tl;dr: Using the Inouye Solar Telescope, researchers directly observed Kelvin-Helmholtz instability (KHI) in the Sun's photosphere for the first time, seeing small swirling vortices at the edges of magnetic regions that closely matched MHD simulations. The finding could help explain long-standing puzzles like coronal heating, the rapid diffusion of the Sun's magnetic flux over its 11-year cycle, and the twisting of magnetic field lines that fuels flares and coronal mass ejections. Results are published in Nature.