History
The mathematician Archimedes discovered much of how buoyancy works more than 2000 years ago. In his research, Archimedes discovered that an object is buoyed up by a force equal to the weight of the water displaced by the object. In other words, an inflatable boat that displaces 100 pounds (45 kilograms) of water is buoyed up by that same weight of support. An object that floats in the water is known as being positively buoyant. An object that sinks to the bottom is negatively buoyant, while an object that hovers at the same level in the water is neutrally buoyant. Scientists later discovered ways to manipulate buoyancy and developed equipment such as the life jacket, which is filled with compressed air and helps to lower a person's average density, assisting in floating and swimming, as well as certain diving equipment (including submarines and submersibles) which have air chamber similar to swim bladders to regulate depth.
Read more about this topic: Neutral Buoyancy
Famous quotes containing the word history:
“There is no example in history of a revolutionary movement involving such gigantic masses being so bloodless.”
—Leon Trotsky (1879–1940)
“All things are moral. That soul, which within us is a sentiment, outside of us is a law. We feel its inspiration; out there in history we can see its fatal strength.”
—Ralph Waldo Emerson (1803–1882)
“I believe that history might be, and ought to be, taught in a new fashion so as to make the meaning of it as a process of evolution intelligible to the young.”
—Thomas Henry Huxley (1825–95)