"It's amazing, purely by technology, it can be compared to the magic technology of the demon tail. After carefully looking at all the murals from beginning to end, Ye Wuji nodded with emotion.

There are ways to make various shells on the mural, and what Ye Wuji values most is the energy system inside, and he doesn't know what kind of heart the moon city Bika is in, so he actually made all the finished products into the shape of shells.

At the same time, the mural also depicts the appearance of the moon man, but the figures that appear on the mural are not tall, I don't know if it is the characteristic of the moon man.

But now Bai Hai, Bai Baihai's descendants of the Lunar Bika people are not low in height, I don't know if it is because they have been on this planet for too long, and their descendants have been assimilated by this planet, or those people on the mural are not Moon Bika people.

On the final wall, a huge ship is depicted, each part of which is detailed on the mural, although the ship looks not much different from a normal pirate ship, warship.

But in fact, the difference between the two is huge, this is a ship that can fly like a magic airship, and it can fly not only inside the planet, but also in space.

In fact, this ship was specially left to future generations by the people of Bika who had just come to the Sky Island from the moon, hoping that with the help of this ship, they could return to the moon again, to the infinite earth, and to Bika City.

Infinite Earth.

This is what the Bika people called the moon when they first came to this planet.

"The moon. ”

At this moment, Ye Wuji's strong curiosity about the moon, from the mural, Ye Wuji knew that the so-called shell technology, in the entire Bika City, is not the top technology, the reason why the Bika left by the Bika on the empty island is the shell technology, because the Moon Bika people who fell to the empty island were a shell research center in the Moon Bika City at that time.

From this aspect, you can see what kind of technology the complete Bicca City has.

Although Ye Wuji believes that his own strength is really strong, he does not reject the power of science and technology, after all, if the power of science and technology is strong to a certain extent, the degree of threat is not low.

Just like the platoon shells on the empty island, if there are 10,000 navy with rocket launchers inlaid with platoon shells, this round of salvo fire is almost equivalent to the yellow ape using an eight-foot Qiongyu jade.

And although the rocket artillery can't fire continuously, it can shoot continuously, and it may be a little worse against the top powerhouse, but it is powerful against ordinary pirates.

And even if the top powerhouse is hit by such a rocket launcher in the melee, he will not feel good, and the white beard who is weak in the war will not be hit with several rockets.

It's a pity that the price of platoon shells is too expensive, and even the navy can't be equipped with rocket artillery like 10,000 people.

In fact, the technological shells of the Sky Island are not as powerful as possible, even those shells that ignore them, if they are used properly, the power is not below the platoon shells.

In the original book, Usopp once challenged Luffy, and he used the Sky Island Shell he got to catch Luffy off guard, but unfortunately Usopp's strength was too poor to be affected by the use of the platoon shell, even if he used the impact shell, it almost broke his arm, not to mention the volley shell.

After all, the recoil of the platoon shell is too strong, if you use it directly by hand, the physical strength is not good, even if the bones are broken and the tendons are broken, it will even endanger your own life.

If Usopp had used Shell on Luffy in the first place, Luffy wouldn't have needed to make a move at all, and the recoil of Shell alone would have been enough to kill Usopp.

Usopp saved Robin's ultra-long-range slingshot on Justice Island, which used the air island's squirt shells, so it can be said that if Usopp didn't get all kinds of air island shells on the sky island, Usopp could only abandon the slingshot and use the gun in the end, after all, the range of the slingshot is limited.

On the contrary, after having the Sky Island's Spray Shell, Hot Shell, Flame Shell, Platoon Shell, and Slashing Shell, Usopp's combat power skyrocketed.

However, the first sniper in the future used a slingshot, which made many people very puzzled later, and these people couldn't think of how a slingshot could have such a large range and power.

Not only Usopp, but also the weather rod is strengthened with the shells of the empty island, hot air, cold air, thunderclouds, and it is the hot shell, cold shellfish and electric shellfish of the sky island that are used.

In the original book, because Anilu destroyed Bika Island, ordinary shells for life were fine, but the shells used for combat were directly out of stock, so that many people didn't know that Sky Island also had very powerful Sky Island technology.

But the night Wuji didn't know that in the original book, Anilu destroyed Bika, and after he himself was defeated by Luffy and ran to the infinite land, the shell technology of the Sky Island was almost broken.

Anilu is a very selfish person, and before he got the Thunder Fruit, he planned to destroy the island of Bika in the sky and prepare to dominate the moon with Bika technology.

After accidentally obtaining the Thunder Fruit, Anilu is simply a tiger with wings.

"Hmm. Staring at the murals around the underground space, Ye Wuji was silent for a while, and with a wave of his hand, the ancient book magic appeared in front of him, and after using the ancient book magic to scan all the surrounding murals, he destroyed all the murals on the last wall.

