Stearnsma
| Interval information |
latribiru comma
The stearnsma (monzo: [1 10 0 -6⟩, ratio: 118098/117649) is a small 2.3.7-subgroup comma with a width of about 6.6 cents. It is the amount by which an octave-reduced stack of six 9/7's exceeds 9/8. It is also the amount by which 343/243, equal to a stack consisting of a 7/6 and two 14/9's, falls short of its octave complement.
It is similar in size to the gamelisma, another comma in the same subgroup. Their difference is the septimal ennealimma.
It factors into (540/539)⋅(24057/24010) or (540/539)2⋅(9801/9800) in the 11-limit, which, if we take away another instance of 540/539 from the other ratio, gives rise to the identity (540/539)3/(4000/3993).
Temperaments
Tempering out this comma alone in the 7-limit leads to the rank-3 stearnsmic temperament, which splits the octave into 2 equal parts.
See Stearnsmic clan for the clan of rank-2 temperaments that temper this comma out.
Etymology
The stearnsma is likely named after Daniel Anthony Stearns.