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Ask Dr. Universe Archives

Dr. Universe: Why does oil on the street look like a rainbow? -Jorgos, 10, Bothell, WA

When it rains, sometimes we can see oil on the street rise to the top of puddles and spread out into a rainbow of colors. One of the main reasons we see color is because of light, said my friend Cigdem Capan, a physics instructor at Washington State University. She reminded me that when our eyes sense colors, we can trace those colors back to different wavelengths of light. Perhaps you can make some waves in the air with your hand. Make small, tight waves. Now make a big, wide waves. Read More ...

Dr. Universe: How do people stain glass to make it all the colors it can be? - Emily, 10, Edmonds, WA

Dear Emily, Ever since humans discovered they could use sand to make glass, they’ve been experimenting with it. They even learned how to control the colors. My friend Dustin Regul is a stained glass artist and painter who teaches fine arts at Washington State University. He told me more about where glass gets its color. “It’s actually metals that help change the color of the glass,” he said. Read More ...

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. Read More ...

Dr. Universe: Why do we have a belly button? – Jane, 9, Kennewick, WA

Whether you have an innie or an outie, pretty much all us mammals have a belly button. But before you had a belly button, there was actually a different bit of anatomy in its place. While you were still growing inside of your mother, a small, bendy tube on your tummy connected the two of you. This tube is how you got pretty much everything you needed to grow before you were born into the world. Read More ...