The Physics Factbook™
Edited by Glenn Elert -- Written by his students
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|Longwell, Flint & Sanders. Physical Geology. New York: Wiley, 1969: 70.||"less than a millimeter in diameter"||0.1 cm|
|Blackadar, Alfred. Microsoft Encarta. Microsoft and Funk & Wagnall, 1994.||"up to 7 to 10 cm"||7–10 cm|
|Kirk, Ruth. Snow. New York: William Morrow, 1978: 20.||"as much as an inch, or even two or three inches"||3–8 cm|
|Nakaya, U. Encyclopedia Americana. New York: Encyclopedia Americana, 1966: 149.||"more than one inch in diameter are not rare"||3 cm|
|Ludlum, Dr. David M., Holle Ronald L. and Keen, Dr. Richard A. National Audubon Society Pocket Guide: Clouds and Storms. New York: Knopf, 1995: 150.||"as large as 2"to 3"(5-7.6 cm)"||5–8 cm|
Watching snowflakes slip out of the sky is like seeing a rare wonder that happens on only the most special of occasions. Observing each one fall slowly on to the palm of your hand or the tip of your nose, they seem perfectly alike. But on closer examination you would find that, except in the rarest occasion, every one is different, making it impossible for there to be one measurement for the diameter of a snowflake.
Contrary to the popular belief, snowflakes are not just frozen water. They are actually a cluster of snow crystals. Snow crystals are crystals of ice formed from water vapor condensing on small particles in the atmosphere at below freezing temperatures. When snow crystals fall to the earth they often stick together forming a snowflake. However, this means that two snow crystals could stick together or three thousand snow crystals could stick together and both would still be called a snowflake. Whether a snowflake is two snow crystals or three thousand depends on the conditions that the snow crystals fall through. The speed at which the crystals fall, the temperature, the humidity, the electrical conditions of the air -- all these things influence the final size of a snowflake. These conditions also influence their shape. A snowflake may form into a classical, six-sided shape under the right conditions but it also may become a column, a plate or a needle. Considering the possibilities of shapes and sizes that a snowflake can take, it is true to say that it is impossible for any two snowflakes to be exactly the same.
Because there is no uniform snowflake there can be no set diameter of a snowflake. Each book and encyclopedia consulted about the diameter of a snowflake gave a different diameter of what the number should be. Some books said that a snowflake can be as small as.001 M. Some stated that it is common for a snowflake to be.0254 M. Some said that a snowflake can be as big as.0762 M. Whatever the case, a snowflake as small as a grain of sand or as big as the palm of my hand is a white figure of perfection, a little miracle falling from the sky.
Brigid Irene Naughton -- 1996
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