I Studied Abroad in the Modern Times

Vol 2 Chapter 106: Equation

When Zheng Fa walked into the room, Old Bai and Tang Lingwu were both busy.

Tang Lingwu was processing the data collected from various sensors on her computer—each lightning strike’s current, voltage, temperature, as well as the shape and color of the lightning captured by the high-speed camera.

Old Bai, on the other hand, was examining the diagrams on paper, trying to identify the key patterns.

Zheng Fa sat down beside Old Bai, feeling a rare sense of exhaustion.

The lightning techniques of the Heavenly Monument Realm were strange—Heaven’s Tribulation Lightning had far greater power than ordinary lightning techniques, yet it also had relatively low cultivation requirements.

For instance, Zheng Fa was only in the Foundation Establishment stage, yet he had just released nearly eight or nine bolts of Heaven’s Tribulation Lightning. If he hadn’t wanted to reserve some spiritual power for Lingshan Method, he could have likely managed two more.

He hadn’t felt it at the time, but now his head throbbed, with the most intense pain at his temples—like someone was drilling straight through his skull from one side to the other.

Sitting at the table, he massaged his temples and recalled a record from Jiushan Sect’s texts—this was a sign of minor soul damage caused by excessive divine sense consumption.

Normally, his spiritual power should have been depleted before his divine sense.

This led him to suspect that the overwhelming power of Heaven’s Tribulation Lightning might come from excessive consumption of a cultivator’s divine sense.

"Zheng Fa, what’s wrong?"

Old Bai had been focused on his drafts, but sensing something off, he turned to see Zheng Fa’s pale face and couldn’t help but ask.

"It’s nothing. Just overused my divine sense—I’ll be fine after a few days of rest," Zheng Fa shook his head. "Did you discover anything?"

Heaven’s Tribulation Lightning was considered the most fundamental lightning technique of the Heavenly Monument Realm.

Yet even Yan Wushuang and the others had been unable to master it. There were two main reasons for this:

First, no one actually knew how Heaven’s Tribulation Lightning was generated.

In other words, out of all these diagrams, which one was the true symbol for Heaven’s Tribulation Lightning?

Without understanding this, the second problem naturally arose—how to control its strength.

At the moment, Old Bai was focused on the first issue. His approach was simple: each time Zheng Fa successfully cast Heaven’s Tribulation Lightning, he would record the spiritual power’s movement and use topology to find the common patterns in those paths.

This was the same approach used in talisman studies.

But for cultivators in the Xuanyi Realm, who had no training in topology, these paths might all seem completely different…

"Hmm, this is quite simple." Old Bai pointed at the drafts on the table. "These patterns appear every time—only the number of occurrences varies."

Zheng Fa examined them and nodded. "If we add in the Five Elemental Sub-Talismans, this could very well be the spiritual talisman for Heaven’s Tribulation Lightning."

Based on their hypothesis regarding the Three-Sub-Talisman Rule, if spells were just another form of talismans, then spiritual power itself should provide the Five Elemental Sub-Talismans, while these movement patterns should correspond to the second and third types of sub-talismans.

"Yes… But unfortunately, there are no shared sub-talismans between this Heaven’s Tribulation Lightning pattern and other lightning talismans." Old Bai had been analyzing this issue for a while. "If Lingwu’s theory about interactive sub-talismans is correct, then all lightning techniques should share at least one identical sub-talisman."

Zheng Fa fell into deep thought.

They had chosen to study lightning techniques because their target effects were relatively straightforward. Whether lightning techniques worked by manipulating electrons or electromagnetic fields, their fundamental mechanisms should be the same, meaning they should share some common sub-talismans.

But…

There weren’t any.

This left them feeling like blind men trying to describe an elephant—touching different parts every time, never grasping the whole picture.

…

"Got it!"

As they were discussing, Tang Lingwu suddenly let out an excited gasp. The two turned to see her screen filled with various lightning diagrams, each differing in color and length.

Beside them were fluctuating graphs, displaying the current, voltage, and temperature of each lightning strike hitting the metal rod.

Zheng Fa and Old Bai walked over, staring at the data on the screen.

"Any patterns?" Old Bai asked.

"Nothing special, aside from the expected correlation between current and voltage, and between temperature and lightning color."

Zheng Fa nodded—these relationships were well-documented in physics.

"Look at this," Old Bai handed over the extracted diagrams. Tang Lingwu glanced at them, frowned, then suddenly seemed to realize something. She rapidly typed on the keyboard, too focused to even acknowledge them.

Zheng Fa and Old Bai exchanged glances, then stepped forward to look at the screen.

"Is she… performing a fit analysis?"

After watching for a while, Zheng Fa understood—Tang Lingwu was mapping the frequency of certain talisman patterns to the various lightning data, trying to derive a formula.

