Chapter 48

"Today's class is the last one I will give you, and it is also the last class before I retire. After this class, I will officially retire..." As soon as the second natural history class began, the teacher's first words plunged the entire classroom into absolute silence. Even Zhang Tie didn't expect that this class would be the teacher's last. Since entering the Seventh Middle School, he seemed to have gotten used to the elderly man with completely white hair quietly coming in and quietly leaving after class. He never thought that one day this old man would bid farewell to everyone on the podium. When the natural history teacher spoke, even those who were still dozing off in their seats seemed to wake up, looking at the old man in front of them with surprise, beginning to feel a sense of reluctance.

"Teacher, are you really leaving..." A student in the front row asked, voicing everyone's thoughts.

"I am old enough, and I have served Black Flame City for a long time. It is time for me to retire!" The old man on the podium smiled kindly. "I know what you are worried about. As long as the walls of Black Flame City are not breached by the alien races, my pension should be enough for me to enjoy my retirement. To ensure that the walls of Black Flame City remain strong, it depends on you, not me. So, how my future retirement life will be is up to you all! For this reason, in today's last natural history class, I will use my lifetime of experience and knowledge to talk about the most important question for you all: what is the path of a powerful human warrior who can protect the human race?"

The old man's last words invigorated everyone. They all straightened up, their eyes fixed on the old man who suddenly seemed both reluctant to leave and deeply respected.

The old man didn't speak but took out a small, ordinary snail shell and two pinecones from his pocket, passing them to the front row to be passed around. In a minute, the two ordinary items had been passed through everyone's hands, but no one found anything special about them. Zhang Tie examined the two items for a few seconds but couldn't figure out what was so special about them.

"Has anyone noticed anything special about this snail shell and these two pinecones?" the old man asked.

Everyone shook their heads.

"Do you know that the secret of a human warrior's advancement is hidden in these ordinary things? You all know that a person can continuously improve their strength by igniting the bright points in their body, but what is the standard for the strength of human warriors? Why are some people at level five, some at level six, some at level seven, and some at level ten or higher? Who set the levels and ranks for human warriors? Was it some bigwigs in the Warrior Guild who came up with these standards on a whim?"

Zhang Tie was also stunned. He had always thought that these standards were set by those bigwigs. Wasn't that the case?

"Of course not. In this world, who has the right to set such standards that billions of humans and countless powerful individuals would all follow?"

"Teacher, who set these standards?"

"The one who set these standards is not a human, but a god or, more precisely, the great cosmic law!"

The entire class was in an uproar, with everyone discussing the matter.

"These standards are not specifically set for humans but are established by the cosmic law for everything in the universe. In the snail shell and pinecones I just passed around, these standards are also hidden, but you just didn't notice them!" The old man stood at the podium and then turned to the blackboard, drawing two patterns with chalk: one was a spiral curve resembling a snail shell, and the other was a set of intersecting lines similar to a pinecone.

After drawing these, the old man turned around. "How many bright points does a first-rank warrior need to ignite in their body?"

"One, igniting the Shen Gong bright point is enough..." everyone answered.

The old man then drew a square at the center of the snail shell curve, making the spiral curve pass through two opposite corners of the square...

"What about a second-rank warrior?"

"Still one, igniting the coccyx bright point in the spine is enough..."

The old man expanded the diagram and drew another square of the same size.

"What about a third-rank warrior?"

"Igniting two spinal bright points is enough!"

This time, the side length of the square was doubled.

"What about a fourth-rank warrior?"

"Three!"

"What about a fifth-rank warrior?"

"Five!"

"What about a sixth-rank warrior?"

"Eight..."

As the old man asked each question, the spiral curve on the blackboard was gradually enclosed by squares with side lengths increasing in the same proportion. By the time he asked about the tenth rank, no one in the class could answer. The world of warriors above the tenth rank was completely beyond the reach of the students, as remote as the Great Cataclysm...

The natural history teacher did not mock the students but wrote down the numbers they had just answered on the blackboard: 1, 1, 2, 3, 5, 8, 13, 21, 34... Then he wrote the corresponding ranks and levels below the numbers, from the first 1 corresponding to the first rank to 34 corresponding to the ninth rank. Finally, he turned around and looked at everyone with bright eyes. "Don't you notice a pattern in these numbers representing the ranks and the number of bright points ignited?"

