"This is impossible," the disciple stood up, "The principle of Fireball Spell is that the spiritual power stimulates the resonance of the fire attribute law. I output the spiritual power with all my strength and have maximized the stimulation. How can it be possible with only this efficiency--"
"You output your spiritual power with all your strength," Lin Feng interrupted him, "But the path of converting spiritual power into heat energy, have you ever calculated how much of it is consumed by your own spiritual power circuit?"
The disciple stopped.
"Spiritual power starts from the Dantian, travels through the meridian circuit in your body, reaches the palm of your hand, and is then stimulated," Lin Feng said. "During this process, the friction and consumption of the meridians, the consumption of path bends, and the loss of the boundary from the stimulation layer to the outside. Adding up the three items, the average is 70% to 95% of the input spiritual power. What you finally send out is the remaining bit."
The square was quiet.
This is not a complicated concept. Once it is said, most people can understand it immediately, but it is precisely because they can understand that they are particularly shocked - they have never thought about this problem, and no one has ever mentioned it.
"Then... how to reduce this consumption?" someone asked.
"This is what this course is about," Lin Feng said, "But today, I will show you a conclusion first."
He took out a piece of chalk from his sleeve and started writing on the blackboard behind him.
A line of formula, then derivation steps, then conditional constraints, then conclusion.
The blackboard was not big enough, so he wrote to the edge, and then continued writing. It took more than half of the blackboard space to finish writing the entire set of derivation.
The people below, those in the front row can see clearly, some of them started to frown as they followed the deduction, and the more they pushed, the more they frowned. It's not that they couldn't understand, but they could understand every step, and every step felt right, but the conclusion--
In the last line, the deduced conclusion is:
Under path optimization conditions, the theoretical limit of Fireball Spell's spiritual power conversion efficiency is 91.7%.
"Ninety-one percent?" Some people couldn't believe it. "This is nearly twenty times higher than now...?"
"Yes," Lin Feng put down the chalk, "Now, let me demonstrate the effect of this theoretical limit."
He turned sideways and looked at the training ground on the right side of the square. It was the area where the academy performed daily martial arts. It had a specially reinforced protective formation and the ground was made of three-foot-thick patterned granite.
Then, he raised his right hand with his palm facing the training ground.
There are no movements of power, no light emanating from the spiritual power, and no signs of the resonance of the law.
Just raise your hands quietly, for one second, two seconds.
Then, calmly--
"Bang--!!!!!!"
That sound was not like the sound that Fireball Spell should make, but more like some kind of giant explosive being ignited in a confined space. The entire training ground disappeared with this sound.
It wasn't burned, it was bombed.
The three-foot-thick arrayed granite flew outwards along with the shock wave. Under the dual impact of heat and power, the protective array flashed twice in a row, and then completely failed. The spiritual stone base that framed it melted into a pool of red liquid.
On the ground, where the training ground was originally located, there was an arc-shaped pit with a diameter of about thirty feet, with neat edges. The ground in the center was completely vaporized, leaving a circle of glassy, black lava border.
The shock wave swept across the square and blew away the tables in front of the students in the front row. Several people lost their grip and were pushed backwards by the air wave, falling into the crowd of people sitting behind them.
In the square, the dust dispersed and it was quiet. Then everyone looked at Lin Feng at the same time, then at the pit, and then at Lin Feng.
Lin Feng took back his hand, clapped his palms, and looked normal.
"This is 91% of Fireball Spell," he said. "Everyone, this is not a question of talent, but a question of path optimization. Anyone can approach this efficiency as long as they master the correct spiritual power conversion path."
Below, some people were stunned, some had their mouths open, some were thoughtful, and some began to take out pens and papers to write down the formulas on the blackboard.
The elders standing outside the square looked at each other. No one spoke first, they were all digesting in silence.
The three-hundred-year-old senator stared at the pit for a long time, then turned to his colleague next to him and said:
"I have practiced Fireball Spell for three hundred years, and I have never thought about it."
"Who has thought about it?" said the person next to him, "No one has ever told us that there is such a thing behind cultivating immortals."
On the stage, Lin Feng picked up the chalk and wrote the title of the first part of this lesson on the blackboard:
"Efficiency Optimization of Spiritual Power Transformation Path--Taking Fireball Spell as an Example"
Then he turned around, looked at the more than 300 pairs of eyes below, and began to speak.
This lecture lasted four full hours.
Some people ran to get dry food and water along the way, and they ate and listened on their seats, and no one left.
At the end, Lin Feng finished writing the last line on the blackboard, put down the chalk, and turned around:
"I'm here today. Let's digest it. If you have any questions, ask them in the next class. The homework is--"
He paused for a second and considered:
"Analyze the spiritual power transformation path of your best technique, find out the main consumption points, and submit a written analysis. There is no restriction on the format, as long as it is meaningful."
Below, more than 300 people lowered their heads at the same time and wrote something. The only sound left in the square was the sound of the pen tip rubbing against the paper.
Lin Feng walked off the podium and walked right next to the fifteen-year-old girl whom he had supported on Heaven-Ascending Stairway. She was still writing with her head down, silently writing down the formulas on the blackboard line by line.
Lin Feng looked at what she had written, and there was a wrong symbol on one line. He stopped, picked up the pen on her desk, lightly drew a circle, changed it, put down the pen, and left.
The girl raised her head, looked at the circle, and then looked up at the back of the person who had walked away. Then she lowered her head and traced the changed symbol deeply, carefully as if she were carving something important.
Yun Chengwang stood outside the square, watching Lin Feng leave, then walked to the pit, stood on the edge, and looked down.
Three feet thick granite, nothing is left in the center of the pit.
He stood there for a while, and then called the deacon in charge of the training ground:
"Measure the size of this pit and make a record of it," he said. "Keep it and don't repair it."
The deacon was stunned for a moment. "Keep it?"
"Keep it," Yun Chengwang said, "In the future, add this to the college tour route."
He paused and added:
"On the label, write "Scientific Cultivation Demonstration Site, Lin Feng, built"
Deacon: "... Okay, Dean."