Great Indian Scientists

Note: Here "BCE" means "Before Common era" or "christian Era".
"CE" means "Common era" or "Christian Era"
Dates before the year 1 CE are indicated by the usage of BCE these dates will be in descending order.
CE dates will be in ascending order.

ACHARYA KANADA ( 3000 B.C. to 1000 B.C or 6th Century BCE) 

Expertise : Atomic Theary

ACHARYA KANADA was a Hindu sage and philosopher. He probably lived around the 2nd century BCE, while other sources claim he lived in the 6th Century BC. But some sources are saying that he belongs to the age of 600BCE.

Many believe that Kanada originated the concept of atom. An interesting story states that this theory occurred to him while he was walking with food in his hand. As he nibbled at the food in his hand, throwing away the small particles, it occurred to him that he could not divide the food into further parts and thus the idea of a matter which cannot be divided further came into existence. He called that indivisible matter as ' Anu ' .i.e. atom.

Adherents of the school of philosophy founded by Kanada considered the atom to be indestructible, and hence eternal. They believed atoms to be minute objects invisible to the naked eye which come into being and vanish in an instant. This Indian concept of the atom was developed independently and possibly prior (depending on which dates one accepts for the life of Kanada) to the development of the idea in the Greco-Roman world. Indian theories about the atom are greatly abstract and enmeshed in philosophy as they were based on logic and not on personal experience or experimentation.

According to author Dilip M. Salwi, "if Kanada’s sutras are analysed, one would find that his atomic theory was far more advanced than those forwarded later by the Greek philosophers, Leucippus and Democritus."

ACHARYA CHARAK (3rd to 2nd century BCE)

Expertise: Medicine

Acharya Charak has been crowned as the Father of Medicine. His renowned work, the "Charak Samhita", is considered as an encyclopedia of Ayurveda. His principles, diagoneses, and cures retain their potency and truth even after a couple of millennia. When the science of anatomy was confused with different theories in Europe, Acharya Charak revealed through his innate genius and enquiries the facts on human anatomy, embryology, pharmacology, blood circulation and diseases like diabetes, tuberculosis, heart disease, etc. In the "Charak Samhita" he has described the medicinal qualities and functions of 100,000 herbal plants. He has emphasized the influence of diet and activity on mind and body. He has proved the correlation of spirituality and physical health contributed greatly to diagnostic and curative sciences. He has also prescribed and ethical charter for medical practitioners two centuries prior to the Hippocratic oath. Through his genius and intuition, Acharya Charak made landmark contributions to Ayurvedal. He forever remains etched in the annals of history as one of the greatest and noblest of rishi-scientists.

ACHARYA SUSHRUTA (600 BCE)

Expertise: Medicine & Plastic Surgery

A genius who has been glowingly recognized in the annals of medical science. Born to sage Vishwamitra,Acharya Sudhrut details the first ever surgery procedures in "Sushrut Samhita" a unique encyclopedia of surgery. He is venerated as the father of plastic surgery and the science of anesthesia. When surgery was in its infancy in Europe, Sushrut was performing Rhinoplasty (restoration of a damaged nose) and other challenging operations. In the "Sushrut Samhita," he prescribes treatment for twelve types of fractures and six types of dislocations. His details on human embryology are simply amazing. Sushrut used 125 types of surgical instruments including scalpels, lancets, needles, Cathers and rectal speculums; mostly designed from the jaws of animals and birds. He has also described a number of stitching methods; the use of horse's hair as thread and fibers of bark. In the "Sushrut Samhita," and fibers of bark. In the "Sushrut Samhita," he details 300 types of operations. The ancient Indians were the pioneers in amputation, caesarian and cranial surgeries.Acharya Sushrut was a giant in the arena of medical science.

Sushruta lays down the basic principles of plastic surgery by advocating a proper physiotherapy before the operation and describes various methods or different types of defects, viz., (1) release of the skin for covering small defects, (2) rotation of the flaps to make up for the partial loss and (3) pedicle flaps for covering complete loss of skin from an area. He has mentioned various methods including sliding graft, rotation graft and pedicle graft. Nasal repair or rhinoplasty has been described in greater detail, which to this day has stood the test of time and is mentioned as the Indian method of rhinoplasty in the books of plastic surgery. Lastly, labioplasty too has received his attention. In short, all the principles of plastic surgery, viz., accuracy, precision, economy, haemostasis and perfection find an important place in Sushruta's writings on this subject.

