Physics of Stone Arches

  • By Melissa Salpietra
  • Posted 10.14.10
  • NOVA

Medieval architects were masters at building with stone. But as cathedral design evolved, some medieval architects began to push beyond the boundaries of known structural design and into unknown territory. With the pursuit of taller and taller cathedrals, any errors could lead to catastrophic collapses. In this interactive, try your hand (safely) at constructing a cathedral arch and learn more about the physics behind the arch.

Launch Interactive

See if you can build a cathedral arch without it collapsing, and learn more about the forces at work.

Editor's Note: The arch diagrams and thrust lines are simplified for illustrative purposes. Our interactive arch exists in a virtual world that does not completely reflect real-world physics.

Further Reading

Ochsendorf, John. n.d. Interactive Thrust. October 6, 2010. From

Heyman, Jacques. 1997. The Stone Skeleton: Structural Engineering of Masonry Architecture, Cambridge University Press.

Open University. n.d. The Arch Never Sleeps. October 6, 2010. From

The physics model in this simulation is the Box2D Physics Engine for Flash, originally developed by Erin Catto.


Melissa Salpietra
Tyler Howe
Dan Hart
Special Thanks to John A. Ochsendorf, MIT

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