Home▸Physics & Mechanics▸The Ferrofluid Rosensweig Instability

🧲 The Ferrofluid Rosensweig Instability

Explore how a flat pool of ferrofluid spontaneously erupts into a regular grid of sharp magnetic spikes once an applied field crosses a critical threshold, and why the resulting pattern is almost always hexagonal.

Physics & Mechanics3DModerate60 FPS⚡ Plasma

The simulator demonstrates the full arc of the Rosensweig instability: a stable flat ferrofluid surface below the critical magnetic field, the sudden onset of surface deformation as the field crosses threshold, and the self-organization of that deformation into a regular hexagonal array of peaks, showing directly how magnetic, gravitational, and surface tension energies trade off to select both the peak spacing and the hexagonal symmetry.

🔬 What It Demonstrates

🎮 How to Use

Start with the applied magnetic field set below the critical value and confirm the surface stays flat. Slowly increase the field using the control slider and watch the surface for the onset of rippling, then peaks, noting the field strength at which the transition occurs. Adjust fluid density, surface tension, and layer depth to see how each one shifts the critical field and the spacing between peaks, and lower the field back down to observe the pattern collapsing back to flat, including any hysteresis in the transition point.

💡 Did You Know?

Ronald Rosensweig, who first explained this instability mathematically, was also a key figure in inventing ferrofluid itself while working on ways to pump fuel in weightless conditions for NASA in the 1960s, and the same flux-concentrating effect that builds the hexagonal peaks is what makes ferrofluid sculptures rise into sharp spiky crowns around ordinary bar magnets.

⚙ Under the hood

ferrofluidmagnetismsurface instabilitypattern formationfluid dynamicssurface tensionself-organization

3D · Three.js / WebGL renderer · 60 FPS target · runs fully client-side, no install