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:
“The best history is but like the art of Rembrandt; it casts a vivid light on certain selected causes, on those which were best and greatest; it leaves all the rest in shadow and unseen.”
—Walter Bagehot (1826–1877)
“To summarize the contentions of this paper then. Firstly, the phrase ‘the meaning of a word’ is a spurious phrase. Secondly and consequently, a re-examination is needed of phrases like the two which I discuss, ‘being a part of the meaning of’ and ‘having the same meaning.’ On these matters, dogmatists require prodding: although history indeed suggests that it may sometimes be better to let sleeping dogmatists lie.”
—J.L. (John Langshaw)
“History is more or less bunk. It’s tradition. We don’t want tradition. We want to live in the present and the only history that is worth a tinker’s damn is the history we make today.”
—Henry Ford (1863–1947)