Tuesday, May 29, 2007
Astronomy in Ancient India
Early cultures identified celestial objects with gods and spirits. They related these objects and their movements to predict things like rain, drought, seasons, and tides. The movements of Sun and Moon are used in calendars to measure the day, month and year. It is important to agricultural societies as they need to know the time to plant and harvest. Ancient societies also believed that the position of some celestial bodies have an impact on the human beings. The astronomy and the astrology of
The earliest references to astronomy are found in the Vedas which are dated around 3000 B.C. to 1000 B.C. By 500 AD, ancient Indian astronomy has emerged as an important part of Indian studies and its affect is also seen in several treatises of that period. In some instances, astronomical principles were borrowed to explain matters, pertaining to astrology, like casting of a horoscope. Apart from this linkage of astronomy with astrology in ancient
There are astronomical references of chronological significance in the Vedas. Some Vedic notices mark the beginning of the year and that of the vernal equinox in Orion.
Yajnavalkya (estimated 1800 BC) advanced a 95-year cycle to synchronize the motions of the sun and the moon. The Vedanga Jyotisha, a text on Vedic astrology that has been dated to 1350 BC, was written by Lagadha which describes rules for tracking the motions of the Sun and the Moon, and also develops the use of geometry and trigonometry for astronomical uses.
The sun (Surya) was one of the chief deities in the Vedas. He was recognized as the source of light (Dinkara), source of warmth (Bhaskara). In the Vedas sun is also referred to as the source of all life, the center of creation and the center of the spheres.
In Indian languages, the science of astronomy is called Khagola-shastra. The word Khagola perhaps is derived from the famous astronomical observatory at the
The lack of a telescope hindered further advancement of ancient Indian astronomy. Though it should be admitted that with their unaided observations with crude instruments, the astronomers in ancient
Another astronomer Varahamihira (476 A.D. – 587 A.D.) recognized that there should be a force which might be keeping bodies stuck to the Earth, and also keeping heavenly bodies in their determined places. Also recognized that this force is an attractive force. The Sanskrit term for gravity is Gurutvakarshan which is an amalgam of Guru-tva-akarshan. Akarshan means to be attracted, thus the fact that the character of this force was of attraction was also recognized. This apart, it seems that the function of attracting heavenly bodies was attributed to the sun.
Brahmagupta (598 A.D -668 A.D.) was the head of the astronomical observatory at
Bhaskara (1114 A.D -1185 A.D.) was the head of the astronomical observatory at
Other important astronomers from
Monday, May 21, 2007
Physics in Ancient India
In the late Vedic era(9th–6th century BC), the astronomer Yajnavalkya, in his Shatapatha Brahmana, referred to an early concept of heliocentrism with the Earth being round and the Sun being the "centre of spheres". He measured the distances of the Moon and the Sun from the Earth as 108 times the diameters of these heavenly bodies, which were close to the modern values of 110.6 for the Moon and 107.6 for the Sun.
In 499 A.D., the mathematician-astronomer Aryabhata propounded a detailed model of the heliocentric solar system of gravitation, where the planets rotate on their axes causing day & night and follow elliptical orbits around the Sun causing year, and where the planets and the Moon do not have their own light but reflect the light of the Sun. Aryabhata also correctly explained the causes of the solar and lunar eclipses and predicted their times, gave the radii of planetary orbits around the Sun, and accurately measured the lengths of the day, year, and the Earth's diameter and circumference. Brahmagupta, in his Brahma Sputa Siddhanta in 628 A.D., recognized gravity as a force of attraction and understood the law of gravitation.
Harappan civilization (2400 B.C) used shell objects served as compasses to measure the angles of the 8–12 fold divisions of the horizon and sky in multiples of 40–360 degrees, and the positions of stars.
