Summary
For over 800 years the Leaning Tower of Pisa has tilted without toppling. Alex Gendler explains how soft ground caused the lean, why the tower's center of gravity keeps it standing, and how modern engineers pulled it back from the brink of collapse.
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Ages 7+
TED-Ed lessons move quickly and use rich vocabulary — best for grades 5–6 (some grade 4 with support). No content concerns; preview once for pace.
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Teaching resources
Discussion questions
Discussion
A tower that leans this much should fall — this lesson explains why it doesn't.
- What made the tower start to lean in the first place?
- What is a 'center of gravity,' and how does it keep the tower up?
- How did engineers keep the tower from falling over?
Quick work-a-long
Vocabulary: gravity, center of gravity, balance, foundation.
Try it: Stack blocks and lean the tower until it tips. Where was the center of gravity when it fell?