Quantum Time-Lock

Quantum Time-Locks are a variety of "universal" event implicated in the culling of Adjacent Worlds (並行世界). Within the Thaumaturgical community of the modern world, they are also referred to as Human Order Foundations (人理定礎).  

Overview
A Quantum Time-Lock is a event that manifests at regular intervals within a "universal" domain for the purpose of anchoring the average expression of phenomena and occurences as immutable absolutes within a confirmed History. In the Prologue of the Altera Route in Fate/Extella, it is stated that the intervals between Time-Locks are a century in scale, but Fate/Extella Material in fact indicates that two Time-Locks manifested between the beginning of the game and the ending of True Nero Route.

This universe permits the birth of unlimited possibilities, numerous Adjacent Worlds, and divergent developments of history. However, as the unrestricted propagation of this process would exhaust the lifespan of the "Universe" (宇宙), at set intervals, those extraneous worlds (routes) removed of the category of "routes characterized by strength and stability" are culled (伐採), so as to prevent the needless expenditure of energy. The facilitation of this process is referred to as the Conservation of Phenomena (事象保存).

The Moon Cell Automaton has concluded that the means by which our Universe of Awareness (認識宇宙) -- originally unstable by nature -- is stabilized across Past, Present, and Future lies in the execution of "culling" and the formation of "records" (記録帯).

If left alone, the great tree of Time will branch without restriction, and the behavior of culling serves to remove those divergences that are unnecessary, leaving only the "trunk" -- this is the simplest image by which to comprehend the process.

Fate/Extella states that the energy to account for the ceaseless proliferation of unnecessary worlds exists nowhere within this "Dimension" (次元), and that the Dimension itself may eventually exceed capacity if the process persists unchecked. Furthermore, absent of culling processes, the Earth can persist at its present level of civilization for only another century before the Solar System dissolves beneath the sheer volume of the data produced by humankind. With culling processes in place, however, it's likely that the status quo can be sustained for another hundred million years. In the context of Quantum Time-Locks, it is unknown if "Dimension" and "Universe" refer to the same existence.

Any history that has been secured as a Time-Lock (固定帯) become as existence impervious to interference from the past and future; events or phenomena that exist within the purview of the anchoring band are utterly immovable. Hypothetically, if one were to move to a chronological position in the past of an "anchoring band" to the end of modifying history, as time progresses unto the "anchoring band," history will be forcibly realigned to its state of record.

In those universes wherein Quantum Time-Locks are imposed, the "outcomes" that have been registered to anchoring bands are categorically unchangeable. Thus, that which would be open for time travelers to modify would be restricted to "process."

For example, let us presume that the "outcome" that "Britain was destroyed" is secured as a matter of record. In the circumstance that a process wherein "Britain comes to prosper; its wars are concluded; and happiness is granted to its people" is successfully brought about, in the moment that history advances unto the anchoring band, the outcome whereby "even so, Britain came unto its destruction" manifests.

One or two -- or any number of lives might be saved. However, modification to the overall course of the History of Man (人類史) is decisively beyond possibility.

To rephrase, it is potentially possible that by some immense undertaking, the course of the History of Man could be fundamentally denied by the successful revocation (破壊) of a "Quantum Time-Lock" -- but even by this method, that which is denied is restricted to "the History of Man that falls subsequent to the anchoring band."

The purview of a "Quantum Time-Lock" due to manifest may be dictated only those who live within the era. Intervention from the past or future is incapable of directly influencing the formation of a Quantum Time-Lock.

Terminology
In the Avant Title of the Fate/Grand Order - Accel Zero Order event, Lord El-Melloi II makes references to certain terminology pertaining to the cosmology of Adjacent Worlds and Quantum Time-Locks, available to his comprehension as a consequence of temporarily becoming one with a Heroic Spirit.   It is unclear if these terms are in general parlance within the Thaumaturgical community.

