Merry Christmas! As my gift to you, a collection of snowflakes taken via electron microscope.
Ah, nothing like some snowflake science to get us into the Christmas mood.
Snowflakes grow different crystal patterns based on air temperature, and pollution. Wait, you ask, how is this related to art? Well, looking at these snow crystal patterns always makes me feel better that my paper snowflakes don’t look more “normal.”
Plus, I just think snowflakes are pretty. The fact that nature creates such beautiful structures just as a matter of physics is pretty awesome!
Wired Science has details on the oddly shaped snowflakes:
Flurries of questions about mysterious triangle-shaped snowflakes may soon subside, thanks to new research on snowflake formation. Most snowflakes are hexagons because of the arrangement of hydrogen bonds in the water molecule. But the new study, appearing online at arxiv.org (http://arxiv.org/abs/0911.4267) and in an upcoming issue of The Microscope, suggests that after hexagonal flakes, oddball triangular flakes are the most prevalent.
Study coauthors Kenneth Libbrecht and Hannah Arnold of Caltech in Pasadena propose an aeronautical reason for the triangular geometry. The results help solve the very old puzzle of how the unexpected flakes form, Libbrecht says.
Snowflake enthusiasts — such as Libbrecht, who photographs snowflakes — have spotted triangular snowflakes in the wild. The snowflake scientific literature, which goes back almost two centuries, is thick with such sightings, Libbrecht adds, but no one has explained why. “People have noticed them for hundreds of years.”
To address the mystery, the researchers created snowflakes in the laboratory and recorded the shapes. In conditions that simulate natural snowfall, the vast majority of flakes were the standard hexagons, but more of them were triangular than a statistical model had predicted, the team found. Some of these flakes still have six sides but an overall triangular shape, created by three short edges and three long ones. The abundance of triangle-shaped flakes suggests that they may be more common in nature than chance alone would allow.
Tiny impurities, such as dust particles, can cause one edge of the falling snowflake to tilt up as it falls, Libbrecht says. The snowflake sides that are pointed down grow faster as the wind blows by, leading to a stable triangular pattern. Once a triangle shape gets started, the snowflake remains triangular despite any later bumps as it falls, the researchers propose.
Yes, friends, winter is just not going away anytime soon, so I say let’s embrace it. Let’s talk about all things winter. To start off with: snow.
Although observed throughout cold places in history, Wilson A. “Snowflake” Bentley (1865-1931) was the first photographer of snow, and was the first to document that all his snowflakes were different. His photographs of the six-sided, geometrical wonders are still found in textbooks and posters all over the world. Now, thanks to Bentley’s work, and the advances of x-ray crystallography, physicists like Kenneth Libbrecht have a job, taking photos of and analyzing the math behind snowflakes. In his spare time Libbrecht also researches gravitational-wave signals from supernovae and black holes (or maybe it’s the other way around).
Discover Magazine recently printed pictures from Libbrecht’s new book titled (surprise!) Snowflakes. The book discusses the natural laws behind why snowflakes develop as they do. The book even has pictures of spool-shaped snowflakes. And yes, he backs the claim that no two snowflakes are alike. Sort of like humans: even identical twins are a slight bit different. You can see some of Libbrecht’s labratory-made snow crystals at his CalTech website.