English Dictionary

dark hydrogen

noun

(physics) A state of hydrogen that is poorly electrically conductive (much less conductive than metallic hydrogen).

Dark hydrogen is a hypothetical form of hydrogen that is believed to exist in the universe.

意味（1）

(physics) A state of hydrogen that is poorly electrically conductive (much less conductive than metallic hydrogen).

One particular species of these candidates seems to be not dark at all: so-called dark hydrogen masses located in the optical Galactic disk.