The Samkhya and Vaisheshika schools developed theories on light from the 6th–5th century BC. According to the
Monday, May 14, 2007
Medicines of Ancient India
Ayurveda as a science of medicine owes its origins in ancient
Ancient scholars of
The oldest treatise dealing with surgery is the Shushruta Samahita. Shusruta was one of the first to study the human anatomy. In the Shusruta Samahita he has described in detail the study of anatomy with the aid of a dead body. Shusruta's specialty was rhinoplasty (Plastic surgery) and ophthalmology (ejection of cataracts). Shushruta has described surgery under eight heads Chedya (excision), Lekhya (scarification), Vedhya (puncturing), Esya (exploration), Ahrya (extraction), Vsraya (evacuation) and Sivya (Suturing).
Around 500 AD, Vagbhatt compiled the third major treatise on Ayurveda, Astanga Hridaya. From 500 AD to 1900 AD, sixteen major Nighantus or supplementary texts on Ayurveda like Dhanvantari Bhavaprakasha, Raja and Shaligram among others were written incorporating new drugs, expansion in applications, discarding of old drugs and identification of substitutes. These texts mention about 1814 varieties of plants in vogue.
Yoga is a system of exercise for physical and mental nourishment. Since Vedic times, the principles and practice of yoga have crystallized. But, it was only around 200 BC that all the fundamentals of yoga were collected by Patanjali in his treatise, named Yogasutra, that is, Yoga-Aphorisms. Patanjali says that through the practice of yoga, the energy latent within the human body may be made live and released, which has a salubrious affect on the body and the mind.
Sunday, May 6, 2007
Mathematics in Ancient India
The first appearance of evidence of the use of mathematics in the Indian subcontinent was in the Indus Valley Civilization, which dates back to around 3300 BC. Excavations at
By 1800 BC, Indian mathematicians were discussing the idea of infinity, pointing out that "if you remove a part from infinity or add a part to infinity, what remains is still infinity." By about 400 BC, Indian mathematicians were doing more work on the idea of infinity. The Surya Prajinapti defines five kinds of infinity: an infinite line beginning from an endpoint, an infinite line going directions, an infinite plane, an infinite universe, and the infinity of time.
Around 300 BC, Indian mathematicians began working on the mathematical idea of combinations. This is the study of how many combinations you can make out of the same group of things. They were working on how you could figure that out, and published their ideas in a book called the Bhagabati Sutra. Around the same time, Indian mathematicians worked out the first beginnings of our modern number system. By 100 AD, people in
Indian mathematician’s biggest invention was the use of zero as a placeholder, to make it easier to add and multiply numbers. Our word "zero" comes from the Sanskrit word meaning "nothing." In 458 AD, Indian mathematicians wrote a book, the Lokavibhaaga, that uses zero in this way. In 628 AD, Brahmagupta wrote a book explaining how zero worked, with rules like "The sum of zero and zero is zero" and "The sum of a positive and a negative is their difference; or, if they are equal, zero.”
Algebraic theories, as also other mathematical concepts, which were in circulation in ancient India, were collected and further developed by Aryabhatta, an Indian mathematician, who lived in the 5th century. He has referred to Algebra as Bijaganitam in his treatise on mathematics named Aryabhattiya, composed in A.D. 499. He was first to treat Mathematics as a distinct subject and he dealt with evolution and involution, area and volume, progressions and algebraic identities, and intermediate equations of the first degree. He also arrived at a remarkably accurate value of PI ( 3.1416). Aryabhatta was also the first to hold that the earth was a sphere and rotated on its axis. He says, to a person traveling in a boat trees on the shore appear to move in opposite direction, similarly because earth is rotating on its axis towards east it appears to us as if the sun moves from east to west. He also explained that the eclipses were caused by the shadow of the earth falling on the moon. One of the most important features of Aryabhatta's mathematical system is his unique system of notation. It is based on the decimal place value system, now in use throughout the civilized world.
Another mathematician of the 12th century, Bhaskaracharya also authored several treatises on the subject one of them, named Siddantha Shiromani has a chapter on algebra. He is known to have given a basic idea of the Rolle's theorum and was the first to conceive of differential calculus Bhaskaracharya's Leelavati translated to English in 1816 by James Taylor.
The 14th century Indian mathematician Madhava of Sangamagrama along with other mathematician’s of the
The credit for fine-tuning and internationalizing these mathematical concepts originated in
Will Durant, American historian, said that
Subscribe to Posts [Atom]