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Something like this: https://www.livescience.com/dark-energy-could-lead-to-a-second-and-third-and-fourth-big-bang-new-research-suggests https://www.livescience

Something like this: https://www.livescience.com/dark-energy-could-lead-to-a-second-and-third-and-fourth-big-bang-new-research-suggests https://www.livescience.com/dark-energy-could-lead-to-a-seco... If the ends of the spaghetti can never reach each other after space's rate of stretching passes the speed of light, then the spaghetti can never reach the pit. If the spaghetti never reaches the pit, then everything in the black hole falls forever. If everything falls forever, then the clock outside the block hole is synced to the clock of particles falling inside the black hole. Which suggests that a black hole forms an infinitely deep funnel, and if we entertain the idea that the rules of our universe keep working inside it, an hourglass. What does that look like? On Earth, space pours down our gravity well, reaching a stagnation point sometime before the center, which forms an indentation in spacetime which we ride in as we orbit the sun. In a black hole, there's still a stagnation point, if we consider the entire life of the black hole, including final evaporation. The bottom of the indentation falls at the speed of light, but eventually slows and rebounds as the black hole begins to shrink due to Hawking radiation, then springs back into our reality. In other words, the space inside a black hole is more dynamic than where we are. We're normally shown a picture of that falling floor tearing through our spacetime into an unknown place. But since the space is falling faster than the speed of light, I think that it crosses over itself and diverges, forming a white hole on the other side. The math of that white hole matches the math of the Big Bang. So we can picture the child universe as starting just like ours, and forming a sphere in the bottom of the hourglass expanding faster than the speed of light until its density gets low enough that the expansion proceeds at merely the speed of light. The same way that inflation worked in our universe. Particles at the edge of the sphere are able to leak back into the parent universe via Hawking radiation just like our galaxies at great distance slip out of our universe red-shifted faster than the speed of light. So the mass of the sphere begins to shrink, which slows its rate of expansion. Eventually its space starts to contract, [turning the child Hubble constant negative] <- edit: increasing its Hubble constant even higher. Everything begins to contract back towards one another. The edge of the sphere eventually rushes back inwards at the speed of light, creating a Big Crunch. It's not that matter is crushed together, but that space is contracting so fast out from under it that it has nowhere else to go but back up out of the throat. The final pop is reverse spaghettification, as each particle is torn apart back to quarks, electrons and energy back into the parent universe. The hard part to visualize is that the crunch happens inward towards each particle simultaneously, there is no center. The quantum mechanical aspect and notions like the Planck length are probably a distraction. An electron is always a point charge roughly the size of its uncertainty, in any spacial coordinate system. Maybe it has more mass and is a muon or tau (or something heavier), but it never stops being an electron fundamentally. When it spaghettifies in the throat, its wave function only has 2 degrees of freedom, along the radial axis and rotation, with the third degree along the time axis. Until space diverges again in the white hole on the other side and it's able to exist in 3D again. So our universe is the white hole on the other side of the black hole in the parent universe, and the universe is infinite, looking like swiss cheese with child universes and more black holes inside the bubbles. The centers of atoms may act like miniature black holes, but with slightly different rules involving the electroweak force and probability, creating an emergent force which we think of as the strong force. It's universes all the way down. This is the best mental model of reality that I've stumbled upon, but I'm sure it's wrong in important ways.

