[Pramāṇa](https://indike.org/pramana/) › [Studies](https://indike.org/pramana/ins) › [Science, technology and education](https://indike.org/pramana/ins.science) › [History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray](https://indike.org/pramana/ins.science.ray-1956) › c40.s1 # History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c40.s1: Measures Of Time And Space History of Chemistry in Ancient and Medieval India, Incorporating the History of Hindu Chemistry by Acharya Prafulla Chandra Ray c40.s1 - **Language:** English ### Measures Of Time And Space ### [c40.s1.1](https://indike.org/pramana/ins.science.ray-1956.c40.s1.1) 30 \*kshanas\* = 1 day; 2 \*ghatikas\* = 1 \*kshana\*; 30 \*kalas\* = 1 \*ghatika\*; 30 \*kashthas\* = 1 \*kala\*; 18 \*nimeshas\* = 1 \*kashtha\*; 30 \*tatparas\* = 1 \*nimesha\*; and 100 \*trutis\* = 1 \*tatpara\*. ### [c40.s1.2](https://indike.org/pramana/ins.science.ray-1956.c40.s1.2) This makes a \*truti\* of time equal to 1/33,750 of a second, which is nearly the measure of the \*paramanu\* of time, as given in Vishnupurana (\*vide\* Bhaskara's Siddhanta-Siromani circa 1150 A.D.). ### [c40.s1.3](https://indike.org/pramana/ins.science.ray-1956.c40.s1.3) The above measures were in use among the astronomers, but the physicists computed according to the following Table, given both in Udayana's Kiranavali and Sridhara's Nyayakandali: ### [c40.s1.4](https://indike.org/pramana/ins.science.ray-1956.c40.s1.4) 30 \*muhurtas\* = 1 day (24 hours); 30 \*kalas\* = 1 \*muhurta\*; 30 \*kashthas\* = 1 \*kala\*; 18 \*nimeshas\* = 1 \*kashtha\*; 2 \*lavas\* = 1 \*nimesha\*; 2 \*kshanas\* = 1 \*lava\*. ### [c40.s1.5](https://indike.org/pramana/ins.science.ray-1956.c40.s1.5) This makes 1 \*kshana\* of the Nyaya-Vaisesika equal to 2/45 of a second. The Nyaya assumes that the unit of physical change (or the time occupied by any single antecedent step in a causal series before the succeeding step is ushered in) is equal to a \*kshana\* (2/45 of a second). The astronomers were familiar with far smaller measures of time. ## Cites (2) - [Viṣṇupurāṇa](https://indike.org/pramana/in.purana.visnu) — Vyāsa, Sanskrit - [Siddhāntaśiromaṇi](https://indike.org/pramana/in.astro.siddhanta.early.siddhantasiromani) — Bhāskara II, Sanskrit --- Source: [https://indike.org/pramana/ins.science.ray-1956.c40.s1](https://indike.org/pramana/ins.science.ray-1956.c40.s1) · Pramāṇa