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Making Magic Mud
From spuds to science: Unleash the magic mud!
Dive into the world of weird science with 'Magic Mud'! Scouts will transform humble potatoes into a fascinating non-Newtonian fluid, learning how it behaves like both a liquid and a solid. This hands-on activity is messy, fun, and packed with science magic to amaze and inspire.
What’s the science?
- Non-Newtonian fluids are good at absorbing and dispersing energy
- When the potato and water are mixed, the starch particles from the potato are suspended in the water and then sink to the bottom of the bowl
- When you pour the water away, the starch particles are still surrounded by some of the water
- When this mixture is moved slowly or handled gently the starch particles are allowed to flow over each other, so the mud behaves like a liquid
- When the mixture is moved more suddenly and handled more firmly (try slapping it) the starch particles lock together while the water quickly flows out of the area, so the mud behaves more like a solid
- This behaviour is called shear thickening - viscosity increases with increased stress
What you will need
- Mixing bowls
- Wooden spoons
- Knives
- Chopping boards
- Potatoes
- Water
Magic Mud
- Wash your potatoes well. A few large potatoes will make enough magic mud to play with, but use more if you want to make lots. You could split into smaller Patrols, with each Patrol making their own magic mud.
- Chop the potatoes up into small chunks and make them as small as you possibly can. You could use a grater or food processor if you have access to these.
- Put the chopped potatoes into a large heatproof mixing bowl, then add enough hot water from the tap to cover them. Make sure there is suitable adult supervision while using the hot water.
- Stir the potatoes for a few minutes.
- When ready, an adult should carefully pour the mixture through a sieve into another large bowl.
- Throw away the remaining potatoes in the sieve into a food waste bin or add them to a compost pile.
- Leave the water in the bowl to stand for about 10 minutes until a white layer settles at the bottom of the bowl. You could play some games while you wait.
- Pour off the water and watch as the white layer somehow stays in the bottom of the bowl!
- Add some more cold water and stir it into the mixture. Leave the bowl to sit for another ten minutes. After ten minutes, pour the water away again. This step will have cleaned up your magic mud.
- Now you’re left with your magic mud! Get your hands in, and see what’s so magic about it.
- The magic mud is something called a non-Newtonian fluid. This just means it acts differently when it is poured than when it is pushed.
Change the challenge level
Get more or less involved depending on the ability of the Group. An adult will need to supervise any chopping and when using the hot water.
Decrease the challenge
- You can use Corn Starch mixed with water to quickly make your Magic Mud
- Try adding food colouring to your magic mud.
- What crazy shapes and colours can you make?
Reflection
How can a normal potato make something like magical mud? Sometimes normal things, like potatoes, can hide amazing things inside, just like normal people can do amazing things.
- What other cool science experiments have you seen before?
