8SCIENCE REPORTER, AUGUST 2011
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tory
FROM astronomy to medicine and
from metallurgy to mathematics,
ancient India’s contributions to the
world of science are many. Throughout
the ages, there came people from
different racial, geographical and
religious backgrounds all of whom made
a direct impact on the socio-economic
life and indirectly on the scientific aptitude
and attitude.
Indian science and technology dates
back to prehistoric human activity at
Mehrgarh in present day Pakistan and
continues through the Indus valley
civilization. The Indus Valley civilization is a
term used to refer to the cultures of the
Indus and Ghaggar-Hakra rivers stretching
from Neolithic Mehrgarh period down to
the Iron Age or Indo-Gangetic tradition.
The mature phase of this civilization was
the Harappan civilization (3300-1300 BC),
followed by the Vedic civilization (2000-
600BC).
Mehrgarh Culture
(7000-3300 BC)Mehrgarh is one of the most important
Neolithic sites of the world and lies on the
‘kachi plain’ of today’s Balochistan located
near the Bolan pass, to the west of Indus
valley and between the present day
Pakistani cities of Quetta, Kalat and Sibi.
Mehrgarh shows evidences of tools
with local copper ore, containers made
with bitumen, domestication of plants and
animals and tanning. Bitumen is a mixture
of organic liquids that are highly viscous,
black, sticky, soluble in carbon disulfide and
composed of highly condensed polycyclic
aromatic hydrocarbons.
In Apri l 2006, the journal Nature
announced that the oldest evidence in
human history for the drilling of tooth in vivo,
that is, in a living person, was found in
Mehrgarh around 7000 BC. It involved
curing tooth-related disorders with drills
operated by skilled bead craftsmen. These
interesting findings provide evidence of a
long tradition of a type of proto-dentistry
in an early farming culture.
At Neolithic Mehrgarh, flint drill heads
were found in stone assemblages
associated with beads of bone, steatite,
shell, calcite, turquoise, lapis lazuli and
carnelian. Using models of these drill tips,
methods for dri l l ing based on the
ethnographic literature were constructed
and it was found that a bow drill tipped
with a flinthead required less than a minute
to produce similar holes in human enamel.
Presumably, the know-how originally
developed by skilled artisans for bead
production was successfully transferred to
Here’s a look at some of the significantcontributions to science India has made
through the ages.
Mehrgarh pottery
This image shows a drilled molar crown fromMehrgarh. A hole about a tenth of an inch(2.6 millimeters) wide was drilled in the center of thecrown. The hole shows smoothing, indicating it wasdrilled well before the death of the individual.(Courtesy: Nature)
9 SCIENCE REPORTER, AUGUST 2011
drilling of teeth in a form of proto-dentistry.
A modern reconstruction of this form of
dentistry has shown that the methods used
were reliable and effective.
Harappan Civilization
(3300-1300 BC)The size and prosperity of the
Indus civi l ization grew as a result of
innovations in irrigation and drainage
systems, which eventually led to more
planned settlements. This irrigation system
also included artificial reservoirs at Girnar
dating back to 3000 BC and an early
canal irr igation system from 2600 BC
onwards.
By 2800 BC 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 cases,
provision of a crib for sitting in toilets.
‘Western-style’ toilets were made from
bricks and wooden toilet seats were used
on top. The waste was transmitted via the
extensive drainage systems in their
settlements.
Large-scale sanitary sewer systems
were in place by 2700 BC. 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.
The world’s first dock at Lothal in 2400
BC was built away from the main current
to avoid silt deposition. Contemporary
oceanographers believe that Harappans
must have had knowledge relating to
tides, hydrography and marit ime
engineering in order to build such a dock
equipped to berth and service ships.
Using weights and measures, the
inhabitants developed a system of
standardization. This technical
standardization enabled gauging devices
to be effectively used in angular
measurement and measurement for
construction. In case of some devices,
calibration was also found with multiple
subdivisions.
