Sextillions of snowflakes fell from the sky this winter. There are billions of trillions, now largely melted away as spring approaches.
Few people took a closer look at them one by one.
Kenneth G. Libbrecht, a professor of physics at the California Institute of Technology, has spent a quarter of a century trying to understand how such a simple substance – water – can freeze into a multitude of forms.
“How do snowflakes form?” Dr. Libbrecht said during a Feb. 23 online lecture hosted by the Bruce Museum in Greenwich, Conn. “And what do these structures look like – and just, as I like to say, literally out of the blue?”
One of the people intrigued by Dr. Libbrecht’s snowflake research and photography was Nathan P. Myhrvold, a former Chief Technology Officer at Microsoft who has since conducted projects in numerous scientific disciplines, including paleontology, cooking and astronomy.
Dr. Myhrvold, an avid photographer, met Dr. Libbrecht for the first time more than ten years ago, and in the spring of 2018 he decided he wanted to take photos of the intricate frozen crystals himself. He recalled thinking, “Oh, we’re just throwing something together, and we’re ready for winter.”
However, as with many of his projects, things were not as simple as Dr. Myhrvold had planned.
“It turned out to be vastly more complicated than I thought,” said Dr. Myhrvold. “So it took 18 months to build that damn thing.”
The “damn thing” was the camera system for photographing snowflakes. He wanted to use the best digital sensors, capturing a million pixels. “The real snowflake is very, very fragile,” he said. ‘It’s super complicated. So you want a high resolution. “
But that kind of sensor is much larger in area than the images generally produced by microscope lenses, a result of decisions made by microscope manufacturers nearly a century ago.
That meant he had to find a way to stretch the microscope image to fill the sensor.
In his tinkering, “I came up with a custom optical path that will actually make it work,” he said.
Then there is the housing for the optics. It is usually made of metal, but metal expands when it is hot and shrinks when it is cold. Moving the device from the warm indoor space to an icy balcony where it would collect the snowflakes “would ruin the entire microscope,” said Dr. Myhrvold, making it impossible to keep everything sharp.
Instead of metal, he used carbon fiber, which does not expand or contract noticeably.
Dr. Myhrvold also found a special LED, manufactured by a company in Japan for industrial use, that would emit light bursts 1 / 1,000th as long as a typical camera flash. This minimizes the heat emitted by the flash, which can cause the snowflake to melt a little.
To view something under a microscope, a specimen is usually placed on a microscope slide. But glass retains heat. That also melts the snowflakes. So he switched from glass to sapphire, a material that cools down faster.
He was ready in February 2020. But where can you find the most beautiful snowflakes to photograph? At first he thought he could just go to a ski resort – maybe Aspen or Vail in Colorado or Whistler in British Columbia.
But these places were not cold enough.
“Powder snow that a skier likes to ski through is actually quite a lot of powder,” said Dr. Myhrvold. “There isn’t much beauty in those things.”
Indeed, the snowflakes that usually fall on most people are rarely what people think of as snowflake-shaped.
Water is a simple molecule made up of two hydrogen atoms and one oxygen. When the temperature drops below 32 degrees Fahrenheit, the molecules begin to stick together – that is, they freeze.
A snowflake is born in a cloud when a drop of water freezes into a small ice crystal. Due to the shape of the water molecules, they accumulate in a hexagonal pattern. Therefore, the archetypal snowflake has six arms.
Then the crystal grows, absorbs water vapor from the air and other nearby droplets evaporate to replenish the vapor. “It may take 100,000 water droplets that evaporate to make one snow crystal,” said Dr. Libbrecht.
But how the crystal grows depends on the temperature and the humidity. In the 1930s, a Japanese physicist named Ukichiro Nakaya was the first to grow artificial snowflakes in his laboratory, and by varying the conditions he was able to catalog which types are formed under the most conditions.
At temperatures just below freezing, the snowflakes are generally simple hexagonal plates. At about 20 degrees Fahrenheit, the predominant shape is hexagonal columns. It’s between 15 degrees and -5 degrees Fahrenheit that the archetypically beautiful snowflakes usually form.
At these temperatures, the tips of the hexagon grow into branches. The branches then spawn other branches and smaller hexagonal plates. Small variations in temperature and humidity affect the growth pattern and conditions are constantly changing as the snowflake falls to the ground.
“Because it has this complicated path through the clouds, it gives a complicated shape,” said Dr. Libbrecht. “They all follow different paths, so each one looks a little bit different depending on the path.”
So to find the beautiful snowflakes, Dr. Myhrvold to the north, much further to the north. He and a few assistants hauled about a thousand pounds of equipment to Fairbanks, Alaska; Yellowknife, the largest community in the Canadian Northwest Territories; and Timmins, Ontario, approximately 150 miles north of Lake Huron.
A month later, the coronavirus pandemic put the effort on hold. But Dr. Myhrvold was able to create what he calls the highest resolution images of snowflakes ever.
That claim has irritated others in the snowflake world, including Don Komarechka, a Canadian photographer who takes a decidedly lower technical approach. He uses a store-bought digital camera with a powerful macro lens. He doesn’t even use a tripod – he just holds the camera with the snowflakes on a black mitten that his grandmother gave him.
“Incredibly simplistic,” said Mr. Komarechka. “It’s so approachable to anyone with any camera.”
He said of Dr. Myhrvold: “I think it’s a bit overly designed.”
Mr. Komarechka also takes a different approach to illumination, using light reflected from a snowflake, while Dr. Myhrvold light that is going to catch through it. “You get to see the surface texture, and sometimes beautiful rainbow colors in the center of a snowflake,” said Mr Komarechka.
The rainbow effect is the same as what you see in soap wrap, but the colors are “often rendered much more solid than you’d see in a soap wrap or something else,” he said. “It’s almost psychedelic colors, almost looks like a tie-dye T-shirt.”
To the claims of Dr. To refute Myhrvold, Mr. Komarechka took a photo that he says had an even higher resolution. Dr. Myhrvold responded with an elaborate rebuttal explaining why his images were nonetheless more detailed.
In practice, the images of Dr. Myhrvold sharper when printed on large size paper. They are available in sizes up to 2 meters by 1.5 meters.
“In that very narrow sense, yes, that’s what Nathan is saying, and he’s not wrong,” said Dr. Komarechka.