Science > Physics > Introduction to Physics
1.1.1.1 What is Physics?
Science word is derived from the Latin word ‘Scientia’ which means ‘to know’. Science has many disciplines, Physics being one of them. The word Physics is derived from the Greek word ‘Fusis’ meaning ‘nature’. Physics is that branch of Science which deals with the study of matter and energy or matter or motion i.e. Physics is a study of matter and energy in its different forms. In other words, physics is the study of nature and its laws. We expect that all the different events taking place in nature always take place according to some basic rules and revealing these rules of nature from the observed events in physics.
As physics is a study of nature and its behaviour it is real science. No one has been given authority to frame the rules. Sir Issac Newton, Einstein are the great physicist because using the observations available at that time, they could guess and frame the laws of physics, which explain these events and the observations in a convincing way. If a new phenomenon is observed which can not be explained using existing laws or rules we are always free to change the rules.
Knowledge of Physics overlaps with other sciences considerably, hence such overlapping gives rise to subjects like Biophysics, Biochemistry, Astrophysics, Geophysics, etc.
Physics can be conveniently divided into two parts, classical Physics (Pre-1900) and modern Physics (Post – 1900). Classical physics includes the study of mechanics, gravitation, heat, sound, light, electricity and magnetism. Modern Physics includes the study of quantum mechanics, relativity, atoms, molecules, nuclei, elementary particles, and condensed matter.
The complex physical phenomena involving wide range of length, mass. and time can be easily understood due to following reasons:
- A quantitative study of various natural phenomena shows that there is some regularity and symmetry even in the most complex phenomenon which helps us to understand it.
- All these phenomena can be explained in terms of only a few basic laws.
- Complex phenomena can be separated into simpler phenomena and by understanding these simple phenomena, the complex phenomena can be understood.
Scientific Methods:
The study of science and particularly in Physics is based on systematic observation, logical reasoning, model making, and theoretical prediction and necessary modifications. All the four steps taken together constitute what we call the ‘scientific method’. The scientific method helps us to describe the given physical phenomenon or behavior of a physical system in terms of a limited number of laws. This gives us what we call ‘theory’. The theory should be self-consistent and consistent with known experimental data. The discrepancy between the theory and experimental data has to lead to new theories in Physics.
Relation Between Physics and Mathematics:
Physics is directly related to maths because the description of nature becomes easy if we have the freedom to use mathematics. In physics, we use mathematical techniques like algebra, trigonometry, and calculus. Thus mathematics is a language of physics. Without knowledge of mathematics, it would be much more difficult to discover, understand and explain the laws of nature. But we should note that mathematics itself is not physics. To understand nature is a journey of physics, mathematics is the mean of the journey.
1.1.1.2 Scope of Physics:
The scope of physics is broad and encompasses the study of the fundamental principles governing the natural world. Physics not only explores the properties and behaviour of matter and energy but also plays a crucial role in advancing technology, contributing to other scientific disciplines, and addressing fundamental questions about the nature of the universe. Here are key aspects of the scope of physics:
Mechanics:
Mechanics is a branch of physics, which deals with the motion of material bodies. In this branch, the forces responsible for producing or changing the motion of the body are studied. The energy involved is also studied. Newton’s laws of motion, the law of conservation of momentum and energy, Newton’s gravitation law forms the base of this branch of Physics.
Heat:
Heat is the energy that a body possesses by virtue of the motion of the molecules of which it is composed and the potential energy due to interatomic forces. The term heat is also used to indicate the energy in the process of transfer between an object and its surroundings because a difference exists between their temperatures. Thermodynamics is the name given to the branch of physics which studies the relationship between heat and mechanics.
Acoustics:
Acoustic is a branch which studies sound. Wave motion is studied in this branch. An object in a state of vibration can set medium particles in the vibration and this disturbance in the medium can travel from one point to another. Thus sound is wave motion itself.
Optics:
Optics is a branch of science which studies electromagnetic waves to which the eye responds (light). Propagation of light means the propagation of electromagnetic waves with varying electric and magnetic fields through a vacuum or a transparent medium. It has two broad branches: geometric optics and physical optics.
Electricity and Magnetism:
These topics are interrelated with each other. We have to take the help of another topic when we are studying one of them individually. Electricity deals with the forces on charged particles, the effect of such forces. It also studies the phenomenon caused by the motion of charged particles. Magnetism can have an effect on the electric current. magnetic materials can be used in producing electric currents. Electronics is the branch of electricity.
Modern Physics:
Modern physics is the branch of physics which deals with the recent developments in the science-related to physics such as Radioactivity, X-Rays, Cathode Rays, Atomic and Molecular Structure, Quantum Theory and wave mechanics, etc.
