MigL

And the 'curvature at the singularity of a Black Hole is infinite. Which means that the equations which describe the singularity and the concept of curvature cannot be applied in that domain. Mostly because it is a 'made up' concept, and while you can measure 'effects' because reality acts ( for the most part ) like it is curved, the 'concept is not applicable in some extreme situations.

Yes, it may happen only once, but the relationship with the rest of the universe differs with the frames of reference of different observers in the universe. There is no absolute frame of reference, observer, or 'now'. If you won't believe me, ask the only absolute observer that I know of, God; let me know what He tells you.

As per our PMs Every different observer carries their own different perspective, shaped by different, and unique, trajectories through space-time; it is a tenet of Relativity.

Yes, the space-time of the model acts exactly like the reality ( in most situations ) and has been confirmed to a very high degree. In the model space-time can be curved and is malleable; whether reality is also, is a question for Philosophers to debate.

No it would not. Information, even mechanical, is limited by the speed of light. Is there something you wish to ask, before stating absurdities ?

The old forum software used to send Email notifications to my phone when someone on SFn had sent me a PM. The new software doesn't seem to do this anymore. Is that feature not supported, or can it somehow, be turned on in the settings ?

We are not big fans of the current state of AI on this forum. It is fine for people who want regurgitated, and often wrong, knowledge, albeit drawn from vast sources, but in terms of 'learning', AI isn't even at the level of a month old baby, or a dog for that matter. Quantum computing is in the same boat as Fusion reactors. For 40 years a breakthrough has been just around the corner. Except we have a working example of a Fusion reactor 93 000 000 miles away, so we know it works. Not so sure about Quantum computing. Changing games ? mRNA research changed ( and saved ) lives.

Don't worry so much about Bond villains, but a low flying EA-6B, piloted by 'hot-dogging' American pilots from an |Italian Air Force base, has been know to slice through the supporting cables. 1998 Cavalese cable car crash - Wikipedia

A lot of people start off with the 'pulpy' science fiction of the 40/50s ( E E 'Doc' Smith type ) before moving on to the 'deeper' science fiction which is more social commentary in a sci-fi setting. I started my 'journey' with Galactic Derelict, by Andre Norton ( actually a cat lady ) before she veered off into fantasy while I wanted more science realism of the Dragon's Egg, by Robert L Forward type. Maybe if you indicate what type interests you, we might be able to recommend what you'd like, not what we like.

Does anyone actually look for the +/- markings , or color end coding ? I, like most people, differentiate the positive end by the raised terminal, as opposed to the flat negative end.

"A Feynman diagram is a graphical representation of a perturbative contribution to the transition amplitude or correlation function of a quantum mechanical or statistical field theory. Within the canonical formulation of quantum field theory, a Feynman diagram represents a term in the Wick's expansion of the perturbative S-matrix. Alternatively, the path integral formulation of quantum field theory represents the transition amplitude as a weighted sum of all possible histories of the system from the initial to the final state, in terms of either particles or fields. The transition amplitude is then given as the matrix element of the S-matrix between the initial and final states of the quantum system." Drom Feynman diagram - Wikipedia If you think I scolded you because I can do the path integrals QFT requires, you are mistaken; I use Feynman diagrams because they make life ( and understanding ) so much easier. IOW, I'm giving advice, not chasing you away; you have always been welcome to stay and learn.

Again You might educate yourself on Feynman diagrams before making blanket statements like the above. The fact that in the model, you can consider anti-particles as travelling backwards in time to make calculations easier, has no implications on the real. The fact that you don't understand something should lead you to ask questions, not assert unwarranted conclusions.

Actual Physicist ?? Anti-deSitter space refers to the intrinsic curvature of space-time, absent matter and due to the energy density of the vacuum ( Cosmological Constant ? ), having the opposite sign of deSitter space, hence having hyperbolic curvature and negative Cosmological Constant. I have never read or heard the term anti-time, and would not know what it means. Although in Feynman diagrams, anti-particles can be treated as particles travelling backwards in time.

