### fluid:

Sky
* Most skies are part of worlds.
* Skies are likely to be cloudy during winter, and only partly cloudy during summer
  - cloud over suddenly, and bursts of hail can strike in summer
  - get lighter as they get closer to where the sun is
* Skies includes exospheres
  - mesospheres
  - ozone layers
  - rainbows
  - thermospheres
  - tropospheres
* Some skies are deep in blue, or more brilliant in orange.
* clears Fish species include walleye, northern, bass, bluegill, crappie, perch and bullhead.
* diving The consequence of failure in jumping out of an airplane with a parachute is death.
* glow Many light fixtures shine a large percentage of their light above the horizontal
  - also prevents astronomers from seeing dim objects
* is an atmosphere
  - dark and all stars are visible
  - everywhere, and there certain gravitational pull of it
  - observed to be full of stars
* is the limit for potential in Austin
  - world's biggest digital broadcasting company
* reflects in the surface of a water pond.
+ Light pollution, Types of light pollution: Light :: Pollution
  * Sky glow is the kind of light pollution that prevents people from seeing stars and other deep-space objects. This causes birds to not be able to migrate to the right place because they can not follow the moon and stars. Sky glow also prevents astronomers from seeing dim objects.

### fluid | sky:

Clear sky
* Clear skies allow the sun to warm the ground and the air near it during the day
  - are natural, rain and snow are natural
  - can give way to fog in less than an hour
* is determined by the cloud mask.

Dark sky
* Dark skies are an endangered species
  - essential for observing most galaxies
* is the result of burning oil wells.

Supercritical fluid
* act as low density solvents for organic compounds
  - with the properties of a liquid and a gas
* are high pressure fluids with the properties of both a gas and a liquid.
* have properties that resemble both gas and liquid
  - some very unusual properties

Synovial fluid
* can fill joints creating pain and restricted motion.
* fills the joint cavity completely
* helps improve joint lubrication and eases movement.
* is secretion
  - the primary lubricant for the joints
* lubricant and also disperses waste matter which can cause stiffness at joints
  - in joints, and serum is the fluid portion of the blood
* reduces friction.
* shows nonspecific inflammatory changes.
* surrounds joints.

Synthetic fluid
* Many synthetic fluids offer greater thermal stability at high temperatures.
* contain primarily organic and inorganic salts but no petroleum compounds.

Thixotropic fluid
* are quite common in chemical as well as in food industry.
* lower their viscosity with agitation.

Tissue fluid
* accumulate in the alveoli reducing the surface area exposed to air.
* contain all components of plasma except large proteins.
* is refreshed when oxygen and nutrients exit the blood and wastes enter the blood.

Tubular fluid
* entering the distal tubule is isosmotic to plasma.
* is an ultrafiltrate, meaning that it is relatively free of plasma proteins.

Vaginal fluid
* can also transmit the virus
  - enter a man's body through the head of the penis
* is slippery because of a high content of glycerol.

Viscous fluid
* Some viscous fluid contains fructose.
* have high internal resistance to flow.

Fluke
* Many flukes are parasitic on fishes and invertebrates, and many can infect mammals
  - have immature stages that live in other animals
* Some flukes affect sheep.
* Some flukes cause human diseases
  - severe diseases
* Some flukes enter bile ducts
  - have oral suckers
  - produce mechanical irritation
* are barbs
  - flatworms
* are part of anchors
  - cetaceans
  - projections
  - tails
* cause destruction.
* colonizes human with eating of poorly cooked fish.
* prefer eel grass beds and wharf pilings because of the protection they offer.