Evidence of an early furnace, animal
drawn plough and ovens has been
discovered from excavations at Balakot
(in present day Pakistan). Furnaces might
have been used for the manufacture of
ceramic objects. Malhar, Dadupur, Raja
Nala ka Ti la and Lahuradewa
archeological sites present in Uttar Pradesh
(U.P.) show implements from the period
between 1800 BC-1200 BC.
In the development of swords as
weapons of war, those found at Mohenjo-
daro have a tang and rivet to hold the
handle exactly as found in Palestine, where
such implements were associated with the
Hyksos (1800-1500 BC). Copper harpoons
found in the Indus Valley were similar to
those found in Europe and elsewhere in
Asia.
IndianScienceThrough The
AgesThe Mehrgarh civilization
JAIMINI SARKAR
A complete set of stone tools found in a Mehrgarh grave. Such tool sets were presumably buried with their owner.
Indian war rockets wereformidable weapons beforesuch rockets were used inEurope. They had bamboorods, a rocket-body lashed tothe rod, and iron points.
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Polished Stone Axe Flint Cores
Microliths
Unretouched Flint Blades
10SCIENCE REPORTER, AUGUST 2011
Swords have been recovered in
archeological findings throughout the
Ganges-Jamuna Doab regions of India
consisting of bronze but more commonly
copper. Copper axes were also
discovered at Harappan sites (Harappa,
Shahi-tump and Chanhu-daro) but were
similar to those found at North Persian sites
(Hissar III, Shah Tepe, Turang Tepe) and
Akkadian sites (Assur, Sialk B cemetery).
Early Iron objects found in India can
be dated to 1400 BC by employing the
method of carbon dating. By the early 13th
century BC, iron smelting was practiced
on a bigger scale in India. In case of
southern India especially present day
Mysore, iron was employed on a large
scale as early as 11th to 12th centuries BC.
Vedic Civilization
(2000-600 BC)The Vedic civilization was based in the
northern and northwestern parts of the
Indian subcontinent. Scholars place the
Vedic period in the second and first
millennia BC continuing up to the 6 th
century BC.
The religious texts of Vedic period
provide evidence of the use of large
numbers as high as 1012 (1200-900 BC).
Vedanga Jyotisa details several important
aspects of time and seasons, including
lunar months, solar months and their
adjustment by lunar leap month of
Adhimasa. Twenty-seven constellations,
eclipses, seven planets and 12 signs of the
zodiac were also known at that time.
In the 8 th centur y BC, an Indian
mathematician, Baudhayana composed
the Sulba Sutra giving rules for the
construction of altars which contained
several important mathematical results. The
famous Pythagorean theorem is believed
to have been invented by Baudhayana
first. He solved the problem of finding a
circle whose area is the same as that of a
square as well gave the formula for the
square root of two.
Literature of the Vedic period in India
offers early records of veterinar y and
human medicine. Leprosy is mentioned in
the Sushruta Samhita (6th century BC), which
also mentions cataract surgery performed
with a special tool called the Jabamukhi
Salaka where a curved needle was 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, Sushruta mentioned that it
should only be used when necessary.
During the 5th century BC, the scholar
Panini made several discoveries in the field
of phonetics, phonology and morphology.
Metal currency was minted in India before
5th century BC with coins being made of
silver and copper, bearing animal and
plant symbols on them.
Post Mahajanapadas
(400 BC-400 AD)This era was an interesting era of Indian
histor y. Alexander invaded the
northwestern part of the Indian
subcontinent and the first United Kingdom
was established under the rule of
Chandragupta Maur ya, a student of
Chanakya. The Maur ya Empire
maintained diplomatic relations with the
Greek world as Chandragupta married the
daughter of Alexander ’s general,
Seleucus. This era thus shows prominent
impact of European science and culture
on the Indian subcontinent.
