Praxis Science Outreach Science Smarts Column: “Sink or Float”

January 24, 2026

The latest Praxis ‘Science Smarts’ column in the Medicine Hat News. The article may also be found in the Medicine Hat News (paper) or via digital at https://medicinehatnews.com/life/local-life/2026/01/24/science-smarts-sink-or-float/ or via Press Reader at https://pressreader.com/article/281715506027946.

I have had some fun this week exploring buoyancy. This is a hard scientific concept to understand just by reading about it I feel, so hands on is the way to go. Give this activity a try and make it into a classroom challenge!

Let’s get started.

*Remember to ask an adult before doing this experiment.

Materials

• One piece of aluminium foil (30 cm x 30 cm piece)
• Tub of water or a sink
• Weights (metal washers, paper clips)

Procedure

1. Think carefully and design your boat. Use the piece of aluminium foil to make your design. Remember, this is your design. It does not necessarily have to look like a modern ship — use your imagination.
2. Place the boat on the water and add metal washers to the boat until it sinks.
3. Think about how you could improve your design.
4. Try it again if you wish.
5. Make it into a design contest if you are in a classroom — you will be amazed at the creative designs!

What is going on?

The scientific concept that can be applied here is displacement. Let me give you an example. When you sit in the bathtub, the level of the water rises. It increases because your body occupies a space that was previously filled with water. When you sat down, you pushed away (or displaced) an equal volume of water. When you displace water, you generate an upward force that is equal to the weight of the water you “pushed out.”

This is also what happens when a ship floats in the water. A ship’s hull displaces water. It is designed to displace enough water to keep the entire boat afloat (we hope)!

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Registration for the Regional Science Fair has gone live — it will be open until early March, so if you are thinking of going, do register as soon as possible. As well, the Button Contest has been extended to January 31 — this is a chance to win an amazing cash prize, not to men¬tion, your button design will be featured at the 2026 Regional Science Fair. Visit the praxis website at: https://www.praxismedhat.com/science-fair or the link at our Events, Activities and Services Blog at https://praxisscienceconnection.wordpress.com/2025/10/30/southeast-alberta-regional-science-fair-button-design-contest/ for more information.

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Patty Rooks, Senior Scientific Consultant – PRAXIS: Connecting Science and The Community of SE Alberta

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We also have another blog for events, activities and services that we offer at https://praxisscienceconnection.wordpress.com.

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If you wish to support us (Praxis Science Outreach is a registered charity) please consider doing so below:

https://www.canadahelps.org/en/charities/praxis-society-southeastern-alberta-sciencing-and-teching-center/?mprompt=1.

We are very fortunate to be located in the Community Futures Entre Corp Building at #202 556 Fourth St. SE, Medicine Hat, Alberta, T1A 0K8.

Phone: 403-528-0182 or email: praxis@praxismh.ca

G.Mc (Praxis Board Member)