Lineage of the Multiverse I had a thought a good 10 years or so ago about our universe being contained entirely inside of a black hole and made up of the matter that fell into that black hole. Recently I have been learning about astrophysicists considering this hypothesis as well and finding some basis to support it. I find the idea fascinating because if true then that probably means that there are smaller universes inside some of (all?) of the black holes in this universe (child universes). Also, the "parent universe", the one in which our black hole exists, would necessarily need to be orders of magnitude larger than our own. In addition, there would be other sibling universes in other black holes within our parent universe and our parent universe could be inside of a black hole in a grandparent universe. Likewise we could have grandchild universes. So I started to contemplate what it would feel like if you could travel into these other universes, either child, parent, or otherwise. Would it feel smaller being in a child universe? Would it feel bigger being in a parent universe? Could a universe feel bigger than ours because it feels pretty damn big. Let's first take the idea of a child universe. We go to a black hole in our universe, maybe the super-massive black hole at the center of our galaxy, and we somehow go into it without dying or if dying then being able to reconstitute ourselves out of the matter of that universe as a living, breathing, thinking, self-aware, universe aware being and also retaining (or recapturing) our memories of this universe. Does it *feel* smaller? Is it measurably smaller? Or does it appear and measure nearly the same because everything is smaller. Parsecs are smaller, Astronomical Units are smaller, Meters are smaller, we are smaller, everything is universally reduced. Are atoms smaller? Are electrons smaller? What about proton, neutrons, quarks, strings? Or are things just more compressed? Is there less nothingness between the nucleus of an atom and it's orbiting electrons? Is there less nothingness between the subatomic particles? If there is a non-shrinkable thing, maybe a string if strings even exist, then that puts a lower limit on how small a universe can be and how many child universes there are. Given that assumption then perhaps we can use the size of the nothingness in atoms in our universe (or even the distances between stars) to determine where we are in the family tree of multiverses? Is ours rougly center in the lineage of parent and child universes (the lineage of the multiverse)? This same would probably hold true in parent universes, if you could go there then everything (including yourself and all units of measurement) would be bigger so it would seem roughly the same size as the universe we're in now. How spread out can a universe be and still function, still have black holes? How much nothingness inside of an atom can exist before it can't form bonds and build matter? This would put an upper limit on how many universes exist in the lineage of the multiverse. If it's too spread out then there wouldn't be enough material coalescing to form black holes and therefore couldn't be a parent to child universes. Could this also help us answer the question: "What is the fate of our universe?" We used to think there was enough matter that the expansion would eventually slow, stop, and begin to reverse eventually ending in a "Big Crunch" and starting a whole new Big Bang, thus making our universe cyclical (repeating). But the latest math on the amount of matter in the universe suggests there isn't enough matter and the universe will continue to expand and cool and stars, galaxies, globular clusters, etc... would grow more distant until no more light could be seen and no more heat could be felt. We would cool and die. But maybe now we can ask what is the fate of a black hole? Does it grow without bounds? Does it eventually dissipate and die due to Hawking Radiation? How long would that take? Can we use that knowledge to determine the fate of our universe since it's intrinsically tied to the fate of the black hole it's contained in (or, maybe more accurately "it is", not just "it is contained in", IE: we are a black hole rather than we're in a black hole). One, much less scientific pondering, is this: Are the events happening in this black hole actually new and unique and happening here or is it a projection of events that occurred long ago in the parent universe. Is our entire universe merely a screen onto which is projected a movie? Some period of time, so long ago we don't have a name for that measurement of time, in a parent universe, or a grandparent universe, or great^n grandparent universe there sat someone writing a Phlog post about black holes. Or, am I doing it now? Is it live or Memorex? .