The first method is very simple; it is based on the division of obtuse and acute angles, using the characters "ju" and "gou".

"Ju" indicates obtuse, and "gou" indicates acute.

"Ju and gou with the ruler" means a right angle.

But the second method is more complicated.

It is somewhat similar to measuring directions:

Using the twelve earthly branches: Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, You, Xu, Hai, together with the ten Heavenly Stems: Jia, Yi, Bing, Ding, Geng, Xin, Ren, Gui and the eight trigrams: Qian, Kun, Gen, Xun to create a set of twenty-four specific names to represent angles.

This means each name roughly represents fifteen degrees.

However, it's quite strange... you could even say it's still an unsolved mystery to this day...

The ancient sages of Huaxia actually understood the concept of 360:

The ancestors used a division system for celestial bodies that was actually 365 and 1/4 degrees.

In a sense.

This was infinitely close to the 360-degree method.

Unfortunately, alas.

In occasions other than astronomical angle measurements, the ancestors did not use this system at all.

Therefore.

This method of division had no impact on establishing angle measurement in Huaxia.

So in some media accounts, you might hear claims like "Huaxia was actually the first to define 360 degrees," which uses the celestial division system.

It's a shame.

The latter half of that sentence is correct, but the whole sentence is wrong.

Or to use a more modern example, it should be clearer where the oddity lies:

This is somewhat like a 21st-century scientist rightly discovering the concept of higher-dimensional space, but instead of using this concept in research, he uses it for the basic setting of novels and films.

Strangely, this setting is adopted by many films, so almost every ordinary person on Earth has heard of it.

But in the scientific community, everyone seems to ignore this setting, focusing instead on exploring various inefficient theories.

This is indeed a very strange situation:

Because the celestial circumference is also determined by circular method, given the wisdom of the ancestors, it is unimaginable that they wouldn't consider this.

Therefore, in some later circles of lay scientists, people proposed some strange hypotheses.

For instance, that the cognition of the ancient ancestors was blocked, or fragments related to angles were taken away, etc.

There are even proponents of the 256-degree theory, which is quite bizarre.

Let's return to our original topic.

No matter what system the ancestors used for angle division, after dividing the angles, they must take another step:

Measurement.

Therefore, the Ruler appeared.

This is a right angle ruler with one long side and one short side, and there are also more special arc rulers.

In some places, this is also called an angle ruler, colloquially known as a corner ruler.

At this moment.

Liu Yi was holding the ruler, measuring the angle of the lens:

"Marking below the Chou angle... marking below the Wu angle... marking above the Hai angle... marking above the Yin angle..."

Above, below, and middle marks.

This seems to be a classification Liu Yi devised himself, refining the 24 divisions further.

Yet even so.

This only reached a precision of 72 divisions, five times less precise than 360 divisions.

And to refine this fivefold difference, there is only one method:

By continuously adjusting the lens angle, collecting vast amounts of corresponding information.

Then, through manual calculations, step by step, filter out the most accurate answer.

Seeing this, Xu Yun flashed a hint of unwillingness in his eyes.

You must know.

This is the most fundamental link in the entire process.

Whereas future generations can lock into a certain range with just three to five surveying data, Old Jia might need hundreds of sets.

After all, there's an extraction process here, equivalent to dramatically increasing the amount of calculation.

Thinking of this, Xu Yun couldn't help but open his mouth.

Instinctively wanting to convey the concept of angles to Liu Yi and Old Jia.

But after hesitating several times, he abandoned this idea.

After all, according to his intention.

He really could not be too involved in the deduction of the convex lens this time.....

If he told Old Jia about the angle concept.

Then what about the angle of incidence and angle of refraction?

What about the waist radius?

What about screen function sampling?

What about Fourier transforms?

These are all interconnected concepts.

Although Xu Yun could summarize them in a few words, to break through these barriers, the ancient sages (whether Chinese or foreign) paid a huge price.

Therefore, no matter what, this breach could not be opened.

It's like cross-dressing; once it starts, there will only be zero or countless times.

You should know.

Xu Yun's time in this world is not long, only a little over a year.

If the task is completed ahead of time.

He might even return to reality in just a few months, like in the 1665 dungeon.

Indeed.

He could stir some big news during this time, shocking these ancient people.

But if he only imparted finished knowledge, without hinting at deeper reasons, without establishing a system capable of self-reflective feedback.

Then after Xu Yun leaves, everything will just become superficial 'black technology.'

This rootless floating plant's outcome is vividly demonstrated in the later Huaxia's Jin Yuan football:

When capital flooded in.

Capital introduced famous foreign aid, keeping overseas stars or those likely to go abroad domestically.

Exhausted their youth, not cultivating new talents.

The league prospered temporarily, fan excitement soared, and good results were achieved in the Asian Champions League and even the Club World Cup.

But when the Jin Yuan retreated.

Everything reverted to its original form, even worse than before.

For example, now.

National football fans can even look forward to losing to Myanmar.

This is what Xu Yun is worried about:

Knowing what but not knowing why is a very dangerous situation.

Therefore, Xu Yun would rather slow his pace a little and bring less change to this world.

He also hopes to cultivate a piece of vibrant soil for them.

And the first step in cultivating the soil.

Fell on Old Jia, Han Gonglian, and Liu Yi.

Thinking of this, Xu Yun couldn't help but take a deep breath and said to Old Su:

"Sir, let's talk outside."

......

Note:

6.6K big chapter, all-nighter until now, a total of 13,000 words, please vote for monthly passes!!!

This month's end has no double, only in March, so don't save them....

If you find any errors ( broken links, non-standard content, etc.. ), Please let us know < report chapter > so we can fix it as soon as possible.