Mystery #1Tier 2forces and shapes
Why can a curved stone arch hold up a heavy bridge without any glue?
Some stone arches have carried carts, crowds and lorries for hundreds of years, and not a drop of glue holds them together. Take one stone from the wrong spot and the whole thing could tumble, yet leave them be and they barely age. So how can a curve of loose stones hold up a heavy bridge without any glue?
Your guess
What do you think the curved shape does with all that heavy weight pressing down?
There's no single magic word to type, have a go in your own words, then reveal the answer to see how close you got.
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