn’t a fool who insisted the Earth was flat.
Nihir had quite a good personality.
Seeing her repeat the same explanation countless times with a smiling expression in her eyes was proof of that.
“When we see a ship approaching from over the sea’s horizon, the first thing we see is the top of its mast. And when we climb a high mountain, we can see farther. Why is that? If the world were flat, we couldn’t explain those things, could we?”
“But if the Earth is a sphere, how can we stand on the ground? Why don’t we slip and fall down? Are we living on the top of the sphere while everyone else falls off the bottom?”
Nihir chuckled softly at the student’s comment, which had abruptly designated most of the Earth as a death zone.
So did I.
“That’s because the Earth is at the center of the universe, and the center of the Earth pulls everything towards it. All things move around the Earth as their center.”
Nihir was trapped by the limitations of her time.
The great law of gravity would be discovered by Newton at the end of the Renaissance.
The delusion that the Earth is the center of the universe is merely a trick of the eye presented by the night sky.
In fact, watching this spectacle made me realize just how great Copernicus, who proposed the heliocentric theory, truly was.
It wasn’t called the Copernican Revolution for nothing.
“Then, Professor Nihir? Will the stars eventually fall towards the Earth one day?”
“No, that’s not the case. There are separate laws for the heavens and the earth. The stars are made of a different substance than the Earth and operate in a different way, so that will never happen.”
Another incorrect answer.
Gravity doesn’t distinguish between the heavens and the earth.
They only believed that because they saw the stars in the sky getting closer and farther as they orbited the Earth.
The lecture was full of errors, but it didn’t seem that way to the listening students.
Because their faces were filled with a sense of awe.
A few of the girls even stealthily wiped away tears.
Their worldview had just been shattered.
The moment the Earth changed from a flat plane to a sphere, their way of seeing the universe also changed.
Just like when the ancient Greek sages first attained enlightenment.
The paradoxes of the world that couldn’t be solved in a flat world were all explained in a spherical one.
It’s not for nothing that the theory of a spherical Earth is the first thing introduced in our elementary school textbooks back home.
Science grows through paradigm shifts.
From a flat world to a spherical world.
From geocentrism to heliocentrism.
From universal gravitation to the theory of relativity.
Truth pushes out other truths.
‘Interesting.’
That’s why I was just chuckling at this ridiculous lecture instead of getting annoyed.
Ignorance is the seed of discovery, not a fault.
However, it seemed to Nihir that I wasn’t paying attention in class.
“Student Aren? Is the lecture a bit boring for you?”
Nihir asked, looking at me.
Thinking about it, a student leaning crookedly on his hand and just chuckling.
It was understandable she would misunderstand.
A sudden thought sparked my interest, so I straightened my posture and spoke.
“No, Professor. It’s interesting. But may I ask one question?”
“Oh? What is it?”
“Can you explain the orbits of the planets with that model?”
The eyes of the students, who had been shivering with intellectual pleasure, turned towards me.
Their expressions asked what I was talking about.
“Ah, a good question. That’s very difficult knowledge that even professors don’t fully understand. But I’ll do my best to explain.”
Professor Nihir drew the orbits of the planets—the Sun, the Moon, Venus, and so on—on the blackboard, with the Earth at the center.
The drawing ended at Saturn.
Because people in the Middle Ages couldn’t see beyond Saturn and believed it to be the final celestial body.
“They look something like this…”
A continuous mess of chaos and complexity.
If the sun were placed at the center, the orbits would be neat ellipses.
But with the Earth at the center, how could it possibly be right?
A series of complex orbits, like a child’s scribble, continued on the board.
The students, lacking the intellect to doubt, were admiring this too as new knowledge about the world.
“Have you ever considered placing the sun at the center?”
That was all I asked.