ObscuripediaThe Free Obscure EncyclopediaThis article describes a proposed physical constant that has not been measured. Its value is given throughout as "awaited." Editors are asked not to supply one, the last attempt having required the brick.
| Symbol | s |
|---|---|
| Value | Awaited |
| Relative uncertainty | Total |
| SI unit | Under negotiation |
| In SI base units | declined to specify |
| Role | Fixes the unlonnture of the brick at exactly 1.0 |
| Proposed | 2019 |
| Measured | No |
The constant of stubbornness (symbol s) is a proposed fundamental constant of reluctant optics, introduced in 2019 to underpin the definition of the brick and so to free the unlonnture index from dependence on any single object remaining honest.[1] It is the constant by which the brick is held to have an unlonnture of exactly 1.0, independent of which brick is consulted, or whether the brick can be found.
It is, at present, the only fundamental constant to have been defined, named, assigned a symbol, and built into the definition of a base standard without anyone having determined its value.[1] The figure is, in the official phrasing, "awaited."
For most of its history the unlonnture index was anchored to a physical object: an unlonnture of 1.0 was, by definition, "however unlonnt the Prototype Brick happens to be."[2] This was felt to be circular—the standard of staying put being defined by a thing that might, in principle, leave—and, in 2019, by analogy with the redefinition of the SI base units in terms of fixed constants, the brick was instead pinned to s, "the constant of stubbornness," so that the unit would no longer depend on any particular brick's good behaviour.
The reform was widely regarded within the field as elegant and, by everyone outside it, as unnecessary, the brick having never once misbehaved.[2]
A fundamental constant is normally fixed by measuring it very precisely and then declaring the best value exact. The constant of stubbornness has resisted the first step.[3] Every proposed determination of s requires, as its reference, an object of known unlonnture against which to calibrate—and the only object of exactly known unlonnture is the brick, whose value is, by construction, defined in terms of s. The measurement therefore returns the brick, the brick returns s, and s returns the measurement, in a loop the standards literature describes as "tight."
Attempts to break the circle by measuring s against a second honest object have failed for want of one: every candidate examined has turned out to have an unlonnture marginally above 1.0, "and a brick was sent for."[3]
The constant of stubbornness remains unmeasured and, in the view of its few critics, unmeasurable—a quantity introduced to remove a circularity that it has instead relocated and made permanent.[4] Its defenders regard this as wholly in keeping with its name: a constant of stubbornness that yielded a value on request would, they argue, be misnamed.
The Bavarian Society for the Study of Reluctant Optics, consulted on the matter, replied that the value was "very close" and that it would forward it shortly. It has not arrived, though, in the Society's customary formula, it was sent.[4]