The

hexagonal In geometry, a hexagon (from Greek , , meaning "six", and , , meaning "corner, angle") is a six-sided polygon. The total of the internal angles of any simple (non-self-intersecting) hexagon is 720°. Regular hexagon A regular hexagon is d ...

snowflake, a crystalline formation of

ice Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 ° C, 32 ° F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally oc ...

, has intrigued people throughout history. This is a

chronology Chronology (from Latin , from Ancient Greek , , ; and , ''wikt:-logia, -logia'') is the science of arranging events in their order of occurrence in time. Consider, for example, the use of a timeline or sequence of events. It is also "the deter ...

of interest and research into snowflakes. Artists, philosophers, and scientists have wondered at their shape, recorded them by hand or in photographs, and attempted to recreate hexagonal snowflakes. Wilson Alwyn Bentley (February 9, 1865 – December 23, 1931), also known as Snowflake Bentley, was an American meteorologist and photographer, who was the first known person to take detailed photographs of snowflakes and record their features. He perfected a process of catching flakes on black velvet in such a way that their images could be captured before they either melted or sublimated.

Chronological list

BC to 1900

* or - Han Ying ( 韓嬰) compiled the anthology '' Han shi waizhuan'', which includes a passage that contrasts the pentagonal symmetry of flowers with the hexagonal symmetry of snow. This is discussed further in the '' Imperial Readings of the Taiping Era''. * 1250 - Albertus Magnus offers what is believed to be the oldest detailed description of snow. * 1555 - Olaus Magnus publishes the earliest snowflake diagrams in '' Historia de gentibus septentrionalibus''. * 1611 -

Johannes Kepler Johannes Kepler (27 December 1571 – 15 November 1630) was a German astronomer, mathematician, astrologer, Natural philosophy, natural philosopher and writer on music. He is a key figure in the 17th-century Scientific Revolution, best know ...

, in ''Strenaseu De Nive Sexangula'', attempts to explain why snow crystals are hexagonal. * 1637 -

René Descartes René Descartes ( , ; ; 31 March 1596 – 11 February 1650) was a French philosopher, scientist, and mathematician, widely considered a seminal figure in the emergence of modern philosophy and Modern science, science. Mathematics was paramou ...

' '' Discourse on the Method'' includes hexagonal diagrams and a study for the crystallization process and conditions for snowflakes. * 1660 - Erasmus Bartholinus, in his ''De figura nivis dissertatio'', includes sketches of snow crystals. * 1665 - Robert Hooke observes snow crystals under magnification in '' Micrographia''. * 1675 - Friedrich Martens, a German physician, catalogues 24 types of snow crystal. * 1681 - Donato Rossetti categorizes snow crystals in ''La figura della neve''. * 1778 - Dutch

theologian Theology is the study of religious belief from a religious perspective, with a focus on the nature of divinity. It is taught as an academic discipline, typically in universities and seminaries. It occupies itself with the unique content of ...

Johannes Florentius Martinet diagrams precise sketches of snow crystals. * 1796 - Shiba Kōkan publishes sketches of ice crystals under a

microscope A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic ...

. * 1820 - William Scoresby's ''An account of the Arteic Regions'' includes snow crystals by type. * 1832 - Doi Toshitsura describes and diagrams 86 types of snowflake ( 雪華図説). * 1837 - publishes '' Hokuetsu Seppu''. * 1840 - Doi Toshitsura expands his categories to include 97 types. * 1855 - James Glaisher publishes detailed sketches of snow crystals under a microscope. * 1865 - Frances E. Chickering publishes ''Cloud Crystals - a Snow-Flake Album''. * 1870 - Adolf Erik Nordenskiöld identifies " cryoconite holes." * 1872 - John Tyndall publishes ''The Forms of Water in Clouds and Rivers, Ice and Glaciers''. * 1891 - Friedrich Umlauft publishes ''Das Luftmeer''. * 1893 - Richard Neuhauss photographs a snowflake under a microscope, titled ''Schneekrystalle''. * 1894 - A. A. Sigson photographs snowflakes under a microscope.

