252: Chapter 252: These hypotheses are all wrong!

He picked up the tablet, searched for the hypotheses, and then aimed it at Xiao Yu.

"The first one is the Fission Hypothesis, also known as the Daughter Hypothesis; this hypothesis suggests that the Moon was originally part of the Earth. In the early days, when the Earth was still in a molten state and rotating at an extremely high speed, material from the equatorial region was flung out and later coalesced to form the Moon."

Xiao Yu's eyes lit up immediately. "The equatorial region—this is similar to the Solar Fission Hypothesis you mentioned before, right, Brother?"

Jiang Zhe nodded gently. "That's right, it's the same logic. There are two main pieces of evidence for this hypothesis."

"First: The average density of the Moon is very close to the density of the Earth's mantle."

"Second, the Moon is iron-deficient, and the Earth's core is made of iron—here is a point of doubt: whether the Earth's core is indeed iron is based on speculation; after all, no one can obtain direct evidence of the core."

"Continuing, if the Moon was flung out from the Earth's surface, then its lack of iron makes sense!"

Speaking up to this point, he held up a finger. "But the problem is, this hypothesis was later overturned."

"If the Moon was really flung out by the Earth, then the Moon should be orbiting above the equatorial plane, but in reality, the Moon's orbital inclination is very large, differing from the Earth's equatorial plane by more than 5 degrees."

"Moreover, according to angular momentum calculations, the early Earth would have needed to rotate incredibly fast to fling out such a large chunk, and that rotation speed is not very realistic."

"So, not many people accept this hypothesis!"

Xiao Yu nodded thoughtfully.

She felt that what her brother said made sense; at the very least, her brother did not accept the Daughter Hypothesis either.

Jiang Zhe did not pause and continued, holding up his second finger. "The second hypothesis is called the Capture Hypothesis!"

"This hypothesis suggests that the Moon was originally an asteroid wandering in the Solar System, and when it passed by Earth, it was captured by the nearby Earth's gravity and became Earth's satellite."

"There is also evidence for this hypothesis: the composition of the Moon and the Earth is quite different. If they had formed in the same region, their compositions should be closer. So the Moon might be an outsider!"

As his tone shifted, his expression became serious. "But the Capture Hypothesis also has problems—gravitational capture is a very delicate task. To make a passing celestial body decelerate just right and then enter an orbit around the Earth, the required conditions are too harsh."

"What's more troublesome is that the Moon is too big; it's abnormally large for a satellite. The Moon is one-fourth the size of the Earth, and the probability of Earth capturing such a big chunk is almost negligible."

Xiao Yu frowned. "Then what about the third one?"

"The third one is called the Twin Hypothesis, also known as the Conformal Hypothesis."

As he said this, he tapped the tablet lightly, and a simulation of the Earth-Moon system based on the Conformal Hypothesis began to appear.

"This hypothesis suggests that the Earth and the Moon formed simultaneously in the same nebula, like a pair of twin brothers, held together by gravity."

"This is similar to the 'Twin Stars between Jupiter and Mars' that my brother mentioned earlier."

"The advantage of this hypothesis is that it can explain why the Earth and the Moon are in the same region."

"But the disadvantage is that if they really formed at the same time and in the same place, their compositions should be almost identical."

"But in reality, the difference in composition between the Moon and the Earth is quite obvious. Moreover, according to this model, what should have formed is a double-planet system, not the Earth carrying a small satellite—the ratio of the Earth-Moon system is too special!"

Hearing this, Xiao Yu and countless viewers frowned.

As things stand, each hypothesis seems to only explain one-tenth of the facts.

The other nine-tenths cannot be explained. Either way, Hypothesis A can explain one-tenth of the Moon, and Hypothesis B can also explain one-tenth of the Moon. Consequently, the formation of the Moon has completely become a massive unsolved mystery!

Thinking of this, Xiao Yu couldn't help but ask again: "Then what about the fourth one?"

