Shen Huabei led Qiao Lu into the main body of the Antarctic courtyard project, such a huge building was built around a deep pit with a diameter of hundreds of meters, like a nuclear bomb silo covered with an iron door, and only slowly slid open to both sides after evacuating people.

Qiao Lu stood on a small bridge with tight security measures and slowly built under this deep well, the deck of which was made of high-strength glass, so that he could clearly see the scene beneath his feet.

"Welcome to the entrance to the Earth Tunnel." Shen Huabei introduced to him, "Be careful not to see your feet weak. ”

The vision can indeed make the person with a fear of heights die on the spot, and the large crater with a diameter of hundreds of meters is bottomless, and there are rings of light on the pit wall at intervals, marking the existence of the pit in the darkness where you can't see your fingers.

Looking down from the bridge, the countless circles of light on the pit wall gradually shrink until they shrink into a point of light, as if staring at a large target that glows with blue light, and it is completely impossible to imagine where the bottom of the pit will stretch.

It looks like the gates of hell, and at the same time, it is also a bottomless pit in the literal sense, because it is a tunnel through the earth, and jumping from the south pole can come out of the north pole on the other side, and the fear of falling into it is not to fall to death, but to fall into it, but to change the temperature violently in the middle.

At the same time, it is also necessary to pay attention to nutrition, if you accidentally fall back and forth in the earth tunnel, it is not a joke to starve to death on the way to jump off the building.

"The 12,756-kilometer-long Earth Tunnel is down there?" Qiao Lu asked in amazement.

"At the same time, it is also an earth cannon." Ding Yi on the side added, "This is the loading port for the shells. ”

Facing this bottomless pit can really make people instinctively afraid. As Nietzsche said, when you stare into the abyss, the abyss is staring at you.

Just looking at this abyss, you feel as if your whole person is going to be swallowed up, and it is a kind of fear that comes from the heart, and in the face of something that is completely impossible to see, the human instinct for survival will be awakened.

Qiao Lu also took a little deep breath before he came to his senses and asked Shen Huabei, "Such a large-scale project must be very tricky." ”

"It's more than tricky." Shen Huabei smiled bitterly and said: "In the beginning, the whole project was dancing on the tip of a knife, and a screw falling from here could cause a big explosion at the other end. Later, we added a magnetic levitation force field to the entire tunnel, and we were able to avoid such a catastrophe. However, there are still other problems that I won't say too much about here. ”

"It's so hard for you."

Not to mention, just daring to enter this abyss and build an earth tunnel is already an act of courage, and it is even more difficult to be careful in this situation to avoid making a small mistake.

"Fortunately, most of the projects are now nearing completion, and I can finally feel a little more at ease." Shen Huabei said with relief.

Qiao Lu stared at the earth cannon that was nearly completed, and always felt that it was still a little missing, and suddenly he reacted, turned his head and asked:

"Since it's an Earth Cannon, what about its shells? Can't really use screws as weapons, right? ”

Of course, this so-called screw, as part of the Earth Tunnel, is also a new solid material with extremely high structural strength and can withstand the high temperatures of the center of the earth.

It's just that since even a screw in the Earth Tunnel has to be made of new solid materials, then the cannonballs fired as Earth Cannons certainly need something more exaggerated.

Ding Yi smiled slightly and said, "Haha, Director Qiao Lu, you got the point." ”

Shen Huabei explained: "As you think, the ammunition of the Earth Cannon is of course a new solid substance, but the density is much higher. We can't put it on Earth, otherwise this shell will sink directly to the center of the earth. ”

"So where do you put it?" Qiao Lu asked curiously.

Shen Huabei raised his finger to the sky and replied confidently, "Of course it's in space." ”

In order to get a glimpse of the material fired by the Earth's cannon, Qiao Lu followed Shen Huabei and Ding Yi to the Earth's orbit in the South Pole by taking a space elevator to the Earth's orbit, where a huge space station floats, also built as part of the Antarctic Courtyard Project.

Qiao Lu was surprised to find that this space station was very similar to the previous Navigator space station, that is, there was a prominent protrusion at the tail of the space station, making the entire space station look like a huge key, aimed at the keyhole of the earth tunnel entrance of the Antarctic courtyard project below.

He was walking in the space station with Shen Huabei and Ding Yi, and Qiao Lu asked the two people in front of him in surprise:

"Could it be that this is also part of the Antarctic Courtyard Project?"

Shen Huabei looked back and smiled: "That's right, this is the firing pin of the Earth Cannon." ”

"You call this thing a needle?"

Qiao Lu couldn't help but blurt out, if the firing pin of the planetary engine is as amazing as the ancient battering ram, then the entire giant space station of the same size as the navigator space station is actually the firing pin of the earth cannon, which is even more uncomplainable.

"So, it's a big project." Ding Yi explained, "Our bullet is inside this firing pin. ”

After walking a long way, Qiao Lu and his party came to the central control area of the space station.

Here Qiao Lu finally got his wish and saw the shells of the Earth Cannon, which were kept in a gravity-free glass cabin, surrounded by a large group of staff members who were busy, as if they were going to accidentally break out of the window all the time.

It's just that unlike the people around you, the things kept in the glass cabin are not frightening at all, and they can even be said to be full of beauty.

It was a silver metal sphere that looked like a round drop of mercury, and its surface was smooth enough to resemble a mirror, or even surpass it, perfectly reflecting the faces of everyone present.

There is another characteristic, and that is the circle, the circle that reaches the extreme. Just like its smooth surface, as a sphere, it is also absolutely circular, and no matter how many points are examined on it with an optical instrument, there is not the slightest circumferential error.

Just like the definition of a circle, the distance from each point to the center of the circle is equal, but when there is no error at the atomic level, it is very difficult to achieve!

The entire metal sphere exudes an artistic aura that resembles the magic of nature, and it is hard to believe that it was made with human technology.

"What the hell is this?"

Qiao Lu took a deep breath and asked, even he didn't know that there was such a thing on the Wandering Earth.

"The final form of a new solid material after compressing it to the extreme." Ding Yi replied: "We should call it a strong interaction material. ”