Here’s a simple and fun DIY to demonstrate the Butterfly Effect using things you already have at home or in class:
🦋💥 DIY: The Butterfly Effect in a Double Pendulum
What it shows:
A double pendulum (a pendulum with another pendulum attached to its end) is a perfect example of chaotic behavior—small changes in starting position lead to wildly different outcomes.
🧰 You’ll Need:
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2 thin sticks or rulers
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2 small nuts/weights
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2 strings (about 20–30 cm each)
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A hook or rod to hang it from
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Tape or glue
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A phone to record motion (optional)
🛠️ How to Make It:
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Make the first pendulum:
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Tie a string to one end of a stick or ruler.
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Attach a weight to the bottom.
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Hang the string from a hook or a pencil held horizontally.
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Attach the second pendulum:
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Tie another string to the end of the first pendulum's stick.
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Add a second weight to this string.
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You now have a double pendulum.
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Test it out:
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Lift the pendulum gently and release.
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Observe the motion.
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Now restart it from a slightly different angle or height.
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Notice how the paths diverge dramatically over time.
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🔍 What You’ll Observe:
Even a tiny change in the release position causes the pendulum arms to swing in completely different ways—unpredictable, beautiful, and chaotic.
This is a physical demonstration of the sensitivity to initial conditions—the heart of the Butterfly Effect.
🧠 Think About:
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Could you ever exactly repeat the same path?
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What does this say about predicting the weather?