steady state theory

noun

, Astronomy.

1. a theory in which the universe is assumed to have average properties that are constant in space and time so that new matter must be continuously and spontaneously created to maintain average densities as the universe expands.

steady-state theory

noun

1. a cosmological theory postulating that the universe exists throughout time in a steady state such that the average density of matter does not vary with distance or time. Matter is continuously created in the space left by the receding stars and galaxies of the expanding universe Compare big-bang theory

steady state theory

1. A cosmological theory stating that the universe has always expanded at a uniform rate with no beginning or end, that it will continue to expand and have constant density, and that the distribution of old and new objects in the universe is basically even. The theory has been largely abandoned in favor of the big bang theory, largely due to the discovery of quasars and other entities that appear only at very great distances, suggesting an absolute relationship between the age of objects and their distance. Steady state theory was also discredited by the discovery of cosmic background radiation , which was predicted by the big bang theory but not by the steady state theory.

Word History and Origins

Origin of steady state theory¹

First recorded in 1950–55

Example Sentences

He, Gold and Bondi thus invented the steady state theory, which posited that the universe is infinite both in space and time and constantly generates new matter through some still-unknown mechanism.

From Scientific American

Even the most radical alternative—the latest incarnation of the steady state theory—does not dispute that the universe is expanding and cooling.

From Scientific American

Another theory, the steady state theory, also succeeds in accounting for the expansion and homogeneity of the universe.

From Scientific American

Critics found the steady state theory, which holds that the universe has always existed more or less in its current form, more elegant and plausible.

From Scientific American

The proposal that gained widest support was called the steady state theory.

From Literature