Chapter 550 255: At Kang Bridge, Waving Sleeves to Summon a Dark Cloud (Part 2)

Looking at Xu Yun with a mysterious expression.

Faraday instinctively glanced at his hand.

At this moment.

In the open palm of Xu Yun's hand lay a transparent crystal.

The crystal was about the size of a mint candy in a Green Arrow metal box, with high light transmission.

At this moment, the crystal had been polished into a rectangular shape, tapered at both ends and even in the middle, somewhat resembling a butt plug.

Faraday reached out to touch it a few times, feeling the matte texture, and judged:

"Is this... a crystal?"

Xu Yun shook his head. Nine out of ten people would mistake this thing for a crystal at first glance and explained:

"Mr. Faraday, this is material prepared for me by Dean William Whewell, called a nonlinear optical crystal.

"It can be used to assist in changing the frequency of light. We have prepared seven pieces, and you will soon understand their specific function."

Nonlinear optical crystal.

This is a very common piece of equipment in optical laboratories of later generations.

Its use is similar to that of a grating, capable of performing frequency doubling, sum frequency, difference frequency, and other frequency-changing operations on light.

However, most nonlinear optical crystals in later generations are artificially designed and synthesized, with development closely related to lasers.

For example, lithium triborate crystals, cesium lithium triborate crystals, and so on.

The technological level in 1850 was far from reaching that stage, so Xu Yun chose to use natural crystals for processing, a relatively primitive method.

Fortunately, as one of the world's top universities of this era, the University of Cambridge had some reserves of raw crystals.

After hours of busy work.

The lab workers managed to produce a few potassium dihydrogen phosphate crystals in a rush.

But even the most primitive nonlinear optical crystals perform much better in frequency-changing operations than prisms do, living up to their complexity.

As for the function of the nonlinear optical crystal....

Naturally, it was for the upcoming performance.

Then Xu Yun handed this nonlinear optical crystal to Old Tang, instructing him to place and adjust it as required.

He thought for a while and said to Faraday:

"Mr. Lafayette, you're an expert in semiconductors, so you should know that the speed at which charge leaves a metal plate is directly related to the voltage strength, right?"

Xu Yun's comments might seem somewhat problematic from a modern perspective, but in the year 1850 when electrons had not yet been discovered, this description was quite understandable.

Faraday nodded affirmatively and replied:

"That's right."

He had discovered this phenomenon while researching chlorine cage compounds in 1833 and tested the results with an electrometer.

Later, JJ Thomson's discovery of the electron was also partly related to Lafayette's research manuscripts.

Of course.

If we trace back further, it leads to Coulomb's generation, which won't be elaborated on here.

Xu Yun further asked:

"So the larger the voltage, the faster the charge departs, correct?"

"Correct."

Xu Yun snapped his fingers, believing the groundwork had been laid:

"Then Professor Faraday, what do you think the sparks appearing on the receptors in the photoelectric effect are related to?"

"Sparks on the receptors?"

Faraday was slightly taken aback, thought for a moment, and blurted out:

"Of course, it's related to the intensity of the light."

Xu Yun's lips curved into a slight smile as he pressed on:

"So it's not related to the frequency of the light, is that right?"

Faraday's tone was even more assertive this time, and he shook his head decisively, saying:

"Of course it has nothing to do with it; how could frequency affect the formation of sparks?"

Around them, including Stokes, the observing professors echoed in agreement:

"Of course, it's related to the intensity of light."

"Frequency? How could that have anything to do with sparks?"

"There's no doubt, it must be the intensity of the light, or the amplitude, causing the sparks."

"So does anyone want to see my wife's swimsuit...."

From Faraday's and those professors' perspectives.

Although they were not clear on why the generator produced light, and the receptor generated synchronized sparks.

But clearly.

The condition for the appearance of sparks on the receptor must relate to the intensity of the light.

Which means the greater the intensity of the light, the stronger the sparks will be.

Because in classical theory, the wave is a uniformly distributed energy state, and the charge (electrons) is something bound within the object.

In order to release it, it needs to provide a single charge with enough energy. (From now on, 'charge' will replace 'electron,' as only the concept of 'charge' was recognized in 1850)

Analyzing according to the wave theory.

Light waves distribute energy evenly over many charges, so that they continuously receive the wave's energy and jump out together.

By around 1895.

Scientists would attempt to explain this with the addition of plain wave functions and Bloch functions in periodic potential fields.

Even when Xu Yun came to 2022.

Some alternative-thinking scholars introduced the Born-Oppenheimer approximation in the scattering process of photons and electrons:

They took the first two terms of approximation in actual calculations, and finally obtained the photoelectric effect through the final state electron wave functions.

Yet, it hardly explains why the entire process is described using probability amplitudes, which is quite peculiar.

In his past life, Xu Yun heard some maverick enthusiasts, forced into a corner, even say things like "you just need to be lucky to succeed" during a conversation with a friend who was an external review editor for a journal...