Indian Science

The history of science and technology in India begins with prehistoric human activity at Mehrgarh, in present-day Pakistan, and continues through the Indus Valley Civilization to early states and empires. The British colonial rule introduced western education in India. The British system of education, in its efforts to give rise to a native class of civil servants, exposed a number of Indians to foreign institutes of higher learning. Following independence science and technology in the Republic of India has included automobile engineering, information technology, communications as well as space, polar, and nuclear sciences.

Prehistory

Hand-propelled wheel cart, Indus Valley Civilization (3000–1500 BCE). Housed at the National Museum, New Delhi.

4500 BC in sites such as Kuehgllaldkjg in the Indo-Gangetic Plains.By 5500 BCE a number of sites similar to Mehrgarh had appeared, forming the basis of later chalcolithic cultures. The inhabitants of these sites maintained trading relations with Near East and Central Asia.

Irrigation was developed in the Indus Valley Civilization by around 4500 BCE. The size and prosperity of the Indus civilization grew as a result of this innovation, which eventually led to more planned settlements making use of drainage and sewers. Sophisticated irrigation and water storage systems were developed by the Indus Valley Civilization, including artificial reservoirs at Girnar dated to 3000 BCE, and an early canal irrigation system from circa 2600 BCE. Cotton was cultivated in the region by the 5th millennium BCE—4th millennium BCE. Sugarcane was originally from tropical South and Southeast Asia. Different species likely originated in different locations with S. barberi originating in India and S. edule and S. officinarum coming from New Guinea.

By 2800 BCE private bathrooms, located on the ground floor, were found in many houses of the Indus civilization. Pottery pipes in walls allowed drainage of water and there was, in some case, provision of a crib for sitting in toilets. 'Western-style' toilets were also made from bricks and used wooden toilet seats on top. The waste was then transmitted to drainage systems. Large scale sanitary sewer systems were in place by 2700 BCE. The drains were 7–10 feet wide and 2 feet below ground level. The sewage was then led into cesspools, built at the intersection of two drains, which had stairs leading to them for periodic cleaning. Plumbing using earthenware plumbing pipes with broad flanges for easy joining with asphalt to stop leaks was in place by 2700 BCE.

The inhabitants of the Indus valley developed a system of standardization, using weights and measures, evident by the excavations made at the Indus valley sites. This technical standardization enabled gauging devices to be effectively used in angular measurement and measurement for construction. Calibration was also found in measuring devices along with multiple subdivisions in case of some devices. The world's first dock at Lothal (2400 BCE) was located away from the main current to avoid deposition of silt.Modern oceanographers have observed that the Harappans must have possessed knowledge relating to tides in order to build such a dock on the ever-shifting course of the Sabarmati, as well as exemplary hydrography and maritime engineering. This was the earliest known dock found in the world, equipped to berth and service ships.

Excavations at Balakot (c. 2500-1900 BC), present day Pakistan, have yielded evidence of an early furnace. The furnace was most likely used for the manufacturing of ceramic objects. Ovens, dating back to the civilization's mature phase (c. 2500-1900 BC), were also excavated at Balakot.The Kalibangan archeological site further yields evidence of potshaped hearths, which at one site have been found both on ground and underground. Kilns with fire and kiln chambers have also been found at the Kalibangan site.

View of the Asokan Pillar at Vaishali. One of the edicts of Ashoka (272—231 BCE) reads: "Everywhere King Piyadasi (Asoka) erected two kinds of hospitals, hospitals for people and hospitals for animals. Where there were no healing herbs for people and animals, he ordered that they be bought and planted."

Based on archaeological and textual evidence, Joseph E. Schwartzberg (2008)—a University of Minnesota professor emeritus of geography—traces the origins of Indian cartography to the Indus Valley Civilization (ca. 2500–1900 BCE). The use of large scale constructional plans, cosmological drawings, and cartographic material was known in India with some regularity since the Vedic period (1 millennium BCE). Climatic conditions were responsible for the destruction of most of the evidence, however, a number of excavated surveying instruments and measuring rods have yielded convincing evidence of early cartographic activity. Schwartzberg (2008)—on the subject of surviving maps—further holds that: 'Though not numerous, a number of map-like graffiti appear among the thousands of Stone Age Indian cave paintings; and at least one complex Mesolithic diagram is believed to be a representation of the cosmos.'

Archeological evidence of an animal-drawn plough dates back to 2500 BC in the Indus Valley Civilization. The earliest available swords of copper discovered from the Harappan sites date back to 2300 BCE. Swords have been recovered in archaeological findings throughout the Ganges–Jamuna Doab region of India, consisting of bronze but more commonly copper.

