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:
“What! Would you make no distinction between hypocrisy and devotion? Would you give them the same names, and respect the mask as you do the face? Would you equate artifice and sincerity? Confound appearance with truth? Regard the phantom as the very person? Value counterfeit as cash?”
—Molière [Jean Baptiste Poquelin] (1622–1673)
“Thou loving soul with that unlovely face,
Thou foulest offspring of the fairest race,
Cease to lament: had Nature meant him kind,
She’d not have made him lame, but struck him blind.”
—Horace Walpole (1717–1797)