The dataset wasn’t complex—in fact, it was surprisingly simple.

Soon, the computer displayed an equation.

Old Bai blinked, then summarized, "The current intensity is roughly proportional to the sixth power of this count?"

Zheng Fa was also a little surprised. The result was unexpectedly simple—it was just a straightforward sixth-degree equation. Ignoring the coefficients, the variable X represented the number of times a particular talisman pattern appeared, and the other side of the equation was the peak current.

"In other words, to control the strength of the lightning, we just need to control how many times that talisman pattern appears?"

They all stared at the equation in silence—it was almost too simple, to the point of making them doubt themselves.

"So, the number of times a talisman pattern appears directly determines the energy of Heaven’s Tribulation Lightning?" Old Bai frowned. "That… sounds a lot like how talismans work."

"Exactly," Zheng Fa agreed. "When drawing talismans, the process absorbs symbols from the void. In other words, increasing the number of symbols increases the power."

Zheng Fa gazed at the equation, then suddenly said, "This reminds me of a concept from middle school physics…"

"What?"

"Work." Zheng Fa explained slowly, "Whether it’s spiritual energy or spiritual power, these talisman patterns dictate how they flow—only by following certain paths can they produce the desired effect. It’s almost like performing useful work along these paths."

"And I can feel it—while my spiritual power moves along these paths, it’s being consumed. Meaning, my spiritual power is converting into lightning energy through this trajectory."

"Now that you put it that way…" Old Bai murmured. "It does sound similar! Spiritual power doing work, converting into corresponding electrical energy—but in a nonlinear way…"

"So, we’ve derived the functional equation for Heaven’s Tribulation Lightning?" Tang Lingwu, having listened for a while, summarized.

"It should be called the Heaven’s Tribulation Lightning Spiritual Energy Equation," Old Bai corrected. "With this, at least controlling its strength is no longer an issue."

Then, he sighed, "Why does it feel like every time we research cultivation, we stumble upon a new breakthrough…"

Regretfully, he added, "Too bad we don’t have any journals to publish in… Otherwise, we’d be churning out papers like a mother pig birthing piglets!"

Zheng Fa chuckled.

If they could fully control the Heavenly Monument Realm and establish a secure base, journals and publications… weren’t entirely out of the question.

…

Xuanyi Realm.

In his room, Zheng Fa sat in meditation, slowly recovering his divine sense while his mind lingered on the Heaven’s Tribulation Lightning Spiritual Energy Equation.

This equation revealed a simple yet long-overlooked phenomenon—the power of a spell depended on how much effective path spiritual energy, or spiritual power, had traveled.

In truth, the cultivators of the Xuanyi Realm had already sensed this. They knew that the more similar symbols a talisman attracted, the stronger it became. However, understanding the exact numerical relationship was another matter altogether.

At the very least, Zheng Fa now had a clear direction for controlling the power of Heaven’s Tribulation Lightning.

…

While Zheng Fa was focused on his cultivation, in the grand hall, Martial Uncle Pang was speaking with Senior Sister Zhang. Unsurprisingly, their conversation centered around Zheng Fa.

"If we can gain control of the Heavenly Monument Realm…" Martial Uncle Pang couldn't hide the excitement in his eyes. "Then the future of Jiushan Sect will be secured… But I wonder how confident Nephew Zheng is."

Senior Sister Zhang knew this wasn’t a matter of distrust. When faced with such an immense opportunity, it was only natural for people to feel anxious and overthink things. She reassured him, "Martial Uncle, you know what kind of person Junior Brother Zheng is."

"Hmm?"

"Cautious!"

"…That’s true!"

"Junior Brother Zheng has always been extremely careful. I noticed this when he helped me manage the market—he never makes absolute statements. Even when he’s fully confident, he only ever claims eighty percent certainty at most."

Hearing this, Martial Uncle Pang slowly nodded. "Now that he’s saying he wants to take control of the Heavenly Monument Realm… he must already be quite certain."

As she spoke, Martial Uncle Pang’s expression gradually relaxed, even showing a hint of embarrassment. "You truly have keen insight, Nephew Zhang. I’ve lost my usual composure and needed you to reassure me instead."

Senior Sister Zhang shook her head. "It’s not that you don’t understand this, Martial Uncle—it’s just that you care too much about Jiushan Sect."

Martial Uncle Pang’s smile grew even more self-conscious. Looking toward Zheng Fa’s room, he murmured, "Unfortunately, our sect has too few disciples specializing in lightning techniques… We can’t provide much help to Zheng Fa. No, I need to send people to the market again to see if we can find any new spiritual materials!"

Seeing his concerned expression, Senior Sister Zhang couldn’t help but laugh.

