Atomic Theory of Ancient India (भारतीय परमाणु-विज्ञानम्)

Atom (Sanskrit: परमाणुः) has been described as the smallest, indivisible particle in any substance. Science and philosophy have studied through investigations and experiments, the many forces of nature, such as gravity, electromagnetism, nuclear forces etc., but one of the major theories studied is that of the atom.

In Indian thought, there are two naturalistic theories of the origin of the empirical world. One view accords world to be a product of ordered evolution from an original undifferentiated Nature (one becoming many), while the second views world arising out of atoms combining together in various ways (many becoming one) in a limited sense. The Sankhya represents the first, and the Vaiseshika the second view.

न्याय-वैशेषिक परमाणुवाद सिद्धान्त । Nyaya-Vaiseshika Theory of Atomism

The Atomic Theory of the Nyaya-Vaiseshika system explains the order of creation and destruction of non-eternal objects. Nyaya-Vaiseshika is noted for their logically-structured atomism. According to this theory only the composite substances of the atoms of earth, water, air and fire are produced and destroyed. Atoms are the fundamental building blocks of matter, and the universe consists of multiple entities, both material and spiritual, making up its ultimate constituents. The concept of avayavin (whole) and avayava (constituent part) has shaped the atomic theory of the Nyaya-Vaisesika. This school of thought uses a logical and causal framework to explain how invisible particles combine to form the visible universe.

Attributes of Atoms

According to Maharshi Kanada, every material of this universe is made up of kana or parmanu (atom) which are invisible, indivisible, eternal and indestructible. They possess certain characteristic properties and potentials of sense stimuli.

The Vaiseshika sutras, define and explain the nature of dravya or substance, and classifies all dravyas or things of the world into nine: Earth, water, fire, air, ether/space, time, space, atman and manas (mind).

पृथिव्यापस्तेजो वायुराकाशं कालो दिगात्मा मन इति द्रव्याणि । १,१.४ । Vais. Sutr. 1.1.4

Among these nine, the first four, namely, earth, water, fire and air are considered to be atomic in nature. Each element has own class of atoms with particular attributes by which they can be differentiated, i.e., qualitatively. Maharshi Kanada recognized them as four kinds of atoms each having a unique quality or guna

1. kshiti or earth - smell
2. apa or water - taste
3. tejas or fire - color
4. vayu or air - touch

These four are knowable by outer perception. The substances of earth, water, fire, and air are eternal and non-eternal. The atoms of these four substances are whole (avayavin) and eternal, because as partless they can neither be produced nor destroyed. All other objects made by the combination of atoms are non-eternal and subject to origination as well as destruction. The fifth substance, akasha or ether, has the characteristic of sound and is indivisible, eternal, and non-perceptible. Akasa (ether), according to Maharshi Kanada, has no atomic structure; it is inert and ubiquitous serving only as the substratum of sound which is supposed to travel in the form of waves in the manifesting medium of vayu (air). Atoms are the primordial infinitesimal particles of everything except space or Akasha.

Kshiti or earth has fourteen qualities as follows, among them its unique quality is smell or odour.

• colour
• taste
• smell
• touch
• numerical unit
• mass
• weight
• conjunction
• disjunction
• distance
• proximity
• gravity
• fluidity
• faculty

Apa has the qualities of kshiti with the exception of smell, instead of which viscidity is present; its special quality is taste. Tejas has all the qualities of kshiti with the exception of taste, smell, and weight; its special quality is colour. Vayu has the qualities of kshiti, excepting colour, taste and smell; touch is its special quality. Maharshi Kanada outlines the special qualities of the five elements (including Akasha) as follows

रूपरसगन्धस्पर्शवती पृथिवी । २,१.१ । rūparasagandhasparśavatī pṛthivī | 2,1.1 |

Prithvi or earth has the qualities of form, taste, smell and touch

रूपरसस्पर्शवत्य आपो द्रवाः स्निग्धाश्च । २,१.२ । rūparasasparśavatya āpo dravāḥ snigdhāśca | 2,1.2 |

Apa or water has form, taste, and touch; it has the characteristic of fluidty and viscidity

तेजो रूपस्पर्शवत् । २,१.३ । tejo rūpasparśavat | 2,1.3 |

Tejas or fire has form and touch

वायुः स्पर्शवान् । २,१.४ । vāyuḥ sparśavān | 2,1.4 |

Vayu is known by touch

त आकाशे न विद्यन्ते । २,१.५ । ta ākāśe na vidyante | 2,1.5 |

None of these exist in Akasha or ether

Each atom has its individual characteristics, and it combines with other atoms to form the larger entities similar to molecules.

