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:
“The whole appearance is a toy. For this,
The dove in the belly builds his nest and coos,
Selah, tempestuous bird. How is it that
The rivers shine and hold their mirrors up,
Like excellence collecting excellence?”
—Wallace Stevens (1879–1955)
“Women stand related to beautiful nature around us, and the enamoured youth mixes their form with moon and stars, with woods and waters, and the pomp of summer. They heal us of awkwardness by their words and looks. We observe their intellectual influence on the most serious student. They refine and clear his mind: teach him to put a pleasing method into what is dry and difficult.”
—Ralph Waldo Emerson (1803–1882)