Chapter 75 - 72: I Will Arrange It
Jiangcheng Sixth Middle School, the physics lab.
For the past few days, whenever Li Dong had a spare moment, he would come to the lab with Elder Chen to unwind.
"Hook up that servo motor, and don’t get the wires for the speed encoder backward!"
Elder Chen yelled, directing Li Dong.
Although Li Dong had already given a clear verbal description of the Hysteresis Loop phenomenon and spontaneous symmetry breaking, there was still a ton of foundational work to do when it came to building the actual experimental apparatus.
So far, they had only managed to put together a very rough framework.
On the lab bench, a clear acrylic, ring-shaped track was mounted on a vertical rotating shaft, with a small metal ball nestled inside the loop.
"Teacher Chen, I’ve finished deriving the Lagrangian and the dimensionless effective potential energy model."
Li Dong explained as he wrote on the whiteboard with a marker.
"L=T-V. This is the basic form of the Lagrangian. If we switch to a reference frame rotating in sync with the ring, we can introduce an equivalent centrifugal potential energy and clearly define the system’s effective potential energy."
"Then, we establish an inverse isomorphism between the dimensionless parameter for rotational speed and the reduced temperature from thermodynamics..."
"Once the motor spins the ring, the ball’s effective potential energy within the rotating reference frame is determined by both its gravitational potential and the equivalent centrifugal potential. The two potentials are in competition, one increasing as the other decreases."
Elder Chen stood to the side, looking at the formulas on the whiteboard.
"Yes, yes, exactly. That’s the right line of thought."
"And if we intentionally introduce a slight eccentricity to the rotation axis, that’s equivalent to introducing an asymmetry into the system. Mathematically, it becomes perfectly isomorphic to the effect of an external field in a thermodynamic phase transition."
Elder Chen couldn’t help but marvel at the idea.
Li Dong nodded. Just as he was about to mention that the equipment’s precision might be insufficient, the phone in his pocket began to vibrate.
He took out his phone and saw it was a call from his uncle, Li Yang.
He froze for a moment, and then it hit him.
’Crap, the inventory management system!’
He’d been juggling the physics model for the Qiu Prize and his biology project proposal, so busy these past few days that his head was spinning.
He had completely forgotten all about his uncle’s request.
He answered the phone, feeling a pang of guilt.
"Hello, Uncle."
Li Yang’s laughter came from the other end of the line.
"Xiaodong, you must be busy with your studies, right? I’m not disturbing you, am I?"
"N-no, not at all," Li Dong said, his voice tinged with guilt.
"Uncle, you’re calling... it’s about the system, isn’t it?"
"Yes, that’s right," Li Yang said over the phone.
"Xiaodong, have you finished that system? If you haven’t, then don’t worry about it."
"Huh? Why?" Li Dong was taken aback.
"Well, a software sales rep happened to drop by the workshop today to make a pitch."
"I took a look at their ready-made inventory management system, and it’s actually pretty good! It doesn’t just do barcode scanning for check-in and check-out, it also has... what do you call it... a low-inventory alert. The price is cheap, too, only about a thousand a year."
Li Yang said in a relaxed tone.
"I’m planning to just go with their system, so don’t you waste your energy writing code. You’re a high school senior now; focusing on your studies is what’s important."
Hearing Li Yang’s words, Li Dong fell silent.
If this had been the old Li Dong, he might have actually believed this story. He might have even been relieved to be spared the major hassle.
But now... well, his Logic was at 0.2. Even if he didn’t care for social complexities, how could he possibly not understand his own uncle?
’A workshop with five people, tops.’
’A SaaS sales rep would make a call on them? What a joke.’
’So the truth was—there was no sales rep. Period.’
"Uncle... I get it."
Li Dong took a deep breath and agreed.
"I won’t work on the system for now, then. You should take care of yourself at the workshop, don’t get too worn out."
"Okay! You got it. You focus on your studies. I’m hanging up now!"
Hearing the disconnect tone from the other end, Li Dong lowered his phone.
He stood by the lab window, watching the students playing ball on the field outside.
’Even if I managed to squeeze out the time to write a perfect inventory management system for my uncle, or even buy one for him, what would that really change?’
’The system is just a symptom. What Uncle really needs is an opportunity.’
Li Dong was now well aware of what the two solutions he had proposed at the Huaxuan Cup meant to Huaxuan Technology.
It was an enormous favor.
Using that favor to get money or secure a promising future for himself would have been the logical thing to do.
But now, he wanted to use it for something else.
Li Dong opened his contacts and, without hesitation, dialed a Shanghai number.
...
Shanghai, Huaxuan Technology Research and Development Headquarters.
Zhang Mo hadn’t been home in nearly a month.
The reason, of course... was the idea Li Dong had left on his Huaxuan Cup final exam paper. Although Li Dong later said it wasn’t feasible, what he saw as an unsolvable problem was, in their eyes, merely a difficult one.
Instead of rigidly controlling the immersion fluid’s temperature, they would use a customized, narrow-linewidth, tunable ArF laser to synchronously fine-tune the light source’s vacuum wavelength. This would counteract fluctuations in the refractive index and maintain an absolutely constant phase!
In terms of optical theory, the approach was sound.
As for the computational bottleneck?
That only existed because it hadn’t been worth the effort to solve. Otherwise, that bottleneck would have been eliminated long ago.
Just then, a team member leaped up from his workstation, clutching a stack of printed data reports.
"Team Lead! Team Lead!"
"We’ve made progress! We’ve really had a breakthrough!"
Zhang Mo turned to look at him. "Report!"
"We tried abandoning real-time direct numerical simulation of the entire flow domain. Instead, we first used large eddy simulation to construct a database of the flow field under all operating conditions."
"Then, we built a reduced-order predictive model based on proper orthogonal decomposition and added a local heuristic flow-field correction algorithm for the micron-scale region of the boundary layer near the wafer!"
The team member excitedly pointed at the data plots.
"The results show that within the rated scanning speed range, the prediction error for the refractive index field caused by flow-thermal coupling has been stabilized within the tolerances of the lithography process!"
"It’s only an approximate solution, but the response delay for the feed-forward control has been compressed to a theoretical 300 microseconds!"
Zhang Mo sucked in a sharp breath, feeling his scalp tingle.
"Have you run the numbers? If we want to completely overcome this algorithmic bottleneck and get the delay under the 200-microsecond hard requirement for mass production, how much longer will we need?"
The team member calmed down as well, giving an estimate based on the feedback from the data.
"Immediate implementation is impossible, of course. We have gaps to close in both computational hardware and algorithm optimization."
"But, as long as we keep hammering away in this direction and throw more resources at training the model, we can probably solve it in one to two years."
In a field like semiconductor equipment, where core technologies often have R&D cycles measured in decades, going from proof-of-concept to mass production in just one or two years was practically lightspeed.
Hearing this, Zhang Mo felt completely revitalized.
"Good! Excellent! Keep running the data and monitor the model’s convergence!"
Zhang Mo snatched his work ID from the desk and left the lab.
He hurried to the director’s office on the top floor and knocked.
"Come in."
Zhang Mo pushed the door open and saw Lin Wei on the phone.
"Alright, send me your uncle’s address in a bit. I’ll make the arrangements..."
Lin Wei hung up and turned to face Zhang Mo.
"Zhang Mo, what’s the matter?"