Aerostatics is the study of gases that are not in motion. The corresponding study of gases in motion is called aerodynamics

Aerodynamics

Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

. It is a subfield of fluid statics

Fluid statics

Fluid statics is the science of fluids at rest, and is a sub-field within fluid mechanics. The term usually refers to the mathematical treatment of the subject. It embraces the study of the conditions under which fluids are at rest in stable equilibrium...

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Aerostatics studies density allocation, especially in air. One of the applications of this is the barometric formula

Barometric formula

The barometric formula, sometimes called the exponential atmosphere or isothermal atmosphere, is a formula used to model how the pressure of the air changes with altitude.-Pressure equations:...

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An aerostat

Aerostat

An aerostat is a craft that remains aloft primarily through the use of buoyant lighter than air gases, which impart lift to a vehicle with nearly the same overall density as air. Aerostats include free balloons, airships, and moored balloons...

 is a lighter than air

Lighter than air

Lighter than air refers to gases that are buoyant in air because they have densities lower than that of air .Some of these gases are used as lifting gases in lighter-than-air aircraft, which include free balloons, moored balloons, and airships, to make the whole craft, on average, lighter than air...

 craft, such as an airship

Airship

An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

 or balloon

Balloon

A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

, which uses the principles of aerostatics to float

Buoyancy

In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

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Fields of study

• Atmospheric pressure
  Atmospheric pressure
  Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
  
   fluctuation
• Composition of mountain air
• Cross-section of the atmosphere
  Atmosphere
  An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...
  
  
• Gas density
  Density
  The mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
  
  
• Gas diffusion in soil
• Gas pressure
• Kinetic theory of gases
• Partial pressure
  Partial pressure
  In a mixture of ideal gases, each gas has a partial pressure which is the pressure which the gas would have if it alone occupied the volume. The total pressure of a gas mixture is the sum of the partial pressures of each individual gas in the mixture....
  
  s in gas mixtures
• Pressure measurement