Wikispaces>PiotrGrochowski |
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| <h2>IMPORTED REVISION FROM WIKISPACES</h2>
| | {{Interwiki |
| This is an imported revision from Wikispaces. The revision metadata is included below for reference:<br>
| | | de = 250/243 |
| : This revision was by author [[User:PiotrGrochowski|PiotrGrochowski]] and made on <tt>2016-09-17 04:46:08 UTC</tt>.<br>
| | | en = 250/243 |
| : The original revision id was <tt>592460018</tt>.<br>
| | | es = |
| : The revision comment was: <tt></tt><br>
| | | ja = |
| The revision contents are below, presented both in the original Wikispaces Wikitext format, and in HTML exactly as Wikispaces rendered it.<br>
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| <h4>Original Wikitext content:</h4> | | {{Infobox Interval |
| <div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;white-space: pre-wrap ! important" class="old-revision-html">**250/243**, known as the **porcupine [[comma]]** or maximal diesis, is an interval of size 49.166 [[Cent|cents]]. It is the amount by which two [[10_9|minor whole tones]] exceed a minor third, that is, (10/9)^2/(6/5). Tempering it out leads to [[5-limit]] [[Porcupine family|porcupine temperament]].</pre></div>
| | | Name = porcupine comma, maximal diesis |
| <h4>Original HTML content:</h4>
| | | Color name = y<sup>3</sup>1, triyo 1sn,<br>y<sup>3</sup>M, triyoma |
| <div style="width:100%; max-height:400pt; overflow:auto; background-color:#f8f9fa; border: 1px solid #eaecf0; padding:0em"><pre style="margin:0px;border:none;background:none;word-wrap:break-word;width:200%;white-space: pre-wrap ! important" class="old-revision-html"><html><head><title>250_243</title></head><body><strong>250/243</strong>, known as the <strong>porcupine <a class="wiki_link" href="/comma">comma</a></strong> or maximal diesis, is an interval of size 49.166 <a class="wiki_link" href="/Cent">cents</a>. It is the amount by which two <a class="wiki_link" href="/10_9">minor whole tones</a> exceed a minor third, that is, (10/9)^2/(6/5). Tempering it out leads to <a class="wiki_link" href="/5-limit">5-limit</a> <a class="wiki_link" href="/Porcupine%20family">porcupine temperament</a>.</body></html></pre></div>
| | | Comma = yes |
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| | '''250/243''' is known as the '''porcupine comma''' or the '''maximal diesis'''. Measuring about 49{{cent}}, it is a [[medium comma]]. It is the amount by which two [[10/9|minor whole tones]] exceed a minor third, that is, (10/9)<sup>2</sup>/(6/5). It is also the difference between [[25/24]] and [[81/80]], the two smallest [[5-limit]] [[superparticular]] ratios, and between three syntonic commas and the [[2187/2048|Pythagorean apotome]], putting it on the [[Syntonic–chromatic equivalence continuum]]. |
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| | == Temperaments == |
| | Tempering it out leads to the [[5-limit]] [[porcupine]] temperament. See [[porcupine family]] for the family of rank-2 temperaments where it is tempered out. |
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| | == Approximation == |
| | 250/243 is very close to one step of [[24edo]], which is the quarter tone that is exactly the half of [[12edo]] semitone. Therefore, if 250/243 is not tempered and instead is treated as an identity where it is equated with 1/24th of the octave, it serves as the period in the [[chromium]] temperament. (However, note that 24edo itself maps 250/243 inconsistently, and so chromium temperament starts at [[72edo]].) Thus in the framework of this temperament and the tuning systems associated with it, [[Eliora]] proposes the name ''chromium quartertone''. |
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| | [[Category:Porcupine]] |
| | [[Category:Commas named after compositions]] |