My physics masters couldn't possibly be grand mages.

When Char woke up again, he was awakened by a strange sense of emptiness.

He opened his eyes.

The curtains were drawn, and the room was so quiet that you could hear your own pulse beating behind your eardrums.

He lay there for two seconds, staring at the ceiling.

His mind felt heavy, like it was stuffed with a wad of wet cotton; he couldn't think clearly about anything. It took him about ten seconds to recall why he was in bed.

What time is it now? Night? Or morning?

He turned his head and glanced at the clock on the bedside table.

5:43.

He paused for a moment, then slowly sat up. His body felt as heavy as if he were wearing a lead apron.

If you feel this way when you wake up in the morning, you might think you're sick, but in a sense, Char has overslept during his "lunch break".

He put his feet on the floor and sat for a while before standing up.

As he stepped out of his bedroom, he heard noises coming from downstairs.

The soft clinking of porcelain, the bubbling of boiling water, and the scraping of chalk across the blackboard.

He glanced at himself in the mirror while washing up. Still a little dazed, he wiped his face with a towel, changed his clothes, and went downstairs.

The stairs swayed slightly beneath his feet, as if greeting him.

The bitter aroma of coffee wafted through the living room.

Einstein sat at the dining table, a glass in his hand, his eyes fixed on the valley outside the window, lost in thought. Hearing footsteps, he turned his head, his grey-blue eyes sweeping over Xia.

"morning."

"Good morning." Xia walked to the dining table, poured himself a cup of coffee, took a sip, and then looked up at the blackboard in the living room.

Tesla stood in front of the blackboard, chalk in his hand, writing something.

Three lines of text were written on the blackboard.

First line: Lorentz force

The line below is a formula.

F = q(E + v × B).

Char stood in front of the blackboard, holding his coffee cup, and stared at it for a few seconds.

"Didn't you guys sleep last night?"

"I'm asleep," Einstein said.

"I fell asleep and then woke up again." Tesla turned around, picked up his coffee cup, and took a sip.

Char looked at the formula on the blackboard, then at Tesla, and blurted out a term.

"An electromagnetic railgun?"

Einstein raised an eyebrow. Tesla paused, his hand holding the coffee cup still, glanced at him, and said sarcastically.

"It seems that all this time of teaching has been worthwhile."

"Can you make it?" Xia asked.

"It's at least easier than his accelerated thinking," Tesla said, looking at Einstein. "That thing would be a huge undertaking if it were actually built."

Einstein gave a soft hum, but said nothing.

"The first step we need to take now is to buy a gold plate."

Tesla infused his mental energy into the badge.

Char distributed some of the points he previously obtained from Aldrich to Einstein and Tesla.

Before, they thought 600 points was an astronomical price, but now they can buy it without even blinking.

This was still a "thank you fee." Xia didn't even dare to imagine how much money each of these Golden Families must have.

He could almost hear some kind of background music playing in his ears: "Mistakenly...intruding into the imperial palace..."

Tesla didn't hesitate to buy the gold plate, followed by a large amount of other metals, which were relatively cheap there.

A few minutes later.

-

The melodious and profound cry of an eagle drifted from afar.

Then, there was a sound of something falling to the ground at the doorway.

Char walked to the door and opened it; several cardboard boxes were placed at the doorway.

He carried in the cardboard boxes one by one and opened them. Some of the boxes contained lumps of metal, while one of them contained a square plate measuring 1 meter by 1 meter.

The surface is covered with intricate patterns carved with a carving knife, forming a circular magic circle.

It gleamed with a dazzling golden light under the sunlight streaming through the courtyard.

Tesla walked over and tapped the plate with his finger, making a dull sound.

"No wonder it's so expensive," he muttered to himself, "It's made of gold."

"This would cost several million back home, wouldn't it?" Xia said.

Tesla didn't say anything; he simply placed the plate on the coffee table and then took an aluminum block from a cardboard box on the side and placed it on the plate.

He slowly closed his eyes, reached out his hands to the alchemy plate, and recalled what he had learned in alchemy classes these past few days.

Input magic power... and then recall the main structure of the metal in your mind.

The first step in alchemy is "understanding".

The patterns on the gold plate were gradually filled with Tesla's blue magic.

The aluminum alloy block was quickly submerged in the magical light.

Under Char's watchful gaze, the alloy block gradually turned into liquid, eventually becoming small fragments that then fused together under the control of magic.

This is the process of decomposition and reconstruction.

Then, one aluminum alloy bead after another appeared on the plate, starting slowly and then getting faster and faster.

Tesla slowly opened his eyes, looked at the beads on the table, and smiled at Einstein:

"This thing is much better than those precision lathes."

He picked up a few aluminum alloy beads and walked out of the villa.

Char followed him out.

......

"The principle of an electromagnetic railgun is very simple."

"Tesla said. He didn't look at Char when he spoke; his gaze was fixed on the void in front of him, as if staring at an invisible model."

Tesla possessed exceptional visual thinking abilities. At this moment, he was constructing a completely realistic and functional virtual model in his mind, and testing, modifying, and optimizing it in his mind as if operating a real machine.

Xia stood silently beside him, wisely refraining from disturbing him.

Einstein came out of the living room, but did not sit down. Instead, he leaned against the door frame with his coffee cup in hand, his gray-blue eyes half-closed.

"Electric current generates a magnetic field, and the magnetic field propels the projectile." Tesla raised his right hand, put his index and middle fingers together, and drew a straight line in the air. "Theoretically, as long as a sufficiently large current is output instantaneously, even a coin can penetrate a steel plate."

"As early as the 19th century, scientists had theoretically conceived of electromagnetic emission."

"Then why did it take more than a hundred years to achieve?" Xia asked.

The reason he knew about electromagnetic railguns was because this technology had already been used in the military.

"It's a matter of materials and energy," Tesla said, "but I think magic can solve these problems."

He thought for a moment, then raised two fingers.

"There are two designs for the electromagnetic railgun."

"One type is a railgun, where an electric current passes through two parallel rails and the projectile to generate a Lorentz force, which propels the projectile to accelerate."

One type is a coilgun, where multiple coils are energized sequentially to generate a moving magnetic field, which "drags" a magnetic projectile to accelerate it.

Tesla lowered his hand, and the corner of his mouth twitched slightly.

"The railgun is like a rich and willful nouveau riche. Its solution to the problem is simple and brutal: use a large current, and if that doesn't work, replace it with a stronger and larger current."

Coil guns, on the other hand, are like meticulous old accountants. They are thinking about how to optimize the magnetic field and use the least amount of energy to move the heaviest projectile through complex timing control.

The latter is more energy efficient and has lower instantaneous power requirements than the former, but the problem is... it's too complicated.

He paused, as if thinking, before making a judgment: "Its complexity exceeds the third order."