That matter is ultimately made of indivisible building blocks, thus appeared in India as part of philosophical school of thought long before Western inventions.

Key Features of Atomic Theory

Key Features of the Ancient Indian Atomic Theory based on Nyaya and Vaiseshika texts:

1. Indivisible: Parmanu are considered the smallest, indivisible particles, the limit of division for matter. They have no constituent parts (avayavas) and cannot be further divided.
2. Invisible: Atoms are invisible, they cannot be perceived but that is not the ground for non-existence of atoms.
3. Eternal and Unchangeable: Atoms are eternal, unchangeable, and the basis for all material objects.
4. Qualitative Differentiation: The theory posits four elemental atoms based on the four eternal elements: earth, water, light, and air.
5. Atoms as Building Blocks: These atoms combine to form larger molecules, called "dvyaṇuka" (binary molecules), and then further combine to create various substances.
6. Chemical Change: Chemical reactions, such as changes in color of heated mud utensils, are attributed to the combination and rearrangement of atoms.
7. Properties of Atoms: Atoms of the same element have identical properties, while different elements have different types of atoms.
8. Indestructible: Atoms are indestructible and cannot be created or destroyed.
9. Eternal motion: Atoms are in a state of constant motion.
10. Vibratory motion: According to Vaiseshika, atoms possess an intrinsic vibratory or rotatory motion (parispanda).
11. Spherical Shape: Despite having no magnitude, atoms are theoretically regarded as spherical (parimandaliya)
12. Without Magnitude: They are conceived as having no length, breadth, or thickness (infinitesimal), but their combinations produce matter of visible magnitude.

Maharshi Kanada further logically explained that density of atom in water is more than air. He also gave the theory of chemical changes and claimed that chemical changes occur because of the various factors and especially due to variations in temperature.

Proof of existence of Atoms

The four kind of atoms, namely of kshiti, apa, tejas, and vayu, are characterized by their characteristic mass, basic molecular structure such as dyad, triad, etc, fluidity (or it’s opposite), viscosity (or its opposite), velocity (or quantity of impressed motion- Vega), elasticity, gravity, and other characteristic potential color, taste, smell or touch not produced by chemical operation. It is these four kinds of atoms involved in all chemical reactions while the space remains unaffected.

महत्यनेकद्रव्यवत्त्वाद्रूपाच्चोपलब्धिः । ४,१.६ । mahatyaneka-dravyavattvād-rūpāccopalabdhiḥ | 4,1.6 |(Vais. Sutr. 4.1.6)

Translation: In Mahat (in the Universe) due to the existence of multiple substances or material entities and also due to multiple forms / shapes / colours, attainment or formation (is possible).

Sat or Pure Existence takes multifarious forms as substances with various forms/shapes/colours i.e. the Universe is formed out of Sat or Pure Existence (Brahman in Vedanta). Atoms take different forms of agglomerations. Atoms cannot he perceived. Perception is possible only for those objects which have perceivable dimensions or measure (parimana) and have a form/shape/colour (rupa). In spite of being a large substance (or material entity), Vayu does not get perceived i.e. cannot be observed directly due to its lack of form/shape/colour. Invisibility is not a ground for non existence, as in die case of Vayu. Vayu is invisible but it has existence. So also the atoms are invisible but they exist. Vaiseshika expounded the Atomic theory wherein indivisible atoms are identified as the ultimate building blocks of all previously mentioned 9 dravyas though they cannot be perceived by the sense organs.

