Plateau's Problem

Given a boundary curve, find the minimal surface — interactive wire frame solver

Plateau's Problem

Plateau's problem asks: given a closed curve in space, does there exist a surface of least area spanning that curve? The Belgian physicist Joseph Plateau studied this experimentally in the 1840s by dipping wire frames into soapy water — the films that formed were always minimal surfaces.

The mathematical proof of existence came nearly a century later, independently by Jesse Douglas and Tibor Radó in 1930–1931. Douglas received the first Fields Medal in 1936 for this work.

Interactive: Plateau Solver

Watch a triangulated mesh spanning a circular boundary relax toward the minimal surface via Laplacian smoothing. The area decreases with each iteration as interior vertices slide toward their equilibrium positions.

Boundary points: 0

Interactive: Classic Boundary Gallery

Explore minimal surfaces spanning classic boundary curves. Each boundary produces a different surface — from the flat disk of a circle to the saddle surface of a square to the topologically complex Seifert surface of a trefoil knot.

Area: 0.000
A flat disk is the minimal surface spanning a circle

The Douglas–Radó Theorem

For any rectifiable Jordan curve in , there exists a disk-type surface of least area spanning that curve. The proof uses the direct method of the calculus of variations: take a minimizing sequence of surfaces, show it converges, and prove the limit is smooth.

The solution is not always unique — some boundary curves admit multiple minimal surfaces with different topologies. The question of regularity (smoothness of the solution) remained open for decades and was finally resolved by the deep work of Osserman, Alt, and others.

History of Minimal Surfaces

From Euler's catenoid in 1744 to Costa's genus-1 surface in 1984 — 240 years of discovery. Click through the milestones to trace the evolution of the field.

1849

Plateau's experiments

Joseph Plateau publishes his systematic experimental study of soap films, demonstrating that films spanning wire frames always form minimal surfaces.

Established the physical basis for the mathematical problem

Key Takeaways

  • Plateau's problem: Find the minimal surface spanning a given boundary curve.
  • Physical solution: Soap films solve Plateau's problem automatically.
  • Douglas–Radó (1930): Existence proof for disk-type minimal surfaces.
  • Non-uniqueness: Some boundaries admit multiple minimal surfaces.
  • Numerical approach: Laplacian relaxation approximates the minimal surface iteratively.