Ask Dr. Universe – Snow Globes

Dr. Universe: How do you make a snow globe? – Alexa, 10, Salem, MO

Dear Alexa,

If you have a long winter break ahead and are looking for a great way to spend the afternoon, you might just want to make your very own snow globe. There are a few different ways to build a snow globe, but the first thing you’ll need is the perfect container.

To make a small snow globe, you might use something like an empty baby food jar. Or maybe if you want to make a bigger snow globe, you could choose an empty spaghetti sauce jar.

An empty water bottle could also work well for a snow globe. This is a great project to do if you have a few old items you want to make into something new. Once you have your perfect container, you’ll want to fill it up with certain kinds of liquids.

My friend Lindsay Lightner, a Ph.D. student at Washington State University, teaches people how to become science teachers and knows lots of great science activities to try. Her students make lava lamps to learn about something called viscosity. A lava lamp actually isn’t too different from a snow globe when it comes to viscosity.

Viscosity is a property, or characteristic, of liquids. We often use the word viscosity to describe how fast or slow a liquid flows. If you stuck a spoon into a jar of peanut butter, it would probably stick to the spoon. It’s really thick and has a high viscosity—it behaves almost like a solid.

But if we heated some peanut butter in the microwave, it would move around much more freely and have a much thinner consistency. It now has a much lower viscosity. For your snow globe, you will want to figure out how viscous to make your liquid. You can try it out with an experiment.

You can fill up one jar with water. Then fill another jar with water and a teaspoon of something called glycerin. Glycerin is what we sometimes use to make bubbles and it can make water more viscous. It’s easy to find in many stores. You might even make a third jar with a tablespoon of glycerin. You can adjust the amount, as needed.

Finally, you can add your “snow.” There are all kinds of different things you can use for snow. You might make your snow out of aluminum foil. You can use a hole punch to create some tiny flakes that will reflect the light.

If you want to re-use a material, Lightner said you can also use eggshells to make your snow. You could wash out the eggshells and then crush them up with a rolling pin into snowflake-sized pieces. No matter what solid object you decide to use, you will want to make sure it doesn’t dissolve in liquid. Lightner adds that you could also add little toys, like old Lego people, to decorate the inside of your snow globe.

Finally, you’ll want to put the lids on your containers tightly and give them a shake. Which of your snow globes has snow that falls the slowest or fastest? Tell us about what you created sometime at Dr.Universe@wsu.edu.

Sincerely,
Dr. Universe