A few weeks ago we ran a really awesome science show on the phenomenal science of fluids! I got inspired to write a little bit about fluids.
In Wikipedia a fluid is defined as “a substance that continually deforms under an applied shear stress.” Translation? A fluid is something that takes the shape of its container. Think about pouring water from a mug to a fish bowl. The shape of the water changes to conform to the shape of the fish bowl.
Now, for a water balloon, what shape does the water in the balloon take? (think about this for a few seconds…) Our outreach coop student Alice took the following slow-motion video of her popping a water balloon.
Did you get it right? So the water actually took the shake of the balloon, suspended in the air for a little bit when the balloon broke, and then dropped down all over (Slow motion videos are so cool, I can watch this for the whole day).
Although when we think of “fluids” we usually think of liquids (water, juice, coffee, and more coffee…), gases are also fluids. When we fill a container with a gas, it conforms to the shape of the container.
Now, what happens when we pop a balloon that is fill with a gas? More specifically, what happens when we light a balloon filled with hydrogen gas on fire?!
This happens really fast! Here is a video taken when my colleague Tamara from UBC Chemistry Outreach lit a balloon filled with hydrogen gas (highly flammable, don’t do this at home!).
So fast that we actually cannot see what really happened without using a high-speed camera to take a slow-motion video. Here is a video about hydrogen-filled balloons from the Period Table of Videos (with additional explanation!).
You can even see a little bit of the outline of the balloon in the hydrogen only balloon video. And it is also very nice to see a scientist talking about the mistake he made in thinking what might have happened and how he went about to test a viewer’s suggestion 😀
Hope you enjoyed them!