Galactic metabolism

RSI holds that a galaxy is a fractal copy of the universal toroid. It repeats the same pattern at a smaller scale and acts as a local refinery for the Eternal Consonance. Matter spirals in toward the galactic center, where it gathers into a black hole.

In RSI a black hole is the deepest possible pressure shadow. With enough mass in a small enough space, the slackening becomes total as seen from far away: at a certain surface every wave, as a distant observer sees it, slows to a stop, and light trying to climb out loses all its frequency. That surface is the event horizon, and nothing that moves at or below the speed of light comes back from inside it. To someone falling through it, nothing special happens there. Deriving the horizon's exact size from the medium is still to be done.

RSI proposes that somewhere inside, the balance that keeps knots whole finally fails, and they unzip back into pure vibration of the field. This is the localized Still Core. RSI holds that there is no singularity, because the medium cannot bend more sharply than the Planck length and its tension is finite, though the interior has not yet been worked out in detail.

Two questions remain open. Where the information carried by infalling matter is kept must respect the finding of Bekenstein and Hawking that a black hole's information capacity grows with the area of its horizon. And the jets that active black holes drive are launched just outside the horizon, and the leading model powers them with the black hole's spin through magnetic fields, so how energy from knots unzipping inside could reach them is open. Laboratory experiments show that horizons, and the glow Hawking predicted, arise naturally for waves in a flowing ultracold gas; they show the mathematics is at home in a medium, though they do not by themselves test RSI.

RSI also proposes that a galaxy's black hole is first a result of its gathering matter and only then a cause. Stellar black holes form when massive stars collapse, and giant black holes are generally thought to grow from what falls into them. A galaxy's central black hole holds only about 0.1 to 0.5 percent of the mass of its central bulge, far too little to steer the galaxy's rotation, which RSI credits to the galaxy's vortex. Once formed, an active black hole becomes a regulator: its jets heat and push out gas, limiting star formation, and in RSI each one helps drive the cosmic circuit.

The James Webb Space Telescope has found black holes that seem too massive to have grown from small seeds in the time standard cosmology allows; its own leading explanation is heavy seeds formed by direct collapse. The one in the galaxy UHZ1, seen at a redshift of about 10, is roughly as massive as all the stars around it. RSI's universe has no beginning, so such a black hole need not have grown in the time since the trough. RSI proposes that these are remnants from before the trough of the medium's breathing, matter that never passed through the Still Core in an earlier cycle, around which new galaxies are gathering. RSI must show that a black hole can survive the trough. A remnant black hole returns no heavy elements to the gas around it, since what falls inside unzips, so the galaxy gathering around it can still be young and poor in heavy elements. Why such black holes turn up mainly far away, and why distant galaxies tend to be smaller, bluer and poorer in heavy elements, is taken up in the Chapter XIII explanation on galaxies at great distances.