The simplified drawings Xu Yun saw were very simple, but the information they revealed was also quite obvious:
Little Niu was already curious about universal gravitation.
In terms of its nature, this was undoubtedly a 'milestone' level 'painting'.
However, for Xu Yun, who was playing the role of the apple, the feeling in his heart was slightly subtle.
Of course.
At this time, although Newton had a vague premonition in his heart, he still had a long way to go before fully deriving the law of universal gravitation.
Readers who weren't driven mad by their physics teachers should know this concept:
Gravity and universal gravitation are different.
Gravity is the force that an object experiences due to Earth's attraction, while universal gravitation refers to the tendency for objects to accelerate towards each other.
Moreover, the direction of gravity is always vertically downward, not necessarily towards the center of the Earth—only at the equator and the poles does it point towards the center, while the direction of universal gravitation is towards the center of the Earth.
As far as the Earth's surface is concerned.
The gravitational force on an object is a component of the universal gravitation between the object and Earth, with another component of universal gravitation providing the centripetal force required for the object's rotation with Earth.
Therefore, gravitational acceleration is greatest at the poles and smallest at the equator.
This is also why the derivation process of universal gravitation requires using three concepts:
First, Kepler's Three Laws; second, the Fluxion Technique derived by Little Niu himself; and third, Hook's elliptical orbit.
That's right.
The first to judge the Earth's gravity hypothetical experiment was not Little Niu, but Hook, who later had a love-hate relationship with Old Niu.
This hypothetical experiment was actually quite simple:
If an object is thrown horizontally from a high tower, assuming the Earth is penetrable and without resistance, then what should be the object's final trajectory.
Little Niu proposed that the object's trajectory should be a spiral, ultimately resting at the Earth's center.
Sir Hook believed that if the object didn't lose any energy, it should follow an elliptical orbit around the Earth and return to its original position.
Of course.
Hook made an intuitive guess of the elliptical orbit, but he didn't derive it—he only derived the inverse-square law with Hewgins, which is based on treating planetary orbits as circles rather than ellipses.
So, students who failed this section in high school, don't blame Old Niu, blame Hook.
However, Mr. Niu was quite cunning; in response to Hook's opinion, he accepted it internally but didn't show it externally.
Then he went on to calculate in secret.
At the time, Little Niu had already developed the Fluxion Technique, so with the last piece of the puzzle in place, universal gravitation was thus, or finally, derived by him.
Therefore, the derivation of universal gravitation wasn't as simple as getting hit by an apple; unless Xu Yun lists a bunch of derivations like Å=dA/dt, merely implying 'why am I falling down' doesn't mean anything.
Moreover, if you want the proud Little Niu to quietly watch you derive, without some kind of friendship, it's absolutely impossible:
Just five months before Little Niu returned home, a girl from Trinity College wanted to ask Little Niu a question, and because she wasted some time, she got a face full of ink from Little Niu.
This incident was recorded in the archives of Trinity College, and as a side note, Little Niu had a dozen similar records, truly incorrigible.
So, again, Mr. Niu's academic standing is as high as Mount Everest, while his character is as low as the Mariana Trench...
Xu Yun's mission was to become friends with Little Niu, and in terms of difficulty, it wasn't much less than deriving the law of universal gravitation.
Moreover, considering the nature of that halo, Xu Yun doubted whether he could flawlessly write out the entire derivation process—time travel has already happened, so a speech suppression spell isn't such a big deal.
Therefore, the same saying holds: everything must be planned long-term.
Xu Yun then moved his gaze from the manuscript to a metal pedestal.
The main part of the metal pedestal was a cross, about thirty centimeters tall. The base seemed to be made of copper, with a number engraved on it:
1642.12.25.
12.25, which is Christmas Day.
At the moment Xu Yun saw this number, a flash of insight crossed his mind, but he still asked knowingly:
"Mr. Newton, may I ask what this is..."
Little Niu touched the top of the cross and said calmly:
"As you see, my birthday."
Little Niu's answer was somewhat casual, like introducing 'those are the flowers I planted last year' to a guest without expecting any particular response.
But to his surprise, Xu Yun showed a hint of astonishment on his face:
"The 25th of December? Isn't that Christmas?
So Mr. Aiksa and Jesus share the same birthday?"
Then he pointed to the "Holy Bible" on the desk that had knocked him out and said with a smile,
"Mr. Newton, in my distant homeland in the East, someone like you is generally considered a blessed child.
Perhaps in some years, you will also, like that person, be revered in a certain field."
Upon hearing Xu Yun's words, Little Niu was taken aback at first and then showed a hint of excitement, his tone carrying a slight tremble:
"Blessed child? Fat Fish, are you serious?"
Xu Yun nodded affirmatively and explained:
"Of course it's true; such blessed children sometimes have a nickname, called 'the destined one.'
In their youth, they might face hardships like annulled engagements, bullying, betrayal, or even being rejected by their parents.
But once the right moment arrives, they will soar high, shining as dazzling as the stars, terrifying as they are!"
After hearing this, Newton's eyes immediately brightened:
Initially, he thought Xu Yun might be flattering him, but as he listened to the latter part, he became convinced Xu Yun spoke the truth!
Because, apart from annulled engagements, all the other events had occurred in Little Niu's childhood!
And he could be certain that he had never interacted with Xu Yun before, and Xu Yun had neither the means nor the need to inquire about his past—after all, he was just an ordinary university student, hot-tempered and friendless, who would bother to dig into his history?
Thus, there was only one possibility:
He was indeed the destined one Xu Yun spoke of!
Of course.
The reason Newton arrived at this conclusion wasn't because he was under some intelligence-reducing halo, but rather because it involved a secret he never divulged, only mentioned in a letter to Fumisa in 1719:
He was a veteran adolescent fantasy enthusiast who believed until his death that he was a chosen one bestowed with a divine mission.
And all of this began to bud from Little Niu's birthday—two birthdays assigned to different points in future calendars.
...
Note:
Today, I asked a friend to find out, and surprisingly learned that the internet access at the University of Oxford's Bodleian Library has scanned versions of Newton's manuscripts, totaling over 170 letters. I just downloaded them all.
By the time you read this chapter, I'll still be downloading, the VPN is frustratingly slow, only 23kb per second....