A vortex ring is the phenomenon where a quantity of fluid or gas in a toroid (donut) shape, travels through a medium of fluid or gas, while spinning like a thick circular bracelet that is being rolled off of a person’s arm. (Except the spin is in the opposite direction as when a bracelet is rolled off in this way.)
Your egg geode is formed through a process called sedimentation. The heated alum solution contains suspended particles of alum powder and as the solution cools, these particles of alum begin settling. When the alum particles settle towards the bottom of the beaker or glass, they begin crystallizing. With the alum-covered egg at the bottom, the alum particles from the solution begin attaching themselves to the egg. Covering your egg in alum powder beforehand gives the suspended alum particles a surface to which they can more readily attach themselves. The particles that settle onto the surface of the egg crystallize, and you will also see crystallization on the bottom and sides of the beaker or glass.
Robots have to be able to move, perhaps quickly, on all kinds of terrain — search and rescue missions on remote parts of Earth or explorations on other planets like Mars will require it. So terradynamic researchers at Georgia Tech are creating and testing robots that have different leg shapes, all inspired by animals, to handle movement in a variety of environments. Bonus technology: 3D printing.