Table of Contents
- What is science?
- SCIENTIFIC ATTITUDE AND SCIENTIFIC METHOD
- Scientific theory
- Need for modification of a scientific theory
- Interplay between theoretical models and experiments
- What is physics?
What is science?
It is a systematised and organised knowledge about the various natural phenomena which is obtained by careful experimentation, keen observation and accurate reasoning. The Sanskrit word Shastra and Arabic word Ilm also have a similar meaning i.e., organised knowledge.
What are physical and biological sciences?
Two types of sciences. The knowledge of science can be divided into two broad categories :
1. Biological sciences:
The sciences which deal with the behaviour of living things are called biological sciences. These sciences include Botany, Zoology, Ornithology, Anthropology, Entomology, Forensic Science, etc.
2. Physical sciences.
The two main physical sciences are physics and chemistry. Chemistry is the study of every substance, its structure, its composition and changes in which it takes part. Physics is the study of the natural world which deals with the concepts of space, time, motion, matter, energy, radiation, etc. Other physical sciences include Geology, Geography, Astronomy, Astrology, Oceanology, etc.
SCIENTIFIC ATTITUDE AND SCIENTIFIC METHOD
Scientific attitude
The tremendous growth of science has taken place only due to the use of scientific attitude and scientific method. The scientific attitude requires a flexible, open-minded approach towards solving problems in ivhich other important points of view are not neglected without any reason. First a solution is suggested for a problem. This solution is tried. If it works satisfactorily, it is adopted and otherwise it is replaced by a better solution to the same problem.
Scientific method:
The step by step approach used by a scientist in studying natural phenomena and establishing laws which govern these phenomena is called scientific method.
Generally, it involves the following steps :
1. Taking a large number of systematic observations by doing controlled experiments.
2. Studying these observations and making qualitative and quantitative reasoning.
3. Suggesting mathematical models to account for the observed behaviour.
4. Predicting new phenomena on the basis of suggested model.
5. Modifying the theory, if necessary, in the light of the fresh evidence.
Scientific theory
Theory is the name given to a set of limited number of laws in terms of which the behaviour of a physical system can be explained. A good theory should not only explain the already existing phenomenon but it should be able to predict and explain the new phenomenon.
Need for modification of a scientific theory
In science, no theory is final. A theory must be able to explain what may be observed from time to time. Following two types of problems may arise:
1. When any new observation shows some deviation from the existing theory, the theory has to be duly modified. For example, when Johann Kepler examined the extensive data on planetary motion collected by Tycho Brahe, the planetary circular orbits in heliocentric theory (sun at the centre of the solar system) imagined by Nicholas Coperanicus had to be replaced by elliptical orbits to fit the data better.
2. When even the modification of a theory fails to account for the new observations, the theory has to be replaced by a new theory. For example, it was realised in the beginning of twentieth century that Newtonian mechanics could not explain some basic features of atomic phenomena. Also, the wave theory of light failed to explain photoelectric effect. This resulted in the development of an entirely new theory, called Quantum Mechanics, to deal with microscopic phenomena.
Interplay between theoretical models and experiments
The interplay of theory and experiment (or observation) is important for the progress of science.
This is obvious from the following examples :
1. Sometimes a new experiment suggests an alternative theoretical model. For example, alpha particle scattering experiments in 1911 by Ernest Rutherford established the nuclear model of the atom, which then became the basis of quantum theory of hydrogen atom given by Niels Bohr in 1913.
2. Sometimes a theoretical advancement predicts a new experiment. For example, the concept of antiparticle was introduced theoretically by Paul Dirac in 1930 and was confirmed two years later by the experimental discovery of positron (anti-electron) by Carl Anderson.
What is physics?
The word physics originates from a Greek word which means nature. This word was introduced by ancient scientist Aristotle in the year 350 B.C. The Sanskrit equivalent of physics is bhautiki which refers to the physical world.
Physics is the branch of science that deals with the study of basic laws of nature and their manifestation in various natural phenomena. It is concerned with the interaction of matter with matter or energy. It deals with the various features of the natural world such as space, time, matter, motion, energy, radiation, etc. Physics is the most fundamental of all sciences as it is concerned with the study of various natural phenomena.