Two Snowflakes May Be Alike After All

An anonymous reader writes "LiveScience is reporting that it may be possible for two snowflakes to be alike after all. For anyone who studies probability, this seems reasonable, given that the article mentions that 10^24 snowflakes fall in any given year. The article contains links to fascinating snowflake pictures. From the article: 'A typical snow crystal weighs roughly one millionth of a gram. This means a cubic foot of snow can contain roughly one billion crystals ... "It is probably safe to say that the possible number of snow crystal shapes exceeds the estimated number of atoms in the known universe," Nelson said. Still, while "no two snowflakes are alike" might hold true for larger snowflakes, Nelson figures it might ring false for smaller crystals that sometimes fall before they have a chance to fully develop. "How likely is it that two snowflakes are alike? Very likely if we define alike to mean that we would have trouble distinguishing them under a microscope and if we include the crystals that hardly develop beyond the prism stage--that is, the smallest snow crystals," Nelson said.'"

Comments

Nancy Knight, 1988

[Anonymous Coward]

Nancy Knight, 1988

"The old saw that no two snow crystals are identical was disproved in 1988, when National Center for Atmospheric Research scientist Nancy Knight found two that apparently were. The twin crystals were found by accident when Knight was examining samples collected at 6 kilometers (20,000 feet) over Wisconsin for a cloud-climatology study. Thick, hollow, and columnar, the crystals seem to have been Siamese twins that grew attached to each other. No satisfying explanation has yet been found." -

http://www.proquestk12.com/curr/snow/snow395/snow3 95.htm

Re:Years ago...

[Whiney Mac Fanboy]

as you'd expect, if two flakes of snow form under virtually identical conditions you end up with two virtually identical flakes.

From snowflake chemistry

Is it true that no two snowflakes are identical?

Yes and no. No two snowflakes are exactly identical, down to the precise number of water molecules, spin of electrons, isotope abundance of hydrogen and oxygen, etc. On the other hand, it is possible for two snowflakes to look exactly alike and any given snowflake probably has had a good match at some point in history. Since so many factors affect the structure of a snowflake and since a snowflake's structure is constantly changing in response to environmental conditions, it is improbable that anyone would see two identical snowflakes.