According to Softwareleverage, the earliest records of scientific observations, especially those aspects of nature that Indians, naturally inclined to abstract research, linked to the religious problem, date back to the Vedic cultural world. Astronomy, mathematics and medicine were the sectors of the sciences most under investigation and where, in many respects, discoveries that occurred in the Western world at a much later time were sometimes anticipated. Notions of astronomy are already found in the *Vedas*, the sacred books; however the interpretation of celestial phenomena is closely linked to religious beliefs and is only with the five books of the Siddhānta (treatise that exposes a complete system), whose composition dates back to the first centuries of the Common Era, that Hindu astronomy assumes precise characteristics and fits into the schemes of a more concrete scientific methodology. In this fundamental text, repeatedly later taken up and commented on by various authors, various topics are developed concerning the division of time, revolving movements of the stars, determination of meridians and cardinal points, equinoxes and solstices, lunar and solar eclipses, movements of the planets. To the sec. VI d. C. dates back to one of the first exposures in synthesis of the matter dealt with in the *Siddhānta* due to the astronomer Āryabhaṭa; the work, which took the name of Ā *ryabhaṭīya*, is in verse and in it astronomical calculations are particularly developed within a strictly geocentric system. Indian astronomical studies reached their climax, after which they no longer marked any progress, around the century. XII.

The theories developed in this period of time were collected in the treatise *Siddhāntaśiromaṇi* (The basic principle or diadem of the Siddhānta) by the astronomer and mathematician Bhaskara (or Bhāskarācārya); the pivotal points that are clearly established there are: sphericity of the Earth, position of the poles and of the equator, rotation on its own orbits of the Sun, the Moon and the five planets then known around the Earth which is immobile in space, distinction between solar day and sidereal day, subdivision of the solar year into twelve months and six seasons, precession of the equinoxes and theory of epicycles. The mathematical sciences in ancient India were mainly cultivated as a function of astronomical calculations. However, notions of geometry required for the construction of the altars and for the preparation of the sacred areas, were already known in the Vedic era and collected in a series of aphorisms, the *Sulvasutra*, which reveal good knowledge of plane geometry, solve problems of proportions and surface equivalences (including the wording of the Pythagorean theorem), provide the value of π with considerable approximation. As for pure mathematics, in which the Indians have achieved results of fundamental importance (such as the discovery of positional notation and that, very remarkable, of zero, mathematical transposition and symbolic reproduction of the *sunga*, which in Sanskrit means both empty and zero at the same time), the most notable works are included as integral sections of astronomy treatises. The oldest text is included in the *Āryabhaṭīya* and it is a real arithmetic manual containing various methods of addition, subtraction, multiplication and division even with fractional numbers. The mathematical knowledge, and even more the algebraic one, is better developed in the parts dedicated to them of the works of Brāhmagupta and Bhaskara who came to find the general solution of the indeterminate equations of first and second degree and, in particular cases, also of algebraic problems third degree. The knowledge of trigonometry was also good and it seems probable that the Hindus were responsible for introducing the concepts of sine and cosine. Medicine was the other great science of India with an oral and written tradition that dates back to the Vedic period and is largely linked to religious beliefs.

The first texts written according to a precise scientific methodology date back to the beginning of the Christian era; the best known are the *Carakasaṃhitā* (The collection of Caraka), medical compendium which, in the original draft, has been dated as dating back to the century. II d. C., and the *Suśrutasaṃhitā* (The collection of Suśruta), a treatise on surgery slightly earlier than the previous one. Both collect theories pre-existing at the age in which they were systematically drafted, but, while in the first the notions of general medicine and pharmacopoeia prevail, in the second numerous types of surgical interventions are described that indicate the development and perfection achieved in this field by Hindu medicine. Based on the concept of life force, different from person to person and even in the same person according to various ages and circumstances, on the deep knowledge of the relationship between psychology and physiology (*yoga*) and on the premise that the human body lives for the harmony of the individual parts, Hindu medicine came to formulate concepts anticipating modern endocrinology, such as the theory of the three *doṣa*, or primary forces, that is, the force of anabolism, the force of catabolism and the nervous force, to which the three humors are connected: phlegm, bile and wind. The most characteristic aspect of Hindu medicine is its limitation to the description of the phenomenon, as well as the lack of a real etiology. In the face of illness, nothing was possible but to alleviate the pain and suffering. Hence the great development of pharmaceuticals in ancient India starting from the century. III a. C. All the pharmacology treaties of the time recommended the use of metal preparations, the most common of which were based on gold and mercury as tonics; the use of soporific powders to be inhaled and drugs to provoke local anesthesia in surgical operations was also particularly widespread. In the end, veterinary medicine and phytotherapy were included in medicine for the Indian conception of life which embraces all its aspects as an expression of the one divine principle. Many of these theories and practices of traditional Indian medicine fall under the concept of *ayurveda* (science of life), method of treatment and research of harmony between body and mind, halfway between medicine and philosophy, spread also in the West starting from the last years of the twentieth century.