critical density

American  

[krit-i-kuhl den-si-tee] / ˈkrɪt ɪ kəl ˈdɛn sɪ ti /

noun

Physics.

1. the density of a pure element or compound at a critical point.

   If space has positive curvature, the actual density of matter must be larger than the critical density.

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critical density British  

noun

1. the density of matter that would be required to halt the expansion of the universe

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Etymology

Origin of critical density

First recorded in 1885–90

Example Sentences

A tipping point will occur when there is such a critical density of objects in orbit that one collision could set off a chain reaction and take those systems offline, the report says.

From Los Angeles Times • Oct. 26, 2023

But even if we add an estimate of the dark matter outside galaxies, our total won’t rise beyond about 30% of the critical density.

From Textbooks • Oct. 13, 2016

If the average mass-energy density of space is equal to the critical density on average, how much space would be required to produce a total mass-energy equal to a dust grain?

From Textbooks • Oct. 13, 2016

If the actual density is higher than this critical density, then the expansion will ultimately reverse and the universe will begin to contract.

From Textbooks • Oct. 13, 2016

There may be some laws about this kind of communication, mandating a critical density and mass before it can function with efficiency.

From "The Lives of a Cell" by Lewis Thomas