======Cornstarch and Water======


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**Alternative titles:** Oobleck, Non-Newtonian Fluid Demonstration
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====Summary====                   
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====Procedure====  
  - Pour cornstarch into a large bowl. First explore its dry texture by feeling it with your hands.  
  - Mix water slowly into the cornstarch, about ½ cup of water per cup of cornstarch. Add food coloring to the water first if desired.  
  - Stir and knead the mixture thoroughly with your hands until it flows slowly when at rest but can be rolled into a ball when squeezed.  
  - Experiment with the mixture: press it quickly, punch it, let it drip through your fingers, or place objects on it to see how it behaves.  
  - When finished, dispose of the oobleck in the trash, not the sink.



====Links==== 
The science of cornstarch and water - Massachusetts Institute of Technology (MIT): 
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Cornstarch Walk on Water - Cool Science Experiment - Sick Science!: 
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📄 Oobleck – The Cornstarch And Water Experiment - Science Bob: [[https://sciencebob.com/oobleck-the-corn-starch-and-water-experiment/#google_vignette]]\\

====Variations====
  * Make a larger batch and try walking across it quickly in a shallow container.  
  * Test the effects of adding more or less water to adjust its thickness.  
  * Compare oobleck with other household non-Newtonian fluids like ketchup or slime.



====Safety Precautions====
  * Oobleck is safe to touch, but avoid eating it.  
  * Food coloring may stain skin, clothing, or surfaces—use protective coverings.  
  * Do not pour oobleck down the drain; it can clog pipes. Dispose of it in the trash or mix into soil.




====Questions to Consider====
  * Why is oobleck called a non-Newtonian fluid? (Because its viscosity changes depending on the amount of pressure applied, unlike Newtonian fluids which have constant flow rates.)  
  * What happens to the cornstarch grains under pressure? (They lock together, resisting movement, making the mixture behave like a solid.)  
  * Why does oobleck eventually settle if left alone? (The cornstarch particles are suspended, not dissolved, so they sink over time.)  
  * What real-world materials or situations act like non-Newtonian fluids? (Examples include quicksand, wet sand, ketchup, and some industrial fluids.)