Fig. 0. God starting the Universe.

Why did the big bang go boom? Have there been other big bangs that produced other universes with their own physical laws? What is this black matter and corresponding black energy that permeate the Universe, invisible and untouchable, yet spinning the very galaxies like so many pizzas? And what about black holes – what mysteries lie within their obfuscated cores?

These are questions that are perhaps of more interest to the layman and the reader of science fiction than they are to the physicist, who is more concerned with the observable features of the universe than with such hypothetical speculation. Yet the concepts behind such questions are not beyond the scope of science; it is primarily a difference of framing. The aim here is to examine some of these enigmas with a mixture of the two approaches and see if we can’t come up with a plausible, if somewhat whimsical, scenario about how things might work.

We will start by examining what is perhaps the most puzzling gap in our current understanding of the big bang, the so-called Baryon Asymmetry Paradox, which asks why there was more matter than anti-matter in the early universe.¹ (If there had been equal amounts, the result would have been a completely empty universe!) Not only does the Baryon Asymmetry Paradox thwart science’s efforts to explain its cause, it also poses a philosophical conundrum. Symmetry – recall, “every action has an equal and opposite reaction” – pervades all conceptual thinking about physics. Something like the Baryon Asymmetry just seems wrong -  akin to  a magnet where one side was significantly stronger than the other.

It is here that we will pull from our hat (or our ass), one of science fiction’s favorite notions: the alternate universe located “within” a black hole. While on its face, this concept conjures up images of sweaty, Mountain Dew-fueled role playing sessions, what we mean by “alternate universe” is simply an entirely inaccessible region of space-time.²
However, before explaining how the Baryon Asymmetry Paradox might be resolved by the existence of alternate universes within black holes, black holes have a paradox of their own that must first be discussed. This paradox, known as the Black Hole Unitarity Paradox, arises from the fact that while we can determine a black hole’s mass (as well as its spin and electrical charge), we cannot determine what it is “made of.” It is simply a black hole. The reason for this is something known as the “event horizon,” which surrounds black holes.

Due in part to the time dilation experienced by an object accelerating towards a black hole as its velocity approaches the speed of light, the event horizon is an asymptote, across which no information of any kind may pass. Were we to observe a spaceship as it was drawn into a black hole, it would appear to slow down, becoming redder and dimmer as it neared but never crossed the event horizon. Likewise, once something has passed through the event horizon, all information about it is lost. This creates a paradox, because information, like many physical properties, is thought to be conserved. Given a set of objects and their states (e.g. pool balls and their velocities), we should be just as able to calculate where they were, as where they will be. However, once something has crossed the event horizon, this is no longer the case.

Fig. 12. Harmonious oscillation produced by a black hole, as seen via radio-ethnography.

So where does that information go?

What we would suggest is that it goes “into” an alternate universe. But before you get out your d20, understand that we are not talking about any kind of mystical portal here. Rather, the difference between a “black hole” and an “alternate universe” is simply a matter of perspective. If one is on the outside of an event horizon, the object in question appears finite, and we see it as a “black hole.” If the event horizon surrounds the observer, creating an impression of infinite space, she will describe the “object” as a universe. In a sense, then, a universe can be thought of as an inside-out black hole, with matter and energy expanding outward instead of being pulled inward, and black matter and energy  being the material that continues to fall into the parent black hole, their non-localized nature being a sort of inverse to the Black Hole Unitarity Paradox.

Since universes within black holes could contain their own black holes, and since a universe with more matter (or anti-matter) remaining after the annihilation of particles and anti-particles would have more material to spawn “child” universes, a slight initial baryon imbalance would quickly escalate into the asymmetry observed in this universe as we progressed further “inward,” much as all forms of life on Earth display the same “handedness” of proteins, despite the fact that the two variations are chemically identical and would normally form in equal quantities. This evolution of asymmetry is aided by something known as Hawking Radiation – the slow leaking of energy by black holes in the form of particle/anti-particle pairs, one of which escapes and one of which falls back into the black hole – and the proliferation of micro black holes in the hot, dense aftermath of the big bang³, which would be statistically more likely to be significantly imbalanced due to their small size.

If this is the case, then our universe should continue to expand until, eventually, as our parent black hole consumes everything within its reach, black matter and energy levels fade, and the universe begins to dissipate through Hawking Radiation, ending, as T.S. Elliot put it, “not with a bang but a whimper.”

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1. A similar problem exists regarding the unidirectionality of time.

2. If you are mathematically minded, you can imagine moving along the graph of y=1/x from negative infinity towards zero. No matter how far you travel, you will never get to the positive side. Like the “point” at x=0 in our equation above, black holes are what are known as singularities: gaps, or (if you will) holes, in the continuity of the universe.

3. This of course still begs the question of the origin of the initial black hole and the quantum properties that made it possible. However, it seems more palatable to imagine the universe as booting itself up through a series of gradually escalating processes, rather than coming into being ex nihilo.