fourth dimension

American  

noun

1. Physics, Mathematics. a dimension in addition to length, width, and depth, used so as to be able to employ geometrical language in discussing phenomena that depend on four variables.

   Time is considered a fourth dimension for locating points in space-time.

2. something beyond the kind of normal human experience that can be explained scientifically.

   The story deals with ESP and other excursions into the fourth dimension.

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fourth dimension British  

noun

1. the dimension of time, which is necessary in addition to three spatial dimensions to specify fully the position and behaviour of a point or particle

2. the concept in science fiction of a dimension in addition to three spatial dimensions, used to explain supernatural phenomena, events, etc

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fourth dimension Scientific  

/ fôrth /

1. Time regarded as a coordinate dimension. A fourth dimension is required by relativity theory, along with three spatial dimensions, to specify completely the location of any event.

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Other Word Forms

• fourth-dimensional adjective

Etymology

Origin of fourth dimension

First recorded in 1870–75

Example Sentences

General relativity, proven accurate by countless tests and observations, suggests that gravity impacts not simply three physical dimensions but also a fourth dimension: time.

From Science Daily • May 1, 2024

As Diaz puts it, Calder worked in the fourth dimension — time.

From Seattle Times • Nov. 9, 2023

The fourth dimension offers unlimited space in which to unravel even the most complicated knot.

From Washington Post • May 22, 2020

Time, that fourth dimension, has always been an essential element in Pepper’s work — a desire to create something outside history, something bigger and more enduring than herself, than all of us.

From New York Times • Sep. 10, 2019

To understand Einstein’s universe, we have to accept the idea that time is the fourth dimension.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife