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  2. Jeans instability - Wikipedia

    en.wikipedia.org/wiki/Jeans_instability

    The Jeans instability is a concept in astrophysics that describes an instability that leads to the gravitational collapse of a cloud of gas or dust. [1] It causes the collapse of interstellar gas clouds and subsequent star formation. It occurs when the internal gas pressure is not strong enough to prevent the gravitational collapse of a region ...

  3. Toomre's stability criterion - Wikipedia

    en.wikipedia.org/wiki/Toomre's_Stability_Criterion

    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 ...

  4. Gravitational collapse - Wikipedia

    en.wikipedia.org/wiki/Gravitational_collapse

    Gravitational collapse of a massive star, resulting in a Type II supernova. Gravitational collapse is the contraction of an astronomical object due to the influence of its own gravity, which tends to draw matter inward toward the center of gravity. [1] Gravitational collapse is a fundamental mechanism for structure formation in the universe.

  5. Free-fall time - Wikipedia

    en.wikipedia.org/wiki/Free-fall_time

    The free-fall time is the characteristic time that would take a body to collapse under its own gravitational attraction, if no other forces existed to oppose the collapse.. As such, it plays a fundamental role in setting the timescale for a wide variety of astrophysical processes—from star formation to helioseismology to supernovae—in which gravity plays a dominant ro

  6. Engine block - Wikipedia

    en.wikipedia.org/wiki/Engine_block

    In an internal combustion engine, the engine block is the structure that contains the cylinders and other components. The engine block in an early automotive engine consisted of just the cylinder block, to which a separate crankcase was attached. Modern engine blocks typically have the crankcase integrated with the cylinder block as a single ...

  7. Electron degeneracy pressure - Wikipedia

    en.wikipedia.org/wiki/Electron_degeneracy_pressure

    Electron degeneracy pressure will halt the gravitational collapse of a star if its mass is below the Chandrasekhar limit (1.44 solar masses [6]). This is the pressure that prevents a white dwarf star from collapsing.

  8. Black hole - Wikipedia

    en.wikipedia.org/wiki/Black_hole

    Gas cloud being ripped apart by black hole at the centre of the Milky Way (observations from 2006, 2010 and 2013 are shown in blue, green and red, respectively). [128] Gravitational collapse occurs when an object's internal pressure is insufficient to resist the object's own gravity.

  9. Free body diagram - Wikipedia

    en.wikipedia.org/wiki/Free_body_diagram

    Block on a ramp and corresponding free body diagram of the block. In physics and engineering, a free body diagram (FBD; also called a force diagram) [1] is a graphical illustration used to visualize the applied forces, moments, and resulting reactions on a free body in a given condition. It depicts a body or connected bodies with all the ...