Hinduism is probably the only religion which provides great support for science and scientific discoveries. Most of the modern day inventions can be found in ancient Hindu scriptures. Below is a compiled list of the scientific discoveries of this era which can be found in the ancient scriptures.
Cosmology & psychology
According to India's ancient texts, around 3000 BCE sage Kapil founded both cosmology and psychology. He shed light on the Soul, the subtle elements of matter and creation. His main idea was that essential nature (prakrti) comes from the eternal (purusha) to develop all of creation. No deeper a view of the cosmos has ever been developed. Further, his philosophy of Sankhya philosophy also covered the secret levels of the psyche, including mind, intellect and ego, and how they relate to the Soul or Atma.
Medicine (Ayurveda), Aviation
Around 800 BCE Sage Bharadwaj, was both the father of modern medicine, teaching Ayurveda, and also the developer of aviation technology. He wrote the Yantra Sarvasva, which covers astonishing discoveries in aviation and space sciences, and flying machines - well before Leonardo DaVinchi's time. Some of his flying machines were reported to fly around the earth, from the earth to other planets, and between universes. His designs and descriptions have left a huge impression on modern-day aviation engineers. He also discussed how to make these flying machines invisible by using sun and wind force. There are much more fascinating insights discovered by sage Bharadwaj.
Medicine, Surgery, paediatrics, gynaecology. anatomy, physiology, pharmacology, embryology, blood circulation
Around this era and through 400 BCE many great developments occurred. In the field of medicine (Ayurveda), sage Divodasa Dhanwantari developed the school of surgery; Rishi Kashyap developed the specialized fields of paediatrics and gynaecology. Lord Atreya, author of the one of the main Ayurvedic texts, the Charak Samhita, classified the principles of anatomy, physiology, pharmacology, embryology, blood circulation and more. He discussed how to heal thousands of diseases, many of which modern science still has no answer. Along with herbs, diet and lifestyle, Atreya showed a correlation between mind, body, spirit and ethics. He outlined a charter of ethics centuries before the Hippocratic oath.
Rhinoplasty, amputation, caesarean and cranial surgeries, anesthesia, antibiotic herbs
While Lord Atreya is recognized for his contribution to medicine, sage Sushrut is known as the "Father of surgery". Even modern science recognizes India as the first country to develop and use rhinoplasty (developed by Sushrut). He also practiced amputation, caesarean and cranial surgeries, and developed 125 surgical instruments including scalpels, lancets, and needles.
Lord Atreya - author of Charak Samhita. Circa 8th - 6th century BCE. Perhaps the most referred to Rishi/physician today The Charak Samhita was the first compilation of all aspects of ayurvedic medicine including diagnoses, cures, anatomy, embryology, pharmacology, and blood circulation (excluding surgery).
He wrote about causes and cures for diabetes, TB, and heart diseases. At that time, European medicine had no idea of these ideas. In fact, even today many of these disease causes and cures are still unknown to modern allopathic medicine.
Other unique quality of Ayurveda is that it uncovers and cures the root cause of illness, it is safe, gentle and inexpensive, it sees 6 stages of disease development (where modern medicine only sees the last two stages), it treats people in a personalized manner according to their dosha or constitution and not in any generic manner.
Further, Ayurveda being the science of 'life', Atrea was quick to emphasize, proper nutrition according to dosha, and perhaps above all else, that there was a mind/body/soul relationship and that the root cause of all diseases and the best medicine for all conditions is spiritual and ethical life.
Rishi Sushrut is known as the father of surgery & author of Sushrut Samhita. Circa 5 - 4th century BCE. He is credited with performing the world's first rhinoplasty, using anesthesia and plastic surgery. He used surgical instruments - many of them look similar to instruments used today; and discussed more than 300 types of surgical operations. One of the Ayurvedic surgical practices being used today in India involves dipping sutures into antibiotic herbs so when sewed into the person, the scar heals quicker and prevent infection. The modern surgical world owes a great debt to this great surgical sage.
