{"id":6535,"date":"2011-12-29T14:23:08","date_gmt":"2011-12-29T18:23:08","guid":{"rendered":"https:\/\/esa.org\/esablog\/?p=6535"},"modified":"2011-12-29T14:23:08","modified_gmt":"2011-12-29T18:23:08","slug":"snowflakes-still-hold-mystery","status":"publish","type":"post","link":"https:\/\/esa.org\/esablog\/2011\/12\/29\/snowflakes-still-hold-mystery\/","title":{"rendered":"Snowflakes still hold mystery"},"content":{"rendered":"

This post contributed by Nadine Lymn, ESA Director of Public Affairs<\/em><\/p>\n

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Their silent, shimmery beauty has long stirred human aesthetic appreciation and for centuries individuals have sought to unravel the secrets of snowflakes.\u00a0 Why are there so many varieties?\u00a0 Why do all snowflakes have six \u201carms\u201d?\u00a0 And why does each flake appear unique, no matter how many fall from the sky?<\/p>\n

We know the answers to these questions as described on the National Oceanic and Atmospheric Administration\u2019s website<\/a>: temperature and humidity determine their shape, their six \u201carms\u201d are the result of the internal order of an ice crystal\u2019s water molecules, and, because each crystal encounters slightly different atmospheric conditions, each snowflake appears unique.<\/p>\n

But enough mystery about the particulars remains that some scientists continue to try to unravel it.\u00a0 One such scientist is Caltech physicist Kenneth Libbrecht, who is looking into the physics of exactly how water vapor molecules are incorporated into a growing ice crystal.\u00a0 He has also created a webpage, SnowCrystals.com<\/a> which is a true treasure-trove of information for anyone interested in snowflakes.\u00a0 It includes not only magnificent photographs taken by Libbrecht, such as the one below, but also showcases the science of snowflakes and the historical figures who sought to understand these ephemeral beauties.<\/p>\n

For example, as long ago as 1611, German mathematician Johannes Kepler, put together a \u201ctreatise\u201d for the king which he entitled, A New Year\u2019s Gift or On the Six-Cornered Snowflake. Libbrecht notes that this was the first scientific reference to snow crystals and that Kepler was especially intrigued by the six arms of snowflakes, speculating that it must have something to do with the morphology of the crystals.<\/p>\n

The website includes other individuals, such as \u201cSnowflake Man\u201d Wilson Bentley<\/a>, a self-educated Vermont farmer, who became so enraptured with snowflakes he saw under his microscope that he persuaded his parents to purchase a special bellows camera to try to capture them before they melted.\u00a0 After years of trial and error, Bentley became the first person to take a photomicrograph of an ice crystal and went on to capture 5,000 images of snowflakes.\u00a0 According to Duncan Blanchard, who wrote a biography about him, Bentley\u2019s first article appeared in Popular Scientific Monthly<\/em> in 1898 and included this vivid description of an ice crystal:<\/p>\n

\u201cA careful study of this internal structure not only reveals new and far greater elegance of form than the simple outlines exhibit, but by means of these wonderfully delicate and exquisite figures much may be learned of the history of each crystal, and the changes through which it has passed in its journey through cloudland.\u00a0 Was ever life history written in more dainty hieroglyphics!\u201d<\/p>\n

Part of professor Libbrecht\u2019s research at Caltech focuses on the remaining mystery of why snow crystals change so much with temperature.\u00a0 As seen in the morphology diagram below that Libbrecht has on his website, some generalities are known.\u00a0 For instance, thin plates and stars develop around -2 C (28 F) and columns and slender needle shapes form at around -5 C (23 F).\u00a0 And, drier conditions tend to result in simpler shapes while high humidity drives greater intricacy in crystals.<\/p>\n

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As Libbrecht and others continue to seek answers to the last mysteries of snowflakes, they simply hold \u00a0symmetrical beauty for many of us.\u00a0 Although we may not all be quite as enthusiastic as was \u201cSnowflake Man\u201d Bentley, as quoted in Blanchard\u2019s biography:<\/p>\n

\u201c\u2026from the very beginning, it was snowflakes that fascinated me most.\u00a0 The farm folks, up in the north country, dread the winter; but I was supremely happy, from the day of the first snowfall\u2014which usually came in November\u2014until the last one, which sometimes came as late as May.\u201d<\/p>\n

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Credits: Multiple snowflake image, NOAA; morphology diagram, Kepler treatise, Kenneth Libbrecht, SnowCrystals.com<\/p>\n

\u00a0<\/p>\n

\u00a0<\/p>\n

\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"

This post contributed by Nadine Lymn, ESA Director of Public Affairs Their silent, shimmery beauty has long stirred human aesthetic appreciation and for centuries individuals have sought to unravel the secrets of snowflakes.\u00a0 Why are there so many varieties?\u00a0 Why do all snowflakes have six \u201carms\u201d?\u00a0 And why does each flake appear unique, no matter how many fall from the…<\/p>\n","protected":false},"author":41,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[1072,1002,509,144,113,1146,1342,1343,299,22,1070],"class_list":["post-6535","post","type-post","status-publish","format-standard","hentry","category-research","tag-images","tag-microscope","tag-molecules","tag-morphology","tag-noaa","tag-snow","tag-snow-crystals","tag-snowflakes","tag-temperature","tag-water","tag-winter"],"_links":{"self":[{"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/posts\/6535","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/users\/41"}],"replies":[{"embeddable":true,"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/comments?post=6535"}],"version-history":[{"count":0,"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/posts\/6535\/revisions"}],"wp:attachment":[{"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/media?parent=6535"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/categories?post=6535"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/esa.org\/esablog\/wp-json\/wp\/v2\/tags?post=6535"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}