Appearance in Nature
A fish's swim bladder manipulates neutral buoyancy by controlling the amount of water and air in the swim bladder, allowing it to swim at different depths. This is achieved by having an average density that is lower than the surrounding water, with the density of the fish being counter-acted by the density of the air in the bladder.
On an interesting note, we all deal intimately with the phenomenon of neutral buoyancy every day—with our brains, which exhibit neutral buoyancy as a result of their suspension in cerebrospinal fluid. The actual mass of the human brain is about 1400 grams; however the net weight of the brain suspended in the CSF is equivalent to a mass of 25 grams. The brain therefore exists in neutral buoyancy, which allows the brain to maintain its density without being impaired by its own weight, which would cut off blood supply and kill neurons in the lower sections.
Read more about this topic: Neutral Buoyancy
Famous quotes containing the words appearance and/or nature:
“This mesa plain had an appearance of great antiquity, and of incompleteness; as if, with all the materials for world-making assembled, the Creator had desisted, gone away and left everything on the point of being brought together, on the eve of being arranged into mountain, plain, plateau. The country was still waiting to be made into a landscape.”
—Willa Cather (1873–1947)
“I think that Nature meant kindly when she made our brothers few. However, my voice is still for peace.”
—Henry David Thoreau (1817–1862)