Compared to Anilu's attempt to destroy all this, and thus completely destroy the entire Bika Island, Ye Wuji's means are much kinder, and the reason why he wants to destroy the mural on the last wall is because Ye Wuji has decided to find a chance to go to the moon in the future, and by the way, he is also ready to experience what space is like.

"Pyrobroin, it's strange how the technology of the moon can have this. "It has once again proved that the magic of ancient texts is very helpful to Ye Wuji in some ways.

Just like the shell technology on the walls around the entire underground space now, I am afraid it will take time for Ye Wuji to study it by himself, but with the help of ancient book magic, it didn't take long for a complete model of a ship to appear on the screen, and how many special shells needed on the entire ship were also calculated.

It was at this time that Ye Wuji understood what was the basis of shell technology, and each shell was more or less filled with pyrobroin, which is an element and particle that exists in various water resources in this world, but although it is very common, it is extremely difficult to refine it.

However, there is a large amount of pyrobroin on one thing, that is, Hailou stone, to some extent, Hailou stone is equivalent to pyrobroin particles, the crystallization of elements.

The fundamental reason why Hailou Stone can disable the ability of the Devil Fruit is the pyrobroin particle, so places with a lot of water, such as sea water, lakes, and even hot springs, can make the ability of the Devil Fruit incapacitated.

Of course, there is also a premise for this, that is, the ability person is at least three-quarters of the body under the surface of the water, and the body must be in direct contact with the water to function.

However, even if only a small part of the Hailou Stone touches the human body, it can make the capable person incapacitated, and the fundamental reason is that there are a lot of pyrobroin particles in the Hailou Stone.

It can be said that if anyone can make a weapon other than containing pyrobroin particles that are comparable to the Hailou Stone, it is equivalent to making the Hailou Stone.

It's a pity that even Vegapunk, the most genius scientist in the Navy, can't do this.

For the pyrobroin particle, Ye Wuji is quite understanding, Vegapunk published in the Navy Internal Science Journal, there is a description of this particle, before this, although people know that the sea tower stone and sea water have a restraining effect on the ability of the devil fruit, but why it is restrained, no one can say clearly.

For hundreds of years, it is not that no one has studied the Hailou Stone, but unfortunately in the end it was all in vain, until Vegapunk was born, and the true face of the Hailou Stone was solved at once, and at the same time, he also studied the hemorrhage factor, and became the youngest president of the Naval Academy of Sciences in the history of the Navy from its establishment to the present.

At the same time, Vegapunk is also the first time to research the loading of sea tower stones under the navy warship, so that the navy can be unimpeded in the windless zone, saving a lot of time for the deployment of the navy.

Before Vegapunk researched this method, the navy and the royal families of various countries, chambers of commerce, etc., who wanted to pass through the windless belt, could only rely on tamed powerful sea beasts, or a powerful person to lead the team, all the way through the windless belt.

The Moon may have been formed about 4.5 billion years ago, shortly after the formation of the Earth, and there are several hypotheses about its origin, which are supported by more factual evidence, and the theory is that it was formed by the debris of a huge collision between the Earth and the Mars-sized celestial body "Theia", which gathered in the outer periphery of the Earth. [2]

The front side of the moon is dotted with huge impact craters filled with basalt lava flows ejected from dark volcanoes, forming a vast plain called the "Moon Sea", in fact, there is not a drop of water in the "Moon Sea". Between the outer and lunar seas are bright, ancient plagioclase highlands and conspicuous impact craters. It is the brightest object in the sky other than the Sun, and although it appears a very bright white, its surface is actually very dark and the reflectivity is only slightly higher than that of old asphalt. Because the moon is very conspicuous in the sky, coupled with the regular changes in the phases of the moon, it has had a significant impact on human culture such as myths and legends, religious beliefs, philosophical thoughts, calendar compilation, literature, art, and customs and traditions since ancient times.

The rotation of the Moon is equal to the period of revolution (known as tidal locking), so the Moon always faces the Earth on the same side. The Earth's ocean tides arise mainly due to the gravitational pull of the Moon. Because the tidal force of the earth's oceans is opposite to the direction of the earth's rotation, the earth's rotation is always subjected to an extremely weak force to "brake" the earth's rotation, which has accumulated over a long period of time, and there is ample evidence that the earth's rotation cycle is getting slower and slower, and the time of the day is increasing extremely slowly, about 1 second in a few years, and because of the earth's reaction force, the moon is slowly getting farther and farther away from the earth, and is about 3.8 centimeters away from the earth every year. The ratio of the size of the Moon to the Sun is similar to the ratio of distance, making it almost the same apparent size as the Sun, and during a solar eclipse the Moon can completely obscure the Sun and form a total solar eclipse. [2]

