Physics Branches - Unit 4, Lec 1 | PDF

# Physics ## Introduction to Physics - In the nineteenth century, physical sciences were divided into five distinct disciplines. - Those disciplines are physics, chemistry, astronomy, geology, and meteorology. - The most fundamental of these is Physics. - In Physics, we study matter, energy, and t...

# Physics ## Introduction to Physics - In the nineteenth century, physical sciences were divided into five distinct disciplines. - Those disciplines are physics, chemistry, astronomy, geology, and meteorology. - The most fundamental of these is Physics. - In Physics, we study matter, energy, and their interaction. - The laws and principles of Physics help us to understand nature. - The rapid progress in science during the recent years has become possible due to the discoveries and inventions in the field of Physics. - The technologies are the applications of scientific principles. - Most of the technologies of our modern society throughout the world are related to Physics. - For example, a car is made on the principles of mechanics, and a refrigerator is based on the principles of thermodynamics. ## Daily Life and Physics - In our daily life, we hardly find a device where Physics is not involved. - **Examples:** - **Pulleys:** Make it easy to lift heavy loads. - **Electricity:** Used not only to get light and heat but also mechanical energy that drives fans and electric motors. - **Transportation:** Such as cars and airplanes. Domestic appliances, such as air-conditioners, refrigerators, vacuum cleaners, washing machines, and microwave ovens, are all based on physics. - **Communication:** Means of communication such as radio, television, telephone, and computers are the result of applications of Physics. - **Impact:** The devices have made our lives much easier, faster, and more comfortable than the past. - **For Example:** - A mobile phone smaller than our palm can do many things. - It allows us to contact people anywhere in the world and to get the latest worldwide information. - We can take and save pictures, send and receive messages. - We can also receive radio transmission and use it as a calculator. - **Negative Impact:** Scientific inventions have also caused harm and destruction of serious nature. - One major negative impact is environmental pollution. - Another is the creation of deadly weapons. ## Branches of Physics ### Branches of Physics Diagram - The diagram shows the branches of physics organized inside a circle with the words "Branches of Physics" in the middle. - In this diagram, physics is divided into Classical Physics and Modern Physics. - Classical Physics has 6 branches which are spread around the circle: - Thermodynamics - Optics - Acoustics - Mechanics - Biophysics - Geophysics - Modern Physics also has three branches which are spread around the circle: - Nuclear - Atomic - Modern (no further information is given on modern physics) ### **1. Mechanics** - Mechanics is the study of motion of objects, its causes, and its effects. - The forces that bodies exert on one another are of primary concern in the study of motion. - This leads to the study of topics such as gravity, electricity, and magnetism, according to the nature of the forces involved. - **The father of modern mechanics is Sir Isaac Newton (1642-1727).** - Mechanics is the branch of science which deals with the study of the physical state of bodies at rest and in motion under the action of forces. - **Applications of Mechanics:** - The principles of mechanics have been applied to three general realms of phenomena. - The motions of celestial bodies such as stars, planets, and satellites can be predicted with great accuracy thousands of years before they happen. - Ordinary objects on earth, down to microscopic size, are properly described by classical mechanics without significant corrections. - The behavior of matter and electromagnetic radiation on the atomic and subatomic scale. ### Types of Mechanics - **Statics:** - The study of objects at rest. - We study the motion of objects under the effect of forces in equilibrium. - Time factor has no role to play in statics. - **Kinematics:** - The study of the motion of material objects without considering the cause of motion (i.e., forces). - Time factor plays an essential role in kinematics. - **Dynamics:** - The study of motion of material objects by taking into account the cause of motion (i.e., forces). - Dynamics is based on the concept of force. ### **2. Thermodynamics** - Thermodynamics is the branch of physical science that deals with the relations between heat and other forms of energy (such as mechanical, electrical, or chemical energy). - It studies the relationships between all forms of energy. ### **3. Electricity and Magnetism** - The study of charges at rest and in motion, their effects, and their relationship with magnetism. ### **4. Optics** - The study of physical aspects of light, its properties, working, and