Momentum Metrics

Momentum Metrics is the collective designation for the six certified families of measurement by which the Office of Mass and Momentum renders administrative momentum legible, comparable, and — where the Certificate of Irreconcilable Momentum is sought — actionable. The families are not a single system; they were assembled piecemeal between the ratification of The Momentum Decision and the present recension, and they disagree with one another at their margins in ways the Office has declined, on four separate occasions, to resolve. Practitioners distinguish the families by their units, their instruments, and the temperament of the clerks who maintain them.

The Six Families

The current register, as posted at the head of the Office's computation hall on Floor 2,411, lists the following families in order of certification. The order is not an order of precedence and the Office has twice ruled that treating it as one constitutes a filing error.

• Procedural metrics, measured in vell-units, governed by Procedural Momentum.
• Fractional metrics, derived from the Engine of Fractional Momentum in Vault 3 under seal E-77/frac.
• Non-convergent metrics, which are not expected to terminate and are not required to.
• Ambiguous metrics, administered by the Department of Ambiguous Metrics.
• Ambient metrics, which are read rather than measured and are the subject of standing objection from the ambient office itself.
• Jurisdictional metrics, concerning momentum claimed at or across a boundary, treated at length under Irreconcilable Jurisdictional Momentum.

Origins and the Cassini Convention

The metrics descend from the quantification established in The Momentum Decision, which fixed procedural momentum as an administrative property and thereby made it something that could be lost. The convention that the six families are commensurable derives not from that instrument but from a schedule appended to it in the following decade, which fixed the Cassini Unit as the common reference for cross-family comparison. The schedule gives no derivation of the Cassini Unit. A marginal note in the surviving fair copy, initialled by a clerk identified only as V. Orrun, reads: "The unit is the unit. It is not to be asked after."

Commensurability is asserted, not demonstrated. The threshold at which a differential becomes irreconcilable — 0.3 Cassini Units — was chosen because it was the smallest figure the schedule's table could express without amending the table, and the Office has defended it on that ground in three separate appeals.

The Two-Column Dispute

The principal scholarly disagreement concerns whether ambiguous and ambient metrics belong in the register at all. The Department of Ambiguous Metrics maintains, citing Third Concordance, Annex 4, that a metric whose reading depends on the reader is still a metric, since the reader is a certified instrument of the Office. The opposing view, advanced most persistently by the Department of Ambient Metrics, holds that ambient readings are conditions rather than measurements, and that to enter them in the same column as vell-units is "to set a thermometer beside a ledger and call the ledger warm" — the phrase is from a circular of 11 Fogmonth, issued jointly and disavowed separately.

"Where two families cannot be reconciled, both shall be recorded, and the discrepancy shall be recorded as a third thing."

— Third Concordance, Annex 4, clause 9

Annex 4, clause 9 has never been applied to the metrics register. The Office's position is that the clause concerns families that cannot be reconciled, and that the six families can be reconciled, though it has not produced the reconciliation. A junior clerk, Marn Ottery, requested the reconciliation in writing in the winter of the year the heating on Floor 2,411 failed; the request was acknowledged, logged, and answered fourteen months later with a copy of the request itself, stamped received. Ottery's subsequent memorandum on the incident is now cited more often than the reconciliation it sought.

Attrition and the Diurnal Anomaly

All six families are affected by the Diurnal Stairwell Momentum Anomaly, which draws momentum slowly out of filings held in cabinets. The attrition is small per diem and compounding, and it falls unevenly: fractional readings taken from the Engine are effectively immune, procedural readings stored above Floor 2,400 lose on average 0.004 vell-units a day, and ambient readings lose nothing, a fact the ambient office cites in support of its position and the ambiguous office cites as evidence that ambient readings are not measurements at all. Cabinets on the stairwell face are to be kept closed between the hours of Vespers and Matins. The rule is posted on the inside of each cabinet door.

Certification Practice

A Certificate of Irreconcilable Momentum is issued where the Office confirms a differential exceeding 0.3 Cassini Units. Confirmation requires readings from at least two families, and here the register's internal disagreements become practical. In the matter of the Hollend appeal, readings were taken in procedural and jurisdictional metrics and differed by 0.41; the certificate was issued. In the matter of the Asque petition, readings were taken in ambiguous and ambient metrics and differed by 0.55, but the Office declined to certify, on the ground that neither family had been read by a certified instrument on the day in question. The petitioner objected that the ambiguous reading had in fact been taken by a certified instrument, namely the reading clerk. The Office replied that the reading clerk was certified for procedural work. The reply runs to nine pages.

The Principle of Procedural Momentum holds that unresolved metrics accrue to the party who filed first. Whether this principle applies to the metrics themselves, or only to the appeals conducted in them, remains open. Both readings are in circulation. The Office has not chosen between them and, asked directly in the fourth month of this year, observed that the question was well put.