Heavenly Ding and Heavenly Jia, the Study of Longitude and Latitude

"Haa--"

Chen Zhuangzhi sat cross-legged in the training hall prepared for him, his whole body steaming with white mist that sometimes turned black, his palms taut on either side of his head, facing forward.

The hall was filled with screens and full-length bronze mirrors, vaguely resembling a mysterious formation.

The roof of the palace is very high and is a dome.

This is a three-tiered, pyramidal-roofed hall. From the outside, it appears to have three layers of eaves, black tiles, blue windows, and carved beams and painted rafters.

Inside, there is actually only one layer.

This symbolizes the roundness of the heavens, the sequential descent of heaven, earth, and humanity, and the interconnectedness of the three realms.

At the very center of the roof, a seven-foot square area was not made of ordinary building materials, but of crystal, making it crystal clear.

Although the crystal was carved into a pointed shape, there was no sense of uneven lighting when looking up at the sky.

I felt a clear, empty space above my head, allowing me to look directly at the stars and moon, and gaze up at the night sky.

Chen Zhuangzhi was not sitting directly under the roof of the palace, but rather in a subtle, slightly off-center position.

In this way, at midnight, the moon in the sky, the crystal in the middle, and Chen Zhuangzhi on the ground can be aligned in a straight line.

This allowed him to fully enjoy the moonlight at midnight.

At noon, he would go to the Human Furnace Hall to select a group of disciples and distribute the Moon Turbidity essence he had collected into their bodies.

At his level, he no longer needed to concern himself with how his disciples cultivated demonic arts and refined their internal energy.

Anyway, when his time comes, he will reclaim that essence, no more, no less.

Tonight, the Yellow Mountain Ancestor caused trouble, and Chen Zhuangzhi went out to investigate, wasting some time.

He was quite unhappy that he hadn't been able to use the entire midnight hour to collect moonlight.

Unfortunately, the Yellow Mountain Ancestor and the others were all Zhang Tongxuan's Human Furnace, making it difficult for Chen Zhuangzhi to deal with them, and he felt somewhat restless.

"You old fools... Once Master has worn you out, I'll make you suffer the full force of the Chen Clan's tortures, then you'll know what death truly means!"

Chen Zhuangzhi's mind became agitated, and the white light emanating from his palms flickered slightly, becoming unstable.

Behind him, a light, floating soul appeared, following the rhythm of the flickering light.

Chu Tianshu immediately recognized that the man in black in front of him was the one who had broken into his valley, attacked the child, and injured Old Lu.

That round, plump back of the head is truly tempting.

Chu Tianshu twitched his fingers slightly, but his soul was too far from his body to execute the complete Phoenix Nirvana Sword Strike technique.

He thought about it and decided not to try, whether he could kill this person in one fell swoop using only his soul power.

Let's see where this place is!

Chu Tianshu looked up, his soul silently rising and passing through the roof.

"Who?!"

Chen Zhuangzhi suddenly sensed something, let out a shout, and leaped into the sky.

Chen Zhuangzhi smashed a large hole in the tiles next to the crystal roof. While in mid-air, he spun around and struck out with his palm.

Chu Tianshu raised his hand to block, his palm facing outwards.

Chen Zhuangzhi felt a powerful force, as thick as the ocean tide and as expansive as a sphere, come through and collide with his own fierce palm strike.

The two figures drifted away separately.

Halfway through his retreat, Chu Tianshu looked around and was struck by the beauty of the mountains and rivers, with their distant peaks and overlapping ridges. Even under the cover of night, the picturesque scenery was undeniable.

On the nearby hills, there are palaces and temples everywhere, but they are hidden by maple forests and bamboo groves, and their layout is so ingenious that even if outsiders come to the vicinity, they probably won't be able to tell anything about them.

Only by being there in person can one truly appreciate how much effort went into building these structures on these hilltops.

No wonder you were able to spot me.

Chu Tianshu glanced down at his feet and saw that the entire hall was actually made up of magical artifacts.

The incantations hidden in the roof of the temple pose no threat whatsoever; their aura is minuscule, yet they can serve as a warning.

After just a fleeting glance, Chu Tianshu turned his gaze to the night sky.

This place has excellent feng shui, a pleasant climate, and an endless night sky dotted with countless stars.

At first glance, it was as if starlight had fallen into his eyes.

Only then did Chu Tianshu's retreating momentum come to an end, his toes touching the roof of the palace.

"You bastard!!"

Enraged, Chen Zhuangzhi spread his arms wide and grabbed at the air.

Even after their initial clash, the opponent had time to glance left and right, and look up and down as they retreated.

In short, no one gave him a second glance.

