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Lava Lamp: Wax-Liquid Density Crossover (2D)

2D lava-lamp lab driven by differential thermal expansion: wax and carrier liquid expand at different rates, so their densities cross over at a tunable temperature, with Stokes-drag motion, live Reynolds number and real blob coalescence.

Everyday Physics2DModerate60 FPS📱 Mobile-adapted⇄ 3D version

This 2D companion drives the mechanism that actually makes a lava lamp work: differential thermal expansion between wax and its carrier liquid. Each blob carries a real internal temperature that relaxes toward a height-dependent ambient gradient, its density and the liquid's density are computed independently from their own expansion coefficients, and the net buoyant force minus Stokes drag decides whether it floats or sinks — so changing the carrier liquid's expansion coefficient visibly shifts (or removes) the crossover temperature at which wax starts to float, exactly as it would in a real lamp filled with the wrong fluid.

⚙ Under the hood

2D lava-lamp lab with independent wax and carrier-liquid density models (ρ = ρ₀·(1 − β·(T − T_ref))), Newton's-law thermal relaxation against a height gradient, Stokes drag, live Reynolds number and mass-conserving blob coalescence/splitting.

thermal expansionbuoyancydensity crossoverstokes dragconvectionreynolds number

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install