ARYABHATT (476 CE) 

Expertise: ASTRONOMER AND MATHEMATICIAN 

AryaBhatt was the first indian Mathematician and Astronomer. He belongs to the age of 476CE-550CE. He did the tremendous works in Mathematics and Astronomy. His works and achievements are given below.

His works in Mathematics

• Place value system and zero
• Pi as irrational
• Mensuration and trigonometry
• Indeterminate equations
• Algebra

His works in Astronomy

• Motions of the solar system
• Eclipses
• Sidereal periods
• Heliocentrism

Aryabhatta's work was of great influence in the Indian astronomical tradition and influenced several neighbouring cultures through translations. The Arabic translation during the Islamic Golden Age (ca. 820 CE), was particularly influential. Some of his results are cited by Al-Khwarizmi and in the 10th century Al-Biruni stated that Aryabhata's followers believed that the Earth rotated on its axis.

Varahamihira (505 CE- 587 CE)

Expertise: ASTRONOMER AND MATHEMATICIAN 

Daivajna Varāhamihira is well known as Varaha, or Mihira was an Indian astronomer, mathematician, and astrologer who lived in Ujjain. He belongs to the age of 505 CE – 587 CE. He wrote two books called "Pancha-Siddhantika" and "Brihat-Samhita".

"Pancha-Siddhantika" gives us information about older Indian texts which are now lost. This work mainly deals with the mathematical astronomy and it summarises five earlier astronomical treatises, namely the Surya Siddhanta, Romaka Siddhanta, Paulisa Siddhanta, Vasishtha Siddhanta and Paitamaha Siddhantas.

The Romaka Siddhanta ("Doctrine of the Romans") and the Paulisa Siddhanta ("Doctrine of Paul") were two works of Western origin which influenced Varahamihira's thought. Though this view is controversial as there is much evidence to suggest that it was actually Vedic thought indigenous to India which actually first influenced Western astrologers and subsequently came back to India reformulated.

A comment in the Brihat-Samhita by Varahamihira says: "The Greeks, though foreign, must be honored since they were trained in sciences and therein, excelled others....." ("mleccha hi yavanah tesu samyak shastram kdamsthitam/ rsivat te 'p i pujyante kim punar daivavid dvijah" (Brihat-Samhita 2.15))

Brahmagupta (598CE - 668CE)

Expertise: ASTRONOMER AND MATHEMATICIAN 

Brahmagupta was an Indian Mathematician and Astronomer. he belongs to the age of 598 CE- 668CE. he wrote some important works on Mathematics and astronomy. Brahmasphutasiddhanta is the tremendes work written by him in the year 628 BC. This Brahmasphutasiddhanta contains some remarkable advanced ideas, including a good understanding of the mathematical role of zero, rules for manipulating both negative and positive numbers, a method of computing square root, methods of solving linear and some quadratic equations, and rules for summing series, Brahmagupta's Identity and the Brahmaguota's theorem.

Brhmasphuta-siddhanta is one of the first mathematical books to provide concrete ideas on positive numbers, negative numbers, and zero. He wrote the following rules:

1. The sum of two positive quantities is positive
2. The sum of two negative quantities is negative
3. The sum of zero and a negative number is negative
4. The sum of zero and a positive number is positive
5. The sum of zero and zero is zero.
6. The sum of a positive and a negative is their difference; or, if they are equal, zero
7. In subtraction, the less is to be taken from the greater, positive from positive
8. In subtraction, the less is to be taken from the greater, negative from negative
9. When the greater however, is subtracted from the less, the difference is reversed
10. When positive is to be subtracted from negative, and negative from positive, they must be added together
11. The product of a negative quantity and a positive quantity is negative
12. The product of a negative quantity and a negative quantity is positive
13. The product of two positive, is positive.
14. Positive divided by positive or negative by negative is positive
15. Positive divided by negative is negative. Negative divided by positive is negative
16. A positive or negative number when divided by zero is a fraction with the zero as denominator
17. Zero divided by a negative or positive number is either zero or is expressed as a fraction with zero as numerator and the finite quantity as denominator
18. Zero divided by zero is zero

Bhaskara I (600 CE - 680 CE)

Expertise: ASTRONOMER AND MATHEMATICIAN 

Bhaskara I is a Indian mathematician and he belongs to the age of 600 CE - 680 CE. He is 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. Bhaskara's probably most important mathematical contribution concerns the representation of numbers in a positional system.

