steady state theory

American  

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.

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steady-state theory British  

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

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steady state theory Scientific  

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.

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Etymology

Origin of steady state theory

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 • Apr. 11, 2020

Hoyle thus resurrected his old steady state theory in a new and improved form.

From Scientific American • Apr. 11, 2020

Philosophically, I really liked the steady state theory, with no beginning and no end.

From Slate • Mar. 2, 2014

Robert Wilson: As a graduate student, my one cosmology course was taught by Sir Fred Hoyle, a British astronomer who was a proponent of the Big Bang's biggest competitor, the steady state theory of the universe.

From Slate • Mar. 2, 2014

The steady state theory therefore had to be abandoned.

From "A Brief History of Time: And Other Essays" by Stephen Hawking