use of optical instruments. ### **5. Classical Physics** - Classical Physics describes the motion of macroscopic objects. - Objects can range in size from projectiles to parts of machinery and astronomical objects, such as spacecraft, planets, stars, and galaxies. - If the present state of the object is known, it is possible to predict how it will move in the future, and how it has moved in the past. - Classical mechanics is often referred to as Newtonian. - Mathematical methods invented by Leibniz, Lagrange, Euler, and others in the 17th century helped to describe the motion of bodies under the influence of forces. - Classical mechanics has reformulations known as Lagrangian Mechanics and Hamiltonian mechanics. ### **6. Modern Physics** - Modern Physics deals with the post-Newtonian concepts in the world of physics. - Modern Physics is based on two major breakthroughs of the twentieth century: - Relativity - Quantum Mechanics - Quantum effects typically involve distances related to atoms. - Relativistic effects typically involve velocities compared to the speed of light. - **Albert Einstein** is considered the father of modern physics. - He was a 20th-century scientist who came up with the most important ideas. - One of Albert Einstein's most important works is the theory of relativity, which includes the famous equation E=mc². - He was awarded the Nobel Prize for physics in 1921 for his achievements in theoretical physics. ### **7. Nuclear Physics** - Nuclear Physics deals with the structure of the atomic nucleus and the radiation from unstable nuclei. - The atomic nucleus is 10,000 times smaller than the atom. - The nucleus is composed of protons and neutrons. - Nuclear forces are so strong that nuclear energies are approximately 1,000,000 times larger than typical atomic energies. - Quantum theory is needed for understanding nuclear structure. ### **8. Atomic Physics** - Atomic Physics is the field of physics that studies atoms as an isolated system of electrons and the atomic nucleus. - Atomic physics typically refers to the study of atomic structure and the interaction between atoms - **Note:** - The term atomic physics can be associated with nuclear power and nuclear weapons because of the synonymous use of the terms atomic and nuclear in English. - Physicists separate atomic and nuclear physics. - Atomic physics deals with the atom, a system consisting of a nucleus and electrons. - Nuclear physics studies nuclear reactions and special properties of atomic nuclei. ### **9. Geophysics** - Geophysics studies the physical processes and physical properties of the Earth and its surrounding space environment. - It uses quantitative methods for analysis. - **Applications:** - Geophysics classically refers to solid earth applications, such as: - Earth's shape, - Gravitational and magnetic fields, - Electromagnetic fields, - Internal structure and composition, - The generation of volcanism and rock formation. ### **10. Thermodynamics** - Thermodynamics is the science relating heat, work, temperature, and energy. - In broad terms, thermodynamics deals with the transfer of energy from one place to another and from one form to another. ### **11. Acoustics** - Acoustics deals with the production, control, transmission, reception, and effects of sound. - The term is derived from the Greek akoustos, meaning "heard." - Acoustics has important applications in almost every area of life. ### **12. Astrophysics** - Astrophysics is a branch of space science that applies the laws of physics and chemistry to understand the universe and our place in it. - The field explores topics such as the birth, life, and death of stars, planets, galaxies, nebulae, and other objects in the universe. - It is related to astronomy and cosmology. ### **13. Biophysics** - The science of applying the laws of physics to biological phenomena. - Biophysics helps understand biological systems and how they work. - Biophysics has helped us understand mechanics, the movement and function of cells, and complex systems within organisms including the brain, the circulatory system, and the immune system. - **Note:** Biophysics is a vibrant scientific field where scientists from many fields, including math, chemistry, physics, engineering, pharmacology, and materials sciences, come together to explore and develop new tools for understanding biology. ## References - https://www.theengineeringprojects.com/2021/03/what-is-science-definition-branches-books-and-scientists.html - https://leverageedu.com/blog/branches-of-science/ - https://study.com/learn/lesson/natural-science-branches-topics.html - https://www.allthescience.org/what-are-the-formal-sciences.htm#google_vignette - https://helpfulprofessor.com/social-sciences-examples/ - https://www.youtube.com/watch?v=yWMKYID5fr8 - https://study.com/learn/lesson/what-is-physics-branches.html - https://collegedunia.com/exams/motion-definition-types-examples-physics-articleid-949