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:
“I think I am one of those who can manage not to take on a completely different appearance under their own glance.”
—Jean Rostand (1894–1977)
“The beauty of the internal nature cannot be so far concealed by its accidental vesture, but that the spirit of its form shall communicate itself to the very disguise and indicate the shape it hides from the manner in which it is worn. A majestic form and graceful motions will express themselves through the most barbarous and tasteless costume.”
—Percy Bysshe Shelley (1792–1822)