Fundamental Physics Concepts

• Physics is a natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force.
• Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.

Core Concepts

• Mechanics: Deals with the motion of bodies under the action of forces, including statics (equilibrium), kinematics (motion), and dynamics (forces causing motion).
• Thermodynamics: Deals with heat, work, and energy, and the relationships between them. It includes concepts like entropy, enthalpy, and the laws of thermodynamics.
• Electromagnetism: Deals with the forces that occur between electrically charged particles. It includes electrostatics (charges at rest), electrodynamics (moving charges), magnetism, and electromagnetic waves.
• Optics: The study of light and its behavior, including reflection, refraction, diffraction, interference, and polarization. It also includes the study of optical instruments like lenses and mirrors.
• Quantum Mechanics: Deals with the behavior of matter and energy at the atomic and subatomic level. Key concepts include quantization, wave-particle duality, the uncertainty principle, and quantum entanglement.
• Relativity: Includes two main theories by Albert Einstein: Special Relativity, which deals with the relationship between space and time for objects moving at constant velocity, and General Relativity, which deals with gravity as a curvature of spacetime.
• Nuclear Physics: Studies the constituents, structure, behavior, and interactions of atomic nuclei.
• Particle Physics: Studies the fundamental particles and forces that make up all matter.

Mechanics

• Kinematics: Describes motion without considering the causes.
  • Displacement: Change in position of an object.
  • Velocity: Rate of change of displacement.
  • Acceleration: Rate of change of velocity.
• Dynamics: Describes motion with consideration of forces.
  • Newton's Laws of Motion:
    • First Law (Inertia): An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by a force.
    • Second Law: Force equals mass times acceleration (F = ma).
    • Third Law: For every action, there is an equal and opposite reaction.
  • Work: Transfer of energy when a force causes displacement.
  • Energy:
    • Kinetic Energy: Energy of motion (KE = 1/2 mv^2).
    • Potential Energy: Stored energy (e.g., gravitational potential energy: PE = mgh).
  • Momentum: Product of mass and velocity (p = mv).
  • Conservation of Momentum: In a closed system, the total momentum remains constant if no external forces act on the system.
• Rotational Motion:
  • Angular Displacement: Angle through which an object rotates.
  • Angular Velocity: Rate of change of angular displacement.
  • Angular Acceleration: Rate of change of angular velocity.
  • Torque: Rotational force.
  • Moment of Inertia: Resistance to rotational motion.
  • Angular Momentum: Measure of an object's rotation.
  • Conservation of Angular Momentum: In a closed system, the total angular momentum remains constant if no external torques act on the system.
• Gravitation: Attractive force between objects with mass.
  • Newton's Law of Universal Gravitation: F = Gm1m2/r^2, where G is the gravitational constant.

Thermodynamics

• Zeroth Law: If two systems are each in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.
• First Law: The change in internal energy of a system equals the heat added to the system minus the work done by the system.
• Second Law: The total entropy of an isolated system can only increase over time or remain constant in ideal cases.
• Third Law: As the temperature approaches absolute zero, the entropy of a system approaches a minimum or zero.
• Heat: Transfer of thermal energy.
  • Conduction: Transfer of heat through a material.
  • Convection: Transfer of heat through the movement of fluids.
  • Radiation: Transfer of heat through electromagnetic waves.
• Temperature: Measure of the average kinetic energy of the particles in a system.
• Ideal Gas Law: PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the ideal gas constant, and T is temperature.