After staring at the row of numbers for a while, someone finally had an epiphany. "Teacher, each number in this sequence is the sum of the two preceding numbers!"

"Anything else?"

Zhang Tie looked at the sequence, feeling something trying to emerge in his mind but unable to grasp it.

"Calculate the ratio of adjacent numbers in this sequence and see if you can find a pattern."

The students, who had some mathematical background, immediately started calculating on their desks. The first ratio was 1, the second was 0.5, the third was 0.66666 (a repeating decimal), the fourth was 0.6, the fifth was 0.625, the sixth was 0.61538..., the seventh was 0.619047..., and the eighth was 0.617647...

"Have you noticed that these values are all approaching the golden ratio of 0.618?" The old man revealed the answer, and everyone had an epiphany. Yes, why was that?

"The Shen Gong bright point is 1, and the human spine has 34 vertebrae. When starting from the Shen Gong and igniting all the bright points in the spine, that marks the achievement of a ninth-rank warrior. Each rank has strict standards. Knowing this pattern, calculate how many bright points need to be ignited to become a tenth-rank warrior. Is it 55? What about the next one, 89? The further you go, the more terrifying the number becomes, increasing exponentially. This is why the difference in strength between ranks becomes more significant as you advance. This sequence..." The old man turned and pointed to the sequence on the blackboard, "is called the Fibonacci sequence, discovered by human mathematicians hundreds of years before the Great Cataclysm. It contains countless secrets and the laws of the universe and creation. Look at the spirals on the two pinecones. Count them. The smaller one has five spirals on the left and eight on the right, while the larger one has eight on the left and thirteen on the right. The numbers 5, 8, and 13 are all in the Fibonacci sequence. The snail shell curve I drew on the blackboard is the geometric representation of this sequence, called the Fibonacci curve or the golden curve. This golden sequence and curve can be found in almost any living being. If you observe nature and the things around you, you will find more. For example, the sunflower has two sets of spirals: 34 and 55, 55 and 89, or 89 and 144. You will also find the same in roses, thistle leaves, and other plants. After the Great Cataclysm, humans discovered the secrets of body cultivation from the ruins of the underground world. The path of human advancement and cultivation follows this golden curve and sequence, which is a manifestation of the cosmic law. Therefore, the warrior ranks divided by this curve and sequence are recognized by all humans and all powerful individuals..."

Everyone, including Zhang Tie, felt their horizons broaden. Before, he only knew that to advance, one needed to continuously ignite the bright points in the body, and the number of bright points required for each rank was different. But he never thought about why. It turned out that all these secrets were hidden in the golden spiral and the sequence, which contained the cosmic law.

"Teacher, what is the highest cultivation rank after the tenth rank?" Baghdad raised his hand and asked a question.

"No one can answer this question yet. The cultivation after the tenth rank is the greatest secret in any place. The knowledge beyond the tenth rank is the most secret of secrets. The main reason is that the golden sequence has no end. It continuously expands, approaching the golden ratio of 0.618, which represents the perfect law of the universe and the divine. Humans have been on the path of cultivation for less than 900 years, while the evolution of the universe may have lasted billions of years. The journey on the golden spiral has just begun. Before the Great Cataclysm, humans were blindly arrogant, considering themselves the masters of the universe and all things. After the Great Cataclysm, humans realized that the human race is just a minor part of the countless species in the universe and Kunang Continent. It is even possible that for a long time before the Great Cataclysm, human bodies and civilization were not evolving but regressing. When humans had nowhere to retreat, the Great Cataclysm and the Star of God came, rewriting everything. To survive, humans discovered the secrets of the body's bright points and began to walk the path of evolution again. The Black Iron Age was the end of an era and the beginning of a new one..."

This last natural history class opened a window for everyone, revealing a broader world they had never imagined. In the latter part of the class, everyone manually calculated the next steps in the golden sequence:

1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, 233, 377, 610, 987, 1597...

When Zhang Tie pushed the golden sequence to the 17th position, he was stunned. He looked at the last seven numbers in disbelief. Could this be the world beyond the tenth rank...