The Arthashastra written by Chanakya
in the 4 th centur y BC mentions the
construction of dams and bridges. The use
of suspension bridges using plaited
bamboo and iron chains was also seen in
this period. Apart from trade and
commerce, the book also discusses
about agriculture, working of mines and
factories, horticulture, irrigation, waterways,
ships, navigation, f isheries and
slaughterhouses.
The contacts between India and the
western world, which Chandragupta
Maurya had established, continued during
the reign of his son Bindusara and
grandson Ashoka.
A typical small housewith 2 to 4 rooms atMehrgarh would havelooked like this and waslikely to have housed afamily.
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Reed Thatch
Wooden Poles
Twigs
Window
Mud-brick wall
11 SCIENCE REPORTER, AUGUST 2011
Ashoka was a great builder. His famous
many-pillared hall at Patliputra was dug
out by archeologists and is st i l l in a
marvelous state of preservation. The
wooden logs that were used to build it are
as smooth and perfect as the day they
were laid, more than two thousand years
ago. This would be surprising anywhere,
but in India it is more so, for the climate
wears them away and insects eat them
up. There must have been some kind of
special treatment for the wood used in
such constructions.
Institutions created specifically to
care for the ill appeared in early India.
King Ashoka is said to have founded at
least 18 hospitals around 230 BC, with
physicians and nursing staff, the expense
being borne from the royal treasur y.
Ashoka erected two kinds of hospitals—
for people and for animals. Where there
were no healing herbs for people and
animals, he ordered they should be bought
and planted.
Though the evidence of the first rock-
cut step wells in India dates back to 200-
400 AD, the step wells constructed at
Dhank (550-625 AD) and stepped ponds
at Bhinmal (also known as Shrimal, 72 km
south of Jalore town in Rajasthan) are still
preserved in proper shape. Step wells are
wells in which water can be reached by
descending a set of steps. It can be
multistoried also, in which a bullock turns
the water wheel to raise the water in the
well to the first or second floor.
The city of Mohenjo-daro also had
wells and they may have been the
predecessors of these step wells, as
around 700 wells were discovered in just
one section of the city. Leading scholars
believe that the people of the Indus valley
civilization invented cylindrical brick-lined
wells.
By the beginning of the Common Era
(AD), glass was being used for ornaments
and casing. New techniques were added
in this field because of the contact with
the Greco-Roman world. The Satavahana
period further reveals short cylinders of
composite glass, including those
displaying a lemon-yellow matrix covered
with green glass.
Before the beginning of the Common
Era, Wootz steel originated in India. Wootz
steel was widely exported and traded
throughout ancient Europe and the Arab
world, and became particularly famous in
the Middle East, where it was known as
Damascus steel. Archaeological evidence
suggests that this manufacturing process
was already in existence in South India
even before the Christian era.
The bow instruments used in the
second century in textile are also a gift to
the world from India. These carding
devices are called Kaman and Dhunaki
and would loosen the texture of the fiber
by means of the vibrating string.
Early use of diamonds as gemstones
originated in India. Golconda served as
an important center for diamonds in
central India. Diamonds were exported to
“The Great Bath” at Mohenjo-daro (above);Sewer drains at Mohenjo-daro (right);The city of Harappa had a sophisticateddrainage system perhaps as early as 6,000years before the present (extreme right)
Standardized weights and measures used in the Induscivilization
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12SCIENCE REPORTER, AUGUST 2011
other parts of the world also. Literature
written at the beginning of the third century
describes strength, regularity, brilliance,
abil ity to scratch metals and good
refractive properties as the desirable
qualities of diamond.
The Iron pillar of Delhi constructed at
the time of Chandragupta II Vikramaditya
(375-413 AD) is still a marvel because of
the metals used in its construction. The pillar
is 98% pure wrought iron and is a testament
to the high level of skills achieved by
ancient Indian metallurgists in the
extraction and processing of iron. It has
attracted the attention of archeologists
and metallurgists as it has withstood
corrosion for over 1600 yrs in the open air.
