Snow under the Microscope
For much of the Northeast US, the winter snow has arrived with a vengeance. Schools are closed. Kids are thrilled, but stir crazy and parents are praying for relief. There is only so much sledding you can do and who plays in snow without getting cold and wet? So why not take a closer look?
Snowflakes are not only magical in drifts, but also as individual crystals. With a little bit of patience and a low power microscope, you can successfully engage your kids in a worthwhile activity that will produce some spectacular images. Snowflakes start as water vapor that is supercooled below freezing. It is not frozen rain, which we know as sleet. Rather the water vapor freezes round a particle of dust and grows from there as additional water vapor attaches. The resulting crystals have an extraordinary range of shapes and sizes largely depending on the temperature and humidity outside. In addition, time and the distance additional water vapor has to travel to reach the crystal affects the level of complexity of an individual snowflake.
These four variables: temperature, humidity time and distance are responsible for the fact that every snow crystal is unique although the full science behind it is still a mystery. Interestingly though, snow crystals do fall into approximately 35 different categories that range from the most common, simple hexagonal prism to some extremely complex shapes. The dryer the air (low humidity), typically the simpler the shape. As they grow through a process known as branching, they become more complex
Now, it’s time to try your hand at viewing or photographing a snowflake and an individual snow crystal. You will need a low power microscope (with or without a microscope camera) or a handheld digital microscope. Leave it in the garage so it gets suitably cold although ensure that it is not exposed to any condensation. Similarly, leave a glass slide, small artist’s paint brush and a 3×1” piece of dark-colored, construction paper in the garage or outside where they are protected from the elements. In other words, you want them cold!
Now wrap up warm. First, look at an entire snowflake. Hold the construction paper out in the snow or carefully place a sample of snow on to the paper. Make sure that you keep the underside of the paper dry as you do not want to get your microscope wet. Now quickly place the paper under the microscope and focus it. View it at different magnifications and note the level of detail that you see.
Now take the paint brush and carefully, lift a single flake on to the glass slide Place it quickly, but carefully under the microscope and focus in on the individual crystal. Take a quick picture and try to note its shape and branching characteristics.
You can achieve good results with any low power microscope or digital microscope. You should also try different lighting. For example, use a different color filter for more definition or try a back light. For more sophisticated use, we recommend an OCS digital system that includes a microscope camera with a monocular zoom lens.
In any event, it is a rewarding project that will keep your kids happy outside – and that’s the main thing!