======Cylinder Puzzle Model of Scientific Inquiry====== **Materials: **{{$demo.materials_description}}\\ **Difficulty: **{{$demo.difficulty_description}}\\ **Safety: **{{$demo.safety_description}}\\ \\ **Categories:** {{$demo.categories}} \\ **Alternative titles:** The Mystery Cylinder ====Summary==== {{$demo.summary}} ====Procedure==== See links below for instructions for construction. - Prepare a sealed opaque cylinder with four threaded cords crossing inside, each ending in knots. - Tell students the cylinder represents the “universe”—we can only observe from the outside. - Demonstrate by pulling knots in sequence (e.g., A-B-D-B, then A-D-B-D-A-B) and let students observe carefully. - Ask students to: * Record observations systematically. * Draw and explain possible internal arrangements (hypotheses). * Predict what will happen when a new knot (C) is pulled, then test it. - Encourage refinement of hypotheses after each test. Compare student models and discuss. - Optionally, allow opening the cylinder at the end to reveal the mechanism. ====Links==== Mystery Tube - South East Physics Network: {{youtube>JvY69CipyuA?}}\\ 📄 Cylinder Puzzle - Peter Dekkers: [[https://interactivetextbooks.tudelft.nl/showthephysics/demos/demo70/demo70.html]]\\ ====Variations==== * Let students design their own hidden-string puzzle for classmates to test. * Add more cords or make asymmetrical arrangements to increase complexity. * Keep the cylinder permanently sealed to emphasize the limits of inference in science. ====Safety Precautions==== * None ====Questions to Consider==== * What observations did you record? How consistent were they? * How many different models could explain the same data? * Were your predictions accurate when tested? * Can you be certain about what’s inside without opening the cylinder? * How does this puzzle resemble real scientific work? (data collection, modeling, limits of certainty)