1.1.1.3 Pioneers of Physics
| Name of Scientist | Country | Field / Discovery/Invention |
| Ampere, Andre Marie (1775- 1836) | France | Current Electricity |
| Archimedes (287- 212 B.C.) | Greece | Archimedes principle |
| Avogadro, Amedeo (1776 – 1856) | Italy | Avogadro’s law, Gaseous state |
| Bardeen J. | United States | Transistor |
| Benjamin Franklin (1752) | United States | Lightning conductor |
| Becquerel Henry Antoine (1896) | France | Natural radioactivity |
| Bernouilli, Daniel (1700 – 82) | Sweden | Bernoulli’s principle, working of an aeroplane |
| Bohr, Niels Henrik David (1885 – 1962) | Denmark | Bohr’s theory of hydrogen atom |
| Born, Max (1882 – 1970) | England | Quantum mechanics |
| Boyle, Robert (1627- 1691) | Ireland | Study of gaseous state, Boyle’s law |
| Bethe A. H. (1967) | Germany / France | Theory of nuclear reaction |
| Vatta (1800) | Italy | Electric Battery |
| Jacques Alexander Cesar (1746 – 1823) | England | Study of gaseous state, Charle’s law |
| Clerk-Maxwell, James (1831 – 79) | England | Electromagnetic radiations |
| Compton A. H. (1927) | United States | Compton effect of light |
| Copernicus Nicolas (1473 – 1543) | Poland | Earth revolves around the sun |
| Curie, Pierre (1859-1906) & Marie (1867-1934) | Poland | Radioactivity, Radium , Polonium |
| David Edward Hughes (1878) | England / USA | Microphone |
| de Broglie | France | Wave nature of the electron |
| Dennis Papin (1675) | France | Pressure cooker |
| Dennis Gabor (1859) | Hungary | Holography |
| Edison Thomas Alva | United States | Thermionic emission |
| Einstein Albert (1879-1955) | Germany | Special theory of relativity, Electromagnetic theory of light. Photoelectric effect. |
| Elisha Otis (1853) | United States | Passenger lift |
| Torricelli (1643) | Italy | Barometer |
| Lenoir (1859) | France | Internal combustion engine |
| Enrico Fermi (1938) | Italy/ United States | Demonstration of the existence of new radioactive elements. |
| Caree (1858) | France | Refrigerator |
| Faraday, Michael (1791-1867) | England | Laws of electrolysis, electromagnetic induction, dynamo |
| Galileo Galilei (1791-1867) | Italy | Laws inertia, simple pendulum, Telescope, Law of falling bodies. |
| Goldstein E. | England | Proton |
| Graham Bell (1876) | Scotland | Telephone |
| Fahrenheit (1714) | Germany | Mercury thermometer |
| Marconi (1895) | Italy | Wireless |
| Hertz (1886) | Germany | Electromagnetic waves |
| Hans Lippershey (1608) | Netherlands | Telescope. |
| Hess Victor Franz | Austria | Cosmic rays |
| Hooke, Robert (1635-1703) | England | Elasticity, Hooke’s law |
| K. Onnes (1913) | Holland | Properties of matter at low temperatures |
| Huygens, Christiaan (1629-93) | Holland | Wave theory of light |
| James Chadwick (1932) | England | Neutron |
| James Dewar (1885) | Scotland | Vacuum flask |
| James Watt (1765) | Scotland | Condensing steam engine |
| John Baird (1925) | Scotland | Television |
| John Fleming (1904) | England | Diode |
| John Napier (1614) | Scotland | Logarithms |
| V. Sauerbronn (1816) | Germany | Bicycle |
| Kepler, Johann (1571-1630) | Germany | motion of astronomical bodies, Keppler’s law (Planetary Motion) |
| Lee De Forest (1906) | United States | Triode |
| Lawrence E.O. | America | cyclotron |
| Maxwell | Scotland | Electromagnetic theory |
| Marconi G. | Italy | Wireless telegraphy |
| Millikan R. A. | United States | Atomicity of charge, Charge on electron |
| Newton Issac (1642-1727) | England | Calculus, Laws of motion and gravity |
| Oersted H. C. (1920) | Denmark | Electromagnetism |
| Oppenheimer, J. Robert (1904-67) | America | Nuclear explosion |
| Pauli Wolfgang | Austria | Quantum exclusion principle |
| Planck, Max (1858-1947) | Germany | Quantum theory |
| Raman C.V. | India | Scattering of light by molecules |
| Robert H. Goddard (1926) | United States | Liquid fuel rocket |
| Roentgen (Röntgen), Wilhelm Conrad (1845-1923) | Germany | X-Rays |
| Rudolph Diesel (1897) | Germany | Diesel engine |
| Rutherford Ernest (1871-1937) | England | Radioactivity, the structure of an atom |
| Thomson J. J. | England | electrons, Cathode rays |
| Thomas Newcomen (1712) | England | Steam Engine |
| Wilbur Orville Wright (1903) | United States | Aeroplane |
| William Stanley (1885) | United States | Electric transformer |
| William Sturgeon (1825) | England | Electromagnet |
| Werner Heisenberg (1932) | German | Quantum mechanics |
| Yukawa Hideki | Japan | Theory of nuclear forces |
| Presper Eckert and John W. Mauchly (1946) | United States | Electronic computer |
| John Bardeen, W. Brattain, W. Shockley (1948) | United States | Transistor |
| Theodore Mainmann (1960) | United States | Laser |
1.1.1.4 Click Here to find the List of Noble Prize Winners in Physics
Conclusion:
Physics is a branch of science that seeks to understand the fundamental principles governing the natural world, encompassing everything from the smallest particles to the largest galaxies. It involves the study of matter, energy, space, and time, as well as the interactions between these elements. Physicists explore the fundamental laws and forces that govern the behaviour of the universe and seek to explain and predict the observed phenomena. Physics relies heavily on mathematical models and experimental observations. The scientific method is a fundamental aspect of physics, involving the formulation of hypotheses, experimentation, and the development of theories that can be tested and refined through further observations and experiments.
Related Topics:
One reply on “1.1.1 Introduction to Physics”
So Impressive