Sage who dreamed of the Atom

Acharya Kanada, ancient Indian philosopher, imagined atoms ~2,500 years back and estimated it to be 7.2X10-⁸ meters

Dr. Santanu Bhattacharya
4 min readMar 10, 2021

Acharya Kanada, also known as Kashyapa, an ancient Indian natural scientist and philosopher, formulated the theory of atoms 2500 years before John Dalton’s discovery. He founded the Vaisheshika school of Indian philosophy that epitomized the earliest Indian physics. He used this to explain the creation and existence of the universe by proposing an atomistic theory, applying logic and realism which made his school one of the earliest known systematic realist ontology in human history.

The Story Lane:

Acharya Kanada was born in 600 BC in Prabhas Kshetra (near Dwaraka) in Gujarat, in Eastern India. His real name was Kashyap.

Once on his holy expedition to Prayag, Kashyap saw thousands of devotees littering the streets with flowers and rice grains, which they presented at the temple as a symbol of respect. Fascinated by the broken grains of rice spread on the streets, he started collecting them.

Ancient Indian school system known as “Gurukul”. Source:

A crowd gathered around and asked him that why he is collecting the leftover grains that even a beggar will not eat. He replied that while the individual grain particles may not have any worth, but a collection of hundreds of grains can make up a person’s meal, the collection of many such meals would serve an entire family and ultimately would feed the entire mankind. Therefore even a single grain of rice is as important as all the valuable riches in this world.

Rice has been a key part of Asia’s diet for many millennium. Photo by Sandy Manoa on Unsplash

Impressed by his thoughts and explanation of importance of even a single particle, people began calling him ‘Kannada’, as ‘Kan’ in Sanskrit means ‘the smallest particle’.

Kanada was walking with food in his hand, breaking it into small pieces when he realized that he was unable to divide the food into any further parts. From this moment, he conceptualized the idea of a particle that could not be divided any further. He termed that indivisible matter parmanu or anu (atom). Note that, at later times, anu (atom) was considered to be consisted of paramanu (“sub-atom”), but Kanada used these terms interchangably . He also proposed that this indivisible matter could not be noticed or perceived through any human organ i.e., through naked eyes.

The Vedic Atomic Theory:

Kanada believed that the atom was eternal and has the tendency to bind with other atoms. Vaisesika atomists posited the four elemental atom types.

The union of two atoms forms a double or binary molecule, called “Dwinuka”. According to theory proposed by Kanada, Dwinuka would have similar properties as of the original parmanu (atoms). He also stated that the combinations of different type of atoms result in a non-identical molecule that could chemically change a component in the presence of specific factors such as heat — for example, change in color of utensils made of mud when they are heated. Kanada’s book, called Vaisheshik Darshan (also called Kannada sutras), captured his atomic theory which states the following:

  • Everything can be partitioned
  • Subdivision leads to creation of parmanu (atom) after a while
  • Parmanu is indivisible, that is, it cannot be divided further
  • Subsection of any particle has an end and cannot be carried infinitely.
  • Atom is indestructible
  • It is the foundation for all material existence
  • Parmanu has a specific property which is same as the class of substance to which it belongs
  • It cannot be seen through naked eye
  • Atoms can be combined in different ways to produce chemical changes by heating them or using other measures.
  • Parmanu or atom can have two states — state of motion and state of absolute rest.

“Paramanu” in today’s measurements:

Paramanu (“atom”) is the unit of measurement for any being. A single Paramāṇu represents the smallest unit possible. Combining 8 Paramāṇu units will form a single Rathadhūli unit and so on. Below are proposed units of measurement in relation to one another:

  • 8 Paramāṇu= 1 Rathadhūli, chariot-dust
  • 8 Rathadhūli= 1 Vālāgra, hair-end (today taken to be ~75 μm)
  • 8 Vālāgra= 1 Likṣā, nit
  • 8 Likṣā= 1 Yūka, louse
  • 8 Yūka= 1 Yava, barley-corn
  • 8 Yava= 1 Aṅgula, digit (width of a finger, 3/4 of an inch or ~1.9 cm)

The smallest unit, which is paramāṇu is stated to be perceived only by the sages. For all other practical purposes, aṅgula is the smallest unit of measurement to be used by common people

Using one Aṅgula, width of a finger, 1.9 cm, to be 8*8*8*8*8*8 = 262,144 paramanus, 1 paramanu turns to be about 7.2X10-⁸ meters. The atom, as we know today, is about 10-¹⁰meters, or just about 700 times bigger than Kanad’s paramanu.

While Kanada’s atom was ~ 700 times bigger than what we know today, conceptualizing such small sizes 2,500 years back without the aid of modern scientific instruments is a remarkable feat.

Acharya Kanada defined life as an organized form of atoms and molecules and deaths as an unorganized form of those atoms. His discovery was not without controversy and has been in dispute since the earliest days. The earliest significant discovery of atom that survives today was done in 5th century by Greek philosophers Leucippus and Democritus. Scholars such as McEvilley (2002) assumes that such similarities are due to extensive cultural contact and diffusion, probably in either direction.

Epilogue: I write on Large Numbers, Data Science, Machine Learning, Product Management, Ancient History and Career Success Stories. You can follow me to get these in your Medium feed.

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Dr. Santanu Bhattacharya

Chief Technologist at NatWest, Prof/Scholar at IISc & MIT, worked for NASA, Facebook & Airtel, built start-ups, and future settler for Mars & Tatooine