Special Chapter The Distance from Thoughts to the Starry Sky (Part 2)
"Using this, you can build an elevator on the equator that is higher than the synchronous orbit, where the two forces are balanced,"
After hearing Li Ze continue to explain, Fangran saw him raise his hand and draw, and a slender rectangle extending beyond the outer circle was extended from the inner circle. The point where it intersected with the outer circle was marked r0.
Subtly recalling the feeling of being dominated by physics.
"In this part under the synchronous orbit, the radius becomes smaller, and the gravity formula GMm/r2 means that the gravity is relatively large, and for the part beyond the synchronous orbit, the centrifugal force formula mw2r means that the centrifugal force is relatively large,"
No, wait, it feels like two very familiar formulas have appeared...
Watching Li Ze mark the slender rectangles on both sides of the outer ring in red and blue, indicating that they are 'pulled' in two completely opposite directions by gravity and centrifugal force.
Fangran, who was sweating a little in his heart, saw the last words he looked at her:
"Then as long as the forces on these two parts are equal, the space elevator does not need support and can stand in space."
After hearing this, Fangran felt suddenly enlightened and was astonished.
"The concept of a space elevator has actually been proposed a long time ago, and the relevant principles have been relatively complete."
Li Ze put away the projection, and the warm light of the bonfire returned to the narrow mountain top again, while Krim looked at Fang Ran and added with a smile:
"About a hundred years ago, Tsiolkovsky proposed this idea. Today's jet rockets and staged rockets are all ideas he proposed at that time."
More than a hundred years ago!?
He had a deeper feeling about the era before this time than the two of them. Fangran couldn't believe that when he was driving the carriage through the wheat field,
Someone has already proposed a space elevator, an idea that even today makes him feel incredible.
"Then why don't you build such a good thing?"
Thinking about the series of advantages and meanings they just mentioned, and the principles seemed quite feasible, Fangran asked strangely,
Knowing that he would definitely ask this question, Krim and Rize looked at each other, as if they were communicating about who would explain.
"Because of the tensile strength of the material."
In the end, it was Krim who answered aloud. He recalled the relevant details he knew in as much detail as possible, and explained softly and helplessly:
"The balance between gravity and centrifugal force will produce a very huge pulling force. To meet the requirements of a space elevator, I remember that the specific pulling force per unit area needs to be greater than the material density times..."
"Okay, just give an example."
It always felt like he was recalling a number whose origin he didn't even understand. He was facing four people who were more knowledgeable than him all day long at midnight.
Fangran was used to speaking without any fluctuation.
"Haha, if you use the density of steel as an example, it would require about 4 million times the atmospheric pressure, which means that a steel cable as thick as your thumb would be required to lift a 4,000-ton object."
"But the actual steel cable can only achieve one thousandth of the density. Its density is too high."
Hearing what Fangran said, Krim couldn't help but laugh and directly gave an example.
"That means it's also stuck in the material..."
Regarding such an answer, I remembered the problem I faced not long ago, and Fangran had no choice but to develop something new. Materials are always a problem.
"It's not entirely stuck on the material. In fact, a material that can meet the requirements of the space elevator has been discovered."
Have new materials been discovered?
Surprised that he didn't get stuck on the material, Fangran unexpectedly looked at Krim and saw him smiling and saying a name.
"Carbon nanotubes are materials with excellent tensile strength and only one-sixth of the density of steel. They can already be produced with current technology in reality."
"No, wait a minute, since you have discovered the material and you have never heard of it, you must be saying next that this material is either ridiculously expensive or laborious to make..."
I didn't get too happy too early. I was keenly aware of the strange place. I dug out the relevant memories from the remaining high school knowledge. The fire crackled in the campfire.
Fangran looked at Krim suspiciously and asked silently:
"I remember that the synchronous orbit is more than 36,000 kilometers long. Including the section above, how many carbon nanotubes can be produced?"
"Half a meter."
Fang Ran: "..."
Hey, good guy, he is still talking about rice...
He was simply speechless and choked, staring at Krim speechless.
Half the time,
Just then, he burst out laughing. He held his stomach and looked up at the Milky Way above his head. For some reason, he couldn't help laughing and complained:
"Half a meter...poof, my God, half a meter is too ridiculous, hahahaha!!"
"I remember this was made by one of your laboratories in China."
Knowing that this result was still in the laboratory stage and was indeed a bit far from what they just said, Krim couldn't help but feel helpless.
Even Li Ze smiled slightly.
"At least in terms of ton production, it still gives me some hope..."
She didn't know why she was smiling so happily. Fangran wiped the corners of her eyes and looked at Rize and Klim. It turned out that this was what they called "more realistic".
Half a meter is more than 36,000 kilometers. The difference is not even a tiny bit.
But thinking about the light speed engines mentioned before about deep space navigation, which are not even theoretical, the half meter that has been completed is indeed more realistic.
When I think that even the first step into the universe, space exploration at a close distance from the Earth, is still a gap of half a meter to tens of thousands of kilometers,
At this moment, looking up at the Milky Way,
Only then did he truly understand the distance between the stars above his head.
Even the solar system cannot travel. The Milky Way with hundreds of billions of stars, the Local Group of galaxies to which it belongs, and even the upper constellation Virgo and the Laniakea Supercluster are so huge and far away...
But considering that more than a hundred years ago, before even rockets existed, someone had already proposed the idea of a space elevator.
And suddenly I felt that this distance was not eternal and out of reach.
"In reality, it can be made half a meter long. If the technology level is used for night battles, would it be possible to build a space elevator!?"
As if he suddenly thought of something beyond reality, Fangran asked with bright eyes when he mentioned this.
"It's not that simple. Compared with reality, the level of night combat technology is indeed higher, but most of the unsystematic focus is on weapons and machinery development, and may not necessarily have relevant technologies."
As an elite scientist, Li Ze shook his head in reply, looking at the Milky Way starry sky above his head, and whispered the most important reason.
"And no one knows whether the night war technology that flows into reality will create a space elevator."
"That's it, eh! By the way, is there anything else..."
Following the young man's voice that seemed to be enlightened, he curiously asked his knowledgeable companions again,
In the midnight with rich fantasy colors, we discussed the topics of technology and starry sky.
On the narrow mountain top like an isolated island high in the sky, three young people sat on tree stumps around a campfire. They felt a yearning for the distant starry sky with the magnificent Milky Way above their heads.
The young man's enthusiastic words continued in the fairy mountain night for a long time,
The scene at this moment was recorded by two birds that jumped up to the camera and pecked the shutter out of curiosity...