Adjacent Worlds

 * Adjacent Worlds (並行世界) refer to divergent timelines that advance in adjacence to one another. In Fate/Extella, it is stated that a World qualifies for culling if it entirely lacks the potential to diverge into Adjacent Worlds.


 * "Adjacent Worlds" are terminologically distinct within the canon from Parallel Worlds (平行世界), which refer instead to timelines that advance in perfect parallel with no relationship of divergence.

Primary Branch

 * The Primary Branch (大幹) refers to the cluster of Adjacent Worlds (並行世界群) that form the Great Tree Known as Time (時間という大樹) -- comprising of the confirmed (確定) pathways of the History of Man; that which remains as of the completion of culling (伐採) processes. The worlds of Fate/Zero and Fate/Grand Order are stated by Romani Archaman to "lie near the center" of this cluster, closely approaching one another in their historical course. Worlds within the Primary Branch are said to exist along their "proper axis" (正しい軸).

Items Permissible to Revision

 * Items Permissible to Revision (編纂事象) is a category name applied to the set of worlds within the Primary Branch. Refers to timelines wherein, outside of the Outcomes (結果) confirmed by a Quantum Time-Lock, the Processes (過程) leading up to an outcome may still be modified. Beyond the circumstance that an "immense undertaking" overturns a Quantum Time-Lock, however, confirmed Outcomes within these timelines are immutable, regardless of interference from the past or future. Prior to the manifestation of a Quantum Time-Lock, all open and unculled timelines fall under this category.

Items Designated for Omission

 * Items Designated for Omission (剪定事象) is a category name applied to divergent timelines that have come to exist as realities entirely distinct (完全に別世界になり) from others -- that is to say, Otherworlds (異世界) wherein the Foundation of the World (世界の基盤) is sufficiently divergent that its civilization no longer resembles the those within the timelines of the Primary Branch. As the name implies, these realities are designated for culling.


 * In Fate/Extella, a set of overlapping criteria is outlined for the culling of Items Designated for Omission as of the manifestation of a Quantum Time-Lock :


 * The choices of the timeline's inhabitants can no longer impact its future.
 * Continuous advancement unto ruin or prosperity has occurred, to the extent that the World has been bankrupted of, and its future has been rendered immutable.
 * As of a hueristic audit of capacity to advance prior to the fall of a Quantum Time-Lock, a given World fails to meet the qualifications to ensure "the operation of the subsequent era" (次の時代の運営) in a century's time.

Fate/Prototype: Fragments of Blue and Silver

 * In the case that Manaka Sajyou succeeds in fulfilling Saber's wish of an eternal Britain, the Human Order Foundation collapses and the modern world is destroyed.

Fate/Grand Order

 * Solomon destroys the Human Order Foundation through his Singularities in the beginning of the story.

Fate/Extella

 * In Fate/Extella, the objective of Archimedes was to manufacture an Outcome whereby "Moon Cell is Destroyed" prior to the manifestation of the coming Quantum Time-Lock -- establishing a reality premised upon this condition.


 * Whereas originally, such a development could not occur, Archimedes repeatedly shifted between realities to the end of achieving his goal. From Archimedes' perspective, so long as the operation of Moon Cell could be entirely brought to a halt prior to the fall of the subsequent Quantum Time-Lock, victory would be his.


 * However, even if there were outcomes in which Archimedes was victorious, a route in which the complete termination of Moon Cell's processes occurred could not be reached. In the meantime, the Protagonist was able to confirm "an average world that bears the potential greatest" -- establishing the purview of the coming Quantum Time-Lock. Archimedes' machinations were consequently brought to ruin.


 * Incidentally, Quantum Time-Lock A manifested as of the start of the primary story-arc in Extella, when "the Protagonist enters the Stone Chamber of the Titan with Archimedes, and is split into parts"; Quantum Time-Lock B manifested as of the Ending of the True Nero Route.


 * Regardless of the actions taken by Archimedes between these two points in time, the "Outcome" was already decided.