English Dictionary

ylem

/ˈiːlɛm/

noun

(astronomy, cosmology, physics, now chiefly historical) In the Big Bang theory, the hot and dense plasma which made up the cosmos at the time of recombination in an early stage of its expansion and cooling, when the first atoms formed and photons decoupled. The ylem is regarded as the source of the cosmic microwave background.

Scientists believe that ylem is the primordial substance from which all matter in the universe originated.

意味（1）

(astronomy, cosmology, physics, now chiefly historical) In the Big Bang theory, the hot and dense plasma which made up the cosmos at the time of recombination in an early stage of its expansion and cooling, when the first atoms formed and photons decoupled. The ylem is regarded as the source of the cosmic microwave background.

Very shortly after the beginning of the universal expansion, the ylem was a gas of neutrons only. [Footnote: According to Webster's New International Dictionary, 2nd Ed., the word ‘ylem’ is an obsolete noun meaning ‘The primordial substance from which the elements were formed.’ It seems highly desirable that a word of so appropriate a meaning be resurrected.]