From an objective standpoint, realistically speaking.
If the rabbits don't have the ability to break the helium-iron microcrystalline array, then the presence or absence of a "vacuum" is actually not important.
But now, the rabbits possess the technology to bypass the barrier without much cost.
The difference between the existence and non-existence of a "vacuum" becomes extremely significant.
Of course.
Someone might ask:
Why can't it be the absence of ferrous ions around that prevents the formation of helium iron?
The reason is simple:
This cave is located in the Central State section of Qinling, under the administration of Xinxiang.
Although Xinxiang's iron ore reserves aren't as high as those around Luoyang, they're not that low either.
At least the surrounding iron elements are quite abundant, with three significant mines.
Therefore, theoretically, there's no possibility of a lack of ferrous ions in the area.
Thus, the absence of a barrier outside the ice coffin clearly can only be attributed to internal factors.
The gaze returns to the original spot.
Although Lu Chaoyang had some thoughts in his mind.
But from a broader perspective.
Even if there's no vacuum in the ice coffin, its value still wouldn't decrease by much—it's just a setback for the field of vacuum physics research.
After adjusting his mindset, he took a deep breath.
In as calm a tone as possible, he said to Su Bai beside him:
"Major Su, let's first conduct an inspection of the surroundings.
See if there are any important traces or items.
Once we're done inspecting the surroundings, we can consider the issue of the ice coffin."
Su Bai nodded:
"Understood!"
Five minutes later.
Several cultivators dispersed their divine sense simultaneously, while the remaining people started searching with their naked eyes.
After a few more minutes.
Ouyang Dongshan suddenly raised his hand, his slightly excited voice echoing through the cave:
"Professor Lu, I've made a discovery here!"
Lu Chaoyang quickly walked over to him and asked:
"Researcher Ouyang, what did you discover?"
Ouyang Dongshan pulled at Lu Chaoyang's thermal clothing and pointed to the ground:
"It's this!"
Lu Chaoyang curiously leaned his head over, blinking after seeing what Ouyang Dongshan was pointing at:
"Is this... ice?"
Ouyang Dongshan nodded:
"That's right, ice!"
The ice block discovered by Ouyang Dongshan was outside a groove, behind a protruding rock.
Its size was roughly as large as a packet of Lay's chips costing six and a half yuan, with a thickness of about ten centimeters.
Cold surface, extremely low temperature.
Along with an unknown source of water.
These three factors caused the ice block to form here.
Seeing the slightly perplexed Lu Chaoyang, Ouyang Dongshan smiled.
He explained:
"Professor Lu, let me tell you.
Don't underestimate this thing.
This piece of ice is enough for us to determine its formation time."
"Formation time?"
Lu Chaoyang's eyes lit up with a peculiar gleam upon hearing this.
The main goal of leading the team to Panghu Cave this time was to ensure the ice coffin was safely transported back to the base camp.
Besides this, the team had other secondary tasks that should not be ignored, particularly regarding detection matters.
After all, if it were only for transporting the ice coffin, the higher-ups wouldn't have dispatched so many personnel to accompany him.
Among the various tasks, one was to ascertain the ice coffin—or rather, the onset of low temperature in the cave.
According to Ouyang Dongshan.
They have the capability to determine the age of the ice block using technical means.
This would undoubtedly be a tremendous boost to the task of determining the time of low-temperature occurrence.
Certainly.
The formation time of the ice block might be very short, perhaps decades or even years.
It might have formed just last month.
But likewise.
There's also a possibility of early formation.
These two possibilities exist simultaneously; no one can surely say which probability is higher.
In the absence of other better samples.
The formation time of the ice block represents the lower limit of the cave's ice-point temperature occurrence.
Even if you detect it was formed five months ago, that would rule out occurrence within the past five months, wouldn't it?
Lu Chaoyang then thought it over and said:
"Researcher Ouyang, what method should we use to detect this type of ice?
Could it be optical luminescence signals? Or cold atom physics?"
"Optical luminescence signals definitely won't work, as they detect age by capturing electrons in the quartz or feldspar crystal structure, and they require the mean radiation dose over the years in an environment."
Ouyang Dongshan explained and glanced at him with a peculiar expression:
"As for cold atom physics...
Professor Lu, aren't you just showing off?
Isn't this something only the University of Science and Technology of China works on?
This kind of stuff from their lab, how would someone like me, doing research in Antarctica, know anything about it?"
Lu Chaoyang laughed awkwardly and touched his head:
"Oh... sorry, sorry, I forgot, please continue."
Ouyang Dongshan organized his language and said:
"This type of ice can generally be assessed using O-18 isotope characterization, but the drawback is that it's not very precise.
For example, it can only determine 1000 years, 3000 years, or 20,000 years, a quite rough estimate.
Identifying whether it's 1900 or 1100 would be more difficult.
But it has an exceedingly clear advantage.
That is the result time is extremely short, the equipment requirements and steps are very simple."
Lu Chaoyang nodded thoughtfully:
"O-18 huh..."
Although he's not very knowledgeable about geology, he is familiar with some technical terms.
Therefore, when Ouyang Dongshan mentioned the O-18 identification method, he almost understood the related principles.
People who are familiar with the concept of the ice age should be aware.
If we talk about the historical timeline.
Sudden temperature changes are usually compared through traces found in recorded history.
For example, in the First Year of Zhenghe of Emperor Huizong of Song (1111), Taihu Lake was completely frozen, and historical records show that horse-drawn carriages could run on it.
This corresponds to a small ice age between the two Song dynasties.
