தொல்தமிழர் அறிவியல் – 24
உலகத் தோற்றம் - 7
The system of five elements are found in Vedas, especially Ayurveda, the pancha mahabhuta, or "five great elements", of Hinduism are bhūmi (earth), ap or jala (water), tejas or agni (fire), marut, vayu or pavan (air or wind) and vyom or shunya (space or zero) or akash (ether or void). They further suggest that all of creation, including the human body, is made up of these five essential elements and that upon death, the human body dissolves into these five elements of nature, thereby balancing the cycle of nature.
The five elements are associated with the five senses, and act as the gross medium for the experience of sensations. The basest element, earth, created using all the other elements, can be perceived by all five senses – (i) hearing, (ii) touch, (iii) sight, (iv) taste, and (v) smell. The next higher element, water, has no odour but can be heard, felt, seen and tasted. Next comes fire, which can be heard, felt and seen. Air can be heard and felt. "Akasha" (aether) is beyond the senses of smell, taste, sight, and touch; it being accessible to the sense of hearing alone.
While the classification of the material world by the ancient Indians and Greeks into Air, Earth, Fire and Water was more philosophical, during the Islamic Golden Age medieval middle eastern scientists used practical, experimental observation to classify materials. In Europe, the Ancient Greek system of Aristotle evolved slightly into the medieval system, which for the first time in Europe became subject to experimental verification in the 1600s, during the Scientific Revolution.
Centuries of empirical investigation have proven that all the ancient systems were incorrect explanations of the physical world. It is now known that atomic theory is a correct explanation, and that atoms can be classified into more than a hundred chemical elements such as oxygen, iron, and mercury. These elements form chemical compounds and mixtures, and under different temperatures and pressures, these substances can adopt different states of matter. The most commonly observed states of solid, liquid, gas, and plasma share many attributes with the classical elements of earth, water, air, and fire, respectively, but it is now known that these states are due to similar behaviour of different types of atoms at similar energy levels, and not due to containing a certain type of atom or a certain type of infinitely divisible substance or energy.
--- Origin of the world – Wikipedia.
Origin and definition of the terra firma – Temporal world.
“ The earliest extant grammatical treatise Tolkappiam and other successive classical literary texts define the world as a combination of five elements – earth, air, fire, and water. Ancient literary texts in Greece and Egypt also reiterate the same concept. But nobody is able to observe how these five elements originated and at what stage and how they synthesized themselves into the formation of the physical world, as we see it now. Hence a conceptual definition of the world in a way acceptable but origin of the world is unknown and mysterious. In the absence of any tangible explanation for the origin of the world, Puranic texts attribute it to the activities of God. But still what is known as ‘Atomic theory’ alone seems to be plausible.” –Editor.