Explain two principal thrusts in physics: 'Unification' and 'Reduction'.

Explanation

`to` There are two principal thrusts in physics Unification and Reduction.
`to` In physics, we attempt to explain diverse physical phenomena in terms of a few concepts and laws.
`to` The effort is to see the physical world as manifestation of some universal laws in different domains and conditions.
`to` For example, the same law of gravitation describes the fall of an apple to the ground, the motion of the Moon around the Earth and the motion of planets around the Sun.
`to` Similarly, the basic laws of electromagnetism (Maxwell.s equations) govern all electric and magnetic phenomena.
`to` A related effort is to derive the properties of a bigger, more complex, system from the properties and interactions of its constituent simpler parts. This approach is called reductionism and is at the heart of physics.
`to` For example, the subject of thermodynamics, developed in the nineteenth century deals with bulk systems in terms of macroscopic quantities such as temperature, internal energy, entropy etc.
`to` The subjects of kinetic theory and statistical mechanics interpreted these quantities in terms of the properties of the molecular constituents of the bulk system. In particular, the temperature was seen to be related to the average kinetic energy of molecules of the system.