I tweet much more than I blog… @qraal
Yesterday I tweeted a bunch of preprint links on Black Holes, most of which I was revisiting for the first time in years. Many of the preprints had been revised since I first read them on the arXiv, so they’re worth revisiting in a little more detail here.
This one needs much more attention in discussions of Kardashev III Civilizations, since many of the supposedly null search results were assuming K-III Civilizations that shroud the stars of their galaxies. But what if they industrialise their Galactic Core? Many Active Galactic Nuclei (AGNs) and Quasars (QSOs) so rapid variability and weird iron ionizations, which presently don’t have particularly solid models. So there’s room for an ETI explanation for such data… Type III Dyson Sphere of Highly Advanced Civilizations around a Super Massive Black Hole
The Dyson Sphere doesn’t have to fully enclose the Super Massive Black Hole (SMBH) to capture usable amounts of accretion energy from the infalling matter. There’s good reasons to leave the poles clear. With that in mind, one wonders about the apparent structure (an emission source is meant not built things) that has been observed near the putative Event Horizon of the Milky Way’s own SMBH. Could it be related?
On a smaller scale, there’s energetic and computational reasons why advanced Civilizations might want to tame smaller mini-quasars in the Galaxy at large… Black Holes: Attractors for Intelligence?
Russians always seem to think big. Could Black Holes themselves be like Brains? Cosmic Intelligence and Black Holes …looking at the analogy between the various horizons of a Kerr-Newman black hole and the layers of the brain, in the context of the Holographic Principle. Analogies… but maybe more?
One reason to tame the SMBH is to avoid the inner kiloparsec from being utterly uninhabitable… The habitability of the Milky Way during the active phase of its central supermassive black hole
There’s likely an incredible number of closely packed stars, and tens of thousands of planets per star, close to the SMBH, which makes for a Galactic Empire level of real estate – thus powerful motivation to tame the emissions from the Core. X-rays glow from big bubbles north and south of the Core, indicating it has had recent outbursts in the last few kiloyears. Whether those emissions were at lethal levels for any denizens of the Core, I’m unsure, but I do wonder what our ancestors saw when it was at its peak. Was the Heart of the Milky Way some sort of Sign-Post in the sky?
An intriguing question is what life would see on a planet orbiting close to an SMBH… Life under a black sun
This was visualised on the fictional Miller’s Planet, in the epic movie “Interstellar”, on which an hour was time-dilated to several years when far from the SMBH – a dilation factor of 65,000. Unfortunately the microwave afterglow of the Big Bang (aka the CMB) is so blue-shifted on such a world that the sky itself is lethally hot. The orbit would need to be a bit further out, thus the time dilation not as dramatic as depicted. This preprint is a 2017 update of an original submission from 2016.
Another mode for life-sustaining energy from much smaller black holes is using the Hawking radiation as an energy source… Primordial Black Holes as Heat Sources for Living Systems with Longest Possible Lifetimes Though the power output of a Solar Temperature Black Hole is quite low, so I’m unsure this is a great resource.
A final possibility to mention is Carlo Rovelli’s Quantum Gravity idea that Black Holes will bounce due to quantum effects, but because of the extreme time dilation, the Bounce is seen by external observers as Hawking Radiation… Planck Stars
The remnant mass after the bounce that is no longer behind an event horizon could be quite substantial, which might mean ‘fresh’ mass in the very distant future that they re-emerge in. As protons are composite particles, they’re likely to have a expiry date (observed experimentally to be greater than 10^37 years) due to virtual black holes forming in their centres when their quarks’ wave-functions sufficiently overlap. Fresh concentrated mass in that very distant epoch will be an immeasurably valuable resource. Exactly what Life will survive into that era I’ve no idea beyond the vague hand-wave that it’ll involve leptons, by necessity.
On that final thought, it’s been a mathematical curiosity for decades that electrons and the Kerr-Newman solutions of black holes share a lot in common. Could a viable model of the electron be staring us in the face? Elementary Superconductivity in Nonlinear Electrodynamics Coupled to Gravity
If I understand the author’s historical discussion, one problem of the Kerr-Newman solution was the ring singularity. But what if that’s a feature and not a flaw? Could electron singularities explain the ER=EPR conjecture? That quantum entanglement is a wormhole, from a certain point-of-view?