Chapter 557 257 Witness the Miracle! (Part 1)

A long, long time later.

Wheat, in his memoir "He Changed Cambridge," affectionately mentioned the experiment of today with a sentence:

"Damn it, Luo Feng!"

This sentence contained Wheat's extremely complex emotions, which can be simply described as social death-level embarrassment.

After all, present there besides Wheat himself and Xu Yun were Prince Albert, Faraday, Joule, and a range of textbook physics units…

Of course.

At this moment, Wheat was still a very simple young man, unaware of how silly a thing he had done.

After reading this sentence, he blushed a little but had not yet reached the stage of wanting to axe Xu Yun to death.

Then he handed the piece of paper back to Xu Yun and asked:

"Mr. Luo Feng, what should we do next?"

Xu Yun gave him a look, patted him on the shoulder with deep meaning, and said:

"Didn't I say? We are going to break the seal of the electromagnetic world."

Wheat:

"...."

Then, with a straight face, Xu Yun led him to Faraday and others:

"Mr. Faraday, following the ideas of Fat Fish Ancestor, there are two things we need to do next."

Faraday and others listened intently.

Xu Yun raised one finger and explained:

"First is derivation, second is the experiment."

"Derivation?"

Faraday adjusted his glasses, repeated the word, and asked Xu Yun:

"Derive what?"

Xu Yun didn't answer directly but countered with a question:

"Mr. Faraday, I heard that you once proposed a theory that there must be an electric field around a charge, right?"

Faraday nodded.

Students who studied physics should all know.

Faraday was the first to introduce the concept of the electric field and proposed the idea of using electric field lines to represent electric fields.

He also simulated the situation with magnetic lines using iron filings around a magnet.

Xu Yun showed a slight smile, suppressed his inner emotions, and said as calmly as possible:

"What we are going to derive next is something that exists in the electric field."

Then he picked up a paper and pen and drew a wave graph on the paper.

Which is the graph of the sine function.

Then he drew a circle on the graph and said to Faraday and others:

"Mr. Faraday, the purpose of our study of physics is to summarize some sort of consistency from various phenomena in the ever-changing natural world."

"Then quantitatively and accurately describe this consistent phenomenon using the language of mathematics."

"For example, Newton's F=ma, the 1824 thermodynamic's △S＞0, reader equals handsome beauty, and so on.....

"So the question is, in our current world, is there a mathematical equation that can describe waves?"

Faraday and others remained silent for a moment, then slowly shook their heads.

Wave.

This is a very common term or phenomenon in life.

Apart from apples, a stone falling into the water creates waves.

Shaking a rope also creates waves.

The wind blowing over the lake still creates waves.

It was introduced earlier.

The level of physics in 1850 was actually quite high, and at that time, the scientific community could already measure precise values such as frequency and wavelength.

The described units were simply in negative powers of meters, unlike later times with terms like nanometers and micrometers.

In this situation.

Many people have tried to study waves in the past, from Little Niu to Euler.

But regrettably.

Due to the limitations of the era's thinking, the scientific community never managed to derive a standard mathematical equation that can describe wave patterns.

But now Xu Yun has asked such a question…...

Could it be....

"Classmate Luo Feng, could it be that Mr. Feiyu has already derived the mathematical expression for wave motion?"

Xu Yun still did not directly answer this question but continued writing on the paper.

He first established a basic coordinate system on the previously drawn function graph.

Then he drew an arrow in the X-axis direction and wrote the letter V.

This represents a wave moving in the positive direction of the x-axis at a certain speed v.

Then Xu Yun explained:

"First, we know that a wave is constantly moving."

"This graph is just how the wave looks at a specific moment, and at the next moment, it will move a bit to the right."

Faraday and others all nodded.

This was standard human language, not difficult to understand.

As for how far the wave moved at the next moment, it was easy to calculate:

Since the wave speed is v, after a time Δt, the wave would move a distance of v·Δt to the right.

Then Xu Yun circled one of the wave peaks and said:

"Mathematically, we can view this wave as a collection of a series of points (x, y), so we can describe it with a function y=f(x), right?"

A function is a mapping relationship, and in a function y=f(x), for any given x, you get a y through a specific operation f(x).

This pair (x, y) forms a point in the coordinate system, and connecting all these points forms a curve—this is an authentic first-year concept.

Then Xu Yun wrote a t next to it, which means time.

Because just y=f(x) only describes the shape of the wave at a particular moment.

To describe a complete dynamic wave, you have to consider time t.

This means the waveform changes over time, i.e.:

The y-coordinate of a point on the graph is related not only to the x but also to time t, so you need a bivariate function y=f(x, t) to describe a wave.