Serf's Ultimate Field Theory

I, Li Zhe, have a Ph. D. In physics. I was "lucky" to travel through a brain-computer experiment and became a young serf who had just starved to death in a different world. Good news: I bring with me a treasure trove of knowledge from Earth's civilization. Bad news: The original owner of this body died from eating a piece of moldy black bread from the lord. As a former scientific researcher, I originally wanted to talk about the relationship between "human rights" and "productivity." Until my father was tied to a stake and whipped to death in public, the lord smiled and said: "The life of a serf is no different than the weeds in the field." I fell silent. Then I opened the scientific database in my mind. When the overseer swung his whip, I used the kinetic energy formula to calculate the angle of seizing the weapon with the least effort. When the lord launched the blood curse, I used the principle of quantum entanglement to dismantle it into storable energy. When the Church Inquisitor shouted "heresy", I deduced on the spot how to use the superstring vibration model to make his holy light return to its original path. They taught me what power is with their iron and blood. I responded with mass-energy equations and probability theory - and by the way, I optimized the yield per unit of territory, because I couldn't do scientific research because I was hungry. From thatched hut to castle, from living on your knees to living on your feet. This is not actually a revenge story. Just a large-scale physics experiment about "how knowledge crushes feudalism". (Note: The protagonist's morality is flexible, but energy is conserved; he is reasonable, but he mainly talks to dead people. Please confirm that you have accepted the setting of "Science is the primary productive force" before reading.)