Tag: PTA

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Liquid Nitrogen Smoke Cloud!

Among my favorite new pieces of science equipment are my liquid nitrogen dewars. A dewar is a special container designed to store liquefied gases. It is like a special thermos but much larger. When you have a dewar and are trained in safely handling one, you can do science experiments with liquid nitrogen.

Liquid nitrogen is a super cold liquid version of nitrogen. It is so cold that is boils at −320 °F. That is 352 degrees colder than the temperature that makes water freeze. And it is even colder when it is still a liquid! That’s cold!

My first dewar after filled for the very first time! It weighs over 100 pounds filled and is being loaded into the Yuckmobile with a forklift!
My second dewar is the one I use for shows. It is much smaller and has a blue wrap. My sometimes co-host Luke is shown with it here!

One of my favorite demonstrations with liquid nitrogen is making a ‘smoke cloud.’ The smoke is actually a nitrogen being released as a vapor. In this demonstration, you poor warm water into a container of liquid nitrogen. The extreme temperature change causes the nitrogen to turn into a vapor immediately, and if you watch closely, you can see little chunks fly out, which are piece of a ice that were instantly frozen by the liquid nitrogen. That’s really, really cold!

Making a ‘smoke cloud’ with liquid nitrogen

Follow this blog or subscribe to the Yuck Science youtube channel to see more liquid nitrogen demonstrations soon!

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Public Science – Elephant Toothpaste!

Elephant toothpaste foam swirling in front of Empires13 mural

I hit the streets again and did some elephant toothpaste demonstrations with passersby in front of a really cool mural near downtown Houston. Check out the video below!

Elephant toothpaste is getting to be a really popular science demo! It is a chemical reaction using hydrogen peroxide and a catalyst to increase the release of oxygen. The oxygen in caught in dish soap, creating the foam. I use potassium iodide as the catalyst and a really strong hydrogen peroxide for a really big effect, but those chemicals require careful handling. You can try the demonstration safely at home using the instructions below!

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Is the Sun Yellow?

Typical representation of our yellow sun!

We all reach for the yellow crayon when it’s time to draw the sun, right? And we know the sun is yellow because Superman gets his superpowers from a “yellow star.”

But light is a tricky thing! In space, the sun would appear white. By the time we see light from the sun, it has traveled 92,955,807 miles through space and through our atmosphere, which bends and filters light.

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