Editing World line (section)

==World lines in literature==
In 1884 [[C. H. Hinton]] wrote an essay "What is the fourth dimension ?", which he published as a [[scientific romance]]. He wrote
:Why, then, should not the four-dimensional beings be ourselves, and our successive states the passing of them through the three-dimensional space to which our consciousness is confined.<ref>{{cite book|first = C. H.|last = Hinton|author-link = C. H. Hinton|year = 1884|title = Scientific Romances: First Series|publisher = [[Swan Sonnenschein|S. Sonnenschein]]|chapter-url = https://archive.org/stream/scientificroman01hintgoog#page/n24/mode/2up|chapter = What is the fourth dimension?|pages = 1–32}}</ref>{{rp|18–19}}

A popular description of human world lines was given by [[J. C. Fields]] at the [[University of Toronto]] in the early days of relativity. As described by Toronto lawyer Norman Robertson:
:I remember [Fields] lecturing at one of the Saturday evening lectures at the [[Royal Canadian Institute]]. It was advertised to be a "Mathematical Fantasy"—and it was! The substance of the exercise was as follows: He postulated that, commencing with his birth, every human being had some kind of spiritual aura with a long filament or thread attached, that traveled behind him throughout his life. He then proceeded in imagination to describe the complicated entanglement every individual became involved in his relationship to other individuals, comparing the simple entanglements of youth to those complicated knots that develop in later life.<ref>{{cite book|author-link = Gilbert de Beauregard Robinson|first = Gilbert de Beauregard|last = Robinson|year = 1979|title = The Mathematics Department in the University of Toronto, 1827–1978|page = 19|publisher = [[University of Toronto Press]]|isbn = 0-7727-1600-5}}</ref>

Kurt Vonnegut, in his novel ''[[Slaughterhouse-Five]]'', describes the worldlines of stars and people: 
:“Billy Pilgrim says that the Universe does not look like a lot of bright little dots to the creatures from Tralfamadore. The creatures can see where each star has been and where it is going, so that the heavens are filled with rarefied, luminous spaghetti. And Tralfamadorians don't see human beings as two-legged creatures, either. They see them as great millepedes – "with babies' legs at one end and old people's legs at the other," says Billy Pilgrim.”

Almost all science-fiction stories which use this concept actively, such as to enable [[time travel]], oversimplify this concept to a one-dimensional timeline to fit a linear structure, which does not fit models of reality. Such time machines are often portrayed as being instantaneous, with its contents departing one time and arriving in another—but at the same literal geographic point in space. This is often carried out without note of a reference frame, or with the implicit assumption that the reference frame is local; as such, this would require either accurate teleportation, as a rotating planet, being under acceleration, is not an inertial frame, or for the time machine to remain in the same place, its contents 'frozen'.

Author [[Oliver Franklin]] published a [[science fiction]] work in 2008 entitled ''World Lines'' in which he related a simplified explanation of the hypothesis for laymen.<ref name="Franklin">{{Cite book |author=Franklin |first=Oliver |title=World Lines |publisher=Epic Press |year=2008 |isbn=978-1-906557-00-3}}</ref>

In the short story ''[[Life-Line]]'', author [[Robert A. Heinlein]] describes the world line of a person:<ref>{{Cite web|title=Technovelgy: Chronovitameter |url=http://www.technovelgy.com/ct/content.asp?Bnum=1851 |access-date= 8 September 2010}}</ref>

:He stepped up to one of the reporters. "Suppose we take you as an example. Your name is Rogers, is it not? Very well, Rogers, you are a space-time event having duration four ways. You are not quite six feet tall, you are about twenty inches wide and perhaps ten inches thick. In time, there stretches behind you more of this space-time event, reaching to perhaps nineteen-sixteen, of which we see a cross-section here at right angles to the time axis, and as thick as the present. At the far end is a baby, smelling of sour milk and drooling its breakfast on its bib. At the other end lies, perhaps, an old man someplace in the nineteen-eighties.

:"Imagine this space-time event that we call Rogers as a long pink worm, continuous through the years, one end in his mother's womb, and the other at the grave..."

Heinlein's ''[[Methuselah's Children]]'' uses the term, as does [[James Blish]]'s ''[[The Quincunx of Time]]'' (expanded from "Beep").

A [[visual novel]] named [[Steins;Gate]], produced by [[5pb.]], tells a story based on the shifting of world lines. Steins;Gate is a part of the "[[Science Adventure]]" series. World lines and other physical concepts like the [[Dirac Sea]] are also used throughout the series.

[[Neal Stephenson]]'s novel [[Anathem]] involves a long discussion of worldlines over dinner in the midst of a philosophical debate between [[Platonic realism]] and [[nominalism]].

Absolute Choice depicts different world lines as a sub-plot and setting device.

A space armada trying to complete a (nearly) closed time-like path as a strategic maneuver forms the backdrop and a main plot device of "Singularity Sky" by [[Charles Stross]].