The pillar ’s resistance to corrosion is
explained by a passive protective film at
the iron-rust interface. The presence of
second phase particles (slag and
unreduced iron oxides) in the
microstructure of the iron, that of high
amounts of phosphorus in the metal and
the alternate wetting and drying existing
under atmospheric conditions are the
three main factors in the three stage
formation of that protective passive film.
India is one of the probable places
of origin of the spinning wheel. The device
may have reached Europe from India in
the 14th century AD. The Charkhi in some
parts of the region was also driven by
waterpower. The Ajanta caves yield
evidence of a single roller cotton gin in
use by the 5th century AD.
This period was the golden age of
Indian mathematics and astronomy where
many Indian scholars contributed
The well in the citadel of Harappa (the round opening near the centre of the photograph) was almost certainlythe permanent source of fresh water on top of a defensible hill that made the site of Harappa such an importantcentre of the Indus culture.
The ruins at Patliputra
Tipu Sultan’s rockets
The rustless wonder—Iron Pillar in Delhi(above & right)
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seminally. Pingala (300-200 AD) was famous
for his work, Chandas Shastra, a Sanskrit
treatise on prosody considered as one of
the Vedanga. He developed advanced
mathematical concepts for describing the
patterns of prosody. Pingala presents
the first known description of a binary
numeral system. He described the binary
numeral system in connection with the
listing of Vedic meters with short and long
syllables. His discussion of the
combinatorics of meter corresponds to the
binomial theorem. Pingala’s work also
contains the basic ideas of Fibonacci
number and a presentation of the Pascal’s
triangle.
The use of negative numbers was
known in early India, and their role in
situations like mathematical problems of
debt was understood and consistent rules
for working with these numbers were
formulated.
Medieval Period (500 AD-1600
AD)Aryabhata (476–550 AD) was the great
mathematician-astronomer from the
classical age of Indian mathematics and
astronomy. His most famous works are the
Aryabhatiya (499 AD, when he was 23 years
old) and the Arya-siddhanta.
Brahmagupta (598–668 AD), another
great mathematician and astronomer
wrote important treatise on mathematics
and astronomy in
Brahamasphutasiddhanta in 628 AD. He
gave solutions for the general l inear
equation, two equivalent solutions to the
general quadratic equation, explained
how to find cube and cube root of an
integer, rules for facil i tating the
computation of squares and square roots
and gave rules for dealing with five types
of combinations of fractions.
He was able to find (integral) solutions
of Pell’s equation. Brahmagupta’s most
famous result in geometry is his formula for
cyclic quadrilaterals, a theorem on rational
triangles and values of ð (pi).
In chapter seven of his
Brahmasphutasiddhanta, entitled Lunar
Crescent, Brahmagupta rebuts the idea
that the Moon is farther from the Earth than
the Sun, an idea maintained in scriptures.
He does this by explaining the illumination
of the Moon by the Sun.
During the 1st millennium AD, the
Vaisheshika School of atomism proposed
that atoms are indivisible and eternal, can
neither be created nor destroyed and
each one possessed its own distinct
individuality. This concept was further
elaborated by philosophers of the Buddhist
school of atomism, Dharamkirt i and
Dignaga, in the 7th centur y AD. They
considered atoms to be point sized,
duration less and made of energy.
Bhâskara-I, the 7 th centur y
mathematician, was apparently the first to
write numbers in the Hindu-Arabic decimal
system with a circle for the zero, and who
gave a unique and remarkable rational
approximation of the sine function in his
commentary on Aryabhata’s work.
The decimal number system also
originated in India. Other cultures
discovered a few features of this number
system but the system, in its entirety, was
compiled in India, where it attained
coherence and completion. By the 9 th
century AD, this complete number system
was in existence in India.
The concept of 0 as a number, and
not merely a symbol for separation is
attr ibuted to India where practical
calculations were carried out using zero,
which was treated like any other number
by the 9 th century AD, even in case of
division.
Bhaskara-II or Bhaskara Acharya was
head of an astronomical observatory at
Ujjain, the leading mathematical center
of ancient India. Bhaskara-II mainly
contributed to the field of mathematics,
arithmetic, algebra, tr igonometr y,
calculus, astronomy and engineering.
