# Are there any systems where charts start positive on the left and decrease to the right?

**URL:** <https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184>\
**Category:** Factual Questions\
**Created:** [June 5, 2013, 5:05am UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184 "2013-06-05T05:05:52Z")\
**Posts on this page:** 2\
**Page:** 2

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**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\
**Post date:** [June 9, 2013, 2:33pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/21 "2013-06-09T14:33:52Z")

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For reasons that have never been satisfactorily explained to me, the **Glass Map** (AKA an **Abbe Diagram** ) has the Abbe number of the glass (the V-number, or dispersion index, a measure of how much the index of refraction changes over the visible range) running from larger to smaller numbers along the x-axis, while the indices of refraction increase from bottom to top along the y-axis in the usual fashion. I suspect people just like the way the chart looks with the x-axis reversed. Schott isn’t the only company that does this; every glass manufacturer has aGlass Map that looks like this:

[http://www.us.schott.com/advanced\_optics/english/community/technical-papers-and-tools/abbe-diagramm.html#](http://www.us.schott.com/advanced_optics/english/community/technical-papers-and-tools/abbe-diagramm.html#)

[http://images.search.yahoo.com/images/view;\_ylt=A0PDoTG6kbRRRRQAOFCJzbkF;\_ylu=X3oDMTBlMTQ4cGxyBHNlYwNzcgRzbGsDaW1n?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3F\_adv\_prop%3Dimage%26va%3DSchott%2BGlass%2Bchart%26fr%3Dyfp-t-798%26tab%3Dorganic%26ri%3D2&w=861&h=625&imgurl=www.osdoptics.com%2Fp12.gif&rurl=http%3A%2F%2Fwww.osdoptics.com%2Fblurb.htm&size=103.3KB&name=Glassmap+example&p=Schott+Glass+chart&oid=5eed381cb1990689333a39a459ff0ccb&fr2=&fr=yfp-t-798&tt=Glassmap+example&b=0&ni=84&no=2&ts=&tab=organic&sigr=112f0t7gm&sigb=13gnfeces&sigi=10p90dvh2&.crumb=Sg9tSctXX4o&fr=yfp-t-798](http://images.search.yahoo.com/images/view;_ylt=A0PDoTG6kbRRRRQAOFCJzbkF;_ylu=X3oDMTBlMTQ4cGxyBHNlYwNzcgRzbGsDaW1n?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3F_adv_prop%3Dimage%26va%3DSchott%2BGlass%2Bchart%26fr%3Dyfp-t-798%26tab%3Dorganic%26ri%3D2&w=861&h=625&imgurl=www.osdoptics.com%2Fp12.gif&rurl=http%3A%2F%2Fwww.osdoptics.com%2Fblurb.htm&size=103.3KB&name=Glassmap+example&p=Schott+Glass+chart&oid=5eed381cb1990689333a39a459ff0ccb&fr2=&fr=yfp-t-798&tt=Glassmap+example&b=0&ni=84&no=2&ts=&tab=organic&sigr=112f0t7gm&sigb=13gnfeces&sigi=10p90dvh2&.crumb=Sg9tSctXX4o&fr=yfp-t-798)

> <https://images.search.yahoo.com/images/view?back=http%3A%2F%2Fimages.search.yahoo.com%2Fsearch%2Fimages%3F_adv_prop%3Dimage%26va%3DAbbe%2BDiagram%26fr%3Dyfp-t-798%26tab%3Dorganic%26ri%3D11&w=306&h=240&imgurl=upload.wikimedia.org%2Fwikipedia%2Fcommons%2Fthumb%2F5%2F52%2FAbbe-diagram-fr.svg%2F306px-Abbe-diagram-fr.svg.png&rurl=http%3A%2F%2Ffr.wikipedia.org%2Fwiki%2FFichier%3AAbbe-diagram-fr.svg&size=37.9KB&name=Fichier%3A%3Cb%3EAbbe%3C%2Fb%3E-%3Cb%3Ediagram%3C%2Fb%3E-fr.svg%2B-%2BWikip%C3%A9dia&p=Abbe%2BDiagram&oid=6f458e70383dce16b47307d9184ece41&fr2=&fr=yfp-t-798&tt=Fichier%3A%3Cb%3EAbbe%3C%2Fb%3E-%3Cb%3Ediagram%3C%2Fb%3E-fr.svg%2B-%2BWikip%C3%A9dia&b=0&ni=48&no=11&ts=&tab=organic&sigr=11o1i86c1&sigb=13bb0dfkn&sigi=133pbeqvm&.crumb=Sg9tSctXX4o&fr=yfp-t-798>

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**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\
**Post date:** [June 9, 2013, 5:25pm UTC](https://boards.straightdope.com/t/are-there-any-systems-where-charts-start-positive-on-the-left-and-decrease-to-the-right/660184/22 "2013-06-09T17:25:13Z")

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You could in principle get some sort of manifestation of the photon field with a structure size larger than the observable Universe, but that manifestation, whatever it was, wouldn’t be a wave.

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