COMPETITIVE EXAM CORNER

COMPETITIVE EXAM CORNER - - - - Table A1. Systematic developments in Physics over centuries Observation of motion of Sun, Stars, Planets and Moon Around BC (Early Greeks) In the universe everything is changing. Nothing remains in the same state indefinitely. The idea of ‘time’ started with this understanding. Around BC (Heraclitus). Everything is composed of entirely small indivisible elements called ‘atoms’. Development of theory of ‘atomism’. But that time it is a hypothesis. No experimental proof. End of BC (Democritus and Leucippus) Idea of natural laws behind every day phenomena Idea of motion with gravity Theory of four elements(Everything is made up of Earth, water, fire, air able to inter-transform into each other) Earth is centre of universe(Hypothesis) Force is required to move the object Heavier object falls faster towards Earth than lighter object Around rd century BC (Aristotle) Earth is sphere Measurement of radius of the Earth almost accurately Around BC (Eratosthenes)