Nature of Physical World and Measurement Online Test 11th Science

The word ‘science’ has its root in the Latin verb scientia, meaning “to know”. In Tamil language, it is Ariviyal meaning ‘knowing the truth’.

Science is the systematic organization of knowledge gained through observation, experimentation and logical reasoning.

The knowledge of science dealing with non-living things is physical science (Physics and Chemistry), and that dealing with living things is biological science (Botany, Zoology etc.).

Curiosity-driven observations of natural happenings was the origin of science. The word ‘science’ was coined only in the 19th century.

Natural philosophy was the earlier name given to science, when ancient civilization knew and practised astronomy, chemistry, human physiology and agriculture.

One of the oldest forerunners of scientific advancements, from astronomy to medicine, were the Egyptians.

Scientific and mathematical excellence in India dates back to prehistoric human activity in the Indus Valley Civilization (3300 – 1300 BCE).

According to part IV Article 51A (h) of Indian Constitution “It shall be the duty of every citizen of India to develop scientific temper, humanism and spirit of inquiry and reform’’. This is the aim of our Science Education.

Any scientific method involves the following general features:
• Systematic observation
• Controlled experimentation
• Qualitative and quantitative reasoning
• Mathematical modelling
• Prediction and verification or falsification of theories

Consider a metallic rod being heated. When one end of the rod is heated, heat is felt at the other end. Heat gets transferred from one end to another.

The name Physics was introduced by Aristotle in the year 350 BC. Today’s modern science and technology is an offshoot of the understanding of nature.

The word ‘physics’ is derived from the Greek word “Fusis”, meaning nature. The study of nature and natural phenomena is dealt with in physics. Hence physics is considered as the most basic of all sciences.

Unification and Reductionism are the two approaches in studying physics. Attempting to explain diverse physical phenomena with a few concepts and laws is unification.

Newton’s universal law of gravitation explains the motion of freely falling bodies towards the Earth, motion of planets around the Sun, motion of the Moon around the Earth, thus unifying the fundamental forces of nature.

An attempt to explain a macroscopic system in terms of its microscopic constituents is reductionism. For example, thermodynamics was developed to explain macroscopic properties like temperature, entropy, etc., of bulk systems.

Physics as a fundamental science helps to uncover the laws of nature. The language of its expression is mathematics. In ancient times, humans lived with nature – their lifestyles were integrated with nature. They could understand the signals from the movement of the Stars and other celestial bodies.

They could understand the signals from the movement of the Stars and other celestial bodies. They could determine the time to sow and reap by watching the sky. Thus, astronomy and mathematics were the first disciplines to be developed.

1. Classical mechanics – The study of forces acting on bodies whether at rest or in motion
2. Thermodynamics – The study of the relationship between heat and other forms of energy
3. Optics – The study of light

Explanation

• Electricity and magnetism – The study of electricity and magnetism and their mutual relationship
• Acoustics – The study of the production and propagation of sound waves
• Astrophysics -The branch of physics which deals with the study of the physics of astronomical bodies
• Relativity – One of the branches of theoretical physics which deals with the relationship between space, time and energy particularly with objects moving in different ways.

Discoveries in physics are of two types; accidental discoveries and well-analysed research outcome in the laboratory based on intuitive thinking and prediction. For example, magnetism was accidentally observed but the reason for this strange behaviour of magnets was later analysed theoretically.

The famous equation of Albert Einstein, E=mc² was a theoretical prediction in 1905 and experimentally proved in 1932 by Cockcroft and Walton.

Theoretical predictions aided with recent simulation and computation procedures are widely used to identify the most suited materials for robust applications. The pharmaceutical industry uses this technique very effectively to design new drugs. Bio compatible materials for organ replacement are predicted using quantum prescriptions of physics before fabrication. Thus, experiments and theory work hand in hand complimenting one another.

Physics has a huge scope as it covers a tremendous range of magnitude of various physical quantities (length, mass, time, energy etc). It deals with systems of very large magnitude as in astronomical phenomena as well as those with very small magnitude involving electrons and protons.

Physics has a huge scope as it covers a tremendous range of magnitude of various physical quantities (length, mass, time, energy etc). Range of time scales: astronomical scales to microscopic scales, 10¹⁸s to 10⁻²² s.

Range of masses: from heavenly bodies to electron, 10⁵⁵ kg (mass of known observable universe) to 10⁻³¹ kg (mass of an electron) [the actual mass of an electron is 9.11×10^–31 kg].

The study of physics is not only educative but also exciting in many ways.

• A small number of basic concepts and laws can explain diverse physical phenomena.
• The most interesting part is the designing of useful devices based on the physical laws.
• Carrying out new challenging experiments to unfold the secrets of nature and in verifying or falsifying the existing theories.

Technology is the application of the principles of physics for practical purposes. The application of knowledge for practical purposes in various fields to invent and produce useful products or to solve problems is known as technology. Thus, physics and technology can both together impact our society directly or indirectly.

Microelectronics, lasers, computers, superconductivity and nuclear energy have comprehensively changed the thinking and living style of human beings.

Basic laws of electricity and magnetism led to the discovery of wireless communication technology which has shrunk the world with effective communication over large distances.

In physics, we study the structure of atom, radioactivity, X-ray diffraction etc. Such studies have enabled researchers in chemistry to arrange elements in the periodic table on the basis of their atomic numbers

Biological studies are impossible without a microscope designed using physics principles. Radio-isotopes are used in radiotherapy for the cure of cancer and other diseases. In recent years, biological processes are being studied from the physics point of view.

The invention of the electron microscope has made it possible to see even the structure of a cell. X-ray and neutron diffraction techniques have helped us to understand the structure of nucleic acids, which help to control vital life processes. X-rays are used for diagnostic purposes.

Physics in relation to mathematics: Physics is a quantitative science. It is most closely related to mathematics as a tool for its development.

Astronomical telescopes are used to study the motion of planets and other heavenly bodies in the sky. Radio telescopes have enabled the astronomers to observe distant points of the universe. Studies of the universe are done using physical principles

Diffraction techniques helps to study the crystal structure of various rocks. Radioactivity is used to estimate the age of rocks, fossils and the age of the Earth.

Oceanographers seek to understand the physical and chemical processes of the oceans. They measure parameters such as temperature, salinity, current speed, gas fluxes, chemical components.

Nature teaches true science with physics as an efficient tool. Science and technology should be used in a balanced manner so that they do not become weapons to destroy nature which taught us science. Global warming and other negative impacts of technology need to be checked. Safe science with moderate and appropriate use of technology is the need of this century.

All psychological interactions can be derived from a physical process. The movements of neurotransmitters are governed by the physical properties of diffusion and molecular motion. The functioning of our brain is related to our underlying dualism.