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 in, appearance and/or nature:
“Every natural fact is a symbol of some spiritual fact. Every appearance in nature corresponds to some state of the mind, and that state of the mind can only be described by presenting that natural appearance as its picture.”
—Ralph Waldo Emerson (1803–1882)
“By nature servile, people attempt at first glance to find signs of good breeding in the appearance of those who occupy more exalted stations.”
—Anton Pavlovich Chekhov (1860–1904)
“If from the earth we came, it was an earth
That bore us as a part of all the things
It breeds and that was lewder than it is.
Our nature is her nature. Hence it comes,
Since by our nature we grow old, earth grows
The same. We parallel the mother’s death.”
—Wallace Stevens (1879–1955)