Buoyancy "downward" direction. The center of buoyancy of an object is the centroid of the displaced volume of fluid. Archimedes' principle is named after Archimedes of Syracuse, who first discovered this law in 212 B.C. For objects, floating and sunken, and in gases as well as liquids (i.e. a fluid), Archimedes' principle may be stated thus in terms of forces: — with the clarifications that for a sunken object the volume of displaced fluid is the volume of the object, and for a floating object on a liquid, the weight of the displaced liquid is the weight of the object. More
Neutral buoyancy suited astronaut trainees interact with mock-up space hardware, with the assistance of scuba divers. At the University of Maryland's Space Systems Laboratory, a neutral buoyancy tank is similarly used to evaluate the performance of prototype space robots. When neutral buoyancy is taking place, it appears as though the object/substance is floating in the middle of the fluid, or somewhere in between the bottom and the surface. A fish's swim bladder controls buoyancy by adjusting the amount of gas in the swim bladder, allowing it to achieve neutral buoyancy at different depths. When a fish's overall density becomes higher or lower