Those of us living in the northern half of the country can be forgiven for being tired — at this stage of winter — of shoveling snow. I enjoy the brightness snow can bring to dark winter days, but I’m getting old enough that shoveling the walk in front of my house has very little appeal even though it’s good for me to do some honest work before I head into my desk job. I’ve now hired a man to plow my driveway and I feel fortunate to have that service — even though it means I pay a fee each time we have significant snow.
When I’m not grumbling about the labor or cost involved in shoveling and plowing, I remember there is something magical about falling snow. And, of course, there is considerable beauty in individual snowflakes.
Wilson Bentley of Vermont was the first person to photograph individual snowflakes using a microscope and camera. Bentley, who lived from 1865 to 1931, amassed a collection of some 5,000 snowflake images. His pictures introduced people to the beauty of many diverse snowflake forms. In 1925 Bentley wrote:
“Under the microscope, I found that snowflakes were miracles of beauty… Every crystal was a masterpiece of design and no one design was ever repeated. When a snowflake melted, that design was forever lost…without leaving any record behind.”
You have probably seen a few of Bentley’s pictures at some point or those of the many people who have followed in his footsteps by taking microphotographs of individual snowflakes.
According to the EarthSky Website, scientists in 1951 developed a classification system for the snowflake forms that Bentley had documented. The scheme placed snowflakes into 10 different classes based on their shapes. Some of the 10 are the ones you are familiar with — like the beautiful stellar crystals or flakes that look like needles or dendrites. Some are not so commonly published — like those that look like columns with little caps at their ends.
Recently I read on the EarthSky Website about work on snowflakes done by Kenneth Libbrecht, a physics faculty member at the California Institute of Technology. He has shown that the more intricate snowflake structures are formed when the humidity is higher.
Temperature also affects snowflake formation. At frigid temperatures, like those below 8 degrees Fahrenheit, snowflakes tend to form in simple shapes. Flakes that have the branching patterns we admire tend to form at higher temperatures.
To sum up what I’ve learned from Libbrecht, the more beautiful snowflakes form in relatively wet and warm conditions.
The beauty of snowflakes can slip from our minds when we have work to do like clearing a driveway of mounds of snow. But when I’m inside, sipping a nice cup of steaming coffee, I’m ready to contemplate Mother Nature’s beautiful handiwork as shown in intricate snowflake patterns — beauty that’s all the more exquisite because it is short-lived.
Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human, and Natural Resource Sciences at Washington State University.