Conceptual design for a perpetual motion
machine by Bhaskara II dates to 1150 AD.
He described a wheel that he claimed
would run forever. He used a measuring
device known as Yasti-yantra. This device
could vary from a simple stick to V-shaped
staffs designed specifically for determining
angles with the help of a calibrated scale.
Rasaratna Samuccaya written during
the 8 th centur y AD gives elaborate
description of various complex
metallurgical processes. It explains the
existence of two types of ores for Zinc
metal, one of which is ideal for metal
extraction while the other is used for
medicinal purpose.
India also became a major center
for production and processing of
Indigofera tinctoria, a variety of indigo that
was used and domesticated in India for
use as a dye.
Evidence of microbial inoculation
and variolation for smallpox is found in the
8 th centur y, when Madhav wrote the
The use of mines andcounter-mines with explosivecharges of gunpowder ismentioned for the times ofAkbar and Jahângir.Evidence of an early furnace,animal drawn plough andovens has been discoveredfrom excavations at Balakot(in present day Pakistan).
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14SCIENCE REPORTER, AUGUST 2011
Nidâna, a 79-chapter book that l ists
diseases along with their causes,
symptoms, and complications. He
included a special chapter on smallpox
(Masûrikâ) and described the method of
inoculation to protect against smallpox.
Treatment was done by inoculation with
year-old smallpox matter. The inoculators
would travel all across India pricking the
skin of the arm with a small metal instrument
using “variolous matter” taken from pustules
produced by the previous year ’s
inoculations. The British doctor J.Z. Holwell
based on observations made during his
residence in Bengal in an account to the
College of Physicians in London in 1767
confirmed the effectiveness of this system.
The Scholars of Kerala School of
astronomy and mathematics, especially
Madhava of Sangamagrama, made
important contributions to the field of
geometry by stating the infinite series for ð
(1340-1425 AD). Madhava made use of
the series expansion of arctanx to obtain
an infinite series expression, now known as
the Madhava-Gregory series, for ð. They
used an improved series to derive a
rational expression 104348 / 33215 for ð,
correct up to nine decimal places, i.e.
3.141592653.
Ali Kashmiri ibn Luqman (1589-90 AD)
invented the Seamless celestial globe,
which was later produced in 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.
Indian war rockets were formidable
weapons before such rockets were used
in Europe. They had bamboo 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 Jahângir.
Later, Hyder Ali, prince of Mysore,
developed war rockets with an innovation.
He used metal cylinders to contain the
combustion powder. Although the
hammered soft iron he used was crude,
the bursting strength of the container of
black powder was much higher than the
earlier paper construction. Thus a greater
internal pressure was possible, with a
resultant greater thrust of the propulsive
jet.
Hyder Ali’s son, Tipu Sultan, continued
to develop and expand the use of rocket
weapons, reportedly increasing
the number of rocket troops from 1,200 to
5,000. In battles at Seringapatam in
1792 and 1799, these rockets were
used with considerable effect against the
British.
Fathullah Shirazi, a Persian-Indian
polymath and mechanical engineer who
worked for Akbar in the Mughal Empire,
invented the auto-cannon, the earliest
multi-shot gun in 1582.
The scholar Sadiq Isfahani of Jaunpur
compiled an atlas of parts of the world.
The 32-sheet atlas is part of a larger
scholarly work compiled by Isfahani during
1647 AD.
Dr. Jaimini Sarkar is a freelance science writer.Address: C/o M.L. Dhane, 702, M2/C, PratikshaNagar C.H.S, Pratiksha Nagar, Sion (E), Mumbai-400022; Email: [email protected]
The “Granary” at Harappa
The Indus Valley civilizationis a term used to refer to thecultures of the Indus andGhaggar-Hakra riversstretching from NeolithicMehrgarh period down tothe Iron Age or Indo-Gangetic tradition.
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