Snow Globe Science

photo by Sophia at Mamasaymamaso

I've got a snow globe that I love - and a magic wand full of glitter and tiny stars and moons. And one of the questions that I've been mulling over is: how do they get that glittery stuff to float so gently (instead of fall down fast)?

So I thought it might be fun to explore how things fall in liquid by experimenting with glitter globes - simple globes you can make at your dining room table.

What you need:

• a small glass jar with a tight lid (large baby food jar works well)
• 1 or more skinny jars for liquid testing (like spice jars)
• water
• mineral oil
• glycerin
• glitter (different kinds if you can find them)
• small plastic figures (old holiday ornaments work well)
• hot glue gun
• toothpick & dish soap
• pipe thread tape (to help seal jar lid if it leaks)
• measuring spoons
• optional: stopwatch for timing how fast glitter falls

How fast does glitter fall through different liquids?  
Fill your liquid-testing jar with water fill a  1/2 teaspoon with glitter. Before you add glitter to the water, dip a toothpick into some dish soap and touch it to the surface of the water. This will break the surface tension so the glitter won't glom all together on top. Then add the glitter and start timing.
Do the same thing with a testing jar filled with mineral oil.
Then try different mixes of water and mineral oil.
Try adding small amounts of glycerin (1/4 teaspoon at a time) to see whether that changes how fast your glitter falls.

Do some kinds of glitter fall faster than others?
Test different kinds of glitter with water to see how fast they fall. Use the same amount (1/2 teaspoon) for each type of glitter. Remember to use a toothpick dipped in dish soap to break the surface tension before you add the glitter.

Make a snow globe!
Glue a figure onto the lid of your baby food jar. When it's dry, add the liquid mix you like best, then add your glitter (remember the toothpick/dish soap trick). Put some pipe thread tape around the inside of the jar lid and screw it on. Now shake and enjoy.

 Today is STEM Friday - head over to the STEM Friday blog to see what other people are talking about in science.