11P01
Physical World
11P01 – Physical World
Learning Objectives
Scientific method
What is Physics
Impact and uses of Physics
Scope of Physics
Fundamental Forces
Unification of Forces
11P01.1
CV 1
What is Science
What is Science?
What is Science?
What is Science?
What is Science?
What is Science?
What is Science?
Science is a systematic attempt to understand natural phenomena in as much detail and depth as possible.
Knowledge gained to predict, modify and control phenomena
Science is exploring, experimenting and predicting from what we see around us.
Systematic observations, controlled experiments, qualitative and quantitative reasoning, mathematical modelling, prediction and verification or falsification of theories.
Fundamental Concepts of Physics
Unification
Basic laws of electromagnetism (Maxwell’s equations) govern all electric and magnetic phenomena.
Explain diverse physical phenomena in terms of a few concepts and laws.
See the physical world as manifestation of some universal laws
Eg: Law of gravitation (given by Newton)
Fundamental Concepts of Physics
Unification
Fundamental Concepts of Physics
Fundamental Concepts of Physics
Reductionism
To derive the properties of big, complex system and interaction of its constituents simpler parts.
Eg: Temperature, Pressure , Elasticity etc
Nature of Forces
Gravitational Force
Attractive in nature
Universal force
Weak force
Governs motion of earth, planets and gravity
Nature of Forces
Electromagnetic Force
Attractive & Repulsive
Acts on pair of charges or poles
Strong force
Electric and magnetic forces are not separable
Nature of Forces
Strong Nuclear Force
Binds protons and neutrons in the nucleus
Attractive in nature
100 times stronger than electromagnetic
force
Charge independent
Nature of Forces
Weak Nuclear Force
Seen in nuclear processes such as ß decay
Stronger than gravitational force but weaker than
strong nuclear force
Charge independent
Fg:Fw:Fe:Fs= 1:1025 :1036 :1038
Nature of Forces
Branches in Physics
Use and Impact of Physics
Questions to Think & Discuss??
1. Though India now has a large base in science and technology, which is fast expanding, it is still a long way from realizing its potential of becoming a world leader in science. Name some important factors, which in your view have hindered the advancement of science in India.
2. No physicist has ever “seen” an electron. Yet, all physicists believe in the existence of electrons. An intelligent but superstitious man advances this analogy to argue that ‘ghosts’ exist even though no one has ‘seen’ one. How will you refute his argument ?