Additionally, it can be linked to the historical event of the rise of the Jurchens, the destruction of the Liao, and the Song.
There are even more clues about the Ming-Qing small ice age.
Such as the freezing of Han River, Huai River, Poyang Lake, and so on.
This is considered a judgment method combining historical facts, generally used for answering historical documentation.
On a geological timeline, the method used to identify glacial and interglacial periods is the O-18 identification method.
Chemistry teachers who are healthy and not angered enough to quit should know.
Oxygen has three natural isotopes: O-16, O-17, and O-18.
They all have 8 protons but 8, 9, and 10 neutrons, respectively.
Among them, O-17 is too rare to mention.
Of the remaining two types.
O-16 occurs far more frequently than O-18, but their proportions do not change significantly under normal conditions.
Yet, once the climate changes over large regions, their proportions will differ.
O-18 is heavier; compared to O-16, it requires more energy to evaporate—because it's too heavy to fly away.
Those familiar with hefty fellows can substitute acquaintance for analogy.
As for those who are themselves hefty fellows...
They can look down at their own round belly muscle and then hurry to lose weight!!
Anyway.
In chemistry.
This process is called isotopic fractionation.
Therefore, in polar and inland regions, the ratio of O-18 and O-16 is different at various times.
Moreover, this ratio is very clear and stable; it won't change over a few hundred kilometers.
The specific detection method for O-18 is the isotopic ratio mass spectrometer, also known as the IRMS that many have a love-hate relationship with.
The IRMS's principle is quite simple: ionized samples are shot into a magnetic field through an ion gun.
These charged particles deflect under the influence of the magnetic field, and given equal charge (same force), the degree of deflection (radius of circular motion) is related to their mass.
Thus, different isotopes achieve separation, landing on the sensor on the other side of the magnetic field.
This results in several different electric signals.
By aggregating these electric signals for processing, the proportion of O-18 within the sample can be measured.
An IRMS device is roughly the same size as a printer, even a girl can carry it.
That's why Ouyang Dongshan said the equipment and requirements are simple; this is truly not a figure of speech.
This time Lu Chaoyang and others carried the IRMS in a Spatial Bag, and due to its small size, Cao Yi, who had reached Foundation Establishment Stage, easily retrieved it.
Then, Ouyang Dongshan spent about twenty minutes preparing and everything was ready.
Then he turned on the handheld power reserve and pressed the switch.
The testing commenced in a very straightforward manner.
Buzz buzz buzz——
The IRMS device looks somewhat like a printer, and its operational noise resembles a printer as well.
That's why at a certain university in the country, there once occurred a super super awkward operation:
A pair of graduate student lovers, perhaps in hot pursuit due to their romantic phase, sought excitement.
So the male bought a buzz buzz thing, a high-powered one at that.
One day, while a group of people were conducting experiments using the IRMS, he turned it on simultaneously.
Unexpectedly the buzzing sound was a bit different, and the professor in charge started to feel puzzled:
What was that noise?
Was some equipment malfunctioning?
A device costs millions, and mishaps can't be tolerated, so he turned off the IRMS preemptively.
The professor's shutdown timing was quite sudden, while the male was still examining the mass spectrogram, momentarily stunned.
Resulting in a few seconds before turning off the buzz buzz, so the professor locked onto the female at the scene.
Actually, in hindsight.
At this time, if the female admitted it was a vibrating phone, she might have gotten away with it—although magnetic items are generally not allowed in such labs, exceptions happen in non-critical daily experiments.
Unexpectedly, the female was too nervous and couldn't come up with this excuse, failing to explain adequately.
The professor thought she broke some instrument but dared not speak the truth, so he sought the duty engineer's authority to check the surveillance footage.
Everyone can probably guess the outcome, direct social death—not mentioning which school.
It wasn't Ke University; it was some school in Min Province.
So young people shouldn't play too extravagantly; sometimes when 91 can't be accessed, they end up on the bulletin board themselves.
Back to the cave interior.
The IRMS results were out quickly.
In just about twenty minutes, a δ18O—i.e., the data of the O-18 and O-16 ratio, was released.
Then Ouyang Dongshan took the report and compared it using the D-P diagram (Note 1).
At the moment of seeing the number, Ouyang Dongshan's brow furrowed:
"Hmm? -59.9.....?"
The value seems rather large.....
He shook the D-P diagram and started pinpointing specific years.
Due to frequent contact with icebergs, Ouyang Dongshan couldn't determine the exact era, yet instinctively felt this period wasn't too recent.
"3700 years.....6000 years....43000 years....."
With his index finger gliding over them, his expression suddenly froze.
Seeing this, Lu Chaoyang hurriedly asked:
"Researcher Ouyang, how's the result?"
Ouyang Dongshan's eyes twitched twice, directly handing the report to him:
"Professor Lu, take a look."
Lu Chaoyang received the report and began examining it himself.
As a typical member of the crowd, Lu Chaoyang could still understand this type of report.
Therefore, it wasn't long before he compared and found the results.
Upon realizing the consequences of the time indicated by the result, his pupils suddenly contracted:
"This....this....?"
"Thirty-six.... hundred thousand years ago?!"
.......
Note
Please stamp rigorousness on the public screen; searching such data is too tiring, on Zhiwang I could only find up to sixty thousand years, for three hundred sixty thousand years, I had to go to Nature.
Yet I am particularly fond of being exact, unable to convince myself to create a fake δ18O data =.=
Also, since this chapter was an all-night endeavor, seeking some monthly tickets.
