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A Kerr ( rotating ) BH also has two event horizons. See here Rotating black hole - Wikipedia As with Reissner-Nordstrum ( charged ) or Kerr-Newman ( rotating and charged ), certain values of spin ( angular momentum ), if exceeded, will cause the inner horizon to move outside the outer horizon, leaving a 'naked' singularity. That is what I have read; my math is not advanced enough to 'interpret' the Kerr metric that way. Naked singularities are even more absurd and non-sensical than plain singularities, which must always be hidden by an event horizon. For the reasons presented by Halc above, charged BHs would be extremely rare, if possible, as they tend to 'neutralize' themselves, and a Schwarzschild ( non-rotating ) BH is almost impossible, as collapse increases even the smallest amount of spin ( 'ice skater drawing in her arms' effect ). The most viable solution for almost all BHs, is the Kerr metric or a rotating BH.

Speaking of J Depp ... It definitely seems like he has some substance abuse/anger management issues along with a sense of being 'better' than others. Johnny Depp settles assault lawsuit filed by ‘City of Lies’ crew member (msn.com) Maybe A Heard should have asked G Brooks, the location manager who brought the lawsuit, to testify at her defamation trial.

Might give us an idea how common planets are in our galaxy, and how many are 'earth-like'. It has been suggested that 'rocky' planets, if not 'earth-like' planets, outnumber the stars. If so, we might have an actual number to plug into one term of the Drake Equation, and get a step closer to resolving the Fermi Paradox.

Very self-centered questions. We are not the only life on this planet. The only difference between humans and other life, is that we are more self-aware, and call this effect conciousness ( or a soul, if religious ). This ties in to the second question, as we think we are 'special'; it is simply hubris, we are not special. Otherwise, the purpose of life is to reproduce and die. The only objective reality we have, is what science can measure; everything else is subjective.

Thanks Swansont. The Eddington limit is one other such factor, which I didn't remember.

MOND can be modelled in two ways ... As a modification of Newton's second, where the a in F=Ma is modified. Or the inverse square relation ( 1/r2 ) is modified in Newonian gravity. See here ... Modified Newtonian dynamics - Wikipedia The Wiki article, should you choose to read it, explains some insurmountable problems with MOND and TeVeS, its relativistic formulation, such as the problem with the observations of the Bullet Cluster collision of 2006 which suggests that Modified Newtonian Dynamics is not enough to account for those observations, and that some form of 'dark' matter is still required.

If stars were composed of purely Hydrogen then all stars would be the same size, and limited only by availability of the gas. You could have small, unburning Jupiters, but at a certain mass, all H2 composed stars will start burning ( fusion ). Adding heavier elements to the mix, like Helium, will delay the onset of fusion and allow the star to become larger because Helium will sink to the core and burning starts at much higher temperatures/pressures. Carbon and other heavier cores will start even later. That is the reason our Sun will swell to a red giant in its old age; the build up of 'heavy' elements at its core. Genady mentioned metallicity, the amounts of even heavier elements present in second generation stars, which may act as moderators in the fusion process, and keep it from starting early. These factors, and probably others I haven't thought of, all play a role in the onset of fusion, which then blows the rest of the gas away.

A simple, non-rotating, non-charged Schwarzschild BH has the concept of mass encoded in the size of the EH; increase the mass ( by injesting material ) and the size ( radius ) of the EH increases. The EH is a mathematical construct, not a massive object like a brick wall. Rotating BHs ( Kerr ) and charged BHs ( Reissner-Nordstrom ) ecode angular momentum and charge in differently configured ( multiple ) EHs.

The classically conserved quantity we associate with 'mass' is essentially encoded in the event horizon. As such it is a measure of the local space-time curvature. For all we know ( classically ) there is nothing inside a BH. Gravitational waves are only observable outside the event horizon, and any 'internal', if possible, would simply contribute to energy-momentum of the system, due to self interaction.

Altering the configuration of a system will change its energy-momentum, resulting in a change in the local space-time 'curvature', and possible gravitational wave emission ? Is that not a causal relation ?

