EXA_PICO Universe Wiki
EXA_PICO Universe Wiki

A Heart of Gaea (大地の心臓, daichi no shinzou?, lit. "Heart of the Land") is a crystalline structure that continuously emits Dynamic D-Waves - in other words, Sings - to create and maintain the existence of a given object. Depending on the size of the Heart, it can sustain objects ranging in size from a single continent to an entire planet.

The scientific name for the Heart of Gaea is the Fourth Dimensional Core Square Ring (四次正角性中核環, shiji seikakusei chuukakukan?, lit. "Autostabilizing Nuclear Tesseractal Loop"). It can be thought of as a step up in complexity from a Triangular Nuclear Loop, which serves as the Heart of a Reyvateil.

A Heart of Gaea can output Dynamic H-waves (that is, feelings) with frequencies up to a maximum of 1x10^20Hz. This is several orders of magnitude above a typical Human or Reyvateil, both of which have a maximum frequency of 5.28x10^11Hz.


While Hearts of Gaea do form naturally during the creation of a planet, creating a Heart artificially is incredibly difficult. That is because the maximum power and frequency of the feelings of a Human-level being are far below the requirements for the successful creation of a Heart. If a Heart was created from a Human-level being, the result would be an imperfect creation - a Deathlandia.

Jaza studied the process through which a Heart could be born, but she never finished her research, believing it to be impossible. She sealed her research way, along with her experimental Song EXEC_METAFALICA/. Later, the Wave Scientist Grammul and Infel resumed Jaza's studies. They found that by exploiting a phenomenon they called the "SHW Enhanced Effect", they could fuse the feelings of many Human-level entities and reach the required power levels and frequencies for creating a Heart of the Land. This was the impetus behind the creation of Infel Phira and the IPDs. Infel created a patch to complete Jaza's work, which she called METHOD_METAFALICA/. The complete Song, EXEC_with.METHOD_METAFALICA/., is capable of creating a Heart of Gaea from the feelings of the Reyvateils housed within Infel Phira.

If a Heart already exists, it is possible to hold a kind of Song called a Conversation Song with it in order to extract a piece of the core. Creating this fragment does no harm to the Heart, and the fragment can itself become a complete Heart of the Land. However, upon extraction, the fragment is empty and has no feelings. It must be filled with the feelings of a great many people for it to be capable of creating anything.


A Heart of Gaea is made of three parts: the core, the core glass, and the external shell.

Heart of the Land


The core is the Heart of the Land itself, the place from which its feelings emanate. It usually sits at the very center of the object that it maintains. Ironically, the core itself has no defined shape, and is instead similar to a cloud of plasma.

Core Glass[]

The core glass is a crystalline structure that protects the core and gives it shape. Without the core glass, the core would not be able to exist in the world. The core and the core glass are typically referred to as the same component.

External Shell[]

The external shell is the outside of the Heart of Gaea. It is made of multiple shell plates that rotate around the core. The way they rotate covers any gaps and crevices that could form between them, and this makes it impossible to forcefully remove the core.

The main role of the external shell is to guard the core against the outside world. This includes both physical threats (D-Waves) and mental threats (H-Waves). If the core is removed from the shell, it will start to dissipate from exposure to the negative feelings of the world. Given enough time, it would eventually evaporate completely. Thus, the core almost never leaves the confines of its shell. However, by Singing a Conversation Song with the Heart, the Singer may be able to convince the core to leave its shell. This requires the Singer to show that they have no hostile intentions towards it.

Known Hearts of Gaea[]

  • Ar Ciel's original Heart, destroyed in the Grathnode Inferia
  • Mihoshi, created after singing EXEC_SEED/. and destroyed by Ar Ru using it to create Antibodies
  • Metafalica Alpha, created by Nenesha, Infel, and a small cadre of IPDs in 3310AD
  • Nenesha, after Infel and Nenesha's failed Metafalica in 3313AD
  • Cloche or Luca, depending on the player's choices, after Luca is forced to sing EXEC_METAFALICA/. alone
  • Metafalica, created by Luca, Cloche, and the IPDs in 3774AD
  • Ar Ciel's new Heart, extracted from Metafalica and filled with feelings from the people Cocona met on her journey to Sol Cluster
  • Tyria, after dying and being placed into a Heart extracted from Metafalica


  • There appears to be no consensus as to what the official translation of the scientific name should be. It has been rendered as both "4D Conformal Nucleus Loop" and "Fourth Dimensional Core Square Ring".