Alchemy 101 ..
Before I go further along with Alphonse' story, let me introduce to you the alchemy in the world of Fullmetal Alchemist.
Alchemy, It is the scientific technique of understanding the structure of matter, decomposing it, and then reconstructing it. If performed skillfully, it is even possible to create gold out of lead. However, as it is a science, there are some natural principles in place. Only one thing can be created from something else of a certain mass. This is the Principle of Equivalent Exchange.
- Fullmetal Alchemist Brotherhood Intro
Alchemy is not a form of magic or miracles that can create something out of nothing. It is a scientific process which is about understanding the structure of matter, decomposing it, and reconstructing it. Alchemist can change the density of a matter and making it bigger or smaller. Alchemy is based on the concept of Equivalent Exchange. It is focused on the law of conservation of matter and the flow of life. Equivalent Exchange means that in order to create something something from an equal matter must be lost or in order to create one type of matter it is necessary to supply an equal amount of the same type of matter. For example, you cannot make a stone house out of water.”
ALPHONSE WAS THE FIRST ONE TO SHOW OFF ALCHEMY IN THE FIRST CHAPTER OF THE SERIES
Alchemist must understand the structure of matter and also controls the flow of energy. Transmutation is the alchemical process where the alchemist uses circles and runes in order to manipulate the flow of energy. In Fullmetal Alchemist, the alchemist from the country of Ametris receives their energy from the earth's crust movement, however, their energy is currently controlled by a specific "person" who is contained with millions of Philosopher’s Stone. A Philosopher’s stone is a strong red liquid shaped like a stone which can overpass the law of alchemy or the law of Equivalent Exchange. It contains human souls which becomes a powerful energy needed to perform alchemy without using transmutation. On the other hand, alchemist from the land of Xing uses the Dragon's pulse, the energy that flows to the human's veins. In order to Transmute, alchemist must use energy and must be able to control the flow of it. Or else it will rebound.
A rebound happens if the alchemist does not have enough skill and knowledge. When an alchemist attempts a transmutation beyond their skill level, the amount of material that is lacking from the equivalent exchange is taken from the alchemist’s body. For example, when Edward and Alphonse tried to resurrect their mother with the process of Human Transmutation. The process rebounded because they were lacking a soul. They thought that their blood is enough to resurrect a human. Also, Homunculus which are further metioned in this shrine, are creatures that have a physical appearance of a human being, but they are immortal or can regenerate back to normal with the use of the Philosopher's stone because they are born from one.
Unlike the Flame Alchemist, Col. Mustang, who specializes with fire, Alphonse' alchemy is practically anything. He doesn't have a specialty yet well probably because he is still young and still learning. At first, Alphonse still draws transmutation circles unlike his older brother who can perform alchemy by just clapping his hands. But as Alphonse enters the portal of truth again, he was able to remember what is inside of his gate of truth. Portal of Truth is a white place where the Truth resides. Truth is like a white unknown creature or like the person who brings judgement to each alchemist who enters the gate of truth. The Gate of Truth is a door which contains knowledge and sometimes used as a door to come back to their world and sometimes it's just plain endless blackness.