The theme of this module is on the conceptual development of physics. Several topics will be discussed e.g. (i) Conceptual development of the fundamental constituents of matter from the Greek atomists (Leucippus and Democritus) to the current M-theory. [reference: The Elegant Universe by Brian Greene, W W Norton & Company (1999)] (ii) Conceptual development of quantum theory [Reference: The Fabric of the Cosmos by Brian Greene (2003) ] (iii) Conceptual development of relativity [Reference : Albert Einstein : Opportunity and Perception by C N Yang, International Journal of Modern Physics A (Jan 2006)] (iv) Physical laws and symmetries in physics. (v)Gauge field and its historical development. Core issues of physics.