Nature of Atomic Combinations

Atoms may conjoin or disjoin in reactions. Atoms are invisible though the final substance formed by conjunction of many such atoms is perceived by the sense organs. Atoms are driven by an inherent tendency of constant motion which is their natural property. As a result, atoms of the same bhuta (element) combine to form dvyanuka or dyad according to Prashastapada. It represents the formation of binary molecules of elementary substances according to modern conception. One atom unites with another under an inherent impulse to form a binary molecule or a compound of two atoms. The two like or similar atoms are the material causes for the combination while the other types of atoms are considered to play the role of supportive atoms. Two unlike atoms, i.e. an atom of earth and an atom of water cannot, it is stated, enter into combination. These binary molecules or dyads then combine among themselves by groups of three, four, five, etc., to produce larger aggregates in obedience to the moral law underlying the creation.

Maharshi Kanada, however, maintained that different atoms combine in different patterns, some in pairs, some in triads, tetrads etc.

According to Prashastapada, basic unit of n dyads = 1 dyad + 1 dyad… n dyads where n ≥ 1

These dyad combinations further combine in different proportions to form trayanuka (tertiary) chaturanuka (quarternary) and so on. The minimum visible is a triad, designated as Trayanuka (trasarenu) of the size of a mote in sunbeam. A triad is formed out of three dyads and so on.

While Kanada's Atoms combine = basic unit /molecule with two, three or n number of units

Basic unit of n atoms = 1 atom+ 1 atom…n atoms where n≥1

Nyaya-Vaiseshika views atoms, though eternal in themselves, are non-eternal (anitya) as aggregates which may be organic or inorganic.

Principle of Causality

Nyaya-Vaiseshika is noted for its adherence to the principle of causality. Atoms are the material cause for a dyad, the effect. Dyads are the cause for the production of a triad which is again an effect. After the triad comes into existence, the atoms lose their causal efficiency.

But, why do the primordial atoms unite and produce gross matter? Vaiseshika explains that there is an unseen (adristha) which sets off the process of atoms uniting to form dyads. Adrishta as an unseen force is the efficient cause of the world while atoms are its material cause.

Effect of Heat

A substance may change qualitatively under the influence of heat in its course of existence. Heat and light, are the different forms of the same essential entity, tejas according to Vaiseshika. The Vaisheshika’s stand on such a change is that with application of heat a substance

- decomposes into original homogenous paramanus or the basic unit with zero mass (not the unit of dyad, triad etc)

- transformation of the character of the atoms

- recombination of paramanus with a new basic unit arrangement and order resulting in a new substance.

Molecular Grouping

व्युहः (Vyūha) refers to the structural arrangement of atoms, which ancient thinkers like Prasastapada identified as the reason for different properties in complex substances.

The Vaisheshikas hold that under the influence of heat, substances are broken down to the most basic entity (paramanu) before being transformed in to a new substance whereas the Nyaya school does not believe in decomposition in to the very basic entity.

Combination may also take place either between atoms of two or more substances belonging to the same or different bhuta classes.

(A) Mono-bhautic compounds:—These are the simplest ; i. e., compounds formed by the union of homogeneous atoms of different substances which are isomeric modes of the same bhuta class.

(B) Hetero-bhautic compounds:—These may be bi or polybhautic compounds formed by the union of heterogeneous atoms of substances belonging to the different bhuta classes.

A nature (tattva) of the particular substance when it turns into another nature is called transmutation (Utparivartana) in scientific terms. A study on the changes (Parivartana) and analysis (Visleṣaṇa) of the substance because of its origin and qualities is called Chemical Science of the particular substance. The Change is of two kinds such as

1) Physical Change (Bhautika Parivartana)

2) Chemical Change (Rāsāyanika Parivartana)

The first type of change i.e. the Physical Change, is when the nature of the substance undergoes changes due to various reasons for a particular period of time and returns back to its previous state. For example, a piece of Iron forms into magnet after a deep friction (Gharṣaṇa) on the magnet and returns into being a piece of iron after it loses the magnetic effect. In same manner, water turns into ice at the state of high cooling (Himānka) and returns to liquid state after melting.

