The Good Teacher

379  ICU

Yohn looked around and immersed himself in the world with a completely colouration. It was a wholly different way to see the world.

"They say snakes and few other reptiles have the ability to see infrared. Since their prey is mostly warm-blooded, it helps them track down rodents and birds," the Sect Leader elaborated.

"So this is how I should be processing infrared..." Yohn murmured.

"It is an option," Sect Leader Larks corrected. "If you have a better visualisation strategy, I'm ready to accommodate it here so that it will make it easier for you to conceptualise and internalise the method."

"I think this is sufficient for infrared," Yohn responded. "Since microwaves are line-of-sight based and useful in detection, is it possible to map continuous reflected waves to discrete points in the surrounding space?"

"So... you mean like a point cloud?" Sect Leader Larks rephrased.

"A what?"

"Let me show you," he said while snapping his fingers again. As he did that, Yohn was once again plunged into darkness. Then, in the void, a cluster of white dots started to fill up his field of view. The dots were faint and suspended in the air. As he observed the clusters as a whole, he noticed that the shapes they formed represented the objects he saw in the forest scenery from before. The small fauna, the trees with the swaying branches, the grass, and even the Sect Leader himself. It was all represented as clusters of white points.

"The problem with microwaves, though, is that they aren't naturally emitted by objects, like infrared. You have to depend on reflected microwaves, but there aren't that many natural sources of this EM wave either. So, you will find the ambience scarce in microwaves. If you had a way to generate them, I believe this is what the world would look like to you," the Sect Leader explained.

"I think this is a sufficiently robust visualisation for microwaves, thought," Yohn affirmed. "What do I do about radio waves?"

The Sect Leader pondered on the question for a while before suggesting, "Why don't you try representing radio waves as sound? The primary purpose of radio waves is to communicate, right? So then representing them as sound instead of a visualisation that you see feels more apt."

"How would I do that?"

"First, you need to understand how sound waves can be converted into radio waves." The world returned to the normal white void. The Sect Leader summoned a circuit in front of him. The circuit consisted of a thin film, connected to a coil that was placed inside a magnet.

"The film here is analogous to our ear drums. As sound hits the film, it vibrates, causing the coil attached to it to vibrate as well. In doing so, the movement of the coil in the magnetic field induces an electric signal. This signal is the conversion of physical sound waves into electric signals. This is called the modulation signal. Then, it is just a matter of converting electric signals into radio waves, which we have demonstrated using a simple example in real life."

As the Sect Leader explained the process, the circuit in front of Yohn replicated the steps slowly so that he could grasp what was going on clearly.

"The radio waves that get emitted, however, are a bit different. If you notice, the modulation signal is much, much too low in frequency. This is a problem because it is susceptible to absorption and attenuation as it propagates through the atmosphere. There is also less directionality in low frequencies as the waves tend to get diffracted much more and spread out a lot. So, the standard procedure is to have a radio wave generator that generates a higher fixed frequency of radio waves, which is called the carrier wave. The radio waves of the modulation signal are then convoluted into this constant frequency radio wave and emitted into the world through an antenna. Then, a receiving antenna captures this modulated carrier. To extract the sound, it uses a bandpass filter to separate the carrier frequency and the modulation signal. The modulation signal is demodulated using a reverse set-up of the modulator, thus we get the sound."

"So then how do I see radio waves as sound?" Yohn probed.

"I am going to populate the surrounding area with radio waves of different frequencies, I want you to observe them as you usually do, with the colourful, fluctuating blob vision," the Sect Leader instructed.

As the world returned to darkness, Yohn probed his mana sense and tuned it to the radio band. The world around him was blooming with vibrating, colourful blots of light.

"You can decipher radio waves on a need-to-know basis, instead of visualising them continuously as you did with microwaves, infrared and visible light. This is more practical because radio waves span a very large band," the Sect Leader explained. "Then, when you want to visualise a particular wave, focus on the blot you want."

Yohn searched for the most vibrant blot and focused on it.

