What is Physics?
Physics is the study of objects and their motion through different conditions of space and time. It is the study of properties of matter and energy. It deals with scientific phenomenon like force, wave properties, electromagnetism, atomic structure, etc. In short, physics explains the nature of different objects and finds scientific reasons for many naturally occurring phenomena.
Different Branches of Physics
The study of physics can be broadly classified into 9 branches:
- Classical Mechanics
This branch of physics studies the motion of macroscopic objects through time and space. Newton’s Laws of Motion form the foundation of classical mechanics. Concepts like velocity, acceleration, projectile motion, force, moment of inertia, etc. are an integral part of classical mechanics. Sir Isaac Newton and William Hamilton were the pioneers in the study of classical mechanics.
Thermodynamics is the study of heat and temperature. It also correlates heat with energy and work. Heat, temperature, energy etc. are governed by the Four laws of Thermodynamics. Thermodynamics can be further branched out into classical thermodynamics, statistical mechanics, chemical thermodynamics, and equilibrium thermodynamics. James Clerk Maxwell, Ludwig Boltzmann, Max Planck, Rudolf Clausius, and William Thomson are some of the well-known names in the field of thermodynamics.
- Quantum Mechanics
Quantum mechanics entails the study of energy levels in atomic and subatomic particles. Quantum field theory is one of the most important principles of quantum mechanics as it connects it with relativity and classical mechanics. It is a relatively new branch of physics, with origins dating to early 1900s. Erwin Schrödinger, Werner Heisenberg, and Max Born are considered pioneers of quantum mechanics.
The physical reaction between particles carrying electrical charges can be defined as electromagnetic force. The study of electromagnetic force forms the crux of electromagnetism. Electromagnetic force is one of the four fundamental forces of nature. The other fundamental forces are strong nuclear force, weak nuclear force, and gravitational force. Electromagnetic induction, Faraday’s law, and Maxwell’s equations are some of the basic topics covered in electromagnetism. André-Marie Ampère and Michael Faraday are considered to be the Fathers of Electromagnetism.
The theory of relativity is perhaps the most talked about concept to have originated from the brilliant mind of Albert Einstein. Relativity establishes a relation between space and time. It has two postulates:
a. The laws of physics are identical in all inertial systems.
b. The speed of light in vacuum is the same for all observers, irrespective of the motion of light source.
The theory of relativity can be mathematically explained as E=mc2, where E is energy, m is mass of the object, and c is the speed of light.
- Optics and Optical Physics
Optics involves the study of light, its properties and how it interacts with different surfaces. It explains how light acts as a particle as well as a wave. Optical Physics divides light into three categories: visible light, infrared light, and ultraviolet light. Reflection, refraction, diffraction, and interference are some of the topics covered under optical physics.
- Condensed Matter Physics
The study of macroscopic and microscopic properties of matter in different condensed phases is called condensed matter physics. While solid and liquid are most commonly known condensed phases of matter, superconducting phase, ferromagnetic phase, and antiferromagnetic phase are also discussed in this branch of physics. Condensed matter physics is closely related to chemistry, material science, atomic physics, and nanotechnology.
- Particle and Nuclear Physics
Particle physics discusses the nature of particles that constitute matter and radiation. Nuclear physics entails the study of atomic nuclei and their different properties. Since both these concepts deal with subatomic particles, they are often clubbed together as particle and nuclear physics. Nuclear decay, nuclear fission, nuclear fusion, etc. are a few widely read topics in this field of physics.
The study of how the universe was created, how it is expanding, and how it will end falls under the branch of Cosmology. The theories and philosophies stated in cosmology are mostly based on assumptions and cannot be verified. The Big Bang Theory is one of the popular topics discussed in modern cosmology. It is often studied by astrophysicists, meta physicians, and astronomers.
So, which branch of Physics interests you the most? Tell us in the comments below!