The Magic Academy's Physicist
Chapter 244: True Discipline (2)

Chapter 244: True Discipline (2)

0% Today, walking was more awkward than usual.

I set out from the lab with the attendance in one hand, and worksheets that I had spent all night printing in the other. A yawn escaped my mouth.

I didn’t know how to tie hair so I asked Akasha to do it. Although puzzled, she made me a ponytail.

Good, not bad.

“Good morning, everyone.”

I stepped onto the platform with a formal, western-style greeting. The eyes of the students were unusual. In a ‘great, her again’ kind of way.

I wondered how neglectful one had to be towards the students for it to get like this. Yeah, Yufiel was one of the nice ones. She was perfect grad student material, no?

She became the class president purely because she was a High Elf, although I didn’t think of her as that kind of person. Rather, she suited the position of the book girl more as she was modest and not so fussy for a daughter of an established family.

“I’ll call attendance.”

I spoke in a gentle tone.

I called each name and made eye contact, a method that Miss Heerlein would use.

“...Good, everyone’s present.”

Tap. I closed the attendance and picked up the worksheets.

“Today I’ll hand out the assignment first.”

At that, the students’ faces turned sour. While they weren’t whining like children, their expressions all looked like they’d stepped in poop.

So what.

Take this assignment bomb I stayed up to make.

“Today’s assignment is due by the midterm period.”

Some were happy about it, and others’s faces darkened.

Isn’t it plenty of time if it’s right before midterms? No, it’s Professor Heisenberg so it must be hard–and other such words were being exchanged.

“What you’ve been given is the basic diagram of the scroll formula. In other words, your homework is to make a drawing.”

“What kind of drawing?”

“Whatever you want.”

I planned to give them a mark if they could construct a magic circle that worked within the framework given.

And, the marking criteria were as follows:

“Apply as much of the theory as possible. The output should be 30 times the input. Only four top-grade mana stones may be used. Include the key concepts of the class that will be held for three hours starting today.”

While they weren’t going to get zero if they didn’t meet them, the more they did, the higher their marks were going to be.

At the unheard-of performance assessment, the students’ expressions distorted like an unfortunately-drawn oil painting.

“Then let’s begin class.”

I thought while pulling down the blackboard.

No matter how I thought about it, the last lesson on parity had been a mess.

Parity was an important theory for physics after variational theory, so it needed to be understood as precisely as possible.

But teaching second years graduate-level content?

It was nonsense. That wasn’t the students sucking but the instructor being stupid.

Richard Feynman said that if a theory couldn’t be explained to first-year university students, then it wasn’t complete.

So now, I was going to have to thoroughly wield this chalk in an understandable-to-high-school-students way.

“Just note that the concept you learned last class is something that exists, and we’ll look again at what parity is.”

As I said that, I drew a mirror on the board.

The students’ eyes narrowed as if they hadn’t expected me to start with a random drawing instead of a complicated formula.

“Parity is a mirror.”

Their faces were asking what I was saying.

“Mirrors reflect objects. In the opposite direction, that is. Stand in front of the mirror and hold up your right hand. What hand would you be holding up in the mirror?”

“The left.”

I nodded. This much was known by experience.

“Have you ever thought about the world inside the mirror? I’m right-handed here, and left-handed in the other world.”

At first glance, one could think ‘would that even exist’ or ‘that’s nonsense’.

Reflections in the mirror were only an image, so actually existing?

Then wouldn’t it be like saying that everyone has a doppelgänger?

“It might sound like nonsense, but in the past when there were a lot of superstitions, many people believed it.”

Now I drew coordinate axes and put the mirror drawing at the origin.

Then I put a dot somewhere. It was roughly at about the (3, 4) point. I marked the dot’s coordinates and asked.

“I want to project the mirror on this dot. Which way should I go?”

The students said in unison. (-3, -4). At the same time, Yufiel’s eyes grew wide like a rabbit’s.

“Positive flipped to negative.”

“That’s right. Right went to the left, and up went down.”

The right-handed became left-handed.

“This process is called the ‘parity transformation’.”

It was far more direct than saying that the determinant was -1 or whatever.

I moved with my right hand raised. There was a medium-sized flat mirror in front of the podium. Projecting my hand in the mirror, I continued the lecture.

“Even so, it’s only that the right hand became the left hand; it doesn’t change the fact that it’s still my hand.”

The students nodded.

“This is called ‘parity symmetry’.”

Students could understand with an explanation like this without complicated equations. Also, it gave them time to reflect. Because the idea that the world that we live could actually be an illusion in a mirror stimulated scientific thinking in many ways.

I, too, would often get like this in my undergraduate days. When the prof would toss something, the lecture would stop registering from that moment. I’d be busy imagining ‘What about this? What about that?’

“But let’s think here. This only works when it’s a flat mirror, right? Let’s see what happens when the mirror is different.”

This time, I drew the same coordinate plane and put a convex mirror at the origin.

“What about in this case?”

At my question, the students responded with what they each thought.

“...We don’t know what the focal length is.”

“Won’t it warp to a different position?”

“I think if it was a hand and not a dot, then it could grow longer or shorter.”

I nodded.

They were all correct.

“At that point, can the hand in the mirror be called my hand?”

“.......”

“Let’s make the problem a bit clearer.”

I picked up the mirror on the wall and asked for their pardon in advance.

As they looked curiously, I brought down the mirror on the desk with all my might.

Craaaaaaash─!!

When I broke the mirror, a few of them flinched.

Yufiel and Lotte looked dumbfounded. Leninya scratched her cheek, and Freyr watched cautiously while folding and opening her ears. Vermel watched with a ‘what crap is she up to now’ face.

There were cracks all over the mirror, and I brushed my hand over them. Then, I stood the mirror upright on the desk.

“A broken mirror cannot form a proper image. Now when we look at it, there’s a head where the finger is supposed to be, and the belly where the head should be. Question. Can this be called symmetry?”

The students answered ‘no’.

Correct. They were following along well.

“So symmetry is important when talking about parity. With symmetry, the right hand might become the left hand when you do parity transformation, but it will still remain a hand. This is called ‘conservation of parity’.”

“Then is nothing conserved in a broken mirror?”

“That’s right.”

Transformation, symmetry, conservation.

“These three things are the key points.”

I pushed up the second-storey blackboard. As one went up, another came down.

I was now going to use some equations. Using only first-year level calculus, of course.

“Let’s expand the problem.”

This time, I drew a circle.

“What is it?”

“An eye.”

The eye of a human.

“You all know that the cross-section of an eyeball is circular, right?”

Why did I draw this?

“Checking for symmetry and understanding conservation is actually complicated. You can only understand it clearly through the exact use of the mathematical tool you were taught last class. But since that’s difficult, let’s try to understand parity breaking through the intuition of human eyes.”

There was a curve in the human eye.

Because it was spherical, there was transformation when it took in visual information, so the world that we see wasn’t flat but curved.

“The reason why they teach 4-point, 5-point, 7-point perspective in art is because of the nature of our eyes.”

I drew a stick and calculated with trigonometry how an image formed in our eyes.

During my university years, I had been briefly interested in art. That was when I studied perspective because I was curious about how the world changed through our eyes.

Why did our eyes measure the object’s actual position differently from its visible position? Why did farsightedness occur, what was the principle behind seeing, etc.

Clack.

The answer was there in the complicated formula I’d written. I skipped the other parts and circled just the last one.

When I did, the students scrambled for their pens and notebooks. They were going to copy this formula down.

“Wait.”

I raised my hand and stopped them.

“This won’t be in the exam.”