The Uncounted Worlds

Posted: 2011-09-28
Last Modified: 2021-05-17
Word Count: 1364
Tags: penandpapergames rpg
This essay originally appeared in multiple parts on the Pen and Paper Games Forum. Only some markup (markdown) has changed.

This is an alternate worlds / time travel idea I might use in the future.

The Basic Model

The “Many Worlds” interpretation of quantum mechanics posits that a new universe springs into existence to account for all possibilities. The massive number of quantum events each second would spawn billions of universes. For all practical purposes, there are four categories of alternate timelines:

  1. “The fuzz” consists of universes which differ unnoticeably or trivially from each other. A few extremely powerful beings can manipulate the fuzz to their advantage, but for most travelers it simply makes crossing timelines harder. The “fuzz” ends once one gets far enough into interstellar space; with less matter fewer alternate universes spawn. Consequently, universe jumping becomes much easier in interstellar space. Faster-than-light travel between planets or star systems can also dump the unaware into an alternate version of that planet.

  2. A hysteresis arises when an event creates two timelines resolve to the same end result. The alternate timeline essentially merges back into the branch, creating a single timeline again. Many time travelers try to “set history right” by converting a major divergence into a hysteresis.

  3. At major decision points, different versions of the same event create distinct alternate universes called “branches” or “timelines”. New branches arise naturally at points where a small change can have huge consequences, although travelers from other timelines can, unwittingly or deliberately, interfere with history and spawn another branch. Ethicists debate whether “cloning” a universe in this way is ethical because it creates life, or unethical because these new residents suffer the consequences of an altered time line.

  4. Beyond the branching alternate worlds lie the Anomalies: worlds of fantasy, worlds where sapient reptiles rule, worlds with different physical constants and natural laws. The further one travels from one’s home universe, the more variations accumulate, until universes can no longer sustain carbon-based sapient life.

Time Travel Paradoxes Resolved

The preceding hypothesis solves some classic time travel paradoxes, if we assume the following rules.

The Grandfather Paradox

Shooting one’s grandfather creates a decision point. In one branch, the traveler disappears – or is retroactively erased – from the point of view of observers within the time stream and time proceeds as it always did. In another branch, where the traveler ends up, the grandfather is dead, history changes (perhaps dramatically), and the traveler is now an anomaly, a person without a past.

Ontological Paradoxes, a.k.a. the Bootstrap Paradox

Information or objects “bootstrap” from a parent universe to a new branch. For example, a time traveler jumps backward to give something to his past self. This creates a branching point: along one timeline, the past self never received the object, and in the other he did. The traveler will remember the original timeline in which his past self never got the object.

This gets trickier with information. For example, someone travels backward in time to dictate Hamlet to Shakespeare. Who, then, wrote Hamlet? The time traveler may say the Shakespeare of the original timeline who never received the book. However, this presumes Shakespeare (or someone using his name) would have written Hamlet without interference.

The Predestination Paradox, a.k.a. Causality Loops

Since all possibilities happen simultaneously, a traveler creates a new decision point and a new timeline when and where he travels into the past. In one timeline, he disappeared into a time machine and history proceeds as if he ceased to exist; in the other, he arrives to begin the causal loop.

Consequences of Time Travel

Time travel, as described, moves a traveler back and forth along timelines. From the perspective of a naive time traveler, there’s only one timeline that changes every time the traveler changes the “past”.

Some other consequences of this model:

The observant might note that the “fuzz” consists of hystereses which are too brief or too similar to the major timeline for most travelers to notice.

Other Modes of Travel

Many worlds believe theirs is the only timeline. Even “time travelers” believe in only one real timeline; the others cease to exist when the past changes. Previous timelines become inaccessible through linear time travel, so nothing in their science disproves their theory.

Sufficiently advanced travelers have means beyond these simple “time machines”. World Jumpers can identify a parallel time line in infinite-dimensional space and “jump” to it directly. Jumpers typically arrive at a point in space-time equivalent or at least analogous to the point they left. Consequently, jump does not create a cloned timeline, since the jumper is not native to that time line, nor did he move backwards along it.

Postscript (2021-05-17)

Other people have already used some or all of these ideas. E.g. Ryan North’s How To Invent Everything posits time travel forks off a new copy of the universe, so stranded time travelers can “change history” to their heart’s content, assuming they survive.