Black Holes were originally invented to explain our 'missing' galactic force-centre.
It is assumed by all physicists that galactic force-centres should be hot (like stars) simply because they are bigger than stars. But that light cannot escape their surface because gravitational energy is sufficient to prevent light leaving their surface. This was the origin of Schwarzschild's radius.
The trouble is, all of the above is based upon the photon, which doesn't exist. Light is EME; it is not attracted by the potential energy between masses.
Moreover, because galactic force-centres are not in elliptical orbits, they generate no internal friction from spin, which means no heat, or light; they're cold.
But the biggest problem is that black-holes conform to no known or accepted rules of physics; they were a fantasy, invented to provide an answer to a phenomenon that was also misunderstood at the time and also complied with no known rules of nature; the 'Big-Bang'. But all that has changed; we now know exactly what caused the 'Big-Bang' and how the universe works, so invention and fantasy are no longer needed.
In truth, galactic force-centres are no different to any other celestial body, all of which were ejected from the same ultimate body that comprised all the matter generated during a previous universal period. Their only difference with other celestial bodies is that they follow linear orbits, not elliptical orbits.
From Isaac Newton's laws of orbital motion and planetary spin theory, we can determine quite a lot about our own galactic force-centre (Hades):
average density: ρ ≈ 9000 kg/m³ (est.)
mass: m = 1.76572018982E+41 kg
distance from the great attractor: 4.35308E+23 m
linear velocity: 2.3E+05 m/s (NASA est.)
surface radius: r = 1.67313218954124E+12 m
surface area: A = 3.517794E+25 m²
surface gravitational acceleration: g = 4.20941E+06 m/s² (429,241 g)
potential energy: PE =-2.82436E+53 J
kinetic energy: KE = 4.67032E+51 J
spin energy: SE = -8.75632E+48 J (2E+08 stellar population)
polar moment of inertia: 1.97716E+65 kg.m²
spin-rate: ω = -9.41141E-09 ᶜ/s
temperature <70K
Hades is not in an elliptical orbit. Whilst it does have a force-centre (the great attractor), it will generate very little internal heat energy (only through E₃; E₀ & E₁ are both zero). It is therefore cold; most of the heat it holds and dissipates is that held following the last ‘Big-Bang’, the EME it radiates will be low, it will be dark:
EME radiation:
λ ≈ 4.704644E-04 m
A ≈ 2.509237E-08 m
ƒ ≈ 6.372266E+11 /s
E ≈ 4.597168E-21 J
see electro-magnetic spectrum
Given our sun’s orbital radius (≈2.5E+20 m) and the radius of an iron atom (7.6E-08 m), searching for Hades in the night sky would be like looking for a black atom in the centre of an eleven-metre diameter black disk. That’s why we can’t see it; but it doesn’t mean it isn’t there! We know it exists because it is a fundamental law of nature that every orbital system must have a force-centre, and as we can see above, we know quite a lot about it.
Schwarzschild identified the radius of a given mass (m₁) that would prevent a photon (mₑ) from leaving its surface, so we must begin with his work:
A photon generates the following kinetic energy; KE = ½.mₑ.c²
The potential energy in the mass (m₁) that would hold the photon's KE in check may be calculated by rearranging Newton's gravitational force formula 'F = G.m₁.mₑ / r²' to 'PE = G.m₁.mₑ / r';
First we must estimate a density for force-centre 'm₁' and then define its surface radius; r = ³√[3.m₁ / 4π.ρ]
assuming an average density of ≈9000 kg/m³ (>iron)
PE = G.m₁.mₑ / ³√[3.m₁ / 4π.ρ] = KE
m₁ = √[3.KE³ / G³.4π.ρ.mₑ³] = 8.99936882768670E+37 kg
The surface radius of m₁ must be; r = ³√[3.m₁ / 4π.ρ] = 1.33647337370413E+11 m
Schwarzschild predicted the same result from his own formula:
Rₛ = 2.G.m₁/c² = 1.33647337370413E+11 m
Whereas the known (provable) radius of our galactic force-centre is greater than this; 1.67313218954124E+12 m.
Alternatively;
the term 'Black' implies the retention of light, and the term 'Hole' implies that it has next-to-no mass or volume.
So, what is the smallest mass that will prevent the escape of a photon?
It cannot have a greater density than that of an atomic particle; ρᵤ
black-hole mass: m = r.c² / 2.G
black-hole radius: r³ = ³/₈/π . r.c² / G.ρᵤ
r = √[ ³/₈/π . c² / G.ρ ] = 47494.1512680647 m
V = ⁴/₃.π.r³ = 4.4875469228854E+14 m³
m = ρᵤ.V = 3.19809876372352E+31 kg
which is the smallest possible mass for a black hole; but it is hardly a 'hole'!!
The problem here is of course, that because the photon is fictional, Schwarzschild's radius must also be fictional, so the 'Black-Hole' must be fictional. Moreover, it is't possible for any matter to have the same density of an atomic particle.
But, using genuine densities and the known mass of Hades, we can calculate the density required to satisfy Schwarzschild:
ρ = m₁ / (⁴/₃π.Rₛ³) = 17,658,440.2891913 kg/m³
which is 783.62 times more dense than the densest element in the universe (osmium; 22,534.4 kg/m³)
there is no such element, and Core Pressure cannot generate the forces needed to compress matter to such a density, except for a tiny number of its innermost elements.
And because event horizons were also invented to explain a misunderstanding, these two phenomena were amalgamated, albeit neither of which were either verifiable or even explainable.
There is no need for a black-hole; it is unnecessary, so why invent it?
You will find further reading on this subject in reference publications(55, 60, 61, 62, 63 & 64)