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 simulation as a training aid simulation can advise as to how realistic is the task performance and recommend modifications. Learning and rehearsing an EVA task in neutral buoyancy gives an astronaut or EVA specialist confidence that the planned task may be accomplished. The timeline developed for task performance is similar to the time required in EVA. In general, it is considered that a task performed and practiced in neutral buoyancy simulation can also be performed in EVA. Neutral buoyancy, properly planned and conducted, works because it is a realistic simulation of the physical requirements of performing a task in EVA. The other major method used