---
title: "World line"
chunk: 4/4
source: "https://en.wikipedia.org/wiki/World_line"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:51:27.089519+00:00"
instance: "kb-cron"
---

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.

== See also ==
Specific types of world lines
Geodesics
Closed timelike curves
Causal structure, curves that represent a variety of different types of world line
Isotropic line
Feynman diagram
Time geography

== References ==

Minkowski, Hermann (1909), "Raum und Zeit" , Physikalische Zeitschrift, 10: 75–88
Various English translations on Wikisource: Space and Time
Ludwik Silberstein (1914) Theory of Relativity, p. 130, Macmillan and Company

== External links ==
World lines article on h2g2.
In-depth text on world lines and special relativity Archived 12 April 2023 at the Wayback Machine