Alchemy

Alchemy is, as it is understood in the Fullmetal Alchemist series, the ancient metaphysical science/mystical art of manipulating and altering matter by using natural energy. This act is known as "Transmutation" and its sequence is usually described as:


 * (1) Comprehension - Understanding the inherent structure and properties of the atomic or molecular makeup of a particular material to be transmuted, including the flow and balance of potential and kinetic energy within


 * (2) Deconstruction - Using energy to break down the physical structure of the identified material into a more malleable state so as to be easily reshaped into a new form


 * (3) Reconstruction - Continuing the flow of energy so as to reform the material into a new shape

The proper application of this craft requires not only a full understanding of chemistry and ancient alchemical theory, but also a sort of natural talent towards recognizing and manipulating the physical objects with energy, which require uncommon levels of intelligence and aptitude. Those remarkable individuals capable of studying and practicing alchemy are known as "Alchemists".

There are many paths by which alchemists can transmute the various substances of the world, with some alchemists being said to transmute by way of the Four Classical Elements (Water, Earth, Fire and Air) and some by way of the Three Principles, but the basic tenet at the very foundation of all alchemy is that of Equivalent Exchange.

Equivalent Exchange
The mystical practice of alchemy to create objects out of raw matter or turn one object into another is widely believed to be capable of anything, indeed alchemy is often viewed as magical or miraculous by those unfamiliar with the craft, but it is a science and as such is subject to certain laws and limitations, all of which fall under the concept of Equivalent Exchange: "In order to obtain or create something, something of equal value must be lost or destroyed."

In standard practice, Equivalent Exchange is separated into two parts:

The Law of Conservation of Mass which states that energy and matter can neither be created from nothing nor destroyed to the point of elemental nonexistence. In other words, to create an object weighing one kilogram, at least one kilogram of material is necessary and destroying an object weighing one kilogram would reduce it to a set of parts, the sum of which would weigh one kilogram.

The Law of Natural Providence which states that an object or material made of a particular substance or element can only be transmuted into another object with the same basic makeup and properties of that initial material. In other words, an object or material made mostly of water can only be transmuted into another object with the attributes of water.

Rebound
Since the alchemical forces being manipulated are not human in origin, but of the world as a whole, the consequences for attempting to bypass the Law of Equivalent Exchange in transmutation are not merely failure and cessation. When too much is attempted out of too little, what occurs is called a Rebound, in which the alchemical forces that are thrown out of balance on either side of the equation fluctuate wildly of their own accord in order to stabilize themselves - taking or giving more than was intended in often unpredictable and catastrophic ways such as accidental mutation, serious injury or death.

Transmutation Circle
Additionally, though no machines or equipment is needed to produce the energy necessary for transmutation, merely understanding the sequence of transmutation and the limitations of Equivalent Exchange is not enough. Just as the processes of "Comprehension, Deconstruction, Reconstruction" and "In order to gain, something of equal value must be lost in return" are cyclical concepts, the circle itself is the foundation of alchemy.

In order to begin an alchemical transmutation, a symbol called a Transmutation Circle is necessary. Transmutation Circles can either be drawn on the spot when a transmutation is necessary (in chalk, pencil, ink, paint, blood or even traced in dirt) or permanently etched or inscribed beforehand, but without it, transmutation is generally impossible and all Transmutation Circles are made up of two parts:

The circle itself is a conduit which focuses and dictates the flow of power, tapping into the energies that already exist within the earth and matter. It represents the cyclical flow of the world's energies and phenomena and turns that power to manipulable ends.

Inside the circle are specific alchemical runes. These runes vary widely based on ancient alchemical studies, texts and experimentation, but correspond to a different form of energy, allowing the energy that is focused within the circle to be released in the way most conducive to the alchemist's desired effect. In basic alchemy, these runes will often take the form of triangles (which, when positioned differently, can represent the elements of either water, earth, fire or air), but will often be composed of varying polygons built from different triangles. For example: the hexagram is a commonly used base rune in Transmutation Circles because it creates eight multi-directional triangles when inscribed and can therefore represent all four classical elements at once. Other, more esoteric runes (including astrological symbols, symbolic images and varying lines of text) are prevalent and represent a multitude of other, specific functions for the alchemical energy that is released. Over the nearly 400 year history of alchemy in Amestris, great strides in alchemical research have been made by mixing these runes together to augment their power, converge their results and create entirely new pathways of utilization.

Human Transmutation
Human Transmutation is the act of bringing some living object back to life. For example a person. The Elric Brothers attempted this to bring back their mother. They failed, and their limbs and bodies where taken. This is just one of the many things that happen when you fail at Human Transmutation. It is revealed that no human transumation can be called a "success," as you can not bring back a dead persons person's soul. This is revealed by Van Hohenheim when he visits Pinako Rockbell. He states that the person Alphonse and Edward created was an entirely different being than Trisha, their deceased mother. This fact brings them and Izumi Curtis great comfort. Izumi tried to transmute her stillborn son, which lead to the loss of a majority of her internal organs as her "fee" for Truth. It can also include creating human like creatures with or without the use of human ingredients, like homonculi and certain chimeras.

Unfortunately, these experiments have given birth to a dark and sinister side of alchemy.