Liquid Gallium Experiment Confirms Theoretical Flow Regime in Celestial Bodies
An international research team led by the University of California, Los Angeles (UCLA) has successfully verified a theoretical flow state within rapidly rotating stars and planets through a laboratory experiment using liquid gallium. This breakthrough, published in Physical Review Letters, offers a new experimental basis for understanding the interiors of these celestial bodies.
The experiment, conducted in collaboration with the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), focused on the 'diffusivity-free regime' of convection, where buoyancy and rotation dominate over viscosity and thermal diffusion. The team used a rotating liquid-metal setup to replicate conditions inside rapidly rotating celestial bodies, revealing flow dynamics previously obscured in classical experiments.
Quantitative comparisons across heat transport, flow velocity, and temperature fluctuations confirmed the experimental results, aligning with theoretical predictions. High-resolution numerical simulations further validated these findings. Jewel Abbate from UCLA noted that this was the first laboratory demonstration of the theoretically predicted state, enhancing confidence in models of planetary and stellar interiors.
The experiment utilized UCLA's SPINlab facilities, specifically the Rotating Magneto-Convection device (RoMag), which can spin liquid gallium up to 70 rpm and impose magnetic fields up to 1300 Gauss. These capabilities allowed for precise measurements of convective flows relevant to planetary core analogs.
Tobias Vogt of HZDR emphasized the significance of the agreement between theory, experiment, and simulation, suggesting robust support for applying these models to real celestial interiors.