Revopentisma

From Xenharmonic Wiki
Jump to navigation Jump to search
Interval information
Factorization 247 × 34 × 7-19
Monzo [47 4 0 -19
Size in cents 0.1277805¢
Name revopentisma
Color name ssr19-8, sasa-neru negative octave
FJS name [math]\text{6d}{-8}_{7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7}[/math]
Special properties reduced
Tenney height (log2 nd) 106.68
Weil height (log2 max(n, d)) 106.68
Wilson height (sopfr(nd)) 239
Harmonic entropy
(Shannon, [math]\sqrt{nd}[/math])
~1.19837 bits
Comma size unnoticeable
open this interval in xen-calc

Revopentisma is a 7-limit (and also 2.3.7 subgroup) unnoticeable comma associated with very high accuracy temperaments.

Theory

Revopentisma is the comma shared by 31edo and 270edo in the 2.3.7 subgroup and is notable as supported by many mega-edos. The associated temperament is named revopent, and it's remarkable in its short generator chains for edos in the thousands, with 7/4 being just four generators down and 3/2 being just nineteen, with octave reduction. Tempering it out in the full 7-limit produces rank-3 revopentismic temperament, as well as the 2.3.7 rank-2 revopentic temperament. The rank-2 revopent temperament adds mapping for 5 where it is reached in 287 generators.

Etymology

Comma's name is derived from two edos in the temperament-merging, number 1848 being associated with a year with a large number of revolutions in Europe, and 3125 being equal to 5 to the power of 5, hence pent- meaning five.