To paraphrase the Merovingian ( in the Matrix ) ... "Cause and effect, my dear" Energy-momentum is the 'cause'; space-time curvature is the resulting 'effect'. This is true for any gravitating body, not just Black Holes. The difference is the causal disconnect of the space-time within the event horizon, and outside the event horizon.

You're in 'good' company.

Any change in the arth's orbit, even a doubling of the orbital radius, would have minimal effect on the surface gravity of the Earth. The changes in climate, however would be catastrophic for life. And the mechanism for increasing the orbital radius, whether by impact or other means, would be even more catastrophic. Have you heard of Occam's razor or the KISS principle ?

You should be wrapping your head in aluminum foil ... You are going to great lengths to villify Ukrainians, and excuse the aggression that Russia has perpetrated on another sovereign country, with the feeble excuse that they are 'de-NAZIfying' the Ukraine. How many people need to die for the aggrandizement of one insecure person ? An you want to blame the victims in this ? I'm giving you the benefit of the doubt by assuming you're a foil-hat wearing conspiracy theorist, and not just anothe V Putin 'ball-licker'.

I know the Kerr metric predicts a 'ring' singularity, but as far as 'passages' to other universes, I believe that's due to the possible connections of Penrose diagrams. Whether those connections represent possible realities is a different story, which I will not speculate on.

I'm sure we'll all regret it when you prove us wrong. With some EVIDENCE !

The event horizon is a mathematical construct, which indicates a radius ( or radii ) after which certain effects manifest. Te rules and laws of GR continue to hold until infinities arise, close to the singularity; IOW no faster than light tavel. Te Shwazschild solution is a special case where infinities aise at the event horizon due to choice of co-ordinates. You may have misunderstood the fact that inside the event horizon, the only direction available is forward in time ( due to GR's geodesics, or geometry, terminating at the singularity, with no paths out of the EH ). A Big Bang arising from a 'white' hole connected to a Black Hole in an alternate universe is also a non-starter, as it would have observable differences to our universe, like a discernible center, or a 'rotation'.

You don't understand stellar evolution ... You don't understand 'implosion' as it relates to stellar evolution ... You don't understand stellar formation ... You don't understand reflection from a 'rough' body ... You don't understand how much power our sun actually adiates ... You have no understanding of what a Black Hole is ... Any conclusions drawn from misunderstandings are, by definition, inaccurate. I suggest you get your information from sources other than Reader's Digest.

Even the Speculations forum requires evidence to be presented in support of your 'speculation'. Hand waving arguments are not sufficient. The electromagnetic force, as we know it, did not exist until 10-35 sec after the Big Bang started. Prior to that, it was a unified electroweak field where fermions like electrons, muons, neutrinos and quarks ( and some bosons like W and Z of the weak interaction ) were massless. The Higgs mechanism allowed these particles to gain the property of mass, and the evidence of the Higgs boson, detected at CERN a few years ago, allows for a high degee of confidence in this model. I'll be waiting for you to present evidence supporting your model.

I don't know what you mean. Zero curvatue is flat space, with no gravity fields ( maybe global curvature, if any ), absent any energy-momentum that gives ise to curvature ( like a BH would )

Mass and energy are equivalent ( from E=mc2 ). As is momentum and energy ( from the same equation expanded to include massless particles )

Yes . Tidal forces are a manifestaion of the degree of curvature. Large BHs have more 'gentle' curvature, lessened tidal forces, and you can pass through the event horizon without getting 'spaghettified'. For small BHs the tidal forces are much more extreme, and you should bring along tomato sauce and meatballs.

Again I'm at a loss to understand your meaning. Do you mean 'Has anybody touched it or seen it ?' then , of course not. But science is causal, and hings can be inferred by he effects they have on other hings. Science does not simply rely on the 5 primary senses; mostly it relies on your brain to recognize causal sructures that tell us how nature behaves. IOW start living and learning beyond your fingertips

It only has to store excess electricity generated by solar panels or windmills during he day, and is meant to offload drain on he grid. Not be the sole supply. And yes, at the household level batteries would be more efficient. ( but have you ever seen a Lithium fire when the batteries swell, crack and get wet ? )

Both can be considered 'edges' of space-time, however, a Black Hole singularity ( ? ) is in the future, while the Big Bang singularity ( ? ) is in the past.