Buoyancy tersely: Buoyancy = weight of displaced fluid. Archimedes' principle does not consider the surface tension (capillarity) acting on the body, but this additional force modifies only the amount of fluid displaced and the spatial distribution of the displacement, so the principle that "Buoyancy = weight of displaced fluid" remains valid. The weight of the displaced fluid is directly proportional to the volume of the displaced fluid (if the surrounding fluid is of uniform density). In simple terms, the principle states that the buoyancy force on an object is equal to the weight of the fluid displaced by the object, or
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