.
-as of [21 SEPTEMBER 2024]-
.
-in “astronomy’, ‘gravitational collapse’ is the ‘inward fall’ of a ‘massive body’ under the influence of ‘gravity’-
.
(it occurs when all other forces fail to supply a sufficiently ‘high pressure’ to counterbalance ‘gravity’ and keep the massive body in “hydro-static equilibrium”)
(“gravitational collapse” is at the heart of ‘structure formation’ in the ‘universe’)
(an initial smooth distribution of matter will eventually collapse and cause the hierarchy of structures, such as clusters of ‘galaxies’, ‘stellar groups’, ‘stars’, and ‘planets’)
(for example, a ‘star’ is ‘born’ through the gradual gravitational collapse of a cloud of ‘interstellar matter’)
(the ‘compression’ caused by the ‘collapse’ raises the ‘temperature’ until ‘nuclear fuel’ ignites in the center of the ‘star’ and the ‘collapse’ comes to a halt)
(the ‘thermal pressure gradient’ (leading to ‘expansion’) compensates the ‘gravity’ (leading to ‘compression’) and a ‘star’ is in ‘dynamical equilibrium’ between these 2 ‘forces’)
(“gravitational collapse” of a ‘star’ occurs at the end of its ‘life time’, also called the “death” of the ‘star’)
(when all ‘stellar energy sources’ are exhausted, the ‘star’ will undergo a ‘gravitational collapse’)
(in this sense a star is in a “temporary” equilibrium state between a ‘gravitational collapse’ at ‘stellar birth’ and a further gravitational collapse at ‘stellar death’)
(the end states are called ‘compact stars’)
.
(the types of ‘compact stars’ are:)
‘white dwarfs’
(in which ‘gravity’ is opposed by ‘electron degeneracy pressure’)
.
‘neutron stars’
(in which gravity is opposed by “neutron degeneracy pressure” and “short-range repulsive neutron-neutron interactions” mediated by the “strong force”)
(“black holes”, in which the ‘physics’ at the center is ‘unknown’)
.
(the collapse to a ‘white dwarf’ takes place over tens of thousands of years, while the star blows off its outer envelope to form a ‘planetary nebula’)
(if it has a ‘companion star’, a white dwarf-sized object can accrete matter from a ‘companion star’ until it reaches the ‘chandrasekhar limit’, at which point ‘gravitational collapse’ takes over again)
(while it might seem that the ‘white dwarf’ might collapse to the next stage (‘neutron star’), they instead undergo ‘runaway carbon fusion’, blowing completely apart in a “type Ia supernova”)
(“neutron stars” are formed by ‘gravitational collapse’ of larger ‘stars’, the remnant of “type II supernova” other types of ‘supernova’)
(even more massive ‘stars’, above the “tolman-oppenheimer-volkoff limit” cannot find a new ‘dynamical equilibrium’ with any known force opposing ‘gravity’)
(hence, the ‘collapse’ continues with nothing to stop it)
(once it collapses to within its “schwarzschild radius”, not even ‘light’ can escape from the ‘star’, and hence it becomes a ‘black hole’)
(according to theories, at some point later the collapsing object will reach the maximum possible ‘energy density’ for a certain volume of space or the ‘planck density’ (as there is nothing that can stop it), where the known ‘laws’ of ‘gravity’ cease to be ‘valid’
(there are competing theories as to what occurs at this point, but it can no longer really be considered ‘gravitational collapse’ at that stage)
(it might be thought that a sufficiently large ‘neutron star’ could exist inside its “schwarzschild radius” and appear like a ‘black hole’ without having all the ‘mass’ compressed to a ‘singularity’ at the ‘center’; however, this is a ‘misconception’)
(within the ‘event horizon’, ‘matter’ would have to be accelerated outwards faster than the ‘speed of light’ in order to remain ‘stable’ and avoid collapsing to the ‘center’)
(no physical force can therefore prevent the ‘star’ from collapsing to a ‘singularity’ (at least within the currently understood framework of ‘general relativity’))
.
(a model for ‘non-spherical collapse’ in ‘general relativity’ with emission of ‘matter’ + ‘gravitational waves’ has been presented)
.
.
*👨🔬🕵️♀️🙇♀️*SKETCHES*🙇♂️👩🔬🕵️♂️*
.
.
.
.
.
💕💝💖💓🖤💙🖤💙🖤💙🖤❤️💚💛🧡❣️💞💔💘❣️🧡💛💚❤️🖤💜🖤💙🖤💙🖤💗💖💝💘
.
.
*🌈✨ *TABLE OF CONTENTS* ✨🌷*
.
.
🔥🔥🔥🔥🔥🔥*we won the war* 🔥🔥🔥🔥🔥🔥