raattgift 4y ago
> I'm sure it's wrong in important ways I'm afraid so. I'll just pick on two important ways found in one of your key sentences, and I'll stick to widely accepted results from Hawking, Unruh, Gibbons and Giddings. > Particles at the edge of the sphere are able to leak back into the parent universe via Hawking radiation just like our galaxies at great distance slip out of our universe red-shifted faster than the speed of light. Firstly, Hawking radiation doesn't leak anything out of the black hole itself; it's produced by interactions between the outside matter fields and the dynamical spacetime outside an evolving black hole. Secondly, you have the relevant part of cosmic horizons backwards. They also produce a form of Hawking radiation in the far future. So, since nothing ever comes from inside the black hole's horizon even at final evaporation, or from outside the cosmic horizon, I don't see how you can recover your more cosmological ideas. Now some technical detail: The origin of Hawking radiation is well outside the horizon of the black hole. Quoting Unruh in <https://doi.org/10.1103/PhysRevD.78.041504 https://doi.org/10.1103/PhysRevD.78.041504> (corresponding to the preprint at <https://arxiv.org/abs/0804.1686 https://arxiv.org/abs/0804.1686>): "One way of achieving a better understanding of [why black holes seem to behave by thermal objects and evaporate by emitting Hawking radiation] is to study the origin of particles in black hole evaporation, .i.e., the question of where they are created." [authors' emphasis] The paper goes on to show that because Hawking radiation is a low-energy process, the origin of particles must be from a distance outside the horizon proportional to the radiation wavelength, and cannot originate very close to the horizon (much less from inside it). This follows from his earlier conference presentation <https://inspirehep.net/literature/775859 https://inspirehep.net/literature/775859> (pdf available at <https://pos.sissa.it/043/039/ https://pos.sissa.it/043/039/>), "Where are the particles created in Black Hole evaporation?" Giddings makes the same point in <https://www.sciencedirect.com/science/article/pii/S0370269316000022?via%3Dihub https://www.sciencedirect.com/science/article/pii/S037026931...> (open access, but easier to read as a preprint at <https://arxiv.org/abs/1511.08221 https://arxiv.org/abs/1511.08221>). From the abstract: "Where does Hawking radiation originate? A common picture is that it arises from excitations very near or at the horizon ... However, closer investigation of both the total emission rate and the stress tensor of Hawking radiation supports the statement that its source is a near-horizon quantum region, or "atmosphere," whose radial extent is set by the horizon radius scale". The last clause there is expanded in the text: "... the source of Hawking radiation is a quantum region of size \Delta r ~ R outside the black hole horizon" R there means the Schwarzschild radius, so particles originate in a fairly voluminous region with the lower edge at about a Schwarzschild radius above the black hole's horizon, i.e., at about 2R. On Hawking radiation from cosmic horizons, Gibbons and Hawking's 1977 paper 1<https://journals.aps.org/prd/abstract/10.1103/PhysRevD.15.2738 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.15.27...> details the production there. You can get this paper from <https://sci-hub.ru/https://doi.org/10.1103/PhysRevD.15.2738 https://sci-hub.ru/https://doi.org/10.1103/PhysRevD.15.2738>. "We have shown that the close connection between event horizons and thermodynamics has a wider validity than the ordinary black-hole situation in which it was first discovered. An observer in a cosmological model with a positive cosmological constant will have an event horizon whose area can be interpreted as the entropy or lack of information that the observer has about the regions of the universe that he cannot se. When the solution has settled down to a stationary state, the event horizon will have associated with it a surface gravity K which plays a role similar to the temperature in the classical first law of event horizons ... this similarity is more than an analogy: The observer will detect an isotropic background of therman radiation ... coming, apparently, from the event horizon". The 21st century updates from Unruh and Giddings applies to this 1977 paper by Gibbons and Hawking: "from the event horizon" -> "from a region closer to the observer than the horizon". The above assumes General Relativity is a good physical model at the length scales in question. If you don't assume that, then you might be able to ignore the results above if black holes and expanding space are substantially different from their standard descriptions in General Relativity. How different? Would the recent data from the Event Horizon Telescope still be produced? Would the waveforms from binary black hole and black hole-neutron star mergers found by LIGO and Virgo still be produced? Would the cosmic microwave background have the same temperature and power spectrum?