Just as Martial Uncle Pang was about to call for disciples to head to the market, the two of them suddenly sensed something and turned to look beyond the market.

A streak of purple light descended from the horizon, landing before the Thunder Pool Market in the blink of an eye. As the radiance scattered, a tall, stunning woman stood at the entrance. Her hair was styled in a high bun, adorned with a small bell. She cupped her hands toward Five Dragons Palace and said, "Is Martial Master Pang of Jiushan Sect present? I, Xiao Yuying, have come to visit."

She appeared to be in her twenties, yet her words carried a tone of equal standing with Martial Master Pang.

For a moment, the lively Thunder Pool Market fell into complete silence. The cultivators inside cautiously observed the woman, unsure how she could speak with such confidence.

"Xiao Yuying?" Martial Uncle Pang hesitated, as if recalling something, then his expression changed dramatically, and he strode out.

The gates of Five Dragons Palace swung open as Martial Uncle Pang hurried toward the market entrance to personally greet her.

"Fairy Lingye’s visit brings great honor to Five Dragons Palace… Please, come inside!"

Hearing this, the cultivators in the market finally realized who she was.

"Fairy Lingye? No wonder Martial Master Pang is treating her so seriously."

"She’s here for the Thunder Pool too?"

"Obviously! Back when she was in the Golden Core stage, she was already considered the best in lightning techniques, on par with Jiushan Sect’s Fairy Zhang. She even reached Nascent Soul before Zhang Wuyi… Besides the Thunder Pool, what else would bring her here?"

"Or maybe the Heavenly Monument itself?"

…

Inside Five Dragons Palace, Martial Uncle Pang and Senior Sister Zhang were hosting Fairy Lingye, Xiao Yuying. After exchanging a few pleasantries, she finally stated her purpose.

"Indeed, I’ve heard that this Heavenly Monument is closely tied to lightning techniques, so I wish to investigate it. I also wished to consult with you, Martial Master Pang, to see if your sect has any insights regarding the monument."

"We do… have some understanding." Martial Uncle Pang exchanged a glance with Senior Sister Zhang. He knew that for a Nascent Soul cultivator like Xiao Yuying, gathering information was not difficult, and withholding knowledge would seem petty.

So, he simply explained what they knew about the Sealed Land and the lightning techniques of the Heavenly Monument. As he spoke, Xiao Yuying’s eyes sparkled with clear interest.

Martial Uncle Pang and Senior Sister Zhang exchanged another look, feeling increasingly uneasy. Martial Uncle Pang hesitated before asking, "The Thunder Pool has been present for quite some time—why is Fairy Xiao only coming now?"

Xiao Yuying seemed slightly embarrassed. "The Thunder Pool is dangerous enough as it is, and with the Great Freedom Demonic Sect lurking nearby… I had to be cautious."

"…"

Senior Sister Zhang was speechless.

So, now that we’ve beaten the Great Freedom Demonic Sect into hiding, now you feel safe enough to come?

"But… wouldn’t you risk missing out on the Heavenly Monument if someone entered before you?"

Xiao Yuying smiled. "Someone else? Who? Yan Wushuang of Tianhe Sect?"

She then began casually evaluating Yan Wushuang. "He has determination and perseverance, I’ll give him that. But his talent and comprehension are just a little lacking… Even if I let him have a few months’ head start, it won’t make a difference."

Her tone carried an overwhelming confidence in her own abilities.

After gathering the information she wanted, Xiao Yuying suddenly said, "There’s another reason I came here."

"Hmm?"

"If I take control of the Heavenly Monument, then I’m afraid this Thunder Pool won’t be able to hold off the Great Freedom Demonic Sect anymore."

She actually said it outright. "I specifically came to inform you, Martial Master Pang, so that your Jiushan Sect can prepare in advance."

"…"

Martial Uncle Pang was momentarily speechless. "Thank you for the warning, Fairy Xiao."

"That’s good." Xiao Yuying nodded. She turned to the two and said, "Then I shall take my leave. Thank you again for the information, Martial Master Pang."

"Of course, of course…"

Watching her leave, Martial Uncle Pang remained silent for a long time before suddenly saying, "This woman is truly extraordinary."

"Hmm?"

"If she didn’t possess astonishing ability, with a personality like that—so bluntly phrasing her intentions in the most irritating way possible…" Martial Uncle Pang sighed. "Could she have survived to Nascent Soul?"

Senior Sister Zhang thought about it, then glanced at herself.

She had to admit…

Martial Uncle Pang had a very good point.

"But her talent in lightning techniques is likely on par with your talent in talisman arts," Martial Uncle Pang said seriously. "She will be a formidable rival for Zheng Fa."

His tone carried deep concern.