Jiang Zhe smiled slightly. "The fourth one is also the most mainstream hypothesis in the astronomical community at present: the Giant Impact Hypothesis."

"This hypothesis suggests that shortly after the Earth formed, about 4.5 billion years ago, a protoplanet the size of Mars collided with the primordial Earth."

"The super-strong impact ejected the Earth's outer material and fragments of the impactor into space. These fragments gathered around the Earth to form a ring, and finally, the material in the ring slowly accreted to form the Moon."

Speaking to this point, he tapped his finger on the tablet, and a blue ring appeared around the azure planet. Then the ring was flung out, and over time, it became a frozen Moon. As time passed, the Moon gradually became barren, turning into its current appearance!!!

Seeing this, in Principal Fu's office, Ren Xiaoyao pointed at this hypothesis and nodded frequently. "This hypothesis is the most reasonable one at present. The Giant Impact Hypothesis—the original Earth might have had an Earth ring, just like Saturn; this way, it can explain more!"

"If nothing unexpected happens, the Giant Impact Hypothesis is the truth, but in Jiang Zhe's eyes, it is clearly not the case!"

Principal Fu, Old Wang, and Xiao Wang listened with great interest; it was very, if not extremely, tasty!

On the screen, Xiao Yu listened intently and spoke up: "Brother, then what about the evidence for the Giant Impact Hypothesis!"

"There are several pieces of evidence; first, the Moon is iron-deficient because the material ejected by the impact was mainly from the mantle and the outer material of the impactor, while the iron core remained in the new Earth after it merged with the impactor."

"Second, the rock samples brought back by Apollo landing on the Moon show that the oxygen isotope composition of lunar rocks is basically identical to that of Earth rocks, indicating they came from the same region."

"Third, computer simulations can replicate this process, although it requires very precise initial conditions."

However, he still shook his head slightly. "Even so, the Giant Impact Hypothesis is not perfect; the biggest problem is that there is too little sampling."

At this moment, in the live broadcast room, the barrage was flying rapidly.

"So there are so many theories!"

"I only knew about the Giant Impact Hypothesis before; I didn't expect there to be a Fission Hypothesis and a Capture Hypothesis."

"So which one is actually correct?"

"My brother just said that the Giant Impact Hypothesis has too little sampling and too few samples, does that mean we haven't figured it out yet?"

"..."

Inside Qingfeng Temple.

Robert looked at Jiang Zhe's calm appearance on the screen and nodded slightly.

"Very basic astronomical hypothesis content." He said in a very professional tone, "These four are indeed mainstream hypotheses, but he only talked about the most common ones."

Zheng Ming immediately leaned over, full of curiosity. "Mr. Robert, do you know others?"

Robert responded arrogantly: "Of course. For example, there is the Nuclear Explosion Hypothesis, which believes that after the Moon separated from the Earth, some kind of nuclear reaction occurred between the core and the mantle."

"There is also the Capture-plus-Fission Hybrid Hypothesis, which believes that the Moon was captured and then torn apart and reassembled by the Earth's tidal forces."

"There is even the Asteroid Impact Disintegration and Re-accretion Hypothesis—this is not one big collision, but a 'Pinduoduo' satellite made up of multiple small impacts!"

He turned his head and looked at Zheng Ming.

"But these are all too marginal, and the academic circle basically doesn't mention them."

Zheng Ming nodded repeatedly, giving a thumbs up. "As expected of Mr. Robert, you really know a lot!"

Looking directly at Jiang Zhe on the big screen, the corners of Zheng Ming's mouth curled slightly. Let's see if you will end up with a ruined reputation tonight because you can't justify your own words!

...

Inside the villa's living room.

After Jiang Zhe finished talking about the four hypotheses, he took a sip of black tea and put it back on the table.

Xiao Yu tilted her head and thought for a long time before asking:

"Brother, you've said so much, so which one is actually more likely?"

"I feel that the Accidental Capture Hypothesis seems quite reasonable; after all, the compositions of the Moon and the Earth are so different."

