Li Qingsong named the particle produced by proton decay the Light Neutrino, signifying a tiny particle similar to a photon.
The Light Neutrino seemed to possess every trait that made detection difficult, and for a time, even Li Qingsong couldn't find a suitable method.
Given the extremely long lifespan of protons, the density of Light Neutrinos in the cosmos was even lower than that of magnetic monopoles. Detecting magnetic monopoles was already a monumental undertaking; was he really expected to build hundreds of thousands of similar detectors just to try and capture Light Neutrinos?
The scale of such an undertaking was simply immense, far beyond what even Li Qingsong could handle.
A more critical question arose: how did other ordinary Electroweak Civilizations manage to detect Light Neutrinos?
'They couldn't possibly have achieved it by building hundreds of thousands of detectors.'
'If even I don't possess that kind of industrial capacity, how could they?'
This meant that there had to be another detection method, one that could capture Light Neutrinos with a much smaller investment of industrial resources.
'But... what could that method be?'
Li Qingsong descended into a long period of deep thought. He was not alone; the Blueprint Scientists joined him in this task of contemplation and exploration.
Time flowed by quietly, and Li Qingsong's various theoretical breakthroughs continued without pause.
There were breakthroughs nearly every day: minor branches of scientific theory under his grand frameworks, new mathematical insights, and more.
Like flesh and blood, they gradually attached themselves to the "skeleton" of the theoretical framework Li Qingsong had built, making the entire structure increasingly complete.
Unfortunately, his work on proton decay remained a complete blank slate.
He hadn't even managed to build the skeleton, let alone add flesh and blood to it.
Li Qingsong could do nothing about it but persevere, thinking day after day, year after year.
This was the nature of scientific research, especially in fundamental theory. There were no shortcuts. One could only grind away at the problem bit by bit, taking one step at a time, relying on gradual accumulation in the search for a possible groundbreaking theory.
It was under these circumstances that one day, a seemingly insignificant breakthrough caught Li Qingsong's attention.
It was not a breakthrough in fundamental theory, but rather a discovery in a related branch.
The breakthrough concerned the cores of gas giants. Building upon previous theoretical and mathematical developments, Li Qingsong had completed his latest model of gas giant cores. By using more parameters and greater computing power, he created a more realistic simulation of their internal mechanics. This provided theoretical support for phenomena like gas convection and variations in atmospheric elemental abundance.
This meant that Li Qingsong was now able to make highly accurate predictions about weather patterns on gas giants.
This seemingly had nothing to do with proton decay, but it sparked an idea in Li Qingsong's mind.
He realized that the core of a gas giant... seemed to have the potential to serve as a natural laboratory.
A typical gas giant, such as Jupiter in the Solar System, is divided into four main parts, from the outside in: the outer atmosphere, a layer of supercritical molecular hydrogen, a layer of liquid metallic hydrogen, and the core.
The outer atmosphere is about one thousand kilometers thick. Moving inward, pressure and temperature rise sharply until they become high enough for the hydrogen to enter a supercritical fluid state.
Here, the pressure exceeds 10,000 Earth atmospheres, and the temperature reaches several thousand degrees Celsius.
Deeper still, at a depth of over twenty thousand kilometers from the surface, the state of the hydrogen changes once again.
It becomes liquid metallic hydrogen.
Because the pressure and temperature are so high, the electrons are stripped from the hydrogen nuclei and become free electrons. This gives the material metal-like properties, which is why it's called metallic hydrogen.
The pressure in this layer is millions of times that of Earth, and the temperature reaches tens of thousands of degrees Celsius.
Further inward, at the very center of the gas giant, lies a solid core similar to Earth, composed mainly of iron, nickel, and silicate rock.
In the early stages of planetary formation, there isn't much difference between a gas giant and a rocky planet, aside from their size.
A planet with a mass similar to Earth's can only attract a comparable amount of gas for its atmosphere, ultimately becoming a rocky planet.
But when its mass reaches two to three times that of Earth, it can attract far more gas, eventually evolving into a gas giant like Jupiter.
The place Li Qingsong's model identified as having potential as a research environment was the liquid metallic hydrogen layer of a gas giant.
It possessed this potential because Li Qingsong's calculations suggested it was possible to find key evidence of proton decay there!
Of course, this wouldn't involve finding evidence by detecting Light Neutrinos, but rather through a different method.
A gas giant's liquid metallic hydrogen layer has extremely high pressure and material density.
Proton decay causes a proton to turn into a Light Neutrino, which then escapes the gas giant's core.
The process is roughly analogous to a person compressing a spring with all their might, only for the spring to suddenly vanish.
Obviously, the person would be thrown forward, causing a "jolt."
Under normal circumstances, this jolt would be minuscule because the probability of proton decay is incredibly low.
However, in the Pegasus V432 Star System, even the smallest of its multiple gas giants has approximately 1.2 times the mass of Jupiter.
The pressure there is extremely high, which is analogous to the person compressing the "spring" with immense force.
This mechanism would amplify the tiny jolt caused by proton decay.
According to Li Qingsong's estimates, its liquid metallic hydrogen layer had a total mass of about 0.9 times that of Jupiter and contained approximately 10^54 protons.
Current evidence suggests that the lifespan of a proton is 10^37 years.
By this calculation, approximately 10^17 protons in the gas giant's metallic hydrogen layer would decay on average each year. This averages out to about 3.2 billion protons decaying every second.
Within the high-pressure liquid metallic hydrogen layer, the protons themselves help support the material structure, acting like countless tiny springs.
Every second, about 3.2 billion of these tiny springs suddenly vanish. In response, the surrounding matter abruptly loses its support, triggering that "jolt."
'So... could detecting this "jolt" prove the existence of proton decay and allow me to study the process itself?'
Li Qingsong wasn't certain if this detection pathway was actually viable.
After all, 3.2 billion protons might sound like a lot, but their total mass was less than that of a single virus.
'Could a "jolt" caused by such a minuscule loss of mass... truly be observable?'
Intuitively, Li Qingsong felt it was unlikely. But at this stage, there seemed to be no other options. 'I might as well explore it and test its feasibility.'