In second type of change i.e. Chemical Change once the nature of the substance changes it cannot be reversed. For example, Milk turns into curd, and iron turns into rust etc.

States of Matter

As mentioned in the Upanishads, the five elements of the nature are –

• Earth • Water • Air • Fire and • Akasa

The concept of Akasha

• The Earth represents the solid state

• The Water constitutes the liquid state

• The Air forms the gaseous state and

• The Fire constitutes of the plasma as the fourth state of matter.

The western scholars, though, failed to recognize and include nuclear state as part of a state of matter.

• Akasa is a nuclear state in which few nuclear parts are stable.

सांख्य द्रव्य सिद्धान्त । Samkhya Theory of Matter

According to Samkhya the universe, as manifested evolved out of an unmanifested cosmic nature termed prakriti or avyakta, the ultimate ground. Prakriti, is an infinite, eternal, ubiquitous, indestructible, undifferentiated, indeterminate continuum. This was believed to be made up of infinitesimal reals or gunas, representing substances.

In the Samkhya philosophy, the theory of matter is focused on a process of evolution and transformation rather than the mere mechanical aggregation of particles. While schools like the Nyaya-Vaisheshika focus on indivisible atoms (Paramanu), Samkhya explores how gross matter emerges from subtle potentials called Tanmatras.

The atomic theory of Samkhya can be explained through the following key concepts:

The Source: Prakrti and the Three Gunas

According to Samkhya, all material existence originates from Prakrti (primordial nature), which is the basis or "rootless root of the universe" of the universe. Prakrti is composed of three fundamental "reals" or constituent principles called Gunas:

• Sattva: Tendency toward manifestation and intelligence-stuff.
• Rajas: The principle of activity and energy.
• Tamas: The principle of inertia, mass, and heaviness.

All matter is an offshoot of the intermingling and different proportions of these three Gunas.

The Subtle Tanmatras

In the Samkhya system the gross elements (Mahabhutas) do not arise directly from Prakrti but evolve from Tanmatras.

Definition: Tanmatras are the subtle essences or potentials of matter. They are considered invisible, eternal, and represent the finest state of an element.

Function: They have the inherent power to affect the senses. For example, the Gandha-tanmatra is the subtle essence of smell that eventually produces the gross element of Earth.

The tanmatra is considered to be invisible and eternal while the corresponding elements (Panchabhutas), the produced ones, are not eternal. The origin of the concept of tanmatra can be found in some of the later Upanishads. In the Praha Upanishad, the subtle states are called prthvi-matra, apo-matra and the like. The Maitri Upanishad mentions the word tanmatra in the same context. It can be conjectured that these Upanisadic ideas might have influenced the later exponents of the Samkhya school to explain the evolution of the gross matter from the primary tanmatras.

Evolution of the Five Elements (Panchamahabhutas)

Gross matter is generated from these subtle essences in a specific sequence:

• Akasa (Space/Ether): Emerges from the Shabda (sound) tanmatra. शब्दतन्मात्रादाकाशः (śabdatanmātrādākāśaḥ)
• Vayu (Air): Emerges from the Shabda and Sparsha (touch) tanmatras.
• Tejas (Fire): Emerges from the Shabda, Sparsha, and *Rupa* (color) tanmatras.
• Ap (Water): Emerges from the Shabda, Sparsha, Rupa, and Rasa (taste) tanmatras.
• Prthvi (Earth): Emerges from all five tanmatras: Shabda, Sparsha, Rupa, Rasa, and Gandha (smell).

Transformation and Causation (Satkaryavada)

A central pillar of Samkhya is the theory of Satkaryavada, which holds that the effect pre-exists in its cause.

• Rearrangement: Production is not the creation of something entirely new, but a continual transformation (Parinama) or rearrangement of the fundamental constituents.
• Collocation: All visible objects are formed by the grouping and regrouping of the five elements. The differences we see in substances (like hardness or fluidity) are due to different collocations or structural arrangements of these elements.

Formation of Complex Chemical Compounds

The formation of complex matter and diverse substances is explained through the process of evolution (Parinama) and the grouping of the five gross elements (Mahabhutas), rather than through a mechanical atomic theory like that of the Nyaya-Vaisheshika school.