"And the astronomy teacher said that the Giant Impact Hypothesis is the most reasonable; even though there are no traces of a huge collision between the Earth and the Moon, it seems the compositions of the Moon and the Earth are very similar?"

Jiang Zhe nodded gently. "Yes, many people have the same thought as you. But the current mainstream understanding in the astronomical community is the Giant Impact Hypothesis, or the Giant Collision Hypothesis."

"Why?"

"Because of the rocks the Apollo program brought back from the Moon." Jiang Zhe picked up the tablet and pulled up a comparison chart of Earth-Moon data. "In the 1960s and 1970s, Apollo astronauts brought back 382 kilograms of lunar rock from the front side of the Moon; later, after analysis by NASA astronomers, it was found that the oxygen isotope composition of these lunar rocks was almost identical to that of Earth rocks."

"Oxygen isotopes are a very good fingerprint. In a stellar system, celestial bodies formed in different regions will have subtle differences in their oxygen isotope ratios."

"In the Solar System, the oxygen isotopes of Mars are different from those of Earth; if the Moon were an external celestial body captured by the Earth, its oxygen isotopes should be significantly different from the Earth's. But the data came out completely consistent."

Xiao Yu's eyes lit up. "Doesn't that prove that the Moon is really a part of the Earth?"

Jiang Zhe's mouth curled slightly. "Yes and no; this is the strongest and most powerful evidence supporting the Giant Impact Hypothesis."

"The Moon and the Earth came from the same region, and they may even be the same mass of material. Moreover, the Moon's iron-deficient characteristic also fits the Giant Impact model; the iron core remained in the Earth."

His fingers moved, swiping on the tablet, and he pulled up another set of data.

"However, our Chang'e project has discovered some different things, making the Giant Impact Hypothesis less solid and reliable!"

Xiao Yu leaned over and squinted. They were all professional data comparison charts, but one could see they were multiple sets of petrological analysis spectra of the front and back sides of the Moon.

Seeing it wasn't fun, she sat back on the sofa and continued filming secretly.

"What my brother is looking at now are the lunar soil samples brought back by Chang'e 5, from a relatively young region on the front side of the Moon."

"As professionals from the National Astronomical Observatory analyzed, the composition of certain isotopes in these samples is not quite the same as those brought back by Apollo."

"More crucially, the lunar orbiter discovered that there is a systematic difference in the rock composition between the front and back sides of the Moon; the front side is alkaline, like the Earth's continental crust, while the back side is basaltic, like the oceanic lunar crust."

Jiang Zhe nodded slightly, his gaze falling on Xiao Yu.

"What does this mean?"

"It means there are too many elements!"

"1: The Apollo samples are fake, and the samples given to our country might be from Earth; but it cannot be denied that the moon landing wasn't fake, otherwise the former Bear Country wouldn't have gone to such great lengths to compete with the USA in the Space Race; they aren't fools!"

"2: This means the composition of the Moon's surface is not uniform. If the Moon was really accreted from a debris disk after that giant impact, it should have been mixed very evenly, and should not have been divided into two skins, the front and the back!"

"So, in this theory, many people think that the Moon is either the Earth's child or the Earth's debris."

"But even so, the lunar samples brought back are still too few—Apollo sampled entirely from the front, and Chang'e 5 was also on the front, both in roughly the same region, yet the compositions are completely different—there is something to be said here."

"Why the rock compositions of the front and back of the Moon are completely different is a problem that professionals should be having headaches over."

Speaking to this point, Jiang Zhe couldn't stop the corners of his mouth from curling. "Xiao Yu, you should have realized—even though there are so many hypotheses, in fact, it remains an unsolved mystery. No one can provide a definitive truth!"

"It's equivalent to the first hypothesis piecing together one-tenth of the truth, the second hypothesis piecing together three-tenths of the truth, the third hypothesis piecing together two-tenths of the truth—piecing it all together, there is no definitive truth!"

"It seems so!" Xiao Yu listened, somewhat dazed, nodding like a chick pecking at rice. "Then, then how should we explain it?"