Meaning
Supreme God Krishna spoke
As the day breaks on Brahmā's celestial abode, all living beings emerge from the Unmanifest {Nature}, and at the conclusion of his day, they retreat into the Unmanifest, where they rest until the next day. (8:18)
Sanskrit
श्रीभगवान् उवाच
अव्यक्ताद्व्यक्तयः सर्वाः प्रभवन्त्यहरागमे ।
रात्र्यागमे प्रलीयन्ते तत्रैवाव्यक्तसंज्ञके॥
Word-by-word
अ-व्यक्तात् व्यक्तयः सर्वाः प्र-भवन्ति अहः-आगमे,
रात्रि-आगमे प्र-लीयन्ते तत्र एव 'अ-व्यक्त'-सञ्ज्ञके।
Commentary
Supporters of the Big Bang theory acknowledge that the universe originated from a state of “nothingness.” As renowned scientist Stephen Hawking articulated, “At the big bang itself, the universe is thought to have had zero size” (“The Origin and Fate of the Universe” in A Brief History of Time). In addition to the concept of an expanding universe, there is also a contracting universe theory endorsed by numerous cosmologists and scientists. According to this theory, after a certain point, the expanding universe will begin to contract, ultimately culminating in the entire universe reverting to a state of “nothingness." Hawking's "nothingness" is indicative of the "unmanifest" or "Avyakta" in the verse, and closely aligns with what the Bhagavad-Gitā says about the origin and dissolution of the universe.