"The blot's vibration is most likely the frequency. So start to deconstruct the blob into its composing frequencies. Take note of the magnitude with which they oscillate and place them on a plot where you have the frequency on the x-axis and the magnitude on the y-axis."

Yohn followed the instructions and spent an uncountable amount of time deconstructing the signal the way he was told. Near the end, he had a line chart that mapped the frequencies against their magnitude. But there was a problem with the graph - it was too wide and tall. There were a few high frequencies in there that had a very low magnitude, and a lot of low frequencies with high magnitude.

"You're probably facing trouble with scale, right?" The Sect Leader's voice stated, as though he were reading Yohn's mind. "Try to apply a logarithmic correction to the axes. Try to the base of ten."

Like the flip of a switch, the axes started to compress as a logarithmic correction to a base of ten was applied to them. At this point, Yohn started to really question the nature of the space he was in.

All the things he was doing right now: visualising the EM spectrum, processing information, constructing graphs mentally and correcting them, and so on. None of this could have been so easily achieved in reality. In the space he was in right now (brought into by Sect Leader Larks), he and the world around him felt as malleable as clay. He could sense what he wanted to, in the way he wanted to. He could do things in ways that shouldn't be physically possible, even with magic. And he could think in ways that were completely beyond what his mind could fathom.

It was at that moment that Yohn realised just how Senior Brother Markus was able to comprehend such a difficult concept as gravity. Sect Leader Larks' magical space, or whatever this place was called, had the ability to completely negate the truths of reality. It was a playground where anything could make sense, and at the same time, nothing could. It was so miraculous that it could completely break through any preconceived notions and biases a person could have and reconstruct their beliefs from the ground up.

"What you have in front of you, is the Bode plot of the radio wave. If you apply a bandpass filter to remove the carrier signal (which is 100kHz) you should be able to hear the sound."

Yohn removed the 100kHz band and obtained the modulation signal. He then sent it through the demodulator circuit which had presented itself before him in the white void and suddenly, a noisy sound started to resonate around him.

"Congratulations," the sound said, in the Sect Leader's voice but with a very gravelly and noisy texture. "You can now sense radio waves!"

At that instant, Yohn's core started to undergo a drastic change. The mana in his body started to surge and circulate all over. The sudden disruption was significant enough to pull him out of the Sect Leader's magical space, but Yohn still remained in a meditative trance. His mind was restructuring all the knowledge he had recently gained. All of it was getting slotted into place like an elaborate puzzle coming together.

The mana in the atmosphere started to form a whirl above him and got channelled into his core - he was undergoing both a perfected resonance and an advancement. The siphoned mana started to converge at his abdomen, to form a rapidly spinning, condensed sphere.

Suddenly, Yohn opened his eyes.

"I-I can see!" Yohn exclaimed in surprise. In place of his empty sockets, were two rapidly whirling balls of pure mana cycling through all the colours in the visible light spectrum.

"I can see again!" Yohn repeated with increased vigour. He looked around, absorbing the visuals in the room once again. Tears of joy started to rain out of his empty sockets, though the water did not hinder the clarity of his sight one bit.

As he turned around one final time, his vision landed on an interesting cylinder in front of him. At the centre of the cylinder, was a single candle. And circling the candle, was the text, "Congratulations on your Advancement, Yohn!"

"Huh?" Yohn looked up and saw the Sect Leader's beaming face.

"It's in moments like these that I am grateful that I commissioned tougher fabric for the Sect's jacket," the Sect Leader expressed while gesturing at the disintegrated mess (or what remained of the clothing underneath his jacket).

"Nonetheless, congratulations and celebrations are in order," he added. "But first, we need to make you decent. Can't have you naked in front of everyone, can we? Get changed and come to the recreation hall. This cake will be waiting for you there!"

"I can see..." Yohn mumbled with a fulfilled smile, as he left the Sect Leader's room with an elated skip. It didn't matter that he had advanced. What mattered was that his empty sockets were of use once again.