6656/6655: Difference between revisions

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'''6656/6655''', the '''jacobin comma''', [https://en.xen.wiki/index.php?title=List_of_superparticular_intervals&diff=next&oldid=18864 apparently named] by [[Gene Ward Smith]] in 2014, is a [[13-limit]] (also 2.5.11.13 [[subgroup]]) [[superparticular]] interval of about 0.26{{cent}}. It is the difference between a stack of three [[11/8]] superfourths and one [[13/10]] [[naiadic]] plus an [[octave]]. In terms of commas, it is the difference between [[364/363]] and [[385/384]], between [[2080/2079]] and [[3025/3024]] as well as between [[4096/4095]] and [[10648/10647]]. In the 17-limit, it factors neatly into [[12376/12375]] × [[sparkisma|14400/14399]].  
'''6656/6655''', the '''jacobin comma''', [https://en.xen.wiki/index.php?title=List_of_superparticular_intervals&diff=next&oldid=18864 apparently named] by [[Gene Ward Smith]] in 2014, is a [[13-limit]] (also 2.5.11.13 [[subgroup]]) [[superparticular]] interval of about 0.26{{cent}}. It is the difference between a stack of three [[11/8]] superfourths and one [[13/10]] [[naiadic]] plus an [[octave]]. In terms of commas, it is the difference between [[364/363]] and [[385/384]], between [[2080/2079]] and [[3025/3024]] as well as between [[4096/4095]] and [[10648/10647]]. In the 17-limit, it factors neatly into ([[12376/12375]])([[14400/14399]]).  


== Temperaments ==
== Temperaments ==
By tempering it out, the '''jacobin temperament''' is defined. Perhaps most remarkably, '''[[1789edo]]''' is an edo that [[support]]s the jacobin temperament. You may find a list of good JI-approximating edos that support this temperament below. Although it is more rational to use such edos for this temperament, 1789edo has a unique position due to its number of steps being a hallmark year of the French Revolution.  
By tempering it out, the '''jacobin temperament''' is defined. Interestingly, [[1789edo]] is an edo that [[support]]s the jacobin temperament. You may find a list of good JI-approximating edos that support this temperament below. Although 1789edo has a unique position due to its number of steps being a hallmark year of the French Revolution, it is more rational to use the other edos for this temperament.  


The 17-limit factorization shows us a natural path of extension, also given below.
=== Jacobin ===
[[Subgroup]]: 2.3.5.7.11.13
[[Subgroup]]: 2.3.5.7.11.13
[[Comma list]]: 6656/6655


[[Mapping]]: <br>
[[Mapping]]: <br>
Line 20: Line 25:
: mapping generators: ~2, ~3, ~5, ~7, ~11
: mapping generators: ~2, ~3, ~5, ~7, ~11


{{Optimal ET sequence|legend=1| 9, 15, 22, 26, 31f, 37, 39df, 41, 46, 63, 72, 87, 111, 152f, 183, 198, 224, 270, 494, 764, 1012, 1084, 1236, 1506, 2814, 2901, 3125, 3395, 8026e, 8296e, 11421e, 11691e, 12927e, 13421e, 16322ee, 16816ee }}
{{Optimal ET sequence|legend=1| 15, 22, 26, 31f, 37, 39df, 41, 46, 63, 72, 87, 111, 152f, 183, 198, 224, 270, 494, 764, 1012, 1084, 1236, 1506, 2814, 2901, 3125, 3395, 8026e, 8296e, 11421e, 11691e, 12927e, 13421e, 16322ee, 16816ee }}
 
==== Septendecimal jacobin ====
Subgroup: 2.3.5.7.11.13.17
 
Comma list: 6656/6655, 12376/12375
 
Mapping: <br>
[{{val| 1 0 0 0 0 -9 6 }}, <br>
{{val| 0 1 0 0 0 0 2 }}, <br>
{{val| 0 0 1 0 0 1 2 }}, <br>
{{val| 0 0 0 1 0 0 -1 }}, <br>
{{val| 0 0 0 0 1 3 -2 }}]
 
Optimal ET sequence: {{Optimal ET sequence| 15g, 22, 37g, 39dfg, 41g, 50, 63g, 72, 111, 152f, 159, 183, 239f, 248, 270, 311, 422, 494, 581, 742, 764, 814, 1075, 1236, 1395, 1506, 2000, 2581, 2814, 2901, 3323, 3395, 8296e, 11691e, 16322ee, 17086cdeeg, 21223cdeefg }}


== See also ==
== See also ==

Revision as of 10:22, 19 July 2023

Interval information
Ratio 6656/6655
Factorization 29 × 5-1 × 11-3 × 13
Monzo [9 0 -1 0 -3 1
Size in cents 0.2601208¢
Name jacobin comma
Color name Thotrilu-agu comma
FJS name [math]\displaystyle{ \text{m2}^{13}_{5,11,11,11} }[/math]
Special properties superparticular,
reduced
Tenney height (log2 nd) 25.4007
Weil height (log2 max(n, d)) 25.4009
Wilson height (sopfr(nd)) 69
Comma size unnoticeable
Open this interval in xen-calc

6656/6655, the jacobin comma, apparently named by Gene Ward Smith in 2014, is a 13-limit (also 2.5.11.13 subgroup) superparticular interval of about 0.26 ¢. It is the difference between a stack of three 11/8 superfourths and one 13/10 naiadic plus an octave. In terms of commas, it is the difference between 364/363 and 385/384, between 2080/2079 and 3025/3024 as well as between 4096/4095 and 10648/10647. In the 17-limit, it factors neatly into (12376/12375)(14400/14399).

Temperaments

By tempering it out, the jacobin temperament is defined. Interestingly, 1789edo is an edo that supports the jacobin temperament. You may find a list of good JI-approximating edos that support this temperament below. Although 1789edo has a unique position due to its number of steps being a hallmark year of the French Revolution, it is more rational to use the other edos for this temperament.

The 17-limit factorization shows us a natural path of extension, also given below.

Jacobin

Subgroup: 2.3.5.7.11.13

Comma list: 6656/6655

Mapping:
[1 0 0 0 0 -9],
0 1 0 0 0 0],
0 0 1 0 0 1],
0 0 0 1 0 0],
0 0 0 0 1 3]]

mapping generators: ~2, ~3, ~5, ~7, ~11

Optimal ET sequence15, 22, 26, 31f, 37, 39df, 41, 46, 63, 72, 87, 111, 152f, 183, 198, 224, 270, 494, 764, 1012, 1084, 1236, 1506, 2814, 2901, 3125, 3395, 8026e, 8296e, 11421e, 11691e, 12927e, 13421e, 16322ee, 16816ee

Septendecimal jacobin

Subgroup: 2.3.5.7.11.13.17

Comma list: 6656/6655, 12376/12375

Mapping:
[1 0 0 0 0 -9 6],
0 1 0 0 0 0 2],
0 0 1 0 0 1 2],
0 0 0 1 0 0 -1],
0 0 0 0 1 3 -2]]

Optimal ET sequence: 15g, 22, 37g, 39dfg, 41g, 50, 63g, 72, 111, 152f, 159, 183, 239f, 248, 270, 311, 422, 494, 581, 742, 764, 814, 1075, 1236, 1395, 1506, 2000, 2581, 2814, 2901, 3323, 3395, 8296e, 11691e, 16322ee, 17086cdeeg, 21223cdeefg

See also