{"id":6321,"date":"2020-10-15T16:02:13","date_gmt":"2020-10-15T16:02:13","guid":{"rendered":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/?post_type=chapter&#038;p=6321"},"modified":"2021-06-25T20:10:32","modified_gmt":"2021-06-25T20:10:32","slug":"discussion-essential-ideas","status":"publish","type":"chapter","link":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/chapter\/discussion-essential-ideas\/","title":{"raw":"Discussion: Defining a Unit of Measurement","rendered":"Discussion: Defining a Unit of Measurement"},"content":{"raw":"This discussion can be found in Google Docs:\u00a0<a href=\"https:\/\/docs.google.com\/document\/d\/1VYpV10NyBkbH852XIME6nEZtXdp0Y6ywQVB5o1oEhak\/edit#heading=h.tgecqyrjfgf7\" target=\"_blank\" rel=\"noopener\">Chemistry for Majors Discussion: Defining a Unit of Measurement<\/a>\r\n\r\nTo make your own copy to edit:\r\n<ul>\r\n \t<li><strong>If you want a Google Doc<\/strong>: in the file menu of the open document, click \u201cMake a copy.\u201d This will give you your own Google Doc to work from.<\/li>\r\n \t<li><strong>If you want a PDF or Word file<\/strong>: in the file menu of the open document, click \u201cDownload\u201d and select the file type you would like to have (note: depending on the file type you select, the formatting could get jumbled).<\/li>\r\n<\/ul>\r\n&nbsp;\r\n\r\nWhen you consider a unit of measurement \u2013 like a mile \u2013 you likely think of it as static, unchangeable, the same across the world to everyone. Isn't that the point of those units, anyway?\r\n\r\nHowever, one unit a measurement \u2013 the kilogram \u2013 was recently redefined.\r\n\r\nIn 1795, the kilogram was originally defined as the mass of one liter of water. Though simple to understand, it can have accuracy issues.\r\n\r\nIn 1889, a cylinder of platinum-iridium became the standard of the unit of mass for the metric system. This cylinder is a one-of-a-kind man-made item.\r\n\r\n[caption id=\"\" align=\"aligncenter\" width=\"476\"]<img src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/a\/ac\/Prototype_kilogram_replica.JPG\" alt=\"A silver colored short cylinder is encased in two glass cloches and secured to a lighted based with strong looking metal clamps.\" width=\"476\" height=\"357\" \/> A replica of the International Prototype of the Kilogram on display at Cit\u00e9 des Sciences et de l'Industrie, featuring the protective double glass bell. The IPK served as primary standard for the kilogram until 2019.[\/caption]\r\n\r\n&nbsp;\r\n\r\nIn May 2019, the definition of a kilogram was changed by the vote of a multi-national group of scientists. Read more about this decision in\u00a0<a href=\"https:\/\/www.nist.gov\/si-redefinition\/kilogram\" target=\"_blank\" rel=\"noopener\">this article by the National Institute of Standards and Technology<\/a>.\r\n\r\nThink about the following questions as you read:\u00a0Why do you think the definition was ultimately changed? What might be some problems with the physical standard of the old definition? What could be some issues that arise with the new definition? Feel free to do some additional research to better understand the sides of this debate.\r\n\r\nAfter reading the article, pick a side in the debate \u2013 are you for or against changing the definition of the kilogram? Write a brief argument with your reasoning and then respond to at least one classmate.","rendered":"<p>This discussion can be found in Google Docs:\u00a0<a href=\"https:\/\/docs.google.com\/document\/d\/1VYpV10NyBkbH852XIME6nEZtXdp0Y6ywQVB5o1oEhak\/edit#heading=h.tgecqyrjfgf7\" target=\"_blank\" rel=\"noopener\">Chemistry for Majors Discussion: Defining a Unit of Measurement<\/a><\/p>\n<p>To make your own copy to edit:<\/p>\n<ul>\n<li><strong>If you want a Google Doc<\/strong>: in the file menu of the open document, click \u201cMake a copy.\u201d This will give you your own Google Doc to work from.<\/li>\n<li><strong>If you want a PDF or Word file<\/strong>: in the file menu of the open document, click \u201cDownload\u201d and select the file type you would like to have (note: depending on the file type you select, the formatting could get jumbled).<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<p>When you consider a unit of measurement \u2013 like a mile \u2013 you likely think of it as static, unchangeable, the same across the world to everyone. Isn&#8217;t that the point of those units, anyway?<\/p>\n<p>However, one unit a measurement \u2013 the kilogram \u2013 was recently redefined.