raattgift 4y ago

> I'm sure it's wrong in important ways I'm afraid so. I'll just pick on two important ways found in one of your key sentences, and I'll stick to widely accepted results from Hawking, Unruh, Gibbons and Giddings. > Particles at the edge of the sphere are able to leak back into the parent universe via Hawking radiation just like our galaxies at great distance slip out of our universe red-shifted faster than the speed of light. Firstly, Hawking radiation doesn't leak anything out of the black hole itself; it's produced by interactions between the outside matter fields and the dynamical spacetime outside an evolving black hole. Secondly, you have the relevant part of cosmic horizons backwards. They also produce a form of Hawking radiation in the far future. So, since nothing ever comes from inside the black hole's horizon even at final evaporation, or from outside the cosmic horizon, I don't see how you can recover your more cosmological ideas. Now some technical detail: The origin of Hawking radiation is well outside the horizon of the black hole. Quoting Unruh in <https://doi.org/10.1103/PhysRevD.78.041504 https://doi.org/10.1103/PhysRevD.78.041504> (corresponding to the preprint at <https://arxiv.org/abs/0804.1686 https://arxiv.org/abs/0804.1686>): "One way of achieving a better understanding of [why black holes seem to behave by thermal objects and evaporate by emitting Hawking radiation] is to study the origin of particles in black hole evaporation, .i.e., the question of where they are created." [authors' emphasis] The paper goes on to show that because Hawking radiation is a low-energy process, the origin of particles must be from a distance outside the horizon proportional to the radiation wavelength, and cannot originate very close to the horizon (much less from inside it). This follows from his earlier conference presentation <https://inspirehep.net/literature/775859 https://inspirehep.net/literature/775859> (pdf available at <https://pos.sissa.it/043/039/ https://pos.sissa.it/043/039/>), "Where are the particles created in Black Hole evaporation?" Giddings makes the same point in <https://www.sciencedirect.com/science/article/pii/S0370269316000022?via%3Dihub https://www.sciencedirect.com/science/article/pii/S037026931...> (open access, but easier to read as a preprint at <https://arxiv.org/abs/1511.08221 https://arxiv.org/abs/1511.08221>). From the abstract: "Where does Hawking radiation originate? A common picture is that it arises from excitations very near or at the horizon ... However, closer investigation of both the total emission rate and the stress tensor of Hawking radiation supports the statement that its source is a near-horizon quantum region, or "atmosphere," whose radial extent is set by the horizon radius scale". The last clause there is expanded in the text: "... the source of Hawking radiation is a quantum region of size \Delta r ~ R outside the black hole horizon" R there means the Schwarzschild radius, so particles originate in a fairly voluminous region with the lower edge at about a Schwarzschild radius above the black hole's horizon, i.e., at about 2R. On Hawking radiation from cosmic horizons, Gibbons and Hawking's 1977 paper 1<https://journals.aps.org/prd/abstract/10.1103/PhysRevD.15.2738 https://journals.aps.org/prd/abstract/10.1103/PhysRevD.15.27...> details the production there. You can get this paper from <https://sci-hub.ru/https://doi.org/10.1103/PhysRevD.15.2738 https://sci-hub.ru/https://doi.org/10.1103/PhysRevD.15.2738>. "We have shown that the close connection between event horizons and thermodynamics has a wider validity than the ordinary black-hole situation in which it was first discovered. An observer in a cosmological model with a positive cosmological constant will have an event horizon whose area can be interpreted as the entropy or lack of information that the observer has about the regions of the universe that he cannot se. When the solution has settled down to a stationary state, the event horizon will have associated with it a surface gravity K which plays a role similar to the temperature in the classical first law of event horizons ... this similarity is more than an analogy: The observer will detect an isotropic background of therman radiation ... coming, apparently, from the event horizon". The 21st century updates from Unruh and Giddings applies to this 1977 paper by Gibbons and Hawking: "from the event horizon" -> "from a region closer to the observer than the horizon". The above assumes General Relativity is a good physical model at the length scales in question. If you don't assume that, then you might be able to ignore the results above if black holes and expanding space are substantially different from their standard descriptions in General Relativity. How different? Would the recent data from the Event Horizon Telescope still be produced? Would the waveforms from binary black hole and black hole-neutron star mergers found by LIGO and Virgo still be produced? Would the cosmic microwave background have the same temperature and power spectrum?