Stony Brook has been hit with a tremendous amount of snow so far this winter. Whether you celebrate the snow days or curse the driving conditions and dirtying piles of snow, snow itself has a very interesting life story.
Picture a snowflake. Chances are, you are imagining a beautiful, symmetrical, six-pointed branched crystal—not surprising as that has become the image of winter, its likeness plastered on every holiday card, wrapping paper and ugly Christmas sweater.
That image, however, is a lie. At least, partially.
When water freezes into ice in the atmosphere, it forms sleet. But when water vapor skips the liquid state and goes directly from gas to ice, snow crystals form. Ice forms crystals in a very specific way, with the oxygen and hydrogen atoms of separate water molecules attracting each other and creating a six-sided crystalline structure.
As water vapor begins to freeze, it often does so imprecisely and rather than forming in a perfectly symmetrical way, bumps begin to form. As water vapor travels through the air and freezing onto growing snow crystals, it takes the path of least resistance. The small bumps sticking out from the new snow crystal are physically closer to the traveling water vapor molecules. Once the water vapor comes into contact with the bumps, they freeze onto them, causing the bumps to grow larger. As this happens repeatedly, the branched arms of the snow crystal begin to develop and become more elaborate.
The lie behind those pictures of snowflakes, the ones every child attempts to mimic by cutting pieces out of folded sheets of paper, is in their perfection. The perfect, symmetrical snowflake is exceedingly rare and more often than not, snow crystals are lopsided, underdeveloped, bulky and irregular.
One man is responsible for the perpetuated perfect snowflake lie—Wilson Bentley.
As a farmer in Vermont with an interest in snow, he became the first person to photograph a snowflake in 1885. In 1925, Bentley stated, “under the microscope, I found that snowflakes were miracles of beauty; and it seemed a shame that this beauty should not be seen and appreciated by others.”
In his lifetime, Bentley photographed thousands of snowflakes. His pictures appeared in numerous magazines, books, museums and universities.
However, after Bentley created a name for himself as the premier snowflake photographer, a meteorologist named Gustav Hellmann began taking pictures as well and found that none of his images looked like the perfect ones being sold all over the world by Bentley.
Confronting Bentley’s ethics, Hellmann charged that Bentley’s images were produced through significant manipulations of the pictures and that Bentley was physically cutting out imperfections from the photograph negatives.
In response, Bentley argued that not only did he practice such manipulations, but that not doing so would be inaccurate. What ensued was essentially a debate on scientific ethics, with Hellmann arguing that altering the pictures led to misrepresentations of the snow crystals and Bentley arguing that untouched pictures misrepresented the crystals that in their truest form were nothing short of perfection. Should the pictures show snow crystals how they are or how they could be?
Though the debate never came to any definite conclusions, Bentley’s photographs are still the most recognized and printed images of snow crystals today.
Further, no matter what each individual snow crystal looks like, they all come to the same conclusion. With a lifespan often measured in minutes—they form, fall and melt—the vast majority will never be photographed or documented.
With the help of salt, snow and ice on campus are forced to melt even more quickly. This occurs because as the salt dissolves into the ice, the salt particles disrupt the distinct crystal structure formed by the water molecules. With the extra salt particles in the way, water molecules cannot bond they way they normally would, and in order to get them to do so, the temperature needs to be even colder.
The more salt, the harder it is for the ice to form.
However, because the salt is just disrupting the freezing process by being in the way, almost any particle would produce the same result. Sugar could do the same thing, but salt is chosen because it is inexpensive and plentiful.
Thus, whether the snowflakes that fall on Stony Brook’s campus are Bentley’s beauties or Hellmann’s humdrums, they all fall to a salty, watery end, but for just a few minutes, they are pretty spectacular.