Early kingdoms

Ink drawing of Ganesha under an umbrella (early 19th century). Ink, called masi, an admixture of several chemical components, has been used in India since at least the 4th century BC. The practice of writing with ink and a sharp pointed needle was common in early South India. Several Jain sutras in India were compiled in ink.

The Hindu-Arabic numeral system. The inscriptions on the edicts of Ashoka (1st millennium BCE) display this number system being used by the Imperial Mauryas.

The religious texts of the Vedic Period provide evidence for the use of large numbers. By the time of the last Veda, the Yajurvedasaṃhitā (1200-900 BCE), numbers as high as 1012 were being included in the texts. For example, the mantra (sacrificial formula) at the end of the annahoma ("food-oblation rite") performed during the aśvamedha ("horse sacrifice"), and uttered just before-, during-, and just after sunrise, invokes powers of ten from a hundred to a trillion.The Satapatha Brahmana (9th century BCE) contains rules for ritual geometric constructions that are similar to the Sulba Sutras.

Baudhayana (c. 8th century BCE) composed the Baudhayana Sulba Sutra, which contains examples of simple Pythagorean triples, such as: (3,4,5), (5,12,13), (8,15,17), (7,24,25), and (12,35,37) as well as a statement of the Pythagorean theorem for the sides of a square: "The rope which is stretched across the diagonal of a square produces an area double the size of the original square." It also contains the general statement of the Pythagorean theorem (for the sides of a rectangle): "The rope stretched along the length of the diagonal of a rectangle makes an area which the vertical and horizontal sides make together." Baudhayana gives a formula for the square root of two.

The earliest Indian astronomical text—named Vedānga Jyotiṣa—dates back to around 1200 BC, and details several astronomical attributes generally applied for timing social and religious events.The Vedānga Jyotiṣa also details astronomical calculations, calendrical studies, and establishes rules for empirical observation. Since the texts written by 1200 BCE were largely religious compositions the Vedānga Jyotiṣa has connections with Indian astrology and details several important aspects of the time and seasons, including lunar months, solar months, and their adjustment by a lunar leap month of Adhimāsa.  Ritus and Yugas are also described.  Tripathi (2008) holds that ' Twenty-seven constellations, eclipses, seven planets, and twelve signs of the zodiac were also known at that time.' 

The Egyptian Papyrus of Kahun (1900 BCE) and literature of the Vedic period in India offer early records of veterinary medicine.  Kearns & Nash (2008) state that mention of leprosy is described in the medical treatise Sushruta Samhita (6th century BCE).  However, The Oxford Illustrated Companion to Medicine holds that the mention of leprosy, as well as ritualistic cures for it, were described in the Hindu religious book Atharva-veda, written by 1500–1200 BCE.  Cataract surgery was known to the physician Sushruta (6th century BCE).  Traditional cataract surgery was performed with a special tool called the Jabamukhi Salaka, a curved needle used to loosen the lens and push the cataract out of the field of vision. The eye would later be soaked with warm butter and then bandaged.  Though this method was successful, Susruta cautioned that it should only be used when necessary. Greek philosophers and scientists traveled to India where these surgeries were performed by physicians. The removal of cataract by surgery was also introduced into China from India.  Brahmanic hospitals were established in what is now Sri Lanka as early as 431 BCE.  Ashoka (reign: 273 BCE to 232 BCE) also established a chain of hospitals throughout the Mauryan empire (322–185 BCE) by 230 BCE. 

During the 5th century BCE, the scholar Pāṇini had made several discoveries in the fields of phonetics, phonology, and morphology.  Metal currency was minted in India before 5th century BCE,[33][34] with coinage (400 BCE—100 CE) being made of silver and copper, bearing animal and plant symbols on them. 

Zinc mines of Zawar, near Udaipur, Rajasthan, were active during 400 BC.  Diverse specimens of swords have been discovered in Fatehgarh, where there are several varieties of hilt. These swords have been variously dated to periods between 1700-1400 BCE, but were probably used more extensively during the opening centuries of the 1st millennium BCE.  Archaeological sites in such as Malhar, Dadupur, Raja Nala Ka Tila and Lahuradewa in present day Uttar Pradesh show iron implements from the period between 1800 BC - 1200 BC. Early iron objects found in India can be dated to 1400 BC by employing the method of radio carbon dating.  Some scholars believe that by the early 13th century BC iron smelting was practiced on a bigger scale in India, suggesting that the date of the technology's inception may be placed earlier.  In Southern India (present day Mysore) iron appeared as early as 11th to 12th centuries BC.  These developments were too early for any significant close contact with the northwest of the country. 