1901 to 2000

* 1901 - Wilson Bentley publishes a series of photographs of individual snowflakes in the '' Monthly Weather Review''. * 1903 -

Svante Arrhenius Svante August Arrhenius ( , ; 19 February 1859 – 2 October 1927) was a Swedish scientist. Originally a physicist, but often referred to as a chemist, Arrhenius was one of the founders of the science of physical chemistry. In 1903, he received ...

describes crystallization process in ''Lehrbuch der Kosmischen Physik''. * 1904 - Helge von Koch discover the fractal curves to be a mathematical description of snowflakes. * 1931 - Wilson Bentley and William Jackson Humphreys publish ''Snow Crystals'' * 1936 - Ukichiro Nakaya creates snow crystals and charts the relationship between temperature and

water vapor Water vapor, water vapour, or aqueous vapor is the gaseous phase of Properties of water, water. It is one Phase (matter), state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from th ...

saturation, later called the ''Nakaya Diagram''. * 1938 - Ukichiro Nakaya publishes * 1949 - Ukichiro Nakaya publishes * 1952 - Marcel R. de Quervain '' et al.'' define ten major types of snow crystals, including

hail Hail is a form of solid Precipitation (meteorology), precipitation. It is distinct from ice pellets (American English "sleet"), though the two are often confused. It consists of balls or irregular lumps of ice, each of which is called a hailsto ...

and graupel in IUGG for the Swiss Federal Institute for Snow and Avalanche Research. * 1954 - Harvard University Press publishes Ukichiro Nakaya's ''Snow Crystals: Natural and Artificial''. * 1960 - , verifies and improves the ''Nakaya Diagram'' with the ''Kobayashi Diagram''. * 1962 - describes meteorological sorting of snow crystal types in clouds. *1979 - and Rolf Lacmann, of the Braunschweig University of Technology, publish ''Growth Mechanism of Ice from Vapour Phase and its Growth Forms''. * 1983 August - Astronauts make snow crystals in

orbit In celestial mechanics, an orbit (also known as orbital revolution) is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an ...

on the Space Shuttle ''Challenger'' during mission STS-8. * 1988 - et al. make artificial snow crystals in an

updraft In meteorology, an updraft (British English: ''up-draught'') is a small-scale air current, current of rising air, often within a cloud. Overview Vertical drafts, known as updrafts or downdrafts, are localized regions of warm or cool air that mov ...

, confirming the ''Nakaya Diagram''.

2001 and after

* 2002 - devises a simple snow crystal growth observatory apparatus using a PET bottle cooled by

dry ice Dry ice is the solid form of carbon dioxide. It is commonly used for temporary refrigeration as CO2 does not have a liquid state at normal atmospheric pressure and Sublimation (phase transition), sublimes directly from the solid state to the gas ...

in an expanded

polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It i ...

box. * 2004 September - invented the apparatus named lit. ''Murai-method Artificial Snow Crystal producer'' (Murai式人工雪結晶生成装置) which makes various shape of artificial snow crystals per pre-setting conditions meeting to ''Nakaya diagram'' by vapor generator and its cooling Peltier effect element. * 2008 December - demonstrates conditional snow crystal growth in

space Space is a three-dimensional continuum containing positions and directions. In classical physics, physical space is often conceived in three linear dimensions. Modern physicists usually consider it, with time, to be part of a boundless ...

, in ''Solution Crystallization Observation Facility (SCOF)'' on the JEM (Kibō), remotely controlled from Tsukuba Space Center of JAXA.Approximately 100 times of experiments till March 2009, outcome would be good hint for ultra-pure silicon crystallizing,

Yomiuri Shimbun The is a Japanese newspaper published in Tokyo, Osaka, Fukuoka, Fukuoka, Fukuoka, and other major Japanese cities. It is one of the five major newspapers in Japan; the other four are ''The Asahi Shimbun'', the ''Chunichi Shimbun'', the ''Ma ...

2 Dec. 2008 Evening edition page 14

Notes and references

Sources cited

* * * *

External links

The history of the science of snowflakes
(3 times fast replay) (in Japanese)
SnowCrystals.com
{{DEFAULTSORT:Timeline of snowflake research Snow Science experiments Snowflake Research