What is the Scope of Physics?
What is the Scope of Physics?
The two domains of interest in physics are: Macroscopic and Microscopic.
The macroscopic domain includes the study of the phenomena involving objects of finite size on terrestrial scale and even on astronomical scale.
This makes up Classical Physics. Most of it was developed up to the year 1900.
The microscopic domain includes the study of phenomena involving molecules, atoms, nuclei, electrons and other elementary particles.
This makes up Modern Physics. Most of it was developed after the year 1900.
Recently, the domain intermediate between the macroscopic and the microscopic domains had emerged. It involves the study of a few
tens or hundreds of atoms or molecules. It is called Mesoscopic Physics. This domain is emerging as an exciting field of research.
The Classical Physics includes subjects like Mechanics, Thermodynamics, Electrodynamics and Optics.
Mechanics deals with deals the study of general systems of particles, rigid bodies, deformable bodies, liquids etc. propulsion of rockets,
propagation of water waves, sound waves etc.
Thermodynamics deals with the study of gaseous systems. The changes in temperature internal energy and entropy of the system through
external work are investigated. Modes of transfer of heat, efficiency of heat engines and refrigerators are also included in thermodynamics.
Electrodynamics deals with the study of electric and magnetic phenomena associated with charged particles and magnetic materials. The basic
laws governing these phenomena were given by Coulomb, Oersted, Ampere and Faraday. These laws were encapsulated by Maxwell in his famous
set of equations. The generalization of electric power response of a circuit to alternating current, propagation of electromagnetic waves etc also
comes under electrodynamics.
Optics deals with the study of various phenomena connected with light and optical instrument like microscope, telescope etc.
The Classical physics is inadequate to handle the microscopic domain, where we deal with the constitution and structure of matter at the minute
scales of atoms, nuclei and even smaller scales of length. Quantum Theory is currently accepted as the proper framework for explaining microscopic domain.
From what we have studied above, we can realize that the scope of physics is truly vast. It covers very wide range magnitudes of physical quantities
like length, mass, time, energy etc. At one end, Physics includes the study of electron, proton, nuclei etc of size 10 to the power -14 m or even less.
And at other end it deals with astronomical phenomena involving galaxies and even the entire universe of size 10 to the power 26 m. The two length
scales differ by a factor of 10 to the power 40 or even more.
The phenomenal progress of physics in the last few centuries is due to the following three reasons:
1. Quantitative measurement is central to the growth of physics as the laws of nature can be expressed in precise mathematical equations.
2. The basic laws of Physics can are universal i.e. the same basic laws can explain diverse physical phenomena.
3. The strategy of approximation is very successful. Most of the observed phenomena in daily life are rather complex manifestations of the simple basic laws. Therefore, it is good to focus first on the essential features, discover the basic build and then introduce modifications to build a more refined theory of the phenomenon.