Classical Physics: Mechanics, Optics, and Thermodynamics

• Physics is a natural science concerning matter, its basic parts, movement and behavior across space and time, and related concepts like energy and force.
• It is a fundamental scientific field aimed at understanding the universe's behavior.
• As one of the oldest academic fields, through astronomy, it may be the oldest.
• Used extensively in engineering.
• Related to mathematics.
• Applied in areas like biophysics and quantum chemistry.
• Commonly split into classical and modern physics.

Classical Physics

• Encompasses branches recognized and developed before the 20th century.
• Includes mechanics, thermodynamics, optics, and electromagnetism.
• Classical mechanics looks at the motion of objects under forces and includes statics, dynamics, kinematics, and continuum mechanics.
• Statics concerns bodies at rest, while dynamics addresses bodies in motion.
• Kinematics explains motion without looking at causes.
• Continuum mechanics views matter as continuous in solids and fluids.
• Thermodynamics studies temperature, pressure, and volume changes in physical systems.
• Optics studies light behavior and its interaction with matter, covering infrared, ultraviolet, and visible light.
• Electromagnetism studies interactions of electric currents and magnetic fields.

Modern Physics

• Includes quantum mechanics and relativity.
• Quantum mechanics looks at atoms and subatomic particles.
• Relativity looks at object behavior at high speeds, around the speed of light.

Core Concepts

• Energy, matter, space, and time are central concepts.

Matter and Energy

• Matter is substance with mass occupying volume.
• It exists in solid, liquid, gas, and plasma states.
• Energy is needed to do work or heat a body/system.
• Energy is conserved.
• Energy types: kinetic, potential, thermal, gravitational, sound, light, elastic, electromagnetic, nuclear, and mass.
• Energy can change forms.
• Mass and energy are equal.
• Mass-energy equivalence is shown by $E=mc^2$.

Space and Time

• Space is a basic physical quantity.
• Space is a three-dimensional area where objects have relative position and direction.
• Time is another basic quantity involving events from past to future.
• Space and time together form space-time.

Forces

• Force is interaction changing an object's motion.
• Forces change the velocity of objects with mass.
• Forces accelerate objects.
• Forces are measured in newtons (N).
• Four fundamental forces exist: strong nuclear, weak nuclear, electromagnetic, and gravitational.
• The strong nuclear force holds the atomic nucleus, and the weak nuclear force causes radioactive decay.
• The electromagnetic force acts between charged particles, and gravitational force acts between objects with mass.

Laws of Physics

• Physical laws are conclusions universally accepted from experiments and observations carried out over many years.

Scientific Method

• Physics uses the scientific method to test theories.
• The scientific method is an empirical method.
• Steps: Observation, Hypothesis, Prediction, Experimentation, Analysis, Conclusion.

Branches of Physics

Acoustics

• Acoustics studies sound, including its production, transmission, and reception.
• Applications: music, noise control, and medical imaging.

Astronomy

• Astronomy studies celestial objects/phenomena and the universe.
• Includes planets, stars, galaxies, and black holes.
• Cosmology studies the origin and evolution of the universe.

Atomic, Molecular, and Optical Physics

• Atomic, molecular, and optical (AMO) physics studies atoms, simple molecules, light, and their interactions.

Biophysics

• Biophysics uses physics in biological systems and studies living things' physical processes.

Chemical Physics

• Chemical physics uses physics in chemical systems and studies the physical basis of chemistry.

Condensed Matter Physics

• Condensed matter physics studies condensed phases, like solids and liquids, seeking to link macroscopic properties to microscopic structure.

Cryophysics

• Cryophysics studies the production and effects of very low temperatures.

Electromagnetism

• Electromagnetism studies interactions of electric currents and magnetic fields, including electrostatics and electrodynamics.

Fluid Dynamics

• Fluid dynamics studies fluid motion, used in aerodynamics and hydraulics.

Geophysics

• Geophysics studies the Earth's physical properties, including seismology, volcanology, and hydrology.

Materials Science

• Materials science is the interdisciplinary study of material properties, applying physics, chemistry, and engineering to design new materials.

Mathematical Physics

• Mathematical physics uses mathematical methods to solve physics problems.

Mechanics

• Mechanics studies the motion of bodies under forces, including statics, dynamics, kinematics, and continuum mechanics.

Nuclear Physics

• Nuclear physics studies atomic nuclei, used in nuclear power