Han Lingyun didn't run into Shen Lin again after coming back from the library. He was very curious as to what magic art his new friend chose. Anyway, he would still get his answer tomorrow. Now was the time to dive into the content of his two new manuals. Han Lingyun first picked the cultivation manual for the body tempering stage.

With the help of breathing exercises, cultivators absorb the natural qi of the environment around them into their dantian. The qi then flows into their body to strengthen it. At this stage, the dantian cannot hold qi, when qi is absorbed, if it isn't used to strengthen the body, it will naturally dissipate. A stronger body is also necessary in order to wield the power a cultivator can unleash at the qi cultivation realm without hurting himself.

The body strengthening realm follows 5 stages: Flesh, Viscera, Muscles, Bones, Marrow. Each stage after flesh training will provide an explosive growth in strength and toughness. At the flesh training stage, the qi condenses the muscles slightly, strengthens the tendons and hardens the skin. Without gaining too much in pure strength, the cultivator can punch a lot harder simply because he doesn't need to fear about hurting himself anymore.

At the Viscera stage: the 2nd stage, the qi strengthens the internal organs. First the heart which can pump a lot more blood. The lungs become more powerful and efficient. The liver detoxifies any food faster and speeds up digestion. At this stage, the cultivator gains a huge endurance compared to a mortal, he can run a marathon and fight at full strength 3 times longer than at the 1st stage.

The 3rd stage is the muscles stage. Every muscle of the body gains a huge amount of strength. A 3rd stage cultivator punches at least 10 times stronger than a 2nd stage cultivator. That's because a punch involves many muscles to provide speed and force and they are all strengthened, stacking up the effect.

The quadriceps tighten and loosen to move your feet, the obliques create the torso rotation, the deltoids raise your arm and provide momentum, the serratus anterior and the triceps create your arm extension. This is just one example to illustrate how much a 3rd stage cultivator dominates the 2nd stage. But at the 3rd stage, you also run faster, kick stronger…

The 4th stage strengthens the bones, enabling the cultivator to un leash more force without hurting himself. It is not well known, but the brain instinctively knows how much force one can use before having a detrimental effect. The brain simply blocks any self-harming action. That is why you will never accidently cut your tongue off, yet your jaw muscles are strong enough to do so. This is one of the reasons why the human body has so much untapped potential. At this stage, punching through rocks isn't an issue.

Finally, the marrow stage provides another comprehensive enhancement, strengthening the core of the bone and providing another boost in strength. Cultivators at this stage also gain a huge improvement in restorative ability. Regrowing a limb still isn't possible but blood is regenerated at a breakneck pace, and light damage to internals, some bones breaking, cuts will naturally heal in a couple of minutes, hours or days depending on the severity and the individual.However, that is not all, at each stage the body will eject a bit of impurities it had accumulated over time. Also, all the elements of the previous stages are strengthened again as qi permeates the body.

Han Lingyun read everything with fascination. The knowledge of the anatomy was quite deep with many details he had no idea about. The manual went into great lengths on how to sense qi, how to guide it to your dantian and how it has to traverse the body at every stage.

'I wonder what qi is. The rules of physics like gravity and electrical interactions seem to be the same as during my last life. If I throw a rock, it will follow a parabola with a landing point I can calculate, thunder has the same properties and I can still get shocked with electrostatic phenomenon if I rub my hand and touch a metal bar. Friction behaves the same way too.

Yet, I don't have a good understanding of qi, with a lack a theoretical knowledge and reference points. For now, I will consider it to be a pure form of energy. I wonder if it has any mass or if it is comparable to light. Crystals are often used as solid containers of pure qi but they are only containers. I wonder how they can retain energy too. It might be because the atoms composing the crystals have a particular structure that just so happens to be able to trap qi. Hmm, that seems highly likely. On earth, it wasn't a big problem to trap light using mirrors. Some researchers also found a way to trap light using a particular geometrical form, by making the electromagnetic waves cancel out each other [1].