Electromagnetism

• Electrostatics:
  • Electric Charge: Fundamental property of matter that causes it to experience a force in an electromagnetic field.
  • Coulomb's Law: F = k q1q2/r^2, where F is the electrostatic force, k is Coulomb's constant, q1 and q2 are the charges, and r is the distance between them.
  • Electric Field: Region around a charge where another charge would experience a force.
  • Electric Potential: Electric potential energy per unit charge.
  • Capacitance: Ability of a system to store electric charge.
• Electrodynamics:
  • Electric Current: Flow of electric charge.
  • Resistance: Opposition to the flow of electric current.
  • Ohm's Law: Voltage (V) = Current (I) x Resistance (R).
  • Electric Power: Rate at which electrical energy is transferred.
• Magnetism:
  • Magnetic Field: Region around a magnet or moving charge where a magnetic force is exerted.
  • Magnetic Force: Force exerted on a moving charge in a magnetic field.
  • Electromagnetic Induction: Production of an electromotive force (EMF) across an electrical conductor in a changing magnetic field.
• Electromagnetism Waves
  • Electromagnetic Waves: Propagating waves composed of electric and magnetic fields.
  • Speed of Light: Speed at which electromagnetic waves propagate in a vacuum (approximately 3.0 x 10^8 m/s).
  • Electromagnetic Spectrum: Range of all possible electromagnetic radiation frequencies (e.g., radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays).

Optics

• Reflection: Bouncing back of light from a surface.
  • Law of Reflection: Angle of incidence equals the angle of reflection.
• Refraction: Bending of light as it passes from one medium to another.
  • Snell's Law: Relates the angles of incidence and refraction to the refractive indices of the media.
• Lenses: Devices that refract light.
  • Converging Lenses: Cause parallel light rays to converge.
  • Diverging Lenses: Cause parallel light rays to diverge.
• Interference: Superposition of waves.
  • Constructive Interference: Amplitudes add together.
  • Destructive Interference: Amplitudes cancel each other out.
• Diffraction: Spreading of waves as they pass through an opening or around an obstacle.
• Polarization: Property of waves that describes the direction of their oscillations.

Quantum Mechanics

• Quantization: Energy, momentum, and other physical quantities are restricted to discrete values.
• Wave-Particle Duality: Matter exhibits both wave-like and particle-like properties.
• Uncertainty Principle: There is a fundamental limit to the precision with which certain pairs of physical properties of a particle, such as position and momentum, can be known simultaneously.
• Quantum Entanglement: Two or more particles become linked in such a way that the state of one particle instantly affects the state of the other, regardless of the distance between them.
• Schrödinger Equation: Describes how the quantum state of a physical system changes over time.

Relativity

• Special Relativity:
  • Postulates:
    • The laws of physics are the same for all observers in uniform motion (inertial frames).
    • The speed of light in a vacuum is the same for all observers, regardless of the motion of the light source.
  • Time Dilation: Time passes slower for moving objects.
  • Length Contraction: Length of an object is shorter in the direction of motion.
  • Mass Increase: Mass of an object increases as its velocity approaches the speed of light.
  • Mass-Energy Equivalence: E = mc^2, where E is energy, m is mass, and c is the speed of light.
• General Relativity:
  • Gravity is the curvature of spacetime caused by mass and energy.
  • Gravitational Lensing: Bending of light around massive objects.
  • Black Holes: Regions of spacetime with such strong gravitational effects that nothing, not even light, can escape from inside it.
  • Gravitational Waves: Ripples in spacetime caused by accelerating massive objects.

Nuclear Physics

• Atomic Nucleus: Central part of an atom consisting of protons and neutrons.
• Radioactivity: Emission of particles or energy from unstable nuclei.
  • Alpha Decay: Emission of an alpha particle (helium nucleus).
  • Beta Decay: Emission of a beta particle (electron or positron).
  • Gamma Decay: Emission of a gamma ray (high-energy photon).
• Nuclear Fission: Splitting of a heavy nucleus into two or more lighter nuclei.
• Nuclear Fusion: Combining of two light nuclei into a heavier nucleus.

Particle Physics

• Standard Model: Theory describing the fundamental particles and forces of nature.
  • Fundamental Particles:
    • Quarks: Building blocks of protons and neutrons.
    • Leptons: Include electrons, muons, taus, and their respective neutrinos.
    • Bosons: Force carrier particles (e.g., photons, gluons, W and Z bosons, Higgs boson).
  • Fundamental Forces:
    • Strong Force: Holds quarks together in protons and neutrons.
    • Weak Force: Responsible for radioactive decay.
    • Electromagnetic Force: Acts between electrically charged particles.
    • Gravitational Force: Acts between objects with mass.