What is firmament definition?

The firmament, also known as the rakia (רָקִיע‎), is the structure above the atmosphere conceived as a solid, arched vault. According to some beliefs, it was created by a divine being to separate the "waters above" (rain, snow, etc.) from the "waters below" (oceans, rivers, etc.). The concept originates from ancient Mesopotamian cosmology and was adopted by the authors of the Hebrew Bible.

• It is seen as a physical barrier or dome.
• It holds celestial bodies like the sun, moon, and stars.
• It has "windows" or "gates" through which rain falls.

The concept of a firmament is often associated with ancient cosmologies and is not consistent with modern scientific understanding of the universe. Modern science demonstrates that the sky is not a solid dome but rather an atmosphere that gradually thins into the vacuum of space. The idea has been extensively discussed in relation to interpretations of the Hebrew Bible and ancient Near Eastern religious beliefs.