Search results
Results from the WOW.Com Content Network
The Jeans mass is named after the British physicist Sir James Jeans, who considered the process of gravitational collapse within a gaseous cloud. He was able to show that, under appropriate conditions, a cloud, or part of one, would become unstable and begin to collapse when it lacked sufficient gaseous pressure support to balance the force of gravity.
Sir James Hopwood Jeans OM FRS [1] (11 September 1877 – 16 September 1946 [2]) was an English physicist, mathematician and an astronomer.He served as a secretary of the Royal Society from 1919 to 1929, and was the president of the Royal Astronomical Society from 1925 to 1927, and won its Gold Medal.
Faraday instability: Vibrating fluid surfaces: M. Faraday: Farley–Buneman instability: Plasma instability: Donald T. Farley and Oscar Buneman: Görtler instability: Stability of flow along a concave boundary layer: H. Görtler: Holmboe instability: Stratified shear flows: Jørgen Holmboe: Jeans instability: Stability of interstellar gas ...
The most basic gravitational stability analysis is the Jeans criteria, which addresses the balance between self-gravity and thermal pressure in a gas. In terms of the two above stability conditions, the system is stable if: i) thermal pressure balances the force of gravity, and ii) if the system is compressed slightly, the outward pressure ...
Firehose instability (a.k.a. hose instability), not to be confused with the similarly named Firehose instability in galactic dynamics; Fish instability, Free electron maser instability, Gyrotron instability, Helical (Helix) instability, Jeans instability, [23] [24] Magnetic buoyancy instability. Interchange instability (a.k.a. flute instability ...
As gas clouds move into the density wave, the local mass density increases. Since the criteria for cloud collapse (the Jeans instability) depends on density, a higher density makes it more likely for clouds to collapse and form stars. As the compression wave goes through, it triggers star formation on the leading edge of the spiral arms.
If the thermal motion of the electrons is ignored, it is possible to show that the charge density oscillates at the plasma frequency =, [/] (), =, [/] (), where is the number density of electrons, is the electric charge, is the effective mass of the electron, and is the permittivity of free space.
After the instability has run its course, the system is typically "hotter" (the motions are more random) or rounder than before. Instabilities in stellar systems include: Bar instability of rapidly rotating disks; Jeans instability; Firehose instability [4] Gravothermal instability [5] Radial-orbit instability