The Moon was the first extraterrestrial object ever landed by humans. In 1958, lunar probes launched by the United States and the former Soviet Union failed. In 1959, the former Soviet Union and the United States successfully launched the "Luna" and "Pioneer" lunar probes respectively. In 1969, the Apollo-11 of the United States achieved the first manned landing of mankind on the moon, and the successive Apollo-12, 14, 15, 16 and 17 achieved manned lunar landing, and a total of 12 American astronauts landed on the moon to carry out scientific investigations, collect lunar samples and bury scientific instruments for long-term exploration of the moon, bringing back a total of 381.7 kilograms of lunar samples to the earth, which greatly increased mankind's understanding of the origin and evolution of the moon. To date, only these 12 U.S. astronauts have landed on a celestial body other than Earth. [2]

In April 2018, NASA released a video made from data collected by a lunar orbiter. The data in this video was collected over a nine-year period by the Lunar Reconnaissance Orbiter (LRO). Since June 2009, the probe has been observing the moon 50 kilometers above its surface, capturing never-before-seen details on the lunar surface. [3]

Basic data of the Moon: The Moon orbits the Earth in an elliptical orbit. The great circle of this orbital plane on the celestial sphere is called the "white path". The plane of the white path does not coincide with the celestial equator, nor is it parallel to the plane of the ecliptic, and the spatial position is constantly changing. Cycle 27.32 days. The average inclination of the lunar orbit (white path) to the Earth's orbit (ecliptic) is 5°09′. But the Moon is known to be gradually departing from the Earth at an average annual rate of 3.8 cm.

The rotation of the moon

The Moon rotates while revolving around the Earth, with a period of 27.32166 days, which happens to be a sidereal month, so we can't see the far side of the Moon. This phenomenon is called "synchronous rotation", or "tide locking", and is almost a universal law in the world of solar system satellites. It is generally believed to be the result of the long-term tidal action of satellites on planets. The balance movement is a wonderful phenomenon that allows us to see 59% of the surface of the moon. The main reasons are as follows:

1 In different parts of the elliptical orbit, the rotation velocity does not match the angular velocity of the revolution.

2. The intersection of the white and equator.

The Moon moves half a degree per hour relative to the background starry sky, i.e. it is similar to the apparent diameter of the Moon's surface. Unlike other satellites, the Moon's orbital plane is closer to the ecliptic plane than near the Earth's equatorial plane. The time it takes for the Moon to orbit the Earth (one revolution of the Moon) relative to the background sky is called a sidereal month, while the time it takes for a new moon to move to the next new moon (or between two phases of the same moon) is called a synodic month. The synodic moon is longer than the sidereal moon because the Earth itself travels some distance in its orbit around the Sun during its orbit.

The moon is nutated

The Moon's orbital plane (white plane) maintains an angle of 5.145 396° with the ecliptic plane (the Earth's orbital plane), while the Moon's axis of rotation is at an angle of 1.5424° to the normal of the ecliptic plane. Because the Earth is not completely spherical, but more uplifted at the equator, the white surface is constantly precession (i.e., the intersection with the ecliptic rotates clockwise) for one week per day (18.5966). During this period, the angle of the white track relative to the Earth's equatorial plane (the Earth's equatorial plane is inclined to the ecliptic plane at 23.45°) will vary from 28.60° (i.e., 23.45°+5.15°) to 18.30° (i.e., 23.45°-5.15°). Similarly, the angle between the Moon's axis of rotation and the white track will be between 6.69° (i.e. 5.15°+1.54°) and 3.60° (i.e. 5.15°-1.54°). These changes in the moon's orbit in turn affect the inclination of the Earth's axis of rotation, causing it to oscillate ± 0.002 56°, called nutation.

Libra moves

Because the rotation period of the Moon is exactly the same as its rotation period, only the Moon can be seen on Earth forever facing the same Earth. Since the early days of the Moon's formation, the Earth has been subjected to a moment that slows its rotation, a process known as tidal locking. As a result, part of the angular momentum of the Earth's rotation is converted into the angular momentum of the Moon's orbit around the Earth, with the result that the Moon moves away from the Earth at a rate of about 38 millimeters per year. At the same time, the Earth's rotation is getting slower and slower, and the length of the day is getting longer by 15 microseconds per year.

When you look at the Moon from the Earth, you don't see exactly half of the surface of the Moon, because the Moon swings like a scale. Observers on Earth will feel that during the time that the Moon orbits the Earth, the Moon swings back and forth in the north-south direction, that is, in the direction of the dimension, like a scale.