Lucien replied rather innocently. "I was inspired by the amazing result that electrons had the features of waves. So, I modified and abandoned some thoughts I had in the past."

"You resolved the orbit problem by regarding them as waves?" Fernando knew that quantized orbits would be inferred naturally if so.

Lucien shook his head. "The problem might be resolved in such a way, but I have some other thoughts. If they don't walk out, I'll reconsider from the perspective of waves."

"You are not comparing electrons to waves?" Fernando had always been serious in arcana discussions. He wondered what Lucien could have possibly come up with from the experiment.

Lucien said rather cautiously, "It's the epistemology behind the phenomenon. Like I said before, the problems within the atom should only be handled based on the phenomena and results that can be observed. We cannot consider the previous concepts that are not directly observable, such as orbit, as our basis, as we can only describe electrons as matter with the features of waves and particles."

"Then you inferred it with mathematical tools?" asked Fernando rather interestedly.

Lucien nodded. "Yes. I ignored the arcana significance of certain things and associated problems within the atom with the problems in reality through mathematical tools."

"Didn't you say that the microscopic realm could not be associated with the real world?" Fernando was puzzled.

Lucien smiled. "That's why I used mathematical approaches. The microworld and the real world indeed abide by different laws, but when the laws of the microworld are extended to the real world, our observation will agree with the classical laws. Otherwise, it will be inexplicable why we exist in reality instead of turning into waves. Therefore, we should not consider the arcana significance of the laws but focus on constructing a model that is similar to classic theories with pure mathematical tools, making the solution identical to the experiment, before we discuss the actual significance of the model."

"This is the most primitive and classic approach, but we have long forgotten it," Fernando remarked with mixed feelings. In the beginning, before the concepts took shape, many theories had been constructed based on the explorations and experiments via such means. There were functions first before the actual significance of functions was discussed. However, as there were more and more theories and concepts, while it was easier for the arcanists to explore the world with previous concepts and definitions, they were also restrained by such ideas in the meantime. "Where do you plan to begin?"

Lucien did not hide. "From the sum of the information in the atomic system that we can observe or the general status of the system—if you will—I will introduce a state function and use the observable arcana concepts as operators. By operating and changing the state function with it, I will have corresponding results, which must be a match with the experiment results."

Fernando was silent for a while as if he were considering what Lucien meant. In the end, he could only compliment, "A very amazing idea. Introducing the state function in thermodynamics into the atomic system, and regarding the observable arcana concepts as the operator, those are inspirations that only the avid lovers of mathematics can come up with. However, cold and complicated math models will never be generally accepted until they reveal their arcana significance."

He did not ask for more details since Lucien didn't ask him, because it was Lucien's work. "You've found a new approach. You should be able to construct a theoretical system soon. I look forward to your bringing good news to my studies."

"Master, what are you working on?" asked Lucien curiously.

Fernando said gravely, "Two directions. The first is the abnormal splitting experiment. I discovered that it could only be resolved by introducing a half quantum number, which doesn't agree with our understanding that quantum numbers can only be integers. The second is that I was inspired by my previous studies and believed that there can't be two identical electrons in an atom. That is to say, at least one of their quantum numbers is different."

So far, three quantum states regarding electrons had been discovered.

"That seems able to resolve the problem of the distribution of electrons, as well as the electronic exchange in the old alchemical reactions. Mr. Gaston's studies in life synthesis will have certain theoretical support." Lucien did not expect that his teacher could find out the Pauli exclusion principle so quickly.

Not too delighted, Fernando nodded his head. "There's still a long way ahead. As you said, this is a realm that was unimaginable in the past. Also, it will be my turn to supervise the advance base in the World of Souls next year."

Ever since the Lord of the Undead betrayed the World of Souls, the Congress had established bases near the gaps of the World of Souls in Heidler city to explore the World of Souls. Because they were suspicious that the disappearance of Maskelyne, Viken and some other legendary sorcerers was related to the World of Souls, their exploration had been very prudent. It took them several years before they finally reached the depths of the World of Souls. Also, one legendary sorcerer, usually a grand arcanist, guarded the base all the time, except for special occasions like the time when war was waged against the Church.

"You must be careful, master," said Lucien in concern. The World of Souls was as dangerous as hell. When he checked Adol's memories with his permissions in the Highest Council, he saw the most unimaginable and astounding picture.

In Adol's memories, black, white and grey covered everything in the world of silence that was devoid of any sound. At the center of this world was a magnificent, splendid palace that was half the size of Holm. The high steeple pierced into the sky and extended into the void, connecting the sky and the earth of the World of Souls.

In the areas that Adol could reach, terrifying specters were everywhere. There were primeval vampires and mummies, there were Wraith Lords, and there were 'Servants of Death', which was the name of a specter and was not about the real God of Death. There were also skeleton kings, dragon liches and 'demigod-liches'. The number of legends was almost close to the sum of all the three biggest groups. Thankfully, most of the specters were unintelligent and acted according to instinct. They could barely be manipulated by the intelligence specters, either. So, they were not as strong as Congress as a whole.

Of course, Congress couldn't devote all the legends to the exploration, which would give the South Church and the North Church an opportunity. Also, nobody knew what kind of monsters were hiding in the areas deep inside the 'Temple of Spirits'.

Among them, what shocked Lucien most of all was the 'Furnace of Souls' inside the Temple of Spirits. Located in the deepest parts that Adol could reach, it was a gray curtain that dangled from the intangible heights of the Temple of Spirits like a wall. Inside it was the frozen faces of souls, which were sometimes peaceful and sometimes twisted. Some of them were even swirling around the white fire of soul.

Those souls were so dense that Lucien suspected that their number surpassed the population of all the intelligent creatures in the world.

Also, except for part of the intelligent, legendary creatures who could touch the Furnace of Souls by the bliss of the mysterious existence of the World of Souls, embed their subordinates into it, and burn them with the white fire, the senior-rank specters including Adol could only see it but could not touch it, just like when the sorcerers saw the tantalizing ball of divinity during their advancement. It was high above somewhere that they could never reach.

Adol had scrutinized the Furnace of Souls, only to discover his face somewhere high above. He had already been caged inside the Furnace of Souls!

Even though he was a specter that had few feelings, his spiritual power still shook violently, making it difficult for him to carry on his exploration.

Perhaps, the mysteries of souls are hidden behind that. That was the only idea Lucien had after retrieving and reading the files.

Fernando glared at Lucien rather impatiently. "Up to this point, few of the legendary specters in the periphery are at the third level of legendary. We have also set up communication methods. The mysterious existence in the World of Souls has fallen asleep again. What dangers can I possibly run into? Just focus on the model of your new alchemy!"

After he left his teacher's place, Lucien went directly to the Affair Committee, and the record of the discussion in the meeting began to spread among a few arcanists.The Pauli exclusion principle is the quantum mechanical principle that states that two identical fermions (particles with half-integer spin) cannot occupy the same quantum state simultaneously.