These “flowers” blossom as two injected chemicals react in the narrow space between two transparent plates. The chemical reaction produces a darker ring that develops a streaky outer edge due to competition between convection and chemical diffusion.
To show how gravity affects the instability, the researchers repeated the experiment on a parabolic flight. In microgravity conditions, no instability formed. That’s exactly what we’d expect if convection (i.e. flow due to density differences) is a major cause. No gravity = no convection. In contrast, under hypergravity conditions, the instability was initially spotty before developing streaks. (Image and video credit: Y. Stergiou et al.)