Ayuga, in Hinduism, is generally used to indicate an age of time.[1][2]
In the Rigveda, a yuga refers to generations, a period of time (whether long or short), or a yoke (joining of two things).[3] In the Mahabharata, the words yuga and kalpa (a day of Brahma) are used interchangeably to describe the cycle of creation and destruction.[4]
Yuga (Sanskrit: युग) means "a yoke" (joining of two things), "generations", or "a period of time" such as an age, where its archaic spelling is yug, with other forms of yugam, yugānāṃ, and yuge, derived from yuj (Sanskrit: युज्, lit. 'to join or yoke'), believed derived from *yeug- (Proto-Indo-European: lit. 'to join or unite').[8]
The term "yuga" has multiple meanings, including representing the number 4 and various periods of time. In early Indian astronomy, it referred to a five-year cycle starting with the conjunction of the sun and moon in the autumnal equinox. More commonly, "yuga" is used in the context of kalpas, composed of four yugas. According to the Manusmriti, a kalpa starts with a Satya Yuga (4,000 years), followed by a Treta Yuga (3,000 years), a Dvapara Yuga (2,000 years), and ends with a Kali Yuga (1,000 years). According to Vishnu Purana, each Mahayuga comprises a Satya Yuga (1,728,000 human years), a Treta Yuga (1,296,000 years), a Dvapara Yuga (864,000 years), and a Kali Yuga (432,000 years).[9]
^The general word "yuga" is sometimes used instead of the more specific word "catur-yuga". A kalpa is described as lasting 1,000 catur-yugainBhagavata Purana 12.4.2 ("catur-yuga")[6] and Bhagavad Gita 8.17 ("yuga").[7]
^Sundarraj, M. (1997) [1st ed. 1994]. "Ch. 4 Asvins—Time-Keepers". In Mahalingam, N. (ed.). RG Vedic Studies. Coimbatore: Rukmani Offset Press. p. 219. It is quite clear that the smallest unit was the 'nimisah' ['winking of eyes'], and that time in the general sense of past, present and future was indicated by the word 'yuga'.
^Kane, P. V. (September 1936). Sukthankar, V. S.; Fyzee, A. A. A.; Bhagwat, N. K. (eds.). "Kalivarjya (actions forbidden in the Kali Age)". Journal of the Bombay Branch of the Royal Asiatic Society. 12. The Asiatic Society of Bombay: 1–2. The word yuga occurs at least thirty-eight times in the Rigveda, but the meaning is rather doubtful. In a few places yuga means yoke ... In many places it appears to refer to a very brief period ... Generally yuga appears to mean in the Rigveda 'generation' (lessening the life of human generations) ... In other places 'yuga' must be given the sense of a 'long period of time' ...
^González-Reimann, Luis (2018). "Cosmic Cycles, Cosmology, and Cosmography". In Basu, Helene; Jacobsen, Knut A.; Malinar, Angelika; Narayanan, Vasudha (eds.). Brill's Encyclopedia of Hinduism. Vol. 2. Leiden: Brill Publishers. p. 415. doi:10.1163/2212-5019_BEH_COM_1020020. ISBN978-90-04-17641-6. ISSN2212-5019. The cycle [of creation and destruction] is either called a yuga (MBh. 1.1.28; 12.327.89; 13.135.11), a kalpa, meaning a formation or a creation (MBh. 6.31.7 [= BhG. 9.7]; 12.326.70; 12.327.23), or a day of the brahman, or of Brahmā, the creator god (MBh. 12.224.28–31). Sometimes, it is simply referred to as the process of creation and destruction (saṃhāravikṣepa; MBh. 12.271.30, 40, 43, 47–49).
^Burgess, Rev. Ebenezer (1935) [1st ed. 1860]. Gangooly, Phanindralal (ed.). Translation of the Surya-Siddhanta, A Text-Book of Hindu Astronomy; With notes and an appendix. University of Calcutta. p. 9. The period of 4,320,000 years is ordinarily styled Great Age (mahayuga), or, as above in two instances [1.15-16], Quadruple Age (caturyuga). In the Surya-Siddhanta, however, the former term is not once found, and the latter occurs only in these verses; elsewhere, Age (yuga) alone is employed to denote it, and always denotes it, unless expressly limited by the name of the Golden (krta) Age.
^"Śrīmad-Bhāgavatam (Bhāgavata Purāṇa) 12.4.2". Bhaktivedanta Vedabase. Retrieved 2020-05-10. catur-yuga-sahasraṁ tu brahmaṇo dinam ucyate । sa kalpo yatra manavaś caturdaśa viśām-pate ॥ 2 ॥ (2) One thousand cycles of four ages [catur-yuga] constitute a single day of Brahmā, known as a kalpa. In that period, O King, fourteen Manus come and go.
^"Bhagavad-gītā As It Is 8.17". Bhaktivedanta Vedabase (in Sanskrit and English). Translated by A. C. Bhaktivedanta Swami Prabhupada. Bhaktivedanta Book Trust. 1968. LCCN68008322. WikidataQ854700. Retrieved 2020-05-10. sahasra-yuga-paryantam ahar yad brahmaṇo viduḥ । rātriṁ yuga-sahasrāntāṁ te 'ho-rātra-vido janāḥ ॥ 17 ॥ (17) By human calculation, a thousand ages [yuga] taken together form the duration of Brahmā's one day. And such also is the duration of his night.
