1 Physical World
WHAT IS SCIENCE ? Keep in Memory
Science refers to a system of acquiring knowledge. This system
uses observation and experimentation to describe and explain 1. Information received through the senses is called observation.
natural phenomena. The term science also refers to the organized 2. An idea that may explain a number of observations is called
body of knowledge that people have gained using that system. hypothesis.
Less formally, the word science often describes any systematic
3. A hypothesis that has been tested many times is called
field of study or the knowledge gained from it.
scientific theory.
The purpose of science is to produce useful models of reality.
Most scientific investigations use some form of the scientific 4. A scientific theory that has been tested and has always
method. proved true is called scientific law.
The scientific method is a logical and rational order of steps by
SCOPE AND EXCITEMENT OF PHYSICS
which scientists come to conclusions about the world around
them. The Scientific method helps to organize thoughts and The scope of physics is very vast. It covers a tremendous range
procedures so that scientists can be confident in the answers of magnitude of physical quantities like length, mass, time, energy,
they find. Scientists use observations, hypotheses, and deductions etc. Basically, there are two domains of interest : macroscopic and
to make these conclusions. microscopic. The macroscopic domain includes phenomena at
Science as defined above, is sometimes called pure science to the laboratory, terrestrial and astronomical scales. The microscopic
differentiate it from applied science, which is the application of domain includes atomic, molecular and nuclear phenomena.
research to human needs. Fields of science are commonly divided Classical physics deals mainly with macroscopic phenomena
into two major categories.
consisting of the study of heat, light, electricity, magnetism, optics,
1. Natural science : The science in which we study about the
acoustics, and mechanics. Since the turn of the 20th century, the
natural world. Natural science includes physics, chemistry,
biology, etc. study of quantum mechanics and relativity has become more
2. Social science : It is the systematic study of human behavior important. Today, physics is often divided into branches such as
and society. nuclear physics, particle physics, quantum physics, theoretical
WHAT IS PHYSICS ? physics, and solid-state physics. The study of the planets, stars,
and their interactions is known as astrophysics, the physics of
The word physics originates from a Greek word which means
nature. Physics is the branch of science that deals with the study the Earth is called geophysics, and the study of the physical laws
of basic laws of nature and their manifestation of various natural relating to living organisms is called biophysics.
phenomena. Physics is exciting in many ways. Application and exploitation of
There are two main thrusts in physics : physical laws to make useful devices is the most interesting and
1. Unification : In physics, attempt is made to explain various exciting part and requires great ingenuity and persistence of effort.
physical phenomena in terms of just few concepts and laws. PHYSICS, TECHNOLOGY AND SOCIETY
Attempts are being made to unify fundamental forces of Physics generates new technologies and these technologies have
nature in the persuit of unification. made our lives comfortable and materially prosperous. We hear
2. Reductionism. Another attempt made in physics is to explain terms like science, engineering , technology all in same context
a macroscopic system in terms of its microsocopic
though they are not exactly same.
constituents. This persuit is called reductionism.
, EB
2 PHYSICS
• Science uses a process--the scientific method--to generate
Technology knowledge
Scientists The products and
Investigate the processes created Engineering:
natural world by engineers • Design under constraint
• Seeks solutions for societal problems and needs
• Aims to produce the best solution from given resources and
Society constraints
Values
Needs
• Engineering uses a process–the engineering design
Environment process–to produce solutions and technologies
Economy
Technology:
Scientific • The body of knowledge, processes and artifacts that result
knowledge Engineers
from engineering
Create the
What scientists • Almost everything made by humans to solve a need is a
designed world
have learned about
technology
the natural world
• Examples of technology include pencils, shoes, cell phones,
and processes to treat water
Science: In the real world, these disciplines are closely connected.
• A body of knowledge Scientists often use technologies created by engineers to
• Seeks to describe and understand the natural world and its conduct their research. In turn, engineers often use
physical properties knowledge developed by scientists to inform the design of
• Scientific knowledge can be used to make predictions the technologies they create.
Link between technology and physics
Technology Scientific principle(s)
Aeroplane Bernoulli’s principle in fluid dynamics
Bose-Einstein condensate Trapping and cooling of atoms by laser beams and magnetic fields
Computers Digital logic
Electric generator Faraday’s laws of electromagnetic induction
Electron microscope Wave nature of electrons
Fusion test reactor (Tokamak) Magnetic confinement of plasma
Giant Metrewave Radio Telescope (GMRT) Detection of cosmic radio waves
Hydroelectric power Conversion of gravitational potential energy into electrical energy
Lasers Light amplification by stimulated emission of radiation
Non-reflecting coatings Thin film optical interference
Nuclear reactor Controlled nuclear fission
Optical fibres Total internal reflection of light
Particle accelerators Motion of charged particles in electromagnetic fields
Photocell Photoelectric effect
Production of ultra high magnetic fields Superconductivity
Radio and television Generation, propagation and detection of electromagnetic waves
Rocket propulsion Newton’s laws of motion
Sonar Reflection of ultrasonic waves
Steam engine Laws of thermodynamics
WHAT IS SCIENCE ? Keep in Memory
Science refers to a system of acquiring knowledge. This system
uses observation and experimentation to describe and explain 1. Information received through the senses is called observation.
natural phenomena. The term science also refers to the organized 2. An idea that may explain a number of observations is called
body of knowledge that people have gained using that system. hypothesis.
