Introduction to Physics
Physics is the study of basic laws of nature and their expression in different natural phenomena. For instance, Newton studied the fall of apple to the ground, and formulated, the “ Laws of Gravitation ”. This law helped to explain different natural phenomena like why things do not escape in space on its own, how much force need to be applied to escape the rocket into the space.
Physics is a branch of Science. The word ‘Science’ is used from age old times. In Latin it was called ‘Scientia’, in Sanskrit it was called ‘Vijnan’ in Arabic it was called ‘Ilm’. All of these had the same meaning i.e. ‘Knowledge’. Also, science is a systematic attempt to understand the natural phenomena, and use the knowledge to predict, modify and control the phenomena.
Scientific Method
Stepwise research for any discovery in the nature followed by few interconnected steps is called Scientific Method. These steps are –
- Systematic Observations
- Controlled Experiments
- Qualitative as well as Quantitative Reasoning
- Mathematical Modelling
- Verification or Falsification of Theories
Principal Thrust in Physics
- Unification: When many different phenomena are explained on the basis of very few laws then it is called unification. E.g. Ball Falling on Ground, Earth Revolving Around Sun, Satellite revolving Around Earth, all these can be explained with the help of “ Universal Law of Gravitation ”.
- Reductionism: In contrast to unification, many times a complex system can be explained by breaking it into smaller parts and studying the properties of these parts. Hence, it is called reductionism. E.g. Ball falling on earth is under different forces such as Gravitational Force, Air Resistance but to understand it we just consider effect of gravitation force only.
Scope of Physics
Basically, Physics is divided into two sub-domain, Macroscopic and Microscopic. These are differentiated based on “magnitude of physical quantities”. Some physical quantities are length, mass, time, and energy.
The disciplines that comes under classical physics, such as Mechanics, Electrodynamics, Optics, and Thermodynamics are all belongs to Macroscopic domain. Let us discuss these disciplines, one by one.
- Mechanics is the branch of physics that is founded on Newton’s laws of motion and the law of gravitation. It deals with study of, motion of a body, rigid and deformable bodies and general systems of particles. Some typical problems of mechanics includes, speed, distance and time problems, equilibrium of bodies under action of forces, propagation of water waves and sound waves etc.
- Electrodynamics is a branch of physics that deals with electric and magnetic phenomena that are linked with charged and magnetic bodies. Scientists like Coulomb, Oersted, Ampere, Faraday and Maxwell contributed in this field. Some problems of this field includes motion of current carrying conductor in magnetic field, working of antenna, propagation of radio waves in ionosphere etc.
- Optics includes propagation of ray of light through different media, colors exhibited by rainbow in sky, working of microscope and telescope, etc.
- Thermodynamics is the branch of science that deals with heat and temperature and their relation to energy and work. Moreover, problems in this field includes efficiency of heat engines and refrigerators.
Microscopic Domain
If the magnitude of physicals quantities is minute then all such quantities comes under Microscopic domain. Here, we study the structure and constitution of matter, atoms and nuclei, and their interaction with electrons, photons and other such particles. Currently, Quantum theory is currently accepted as the proper framework to explain the microscopic phenomena.
This article is helpful for Class 11 Physics
Keywords: Unification, Reductionism,Optics, Thermodynamics, Electrodynamics, Mechanics
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