Chapter 1
Science
Science is a systematic and organised attempt to acquire knowledge about the
surroundings through observations, experiments and verifications.
Scientific Method
Several inter-related steps are involved in scientific method. Some of the most
significant steps are as follows:
The systematic observations
Reasoning
Mathematical modelling
Theoretical prediction
Physics
Physics is a fundamental science concerned with understanding the natural
phenomena that occur in our universe.
It has many branches such as Mechanics, Electromagnetism, Thermodynamics, Modem
Physics, etc. Between 1600 and 1900, three broad areas were developed, which is
together called Classical Physics. These three areas of study are classical
mechanics, thermodynamics and electromagnetism. But by 1905 it became apparent
that classical ideas failed to explain several phenomena. Then some new
theories were developed in what is called Modem Physics such as Special
Relativity, Quantum Mechanics, etc.
Scope and Excitement of Physics
The scope of Physics is very broad and covers a wide range of magnitude of
physical quantities such as length, mass, time, energy, etc.
It deals with the macroscopic world like galaxies and universe as well as
microscopic world like nucleus of an atom and fundamental particles like
electrons, protons, neutrons etc.
Immense excitement is involved in the study of physics since it explains every
naturally occuring phenomena with a set of rules, so that clear understanding
can be achieved. The challenge to carry out imaginative new experiments to
unlock the secrets of nature, to verify or refute theories, is really exciting.
Physics in Relation to Other
Sciences
Physics is a very significant branch of science which plays a crucial role in
understanding the developments pertaining to the other branches of science such
as Chemistry, Biology etc.
(i) Physics in relation to Mathematics. Study of physical variables
led to the idea of differentiation, integration and differential equation.
Meaningful interpretation of Mathematics becomes Physics.
(ii) Physics in relation to Chemistry. The concept of X-ray
diffraction and radioactivity has helped to distinguish between the various
solids and to modify the periodic table.
Understanding the bonding and the chemical structure of substances is easy with
the help of the concept of interactions between various particles.
(iii) Physics in relation to Astronomy. Optical telescopes of
reflecting and refracting type enabled man to explore the space around.
Discoveries like radio telescopes have revolutionised the study of Astronomy.
(iv) Physics in relation to Biology. The conceptual study of
pressure and its measurement has helped us to know blood pressure and hence the
functioning of heart. Invention of X-rays developed the field of diagnosis.
Electron and optical microscopic designs have revolutionised the study of
medical science.
(v) Physics in relation to Meteorology. The discoveries regarding
the study of pressure variations help us to forecast the weather.
Various other inventions of physics have opened new vistas of study in the
field of sciences and social sciences.
Physics in Relation to Technology
and Society
Advancement in physics has led to new technologies and vice-versa. Sometimes
technology gives rise to new dimension of physics; at other times physics
generates new technology. In fact, the technological development is closely
related to the application of science and physics in particular. Physics has a
dominant influence on society. It has helped the human being to develop its
ideas. Development of digital communication systems, rapid mass transport
system, lasers making bloodless surgeries, etc., has made human life easy and
pleasant.
There are four fundamental forces in nature that govern the
diverse phenomena of the microscopic and macroscopic world. These are the
‘gravitational force’, the ‘electromagnetic force’; the ‘strong nuclear force’,
and the ‘weak nuclear force’. Unification of forces is a basic quest in
physics. The electromagnetic and the weak nuclear forces have now been unified
and are seen as aspects of a single ‘electro-weak’ force. Attempts are being
made to unify electro-weak and the strong force.
Conservation of energy, momentum, angular momentum, charge,
etc., are considered to be the fundamental laws in physics. Conservation laws
have a deep connection with symmetries of nature. Symmetries of space and time,
and other types of symmetries play a central role in modem theories of
fundamental forces in nature.
IMPORTANT TABLES