Grouping and Regrouping (Collocations)

Samkhya teaches that all gross things in the visible universe are formed by the grouping and regrouping of the five elements (Earth, Water, Fire, Air, and Akasa)

The differences observed in various complex substances—such as their hardness, fluidity, or unique chemical properties—are attributed to different types of collocations or structural arrangements of these elements in various permutations and combinations.

जैन परमाणुवाद सिद्धान्त । Jaina Theory of Atomism

In the Indian Knowledge System (IKS), the heterodox Jaina and Bauddha (Buddhist) schools developed unique atomic theories that differed significantly from each other and from the orthodox Nyāya–Vaiśeṣika system. While both schools used the term paramāṇu (atom), they viewed the nature, qualities, and aggregation of matter through their own philosophical lenses.

The Jaina school views the physical world as eternal, having no beginning or end. Its theory of matter is based on several key principles:

• Pudgala and States of Matter: Matter is referred to as pudgala, a term derived from the processes of combination (pud) and dissociation (gala). It exists in two primary states: the atomic (aṇu) and the aggregate (skandha).
• Uniformity of Atoms: Unlike the Nyāya–Vaiśeṣika school, which assigns specific qualitative differences to atoms (e.g., earthy atoms have odour), the Jainas believe all atoms belong to a single class and are qualitatively uniform. Every atom possesses the potential to produce any colour, taste, odour, or touch.
• Inherent Forces of Combination: Jainas do not believe an external force is required for atoms to combine. Instead, atoms unite due to their inherent attractive (snigdha) and repulsive (rūkṣa) attributes. Combination occurs when there is a sufficient difference in the degree of these cohesive or dry forces between atoms.
• Characteristics: The Jaina atom is conceived as the subtlest, indivisible, and absolute unit of matter that occupies a single point in space (pradeśa). While the atom is eternal, the aggregates (skandhas) they form are not.

बौद्ध-परमाणुवाद-सिद्धान्तः । Bauddha (Buddhist) Theory of Atomism

Atomic theory in Buddhism was primarily developed by the realist schools, specifically the Vaibhāṣika and Sautrāntika. Their view is characterized by the following:

• Momentariness: Following the central Buddhist doctrine that all things are strings of momentary events, atoms are not viewed as permanent particles but as momentary phase-changes. They flash into existence and disappear instantly.
• Atoms as Dynamic Forces: Matter is not seen as a "substance" but as a dynamic force or energy. For instance, an "earthy" atom is viewed as a force of repulsion, while a "watery" atom represents kinetic energy.
• Atomic Aggregates: A visible object is a cluster of at least eight atoms: four fundamental atoms representing the elements (earth, water, fire, air) and four secondary atoms representing the qualities (colour, odour, taste, touch). In this system, even qualities are viewed as atomic in nature.
• Clustering over Combination: Buddhist atoms do not penetrate each other or form "chemical" combinations in the modern sense. Instead, they form conglomerations or clusters. Some schools hold that there is always an intervening space between atoms, while others believe they are in such close proximity that no space remains.

Differences between Jaina and Bauddha Atomism

Feature	Jaina Atomism	Bauddha Atomism
Persistence	Atoms are eternal and absolute.	Atoms are momentary phase-changes.
Nature	Uniform particles of a single class.	Dynamic forces or clusters of energy.
Qualities	Every atom can potentially manifest any quality.	Fundamental elements and qualities are separate types of atoms.
Aggregation	Driven by inherent attractive and repulsive forces.	Form clusters of at least eight fundamental and secondary atoms.

Comparison with Modern Science

Interestingly, some scholars have noted that the Samkhya doctrine of matter bears striking similarities to modern physical concepts. The view of the Gunas as fundamental principles of mass, energy, and intelligence, and the concept of Tanmatras as underlying subtle vibratory potentials, aligns with modern wave mechanics and energy-matter relationships. Unlike Greek atomism, which emphasizes quantitative differences in atoms, Samkhya emphasizes the qualitative evolution of matter from a single primordial source.