Americans, or about half of them, are their own worst enemies.

In GR, gravity is actually sourced by stress-energy-momentum. And as Studiot said, fields including the gravitational field itself, are a source.

Really ? AI and Quantum Computing have, so far, been worthless, and may never amount to much. Although Chinese strides in Fusion Reactor research is commendable. But when it comes to actual, useful research, like developing a successful mRNA vaccine in less than a year, as the Americans did, how did China and India make out ?

I don't know why you guys think this is funny. We are all old, and showing signs of Classical Testicular Extension.

A 'classical' Black Hole conserves three parameters; mass, angular momentum and charge. A semi-classical treatment ( with some QM considerations ) adds entropy ( see J Bekenstein ), and temperature. These properties are 'encoded' in the size/shape of the Event Horizon ( no other features are evident ), but mass/energy-momentum means it will curve space-time and exhibit gravity just like any other massive energetic body. The extreme conditions go even further and it will actually 'drag' space-time, rotating it with its angular momentum.

Why do all your questions seem like homework questions ? They are not general interest but relate to specific problems such as would be found in homework assignments.

Not a cosmologist, and I don't think you need be to offer an answer 🙂 . Hawking radiation depends on a mechanism facilitated by the Event Horizon. IOW, no Event Horizon >> no Hawking Radiation. Neutron stars have no Event Horizon, have a temperature and so produce regular radiation, and also directed gamma rays, because of the rapid rotation/strong magnetic fields. They are composed mostly of extremely dense, degenerate neutrons, and this degenerate pressure ( Pauli exclusion ) keeps them from further collapse. Electron degeneracy pressure keeps white dwarf stars from further collapse, but more massive stars can overcome this pressure and collapse to neutron stars supported by neutron degeneracy. When a star is massive enough such that even neutron degeneracy pressure cannot prevail against gravity, we know of no other mechanism to prevent further collapse. At the mathematical radius where escape velocity becomes equal to c , an Event Horizon is established by nature, and no further information can reach us regarding to the interior composition. The very equations that predict the gravitational collapse, become non-sensical and predict a singularity; an indication that those equations are no longer applicable in that domain. So, while we can say a neutron star is made of dense matter, we can't really say anything about what is inside the Event Horizon of a Black Hole with any certainty. We know a singularity makes no sense, but we know of no mechanism which will prevent any matter from collapsing to one.

This guy's channel ( Physics Explained - YouTube ) has some very interesting videos. He got his PhD at Queen Mary in London, and lectured at Liverpool, before recently quitting to pursue YT interests. Interestingly ( @studiot ), one of his videos relates to the empty space, or 'nothingness', within the atom, and what the fields of QFT tell us about it.

Geodesics continue through the event horizon. In free fall you are moving along a geodesic and experience no forces. Even partially crossing the EH ( assuming the BH is large enough that tidals are trivial ) you will experience no forces. If you are pulling a rope up against any gravitational field you are doing work and expending energy. In effect, you are keeping the rope from travelling along the geodesic and changing its momentum wrt time; the rope will feel a force.

That seems to be your problem; you don't understand stuff, so you make shit up. Are you following the MO of your President ?

Information, including cause and effect, travels at the finite speed of light. You cannot have the same 'now' as an event 1 light year away, for another year. You can always do the 'back calculation', but that is not the same thing. There is no global now. Even a local now is an approximation. Stop confusing yourself with your thought experiments. ( incidentally, pennies are binary, having two states, so binary notation is 2n, where n is the number of pennies. Anyone who grew up in the early days of computers knows about the address space relation to bit length )

Oh, now I understand what you were getting at ( Markus worded it more clearly 🙂 ). False vacuum states are necessarily unstable, and tend to decay, eventually reaching the ground state. Would it not be these fields that go on to infinity ( Space-Time Geometry or Gravitational field, Higgs Field, and possibly EM Field or Photon field ) ) that provide the global energy density ? The source/sink fields only provide a local energy density.