Introduction to Physics

• Physics is a natural science examining matter, its fundamental parts, its motion and behavior through space and time, and related entities like energy and force.
• A primary goal of physics is to understand the behavior of the universe as one of the most fundamental scientific disciplines.

Core Concepts

• Mechanics: Focuses on the motion of objects and the forces influencing their movement.
• Thermodynamics: Studies heat, work, and energy, exploring the relationships between them.
• Electromagnetism: Investigates forces between electrically charged particles.
• Optics: Explores light and its behavior.
• Quantum mechanics: Examines matter and energy behavior at the atomic and subatomic scales.
• Relativity: Explores the relationship between space and time and their effects on physical phenomena.

Mechanics

• Kinematics describes motion without considering its causes, focusing on displacement, velocity, and acceleration.
• Dynamics studies the causes of motion, involving forces and Newton's laws of motion.
• Newton's first law states that an object remains at rest or in uniform motion unless acted upon by a net force.
• Newton's second law states that the force acting on an object is equal to the mass of that object times its acceleration (F=ma).
• Newton's third law states that for every action, there is an equal and opposite reaction.
• Work is the energy transferred to or from an object by a force causing a displacement.
• Energy can exist in several forms, such as kinetic, potential, thermal, and electromagnetic.
• The conservation of energy states that the total energy of an isolated system remains constant.
• Momentum is the product of an object's mass and velocity.

Thermodynamics

• Temperature measures the average kinetic energy of particles in a system.
• Heat is the energy transferred between objects or systems due to temperature differences.
• The first law of thermodynamics states that the change in internal energy of a system equals the heat added minus the work done.
• The second law of thermodynamics states that the entropy of an isolated system tends to increase.
• Entropy measures a system's disorder or randomness.
• Heat transfer occurs through conduction, convection, and radiation.
• Conduction transfers heat through direct contact within a material.
• Convection transfers heat through the movement of fluids.
• Radiation transfers heat through electromagnetic waves.

Electromagnetism

• Electric charge is a fundamental property causing matter to experience force in an electromagnetic field.
• Electric current measures the rate of electric charge flow through a conductor.
• Voltage is the electric potential difference between two points.
• Resistance opposes the flow of electric current.
• Ohm's law states that voltage equals current times resistance (V=IR).
• Magnetism is a force caused by moving electric charges.
• Magnetic fields are created by electric currents and magnetic materials.
• Electromagnetic induction produces voltage across a conductor exposed to a changing magnetic field.
• Maxwell's equations describe the behavior of electric and magnetic fields and their interaction with matter.
• Electromagnetic waves are disturbances in electric and magnetic fields propagating through space, including radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays.

Optics

• Reflection is the change in direction of a wave returning to its original medium at an interface.
• Refraction is the bending of a wave passing from one medium to another due to speed change.
• Lenses use refraction for focusing or dispersing light to form images.
• Diffraction is the bending of waves around obstacles or through apertures.
• Interference is the superposition of waves, creating constructive or destructive patterns.
• Polarization describes the direction of oscillations in transverse waves.

Quantum Mechanics

• Quantum mechanics studies matter and energy behavior at atomic and subatomic levels.
• Quantization of physical quantities characterizes quantum mechanics, including energy and angular momentum.
• Wave-particle duality indicates that matter exhibits both wave-like and particle-like characteristics.
• The Heisenberg uncertainty principle states that accurately knowing a particle's position and momentum simultaneously is impossible.
• Quantum entanglement links two or more particles, where one's state instantly affects the others, regardless of distance.
• The Schrödinger equation describes the time evolution of a quantum mechanical system.

Relativity

• Special relativity relates space and time in inertial frames (constant velocity).
• The speed of light in a vacuum remains constant for all observers.
• Time dilation occurs when time passes slower for a moving object relative to an observer.
• Length contraction occurs when an object's length appears shorter in motion direction.
• Mass-energy equivalence states mass and energy are interchangeable, as per E=mc^2.
• General relativity extends special relativity to include gravity.
• Gravity is described as spacetime curvature caused by mass and energy.
• Black holes are spacetime regions with gravity so strong that nothing escapes.
• Gravitational waves are spacetime ripples caused by accelerating masses.