NAGARJUNA (931 CE) 

Expertise: chemistry and metallurgy

He was an extraordinary wizard of science born in the nondescript village of Baluka in Madhya Pradesh. His dedicated research for twelve years produced maiden discoveries and inventions in the faculties of chemistry and metallurgy. Textual masterpieces like "Ras Ratnakar", "Rashrudaya" and "Rasendramangal" are his renowned contributions to the science of chemistry. Where the medieval alchemists of England failed, Nagarjuna had discovered the alchemy of transmuting base metals into gold. As the author of medical books like "Arogyamanjari" and "Yogasar", he also made significant contributions to the field of curative medicine. Because of his profound scholarliness and versatile knowledge, he was appointed as Chancellor of the famous University of Nalanda. Nagarjuna's milestone discoveries impress and astonish the scientists of today.

BHASKARACHARYA II (1114 CE - 1183 CE)

Expertise: ASTRONOMER AND MATHEMATICIAN 

BHASKARACHARYA is also known as Bhaskara II is also a famous indian mathematician and astronomer. He belongs to the age of 1114-11183 CE.

Bhaskara and his works represent a significant contribution to mathematical and astronomical knowledge in the 12th century. His main works were the Lilavati (dealing with arithmetic), Bijaganita (Algebra) and Siddhanta Shiromani (written in 1150) which consists of two parts: Goladhyaya (sphere) and Grahaganita (mathematics of the planets).

His book on arithmetic is the source of interesting legends that assert that it was written for his daughter,Lilavati. In one of these stories, which is found in a Persian translation of Lilavati, Bhaskara II studied Lilavati'shoroscope and predicted that her husband would die soon after the marriage if the marriage did not take place at a particular time. To alert his daughter at the correct time, he placed a cup with a small hole at the bottom of a vessel filled with water, arranged so that the cup would sink at the beginning of the propitious hour. He put the device in a room with a warning to Lilavati to not go near it. In her curiosity though, she went to look at the device and a pearl from her nose ring accidentally dropped into it, thus upsetting it. The marriage took place at the wrong time and she was soon widowed.

Bhaskara II conceived the modern mathematical convention that when a finite number is divided by zero, the result is infinity. In his book Lilavati, he reasons: "In this quantity also which has zero as its divisor there is no change even when many [quantities] have entered into it or come out [of it], just as at the time of destruction and creation when throngs of creatures enter into and come out of [him, there is no change in] the infinite and unchanging [Vishnu]"

Some of Bhaskara's contributions to mathematics include the following:

1. A proof of the Pythagorean theorem by calculating the same area in two different ways and then canceling out terms to get a² + b² = c².
2. In Lilavati, solutions of quadratic, cubic and quartic indeterminate equations.
3. Solutions of indeterminate quadratic equations (of the type ax² + b = y²).
4. Integer solutions of linear and quadratic indeterminate equations (Kuttaka). The rules he gives are (in effect) the same as those given by the Renaissance European mathematicians of the 17th century
5. A cyclic Chakravala method for solving indeterminate equations of the form ax² + bx + c = y. The solution to this equation was traditionally attributed to William Brouncker in 1657, though his method was more difficult than the chakravala method.
6. His method for finding the solutions of the problem x² − ny² = 1 (so-called "Pell's equation") is of considerable interest and importance.
7. Solutions of Diophantine equations of the second order, such as 61x² + 1 = y². This very equation was posed as a problem in 1657 by the French mathematician Pierre de Fermat, but its solution was unknown in Europe until the time of Euler in the 18th century.
8. Solved quadratic equations with more than one unknown, and found negative and irrational solutions.
9. Preliminary concept of mathematical analysis.
10. Preliminary concept of infinitesimal calculus, along with notable contributions towards integral calculus.
11. Conceived differential calculus, after discovering the derivative and differential coefficient.
12. Stated Rolle's theorem, a special case of one of the most important theorems in analysis, the mean value theorem. Traces of the general mean value theorem are also found in his works.
13. Calculated the derivatives of trigonometric functions and formulae.
14. In Siddhanta Shiromani, Bhaskara developed spherical trigonometry along with a number of other trigonometric results.

Source: Wikipedia.org