Shading Computer

Shading Computer (濃淡コンピュータ) is the tentative name given by fluid mechanics expert Matsusada to a computer that uses the fluidic movements of a medium, such as water, to perform any kind of calculation, like a real computer. It was originally a theoretical model of a next-generation computer as envisioned by Matsusada in his book, The Future of Next-Generation Processors using Viscosity and Density.

The Future of Next-Generation Processors using Viscosity and Density
The explained in the book, The Future of Next-Generation Processors using Viscosity and Density (粘性・濃度と次世代演算装置の未来), Matsusada's original vision had the shading computer be composed of a water tank filled with a special electrolyte solution. Each individual colloid making up the liquid would be moved with the power of electricity to perform caluclations.

The doctor had the computer different from other computers, as they performed calculations using the smallest units of 0 and 1. He compares it to DNA computers and quantum computers, whose crucial aspect is that it destroys the Von Neumann computer architecture. Instead, the Shading Computer constructs its smallest units using the viscosity and density of fluids. This unique property apparently greatly increases the number of caluclations it can make in a second.

AIM-based Shading Computer
According to Matsusada, the architecture of the Shading Computer should work with any liquid, gas, or other medium that can be controlled according to the principles of fluid mechanics. AIM diffusion fields are subjected to the principles of fluid mechanics as well, as such, it can also be used as the medium for the Shading Computer. Moreover, AIM, being found in Academy City, constantly being influenced by its espers, make it an apt medium, as a Shading Computer requires the "fluid" to be constantly controlled and influenced.

There are dangers however, as such, Matsusada advised the use of using the medium in a controlled environment like an isolated box, as the Shading Computer can endager students when there are changes in pressure and it flows back affecting the students.The doctor warns of the possibility that anyone whose AIM diffusion field was part of the medium that the Shading Computer was built upon would be able to manipulate it. Moreover, he speculates that that the "pressure" that flows back into the esper or espers, could alter the statement of the mind producing the esper power or input information they should have not known. Matsusada refers to this as giving "a seemingly divine revelation" to them.

The danger of an esper that is part of the AIM diffusion fields that is being used as a medium for the Shading Computer being able manipulate it is later exemplified by Fremea Seivelun. This is because the shading computer uses every movement of the target fluid, which in this case AIM diffusion fields, to perform calculations. Even the smallest power producing the AIM diffusion fields that forms the Shading Computer has a connection to it.

Abilities
Using the theories of the AIM-based Shading Computer, Yakumi Hisako manipulated the AIM diffusion fields of the espers in the city to create Shading Computer for her ambitious Agitate Halation Project, despite the dangers that were conjectured by Matsusada, who was apparently drawn into the project as well.

The property of "changes in pressure (in the AIM fields) and flowing back affecting the students (espers)," were primarly used to give the "heroes" of Academy City a "divine revelation". This is where the "heroes" were inputted with an artificial sense of justice and a desire to protect Fremea Seivelun, the one chosen as the linchpin for the project, by the Shading Computer. This is due to the fact that by using the AIM diffusion fields, the students and the fields can influence each other. That is why a shading computer can be built and why the city’s heroes can be controlled using it.

Furthermore, the Shading Computer is apparently powerful enough to use the AIM diffusion fields to transfer a person's consciousness into being a part of it, turning them into an AIM thought being. Yakumi Hisako, the architect of the Agitate Halation Project, had her body eaten by her own roaches as a method of safely disposing her body in order to become an AIM thought being. Yakumi Hisako "deepened" her existence as an AIM thought being by using the theory of a Shading Computer on the AIM diffusion fields. Moreover, the AIM thought being was simply a temporary state which she wanted to transcend after completing the Agitate Halation Project. This refers to her shifting the medium that is used by the Shading computer to something that is much grander in scale, such as the world's air, but requires the death of Fremea to free Hisako from the limitations of the AIM diffusion fields.