<\/p>\n<p>In 1795, the kilogram was originally defined as the mass of one liter of water. Though simple to understand, it can have accuracy issues.<\/p>\n<p>In 1889, a cylinder of platinum-iridium became the standard of the unit of mass for the metric system. This cylinder is a one-of-a-kind man-made item.<\/p>\n<div style=\"width: 486px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/a\/ac\/Prototype_kilogram_replica.JPG\" alt=\"A silver colored short cylinder is encased in two glass cloches and secured to a lighted based with strong looking metal clamps.\" width=\"476\" height=\"357\" \/><\/p>\n<p class=\"wp-caption-text\">A replica of the International Prototype of the Kilogram on display at Cit\u00e9 des Sciences et de l&#8217;Industrie, featuring the protective double glass bell. The IPK served as primary standard for the kilogram until 2019.<\/p>\n<\/div>\n<p>&nbsp;<\/p>\n<p>In May 2019, the definition of a kilogram was changed by the vote of a multi-national group of scientists. Read more about this decision in\u00a0<a href=\"https:\/\/www.nist.gov\/si-redefinition\/kilogram\" target=\"_blank\" rel=\"noopener\">this article by the National Institute of Standards and Technology<\/a>.<\/p>\n<p>Think about the following questions as you read:\u00a0Why do you think the definition was ultimately changed? What might be some problems with the physical standard of the old definition? What could be some issues that arise with the new definition? Feel free to do some additional research to better understand the sides of this debate.<\/p>\n<p>After reading the article, pick a side in the debate \u2013 are you for or against changing the definition of the kilogram? Write a brief argument with your reasoning and then respond to at least one classmate.<\/p>\n\n\t\t\t <section class=\"citations-section\" role=\"contentinfo\">\n\t\t\t <h3>Candela Citations<\/h3>\n\t\t\t\t\t <div>\n\t\t\t\t\t\t <div id=\"citation-list-6321\">\n\t\t\t\t\t\t\t <div class=\"licensing\"><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Original<\/div><ul class=\"citation-list\"><li>Discussion: Defining a Unit of Measurement. <strong>Provided by<\/strong>: Lumen Learning. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by\/4.0\/\">CC BY: Attribution<\/a><\/em><\/li><\/ul><div class=\"license-attribution-dropdown-subheading\">CC licensed content, Shared previously<\/div><ul class=\"citation-list\"><li>kilogram. <strong>Authored by<\/strong>: Japs 88. <strong>Located at<\/strong>: <a target=\"_blank\" href=\"https:\/\/commons.wikimedia.org\/w\/index.php?curid=19652787\">https:\/\/commons.wikimedia.org\/w\/index.php?curid=19652787<\/a>. <strong>License<\/strong>: <em><a target=\"_blank\" rel=\"license\" href=\"https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/\">CC BY-SA: Attribution-ShareAlike<\/a><\/em><\/li><\/ul><\/div>\n\t\t\t\t\t\t <\/div>\n\t\t\t\t\t <\/div>\n\t\t\t <\/section>","protected":false},"author":17533,"menu_order":11,"template":"","meta":{"_candela_citation":"[{\"type\":\"cc\",\"description\":\"kilogram\",\"author\":\"Japs 88\",\"organization\":\"\",\"url\":\"https:\/\/commons.wikimedia.org\/w\/index.php?curid=19652787\",\"project\":\"\",\"license\":\"cc-by-sa\",\"license_terms\":\"\"},{\"type\":\"original\",\"description\":\"Discussion: Defining a Unit of Measurement\",\"author\":\"\",\"organization\":\"Lumen Learning\",\"url\":\"\",\"project\":\"\",\"license\":\"cc-by\",\"license_terms\":\"\"}]","CANDELA_OUTCOMES_GUID":"","pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-6321","chapter","type-chapter","status-publish","hentry"],"part":3042,"_links":{"self":[{"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/chapters\/6321","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/wp\/v2\/users\/17533"}],"version-history":[{"count":9,"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/chapters\/6321\/revisions"}],"predecessor-version":[{"id":8162,"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/chapters\/6321\/revisions\/8162"}],"part":[{"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/parts\/3042"}],"metadata":[{"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/chapters\/6321\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/wp\/v2\/media?parent=6321"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/pressbooks\/v2\/chapter-type?post=6321"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/wp\/v2\/contributor?post=6321"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/courses.lumenlearning.com\/chemistryformajors\/wp-json\/wp\/v2\/license?post=6321"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}