Volume 4: Spacetime Singularity Chapter 23: Walking Upright
Fang Cheng walked slowly forward along the coastline, slowing down his pace so that the girl behind him could just keep up. This speed was the sum of his countless times of going out with Ning Yu'an, and it had become a muscle memory.
The sun was still hanging in the sky above the sea, and the light it shed penetrated the distorted atmosphere, casting the shadows of two people, one after the other, onto the asphalt road on the left side of the sidewalk. They were the only two objects still moving on the entire earth.
As Ning Yu'an walked forward, she felt a growing fear in her heart, a fear caused by the disconnection between her vision and other senses. Everything she saw was so familiar, but her ears could not hear any sound, and her skin could not feel the slightly salty sea breeze.
This feeling of fear made her want to say something to break the silence that was like a pool of stagnant water .
"Ah - how long do we have to walk? My shoulders are a little sore again."
"Um... do you want to take a break? We have plenty of time now anyway."
Nothing is more precious than time, because time is the measure of our life. But if the passage of time stops completely, does it mean that we have eternal life?
"No need for that. I still feel pain from where I fell. It's all your fault for not telling me earlier that I can't sit on the chairs here."
"You're right, but..."
"Don't say but, come here and give me a shoulder massage."
Fang Cheng turned around and saw that the light-dark dividing line that was straight just now had now completely curled up into a circle with a diameter of less than one meter. The inside of the circle was pure black without any brightness.
Visually, the spherical shadow was floating less than two meters behind the two of them, so small and deep that it was unfathomable.
Only then did he remember that the boundary line under his feet seemed to have been moving backwards as he was walking forward, but the sky in front of him was so shocking and terrifying that he did not realize that the other world was being left further and further away.
In fact, when he was moving towards the sky, he had to prepare himself mentally with every step he took. After all, fear of heights cannot be overcome in a short time. But it got much better after he got used to it.
The black circle that followed him like a shadow made him feel a little uneasy. Although he knew that was the original Milky Way, the fear of darkness is an instinct of humans as diurnal animals.
The question is, if the Earth leaves the Milky Way, then is our home the Milky Way or the Earth? Are all humans just companions of the Spaceship Earth?
Fang Cheng walked behind her, put his hands on the girl's shoulders, and squeezed them with a little force.
"Oh, yes, it's right here, but don't be so harsh, ah——"
The tendons were pinched.
"I've never pinched it before... I don't know how hard to use... I'm sorry."
"Alright , alright, that's it, get out of here."
But it’s definitely not sour anymore.
"In fact, I have always felt that... the human body has not evolved to be fully adapted to walking upright."
"Hmm? Like what?"
"For example, the meniscus in the knee will wear out , and this process is irreversible. I think it's because it's a bit difficult for both legs to bear the full weight."
"Well...what else?" Ning Yu'an knew that this must be a foreshadowing. He knew Fang Cheng's way of speaking very well.
"There is also plantar fasciitis. The structure of the sole of the foot cannot withstand long-term walking. Walking itself wears out the ligaments."
"Really? Then I see that your small and beautiful steps easily reach tens of thousands. Aren't you afraid of getting fasciitis?"
"I'm used to it...I can't change it in a short time."
"OK, go ahead."
"But... I think the most unreasonable part is the ligaments of the chest..."
"Tsk, I knew you would go around in circles and end up with something like this..."
"Don't be in a hurry. Look, if the limbs are on the ground, the force they are subjected to is completely downward. At this moment, the chest ligaments suspended from above can perfectly balance the gravity. If I were to use a more popular metaphor, I feel that this is like a chandelier hanging from the ceiling..."
Ning Yu'an burst into laughter that was obviously not fake. Normally, she would cover her mouth with her right hand when she laughed, but this time the sound broke out before her hand reached her mouth.
"But, for humans, because they walk upright, the ligaments are no longer suspended from the ceiling, but are pulled from the side. This way, when they are subjected to force, they will receive a huge shear force, just like if you move the chandelier from the ceiling to the side wall, and if shake the light, it will be pulled and collided violently."
"If we draw a force analysis, it will be very obvious. Gravity always has a component force in the direction perpendicular to the ligament. It will generate a torque at all times. The torque is transmitted and the force at the root of the ligament is a shear force..."
Ning Yu'an couldn't stop laughing. She arched her body to reduce the shaking.
"I say... is it really that funny... not really."
"You know... the way you say these things in a serious manner is very funny. I don't know why it's so funny..."
"…Your sense of humour is really strange. I just analysed it a little."
"Yeah, the funniest part is...what you said actually makes sense. What a mess your mind is filled with all day long."
The funniest thing is that he actually came to this conclusion after serious thinking, which is very much like Fang Cheng's style.
"I think what I said is quite right. Ligaments and skin alone are not enough. A bone should grow from the bottom to fully support it. This bone can extend out as part of the ribs..."
"Isn't this thing you're talking about a steel ring?"
"Indeed, this means that humans have already been equipped with exoskeletons..."
"Yes, without the exoskeleton you mentioned, it would be deformed very quickly and become very ugly."
After all, there won’t be any mysterious anti-gravity shapes in the second dimension.
Walking upright has brought huge advantages to humans, greatly reducing the rate at which individuals that are not adapted to the environment are eliminated by nature. Many small evolutionary errors have no time to be eliminated, and evolution stops directly.
You cannot survive in a society without death, because then there would be no evolution.
"But I think humans still have natural selection, such as selection by infectious diseases, but there may not be large-scale evolutionary changes to the body structure. And as you said, these evolutionary flaws will eventually be compensated by equipment, and in the end they will still be able to adapt to the environment."
The flesh is weak, synthetic evolution!