Less formally, the word science often describes any systematic
3. A hypothesis that has been tested many times is called
field of study or the knowledge gained from it.
scientific theory.
The purpose of science is to produce useful models of reality.
Most scientific investigations use some form of the scientific 4. A scientific theory that has been tested and has always
method. proved true is called scientific law.
The scientific method is a logical and rational order of steps by
SCOPE AND EXCITEMENT OF PHYSICS
which scientists come to conclusions about the world around
them. The Scientific method helps to organize thoughts and The scope of physics is very vast. It covers a tremendous range
procedures so that scientists can be confident in the answers of magnitude of physical quantities like length, mass, time, energy,
they find. Scientists use observations, hypotheses, and deductions etc. Basically, there are two domains of interest : macroscopic and
to make these conclusions. microscopic. The macroscopic domain includes phenomena at
Science as defined above, is sometimes called pure science to the laboratory, terrestrial and astronomical scales. The microscopic
differentiate it from applied science, which is the application of domain includes atomic, molecular and nuclear phenomena.
research to human needs. Fields of science are commonly divided Classical physics deals mainly with macroscopic phenomena
into two major categories.
consisting of the study of heat, light, electricity, magnetism, optics,
1. Natural science : The science in which we study about the
acoustics, and mechanics. Since the turn of the 20th century, the
natural world. Natural science includes physics, chemistry,
biology, etc. study of quantum mechanics and relativity has become more
2. Social science : It is the systematic study of human behavior important. Today, physics is often divided into branches such as
and society. nuclear physics, particle physics, quantum physics, theoretical
WHAT IS PHYSICS ? physics, and solid-state physics. The study of the planets, stars,
and their interactions is known as astrophysics, the physics of
The word physics originates from a Greek word which means
nature. Physics is the branch of science that deals with the study the Earth is called geophysics, and the study of the physical laws
of basic laws of nature and their manifestation of various natural relating to living organisms is called biophysics.
phenomena. Physics is exciting in many ways. Application and exploitation of
There are two main thrusts in physics : physical laws to make useful devices is the most interesting and
1. Unification : In physics, attempt is made to explain various exciting part and requires great ingenuity and persistence of effort.
physical phenomena in terms of just few concepts and laws. PHYSICS, TECHNOLOGY AND SOCIETY
Attempts are being made to unify fundamental forces of Physics generates new technologies and these technologies have
nature in the persuit of unification. made our lives comfortable and materially prosperous. We hear
2. Reductionism. Another attempt made in physics is to explain terms like science, engineering , technology all in same context
a macroscopic system in terms of its microsocopic
though they are not exactly same.
constituents. This persuit is called reductionism.
, EB
2 PHYSICS
• Science uses a process--the scientific method--to generate
Technology knowledge
Scientists The products and
Investigate the processes created Engineering:
natural world by engineers • Design under constraint
• Seeks solutions for societal problems and needs
• Aims to produce the best solution from given resources and
Society constraints
Values
Needs
• Engineering uses a process–the engineering design
Environment process–to produce solutions and technologies
Economy
Technology:
Scientific • The body of knowledge, processes and artifacts that result
knowledge Engineers
from engineering
Create the
What scientists • Almost everything made by humans to solve a need is a
designed world
have learned about
technology
the natural world
• Examples of technology include pencils, shoes, cell phones,
and processes to treat water
Science: In the real world, these disciplines are closely connected.
• A body of knowledge Scientists often use technologies created by engineers to
• Seeks to describe and understand the natural world and its conduct their research. In turn, engineers often use
physical properties knowledge developed by scientists to inform the design of
• Scientific knowledge can be used to make predictions the technologies they create.
Link between technology and physics
Technology Scientific principle(s)
Aeroplane Bernoulli’s principle in fluid dynamics
Bose-Einstein condensate Trapping and cooling of atoms by laser beams and magnetic fields
Computers Digital logic
Electric generator Faraday’s laws of electromagnetic induction
Electron microscope Wave nature of electrons
Fusion test reactor (Tokamak) Magnetic confinement of plasma
Giant Metrewave Radio Telescope (GMRT) Detection of cosmic radio waves
Hydroelectric power Conversion of gravitational potential energy into electrical energy
Lasers Light amplification by stimulated emission of radiation
Non-reflecting coatings Thin film optical interference
Nuclear reactor Controlled nuclear fission
Optical fibres Total internal reflection of light
Particle accelerators Motion of charged particles in electromagnetic fields
Photocell Photoelectric effect
Production of ultra high magnetic fields Superconductivity
Radio and television Generation, propagation and detection of electromagnetic waves
Rocket propulsion Newton’s laws of motion
Sonar Reflection of ultrasonic waves
Steam engine Laws of thermodynamics
