From the book…
‘…The law of universal gravitation states that any two bodies in the universe attract each other with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. This was the genius of Newton in seeing the same underlying force that causes all bodies in the universe, big or small, to attract each other. Using his new theory, he was able to predict with considerable accuracy the motion of planets, as well as the tiniest objects known to man in those days.
He himself was not fully comfortable, however, with the force of gravity. In a letter, he wrote ‘That one body may act upon another at a distance through a vacuum without the mediation of anything else, by and through which their action and force may be conveyed from one another, is to me so great an absurdity that, I believe, no man who has in philosophic matters a competent faculty of thinking could ever fall into it.’ He was never able to assign a cause behind the existence of gravity. In the second edition of the Principia he wrote ‘I have not yet been able to discover the cause of these properties of gravity from phenomena and I feign no hypotheses… It is enough that gravity does really exist and acts according to the laws I have explained, and that it abundantly serves to account for all the motions of celestial bodies.’
It is however to be noted that the idea of gravity was not an entirely new concept outside Europe. In Siddhantha Siromani (Supreme Results) gravity was described by the 11th century Indian Mathematician Bhaskaracharya in the following terms:
Aakrishti sakthischa mahee thayaa yathkhastham guru swa abhimukham swa sakthyaa . aakrushyathe thath pathathi iti bhaathi same samanthaath kwa pathathi ayam khe
It says that the earth attracts the objects in the sky by its own force towards itself. He discusses the forces between the celestial bodies using a question: Where can the celestial bodies fall since they attract each other?
It was much after the death of Isaac Newton that modern science began to learn about electricity and magnetism in details. Around the beginning of the nineteenth century a vague relationship between electricity and magnetism began to be understood, especially due to the experiments conducted by Hans Christian Ørsted, André-Marie Ampère, Jean-Baptiste Biot, Johann Carl Friedrich Gauss, Félix Savart, Michael Faraday, etc. However, the knowledge that was being gathered was vastly chaotic. James Clerk Maxwell (1831–1879) organized the knowledge by formulating a few general principles combining, both electricity and magnetism. His work was about finding the underlying principles that causes the various electrical and magnetic phenomena. Maxwell helped develop the Maxwell–Boltzmann distribution, which is a statistical means of describing aspects of the kinetic theory of gases…’
Emergence is the way complex systems and patterns arise out of a multiplicity of relatively simple interactions. This is central to the study of complex as well as chaotic systems. The simple components of the environment may form more complex emergent properties, as a whole. Relating to the closest we can get, the human perception of the world, we can say that what we perceive about the world is way greater than the signals that are fed to our bodies through our senses. When you look at a distant star, your perception of the star is way greater than the light that reaches your eyes from it.
The above image: Snowflakes (by Wilson Bentley) forming complex symmetrical patterns is an example of emergence in a physical system.