Atomic theory
Sage Kanad (circa 600 BCE) is recognized as the founder of atomic theory, and classified all the objects of creation into nine elements (earth, water, light or fire, wind, ether, time, space, mind and soul). He stated that every object in creation is made of atoms that in turn connect with each other to form molecules nearly 2,500 years before John Dalton. Further, Kanad described the dimension and motion of atoms, and the chemical reaction with one another. The eminent historian, T.N. Colebrook said, "Compared to scientists of Europe, Kanad and other Indian scientists were the global masters in this field."
Chemistry alchemical metals
In the field of chemistry alchemical metals were developed for medicinal uses by sage Nagarjuna. He wrote many famous books including Ras Ratnakar, which is still used in India's Ayurvedic colleges today. By carefully burning metals like iron, tin, copper, etc. into ash, removing the toxic elements, these metals produce quick and profound healing in the most difficult diseases.
Astronomy and mathematics
Sage Aryabhatt (b. 476 CE) wrote texts on astronomy and mathematics. He formulated the process of calculating the motion of planets and the time of eclipses. Aryabhatt was the first to proclaim the earth was round, rotating on an axis, orbiting the sun and suspended in space. This was around 1,000 years before Copernicus. He was a geometry genius credited with calculating pi to four decimal places, developing the trigonomic sine table and the area of a triangle. Perhaps his most important contribution was the concept of the zero. Details are found in Shulva sutra. Other sages of mathematics include Baudhayana, Katyayana, and Apastamba.
Astronomy, geography, constellation science, botany and animal science.
Varahamihr (499 - 587 CE) was another eminent astronomer. In his book, Panschsiddhant, he noted that the moon and planets shine due to the sun. Many of his other contributions captured in his books Bruhad Samhita and Bruhad Jatak, were in the fields of geography, constellation science, botany and animal science. For example he presented cures for various diseases of plants and trees.
Knowledge of botany (Vrksh-Ayurveda) dates back more than 5,000 years, discussed in India's Rig Veda. Sage Parashara (100 BCE) is called the "father of botany" because he classified flowering plants into various families, nearly 2,000 years before Lannaeus (the modern father of taxonomy). Parashara described plant cells - the outer and inner walls, sap color-matter and something not visible to the eye - anvasva. Nearly 2,000 years -later Robert Hooke, using a microscope described the outer and inner wall and sap color-matter.
Algebra, arithmetic and geometry, planetary positions, eclipses, cosmography, and mathematical techniques. force of gravity
In the field of mathematics, Bhaskaracharya II (1114 - 1183 CE) contributed to the fields of algebra, arithmetic and geometry. Two of his most well known books are Lilavati and Bijaganita, which are translated in several languages of the world. In his book, Siddhant Shiromani, he expounds on planetary positions, eclipses, cosmography, and mathematical techniques. Another of his books, Surya Siddhant discusses the force of gravity, 500 years before Sir Isaac Newton. Sage Sridharacharya developed the quadratic equation around 991 CE.
The Decimal
Ancient India invented the decimal scale using base 10. They number-names to denote numbers. In the 9th century CE, an Arab mathematician, Al-Khwarizmi, learned Sanskrit and wrote a book explaining the Hindu system of numeration. In the 12th century CE the book was translated into Latin. The British used this numerical system and credited the Arabs - mislabelling it 'Arabic numerals'. "We owe a lot to the Indians, who taught us how to count, without which no worthwhile scientific discovery could have been made." - Albert Einstein.
Metallurgy
India was the world-leader in Metallurgy for more than 5,000 years. Gold jewellery is available from 3,000 BCE. Brass and bronze pieces are dated back to 1,300 BCE. Extraction of zinc from ore by distillation was used in India as early as 400 BCE while European William Campion patented the process some 2,000 years later. Copper statues can be dated back to 500 CE. There is an iron pillar in Delhi dating back to 400 CE that shows no sign of rust or decay.
There are two unique aspects to India's ancient scientists. First their discoveries are in use today as some of the most important aspects of their field; and are validated by modern technological machines. Second, their discoveries brought peace and prosperity rather than the harm and destruction of many of our modern discoveries.