Physical world and measurement

 PHYSICAL WORLD AND MEASUREMENT

Brief summary:

1. Physics deals with the study of the essential laws of nature and their manifestation in
different phenomena. The basic laws of physics are universal and apply in widely different contexts and conditions.
2. The scope of physics is wide, covering a tremendous range of magnitude of physical quantities.
3. Physics and technology are related to each other. Sometimes technology gives rise to
new physics; at other times physics generates new technology. Both have direct impact  on society
4. There are four fundamental forces in nature that govern the various phenomena of the
macroscopic and the microscopic world. These are the ‘gravitational force’, the
‘electromagnetic force’, the ‘strong nuclear force’, and therefore the ‘weak nuclear force’. Unification
of different forces/domains in nature is a basic quest in physics.
5. The physical quantities that remain unchanged during a process are called conserved
quantities. a number of the overall conservation laws in nature include the laws of
conservation of mass, energy, linear momentum, angular momentum, charge, parity,
etc. Some conservation laws are true for one fundamental force but not for the other.
6. Conservation laws have a deep reference to symmetries of nature. Symmetries of
space and time, and other types of symmetries play a central role in modern theories of
fundamental forces in nature.