Science Smarts: Ghosts flying around

By PATTY ROOKS on October 30, 2021.

Well, it would not be Halloween in southeastern Alberta if it was not going to be cold and perhaps snowy! As I write this article, the weather is supposed to take a change for the worse on the weekend, but that is OK. If anyone can do it, we can, as we know how to celebrate this holiday even if we have to wear a winter coat over your costume.

I am VERY excited to see all of the ghosts and goblins at my house in just a few days. In order to keep you busy until then, here is a frightful experiment that MUST be done with an adult. Let’s get started!

Remember you NEED a responsible adult to help you with this experiment.

Disclaimer: Use CAUTION! This activity involves the use of fire. As such, this activity should only be performed under adult supervision in a safe location such as in the safety of a fume hood or far away from buildings, furniture, trees, or other objects than can catch on fire.

Materials

• Tea bags (the kind that will stand up on their own)

• Glass baking dish

• Fire extinguisher (nearby for safety)

• Safety goggles

• Scissors

• Fine tipped black marker

• Bbq lighter

Procedure

• Find a safe location.

• Put your safety glasses on.

• Using the scissors cut the top off of the tea bag. Be sure you make it nice and straight.

• Unfold the tea bag and discard the contents of the tea bag as you do not need these for this experiment.

• Draw a ghostly face on one side of the tea bag with the black marker.

• Place the tea bag, cut side down in the middle of the glass baking dish in a SAFE location.

• Using the lighter, light the top of the tea bag.

• Observe.

Explanation

Once you lit the tea bag, you should have seen it fly off just like a ghost on Halloween night! High up into the sky – this is why you need to do this in a safe location. I cannot stress this enough.

In this experiment there is so much going on. You are learning about convention and air currents. When you light the top of the teabag, the cylindrical shape of the teabag heats the air up inside of the bag. These air molecules start to move around rather quickly and they begin to spread out and take up more space. As the air molecules spread out, the air inside the cylinder becomes less dense. The warm less dense air rises. As well, as the hot air rises, the cool air rushes in to take its place. This also creates a convection current. This convection current pushed on the tea bag and the bag begins to dance around!

The principle displayed here is similar to how a hot air balloon works.

Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. We are located at #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403.527.5365, email: praxis@praxismh.ca.

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