Late Middle Ages

Jantar Mantar, Delhi—consisting of 13 architectural astronomy instruments, built by Jai Singh II of Jaipur, from 1724 onwards.

The infinite series for π was stated by Madhava of Sangamagrama (c. 1340-1425) and his Kerala school of astronomy and mathematics. He made use of the series expansion of arctanx to obtain an infinite series expression, now known as the Madhava-Gregory series, for π. Their rational approximation of the error for the finite sum of their series are of particular interest. They manipulated the error term to derive a faster converging series for π. They used the improved series to derive a rational expression,  104348 / 33215 for π correct up to nine decimal places, i.e. 3.141592653. The development of the series expansions for trigonometric functions (sine, cosine, and arc tangent) was carried out by mathematicians of the Kerala School in the fifteenth century CE. Their work, completed two centuries before the invention of calculus in Europe, provided what is now considered the first example of a power series (apart from geometric series). 

Shēr Shāh of northern India issued silver currency bearing Islamic motifs, later imitated by the Mughal empire.  The Chinese merchant Ma Huan (1413–51) noted that gold coins, known as fanam, were issued in Cochin and weighed a total of one fen and one li according to the Chinese standards. They were of fine quality and could be exchanged in China for 15 silver coins of four-li weight each. 

The Seamless celestial globe was invented in Kashmir by Ali Kashmiri ibn Luqman in 998 AH (1589-90 CE), and twenty other such globes were later produced in Lahore and Kashmir during the Mughal Empire.  Before they were rediscovered in the 1980s, it was believed by modern metallurgists to be technically impossible to produce metal globes without any seams, even with modern technology. These Mughal metallurgists pioneered the method of lost-wax casting in order to produce these globes. 

Portrait of a young Indian scholar, Mughal miniature by Mir Sayyid Ali, ca. 1550.

It was written in the Tarikh-i Firishta (1606–1607) that the envoy of the Mongol ruler Hulegu Khan was presented with a pyrotechnics display upon his arrival in Delhi in 1258 CE.  As a part of an embassy to India by Timurid leader Shah Rukh (1405–1447), 'Abd al-Razzaq mentioned naphtha-throwers mounted on elephants and a variety of pyrotechnics put on display.  Firearms known as top-o-tufak also existed in the Vijayanagara Empire by as early as 1366 CE.  From then on the employment of gunpowder warfare in the region was prevalent, with events such as the siege of Belgaum in 1473 CE by the Sultan Muhammad Shah Bahmani. 

In A History of Greek Fire and Gunpowder, James Riddick Partington describes Indian rockets, mines and other means of gunpowder warfare:[96]The Indian war rockets were formidable weapons before such rockets were used in Europe. They had bam-boo rods, a rocket-body lashed to the rod, and iron points. They were directed at the target and fired by lighting the fuse, but the trajectory was rather erratic. The use of mines and counter-mines with explosive charges of gunpowder is mentioned for the times of Akbar and Jahāngir.



By the 16th century, Indians were manufacturing a diverse variety of firearms; large guns in particular, became visible in Tanjore, Dacca, Bijapur and Murshidabad.  Guns made of bronze were recovered from Calicut (1504) and Diu (1533).  Gujarāt supplied Europe saltpeter for use in gunpowder warfare during the 17th century. Bengal and Mālwa participated in saltpeter production. The Dutch, French, Portuguese, and English used Chāpra as a center of saltpeter refining.

The construction of water works and aspects of water technology in India is described in Arabic and Persian works.  During medieval times, the diffusion of Indian and Persian irrigation technologies gave rise to an advanced irrigation system which bought about economic growth and also helped in the growth of material culture.[100] The founder of the cashmere wool industry is traditionally held to be the 15th century ruler of Kashmir, Zayn-ul-Abidin, who introduced weavers from Central Asia. 

The scholar Sadiq Isfahani of Jaunpur compiled an atlas of the parts of the world which he held to be 'suitable for human life'.  The 32 sheet atlas—with maps oriented towards the south as was the case with Islamic works of the era—is part of a larger scholarly work compiled by Isfahani during 1647 CE.  According to Joseph E. Schwartzberg (2008): 'The largest known Indian map, depicting the former Rajput capital at Amber in remarkable house-by-house detail, measures 661 × 645 cm. (260 × 254 in., or approximately 22 × 21 ft).