Lifthrasirsma
The lifthrasirsma (monzo: [29 -11 -2 0 -2⟩, ratio: 536870912/535869675) is an unnoticeable 11-limit (also 2.3.5.11-subgroup) comma measuring about 3.23 cents. It marks the difference between the rastma and a stack of two schismas.
| Interval information |
reduced subharmonic
Temperaments
Tempering out this comma in the full 11-limit leads to the rank-4 lifthrasirsmic temperament, or in the 2.3.5.11 subgroup, the rank-3 lifthrasir temperament.
Lifthrasir can be extended to the 2.3.5.11.19 subgroup by tempering out 1216/1215. The second comma in the list, 131072/131043, has the effect of equating the undevicesimal schisma of 513/512 with the schisma. Lif is a notable weak extension of lifthrasir.
Lifthrasir
Subgroup: 2.3.5.11
Comma list: 536870912/535869675
Subgroup-val mapping: [⟨1 1 0 9], ⟨0 2 0 -11], ⟨0 0 1 -1]]
Optimal tunings:
- WE: ~2 = 1199.9228 ¢, ~16384/13365 = 351.0529 ¢, ~5/4 = 386.4968 ¢
- CWE: ~2 = 1200.0000 ¢, ~16384/13365 = 351.0805 ¢, ~5/4 = 386.4947 ¢
Optimal ET sequence: 17, 24, 41, 65, 205, 270, 335, 581, 605, 646, 916, 981, 2878e, 3859bcee
Badness (Sintel): 4.48
2.3.5.11.19 subgroup
Subgroup: 2.3.5.11.19
Comma list: 1216/1215, 131072/131043
Subgroup-val mapping: [⟨1 1 0 9 -1], ⟨0 2 0 -11 10], ⟨0 0 1 -1 1]]
Optimal tunings:
- WE: ~2 = 1199.9494 ¢, ~256/209 = 351.0800 ¢, ~5/4 = 386.4828 ¢
- CWE: ~2 = 1200.0000 ¢, ~256/209 = 351.0960 ¢, ~5/4 = 386.4831 ¢
Optimal ET sequence: 17, 24, 41, 65, 181, 205, 270, 581, 646, 851, 916, 1186, 2102
Badness (Sintel): 0.581
Etymology
This comma was named by Flora Canou in 2023 along with the corresponding temperaments, lif and lifthrasir, after the human survivors of Ragnarök in Norse mythology.