Jeans Length
In physics, the Jeans instability causes the collapse of interstellar gas clouds and subsequent star formation. It occurs when the internal gas pressure is not strong enough to prevent gravitational collapse of a region filled with matter. For stability, the cloud must be in hydrostatic equilibrium, which in case of a spherical cloud translates to:
- ,
where is the enclosed mass, is the pressure, is the density of the gas at, is the gravitational constant and is the radius. The equilibrium is stable if small perturbations are damped and unstable if they are amplified. In general, the cloud is unstable if it is either very massive at a given temperature or very cool at a given mass for gravity to overcome the gas pressure.
Read more about Jeans Length: Jeans Mass, Jeans Length, Jeans' Length As Oscillation Wavelength, Fragmentation
Famous quotes containing the words jeans and/or length:
“When children dress like adults they are more likely to behave as adults do, to imitate adult actions. It is hard to walk like an adult male wearing corduroy knickers that make an awful noise. But boys in long pants can walk like men, and little girls in tight jeans can walk like women.”
—David Elkind (20th century)
“And my spirit is grown to a lordly great compass within,
That the length and the breadth and the sweep of the marshes of
Glynn
Will work me no fear like the fear they have wrought me of yore
When length was failure, and when breadth was but bitterness sore,
And when terror and shrinking and dreary unnamable pain
Drew over me out of the merciless miles of the plain,—
Oh, now, unafraid, I am fain to face
The vast sweet visage of space.”
—Sidney Lanier (1842–1881)