Even if qi doesn't have mass it seems to be a material particle so like light it should have an impulsion p, which means it should have an associated wave. Which means if I guess correctly, in order to absorb qi into the dantian, effectively trapping it, the qi flow in the body should form a structure capable of resonating with the qi waves, same for the dantian. I'll have to analyze further its properties and how it interacts with matter.

It is also interesting to note that a greater concentration of qi seems to make nature and life thrive. Maybe it acts as a catalyst to every chemical reaction, thereby accelerating plant growth and cellular growth in general. Another point to look into later.

But there is still one thing I need to do before the qi cultivation stage. I have to explore the structure of crystals used to cultivate. I will then try to infer a resonating structure and the qi passageways based on its geometry. Then I will be able to compare it with the qi method provided by the sect to see if my thesis is right and if by any chance, I could improve the method further.

Maybe I could talk to Elder Wen of the array pavilion to see what he thinks about my hypothesis.

It also means that the dantian is some kind of mini nuclear reactor of pure energy. Or a nuclear battery seems more accurate for a comparison. That explains how qi deviation can be deadly if a cultivator loses control. My thesis would be that the brain is always instinctively monitoring and controlling the dantian.magicHowever, strong emotions, desperation or a wrong state of mind could disrupt the brain's process of control and lead to qi deviation as we know it: with consequence going from the loss of a realm, the crippling of ones cultivation or death. Of course, all this is only valid for the first cultivation realms, I don't have enough of an understanding of a cultivator at a higher realm yet to generalize.

Another important question is how do we actually sense qi. It shouldn't be with the soul as qi interacts with matter. But I don't know if it also interacts with the soul. Maybe we sense qi through our nervous system? If that is true, maybe it has electrical properties? Hmm that doesn't seem right, its properties are too different. What if there a 6th sense?

Of course! Why have I forgotten about the spirit root? My mindset is still influenced by the culture of my last life; I should have thought about it earlier. Only those with a spirit root can sense qi! The name should also be an indication for the nature of qi: spiritual. But what is it exactly? Well, I hope I'll get my answer tomorrow.'

Hours passed by as Han Lingyun was absorbed in his thoughts, with so many new questions and ideas opening up as he learned more about qi and the wonderful world of cultivation.

'Ah before I go to sleep, I should read the blackbird art.'

The book was separated into 3 parts. The first one was focused on the mindset needed to perform the blackbird art. Forgetting most of the world and focusing on a couple of key concepts: silence, death, volatility. The first part developed the meaning of these concepts and the method to reach the suitable state of mind.

Apparently, each of those 3 concepts could be summed up in one character. Visualizing this character was a shortcut to visualizing the corresponding concept. But that was very difficult, not to mention visualizing 3 characters simultaneously. Another way to help getting in the right mindset was to visualize the blackbird and its actions: flying, eating a prey… Han Lingyun now understood why these martial arts often used animals or visual ideas for the names, it was an indication of the concepts they portrayed.

The second part described some movements to execute until they became instinctive. In truth, the footwork encompassed the whole body. Finally, the last part focused on the application of qi within the body, how to make it flow to particular parts of the body when executing the movement. Apparently, the qi used in body tempering remained in the body to some extent.

Han Lingyun wasn't sure about the exact process but he was definitely amazed at the complexity and detail of the flows. It rivaled the electrical circuits of a microchip. How someone could imagine and create such a martial art he didn't know. His best guess was that the creator of the black bird martial art was at a greater cultivation realm.

'The 1st part about the three concepts seems to corroborate my idea about qi being spiritual. It's definitely fascinating. How does the spiritual interact with the soul and with matter? If I continue with this idea then it means that qi is pure spiritual energy, and the point of the 1st part of the martial art is to give it the correct flavor. The possibilities become endless if you start thinking about combining concepts. Qi becomes the ink with which one can write a story, solve equations, paint art.'

Han Lingyun slowly fell asleep with a smile on his face, as his mind started to doze away with many new ideas.

[1] Hsu, C., Zhen, B., Lee, J. et al. Observation of trapped light within the radiation continuum. Nature 499, 188–191 (2013). https://doi.org/10.1038/nature12289