Extended Data Fig. 4. Schematic of the Rayleigh-Plateau instability.

The viscosity of the condensed film is mu, gamma is the surface tension of the interface, and p_infinity is the far field pressure provided by the solvent. The microtubule has radius r_i Initially, the interface is flat at xi(z, t=0) = r_o, but this scenario is unstable against the capillary pressure gamma/r_o, so xi(z, t) will evolve to a lower energy state. The unit normal n and unit tangent t track the geometry of the interface during its evolution.