Since entering the realm of Attaining the Dao, Chen Zhuangzhi had never encountered anyone who dared to underestimate him so much.

Besides, this is the stronghold of him and his apprentice!

In his rage, Chen Zhuangzhi unleashed his most powerful and deadly move.

The Tongxuan Sect's "Great Void Qimen Qi Discernment Method" not only delves deeply into the primordial energy of heaven and earth, but also conducts extensive research on the energy of flowing winds and the energy of breathing.

The wind blows throughout the world, and the air within it is actually of countless different kinds.

Among the Daoist ancestors' numbering system, the Heavenly Jia Qi is an essential gas for combustion.

The Qi of the Heavenly Ding is itself a kind of fuel.

When Ding and Jia are in harmony, they can produce pure water.

However, if one uses Demonic Dao True Qi to entrust Heavenly Jia and Heavenly Ding respectively, allowing them to first become liquid, they can meet again.

With just a little stimulation, it will immediately generate explosive power.

The temperature of this explosive combustion is equivalent to three times that of magma.

If properly controlled, the resulting impact speed can far surpass the movement speed of Attaining the Dao being.

Chen Zhuangzhi spread his hands apart and grasped, and two water spheres, one light blue and one crystal blue, appeared in his palms.

They separated and reunited instantly; the two water spheres had already been sent forward by him, colliding and creating a bright blue flame that hurtled towards Chu Tianshu.

As if he had foreseen the future, Chu Tianshu had already drifted three zhang to the side.

"That move is powerful, but it's not fully mastered yet; the warning signs are too obvious..."

The flames were powerful, but they didn't even graz his edge; his gaze remained fixed on the sky.

Suddenly, Chu Tianshu's expression changed, but instead of looking at Chen Zhuangzhi, he looked towards the mountains.

In the next instant, his figure, like a disturbed reflection in water, rippled and vanished.

A hand suddenly reached out, grasping at thin air, but grasped nothing.

Zhang Tongxuan withdrew his hand, his expression subtle, and glanced around.

"They didn't hide and flee; they truly vanished from here in the blink of an eye?"

Upon hearing this, Chen Zhuangzhi was both shocked and furious. "How is that possible? Even a soul must have its own trajectory; how can it truly disappear into thin air?!"

"Perhaps, it's through the Eighth Consciousness Realm."

Thinking of this, Zhang Tongxuan realized, "I secretly captured and interrogated so many monks, but I still couldn't find out the key to entering the realm. I thought that Qingsheng and Wubei had no intention of passing it on to a third person."

"Unexpectedly, something has still been left behind as a legacy?"

As he spoke, Zhang Tongxuan floated down from the roof of the palace and stood at the base of the wall, stamping his foot.

At the base of the wall, a crimson, Vertical and Horizontal Seal about the size of a finger joint appeared.

Chen Zhuangzhi followed and, upon seeing this scene, his face turned even more ashen.

This must be the mark left by that person when they touched the top of the hall with their toes.

Using objects to transmit force, the mark moves along the way and hides at the base of the wall.

"Don't be embarrassed or angry. Although you haven't noticed it yet, it won't escape your notice once you calm down."

Zhang Tongxuan offered a few words of comfort, then waved his hand to erase the mark.

Chen Zhuangzhi's expression softened slightly. "He underestimates us too much to think he can use this mark to trace our location and find our headquarters afterward."

Zhang Tongxuan stood with his hands behind his back, gazing up at the stars and moon.

When he arrived, he saw Chu Tianshu looking at the sky.

Is it just to express contempt?

"Zhuangzhi, you will stay in the quiet room of my little tower. Do not cultivate, do not use force, and restrain your aura to prevent him from finding you again."

Zhang Tongxuan frowned slightly and said, "I'll go with you."

"There are some things in that tower that you don't yet understand; I will teach you everything today."

"This tower has been idle for many years; perhaps it will come in handy soon."

In the deep valley.

Chu Tianshu's soul appeared in mid-air and fell back to his true form.

"Such a strong sense of threat. Is it because my soul has departed and my strength is incomplete? Or is it because he has some special methods targeting the soul?"

Chu Tianshu opened his eyes in his true form and murmured to himself.

Xiao Liang quickly asked, "You fought someone? Did you leave any backup plans?"

"I left a mark, but I felt that mark was destroyed when I was still in the Eighth Consciousness Realm."

Chu Tianshu couldn't help but smile when he saw the undisguised disappointment and worry on Xiao Liang's face.

"But I looked at the sky over there."

Lu Yuande asked curiously, "Look at the sky?"

"Yes, sometimes you don't necessarily need magic to determine location."

Chu Tianshu gathered his energy in his right hand and imprinted several golden dots on the grass, representing constellations.

Next to each constellation is a line of annotation.

His face would occasionally show a look of reminiscence, his left hand calculating while his right hand constantly drew pictures and wrote words.

Xiao Liang was self-taught, while Lu Yuande's school was even more learned.

But no matter how they looked at him, they still couldn't understand what Chu Tianshu was doing.

I recognize each character individually, but when they are put together, I don't understand their meaning.

Lu Yuande looked at the two characters with the heaviest strokes and a look of confusion on his face.

"Latitude and longitude..."

"It is precisely the warp and weft of heaven and earth."

Chu Tianshu replied casually, still in the process of recalling and calculating, without intending to elaborate further.

His study of latitude and longitude was actually related to his trip to Busan.

Even before going to Busan, he had considered the possibility that something serious might happen there, or that something unexpected might occur.

If all the location and communication tools on my body, such as cell phones and talismans, are rendered ineffective, and I am stranded at sea, how can I determine my location and route on the vast ocean, get back to China, or go back to the scene of the incident?

When Helai, he recommended that he study astronomy and geomancy.

By observing the sun, moon, and stars, one can calculate their own latitude and longitude.

In ancient Huaxia, the term "warp and weft" appeared very early on, referring to textile technology at that time.

However, figures like Zhang Heng, Kong Anguo, and even Liu Xin Wang Mang's advisor, from the Han Dynasty onwards...

They all made new breakthroughs in the development of astronomy, calendar systems, celestial measurements, and arithmetic.

Terms that truly correspond to geographical latitude and longitude existed at least before the Northern and Southern Dynasties period.

However, at this point, longitude is referred to as straightness, and latitude as lateral length.

It was the dynasty's high-ranking officials who, in order to obtain a map of the country, mobilized a great deal of manpower and resources to conduct calculations, and inadvertently discovered the spherical curvature of the earth's overall uplift.

In order to make the map more accurate, when scaling it down to paper, it is necessary to make these two scales and set different scaling ratios for different sections of the map as an aid.

However, the practice of observing stars and calculating latitude and longitude only experienced rapid development during the Song and Ming dynasties.

Calculating geographical latitude is relatively simple.

In the Northern Hemisphere, people can get a rough result by observing the altitude of Polaris and calculating its angle with the sea level. However, to make the conclusion more accurate, more complex observation and calculation are required. On land, the observation methods are even more complicated.

For ordinary people, calculating geographical longitude is extremely difficult from the very beginning.

Because of the Earth's rotation, different time zones exist in different places. Longitude can be used to divide time zones. Conversely, to measure accurate longitude, extremely accurate clocks are needed.

In the history of Chu Tianshu's hometown, it wasn't until modern times that ordinary clocks finally had the technology to meet the required precision, which could be used in this area.

However, for experts who can sense the power of heaven and earth, their sense of day and night is already extremely accurate.

Even when calculating latitude and longitude on complex land, an expert who understands the principles of celestial phenomena can do it much more easily than an ordinary person.

Chu Tianshu calculated for about half a quarter of an hour, came to a conclusion, and then looked up at the stars in the sky above the valley.

This time, there's no need to rely on memory; you can calculate it on the spot, which is much faster.

By comparing the latitude and longitude of the valley with those of the enemy's stronghold, one can determine which direction to take and approximate distance.

It can be continuously corrected along the way.

Although this algorithm still has some errors, it may have a deviation in the range of a town.

However, Chu Tianshu had also seen the terrain and landscape of that area, so he would be able to identify it once he got there.

Although Xiao Liang couldn't understand it, his intuition was very sharp.

"Does this mean you've already figured out a way to find their headquarters?"

Looking at the large amount of calculations on the ground, Chu Tianshu couldn't help but feel a little sense of accomplishment.

"Yes, it really is in the south. It must be the Tongxuan Sect."

Xiao Liang's gaze sharpened.

"Then what are we waiting for, Tianshu? Let's go meet them now. Perfect timing, I've rested enough!"

Chu Tianshu laughed and said, "A well-fed general will not lack hungry soldiers."

Xiao Liang paused for a moment, then chuckled, "That's true, but Lao Xie and Lao Pang are still in Heze, so they probably won't have much good stuff at the tavern."

"What would you like to eat? Still some bread?"

The old scholar's original name Xie Wucan; the old man playing the erhu was surnamed Pang; and the old man playing the pipa was surnamed Fan.

"Of course not pancakes, let me roll out some pills first."

Chu Tianshu stood up. "Don't worry, I can make the dumplings very quickly."

Xiao Liang's friends are mostly there.

Chu Tianshu was also unwilling to let go of the person who had harmed his young apprentice and the old Daoist priest.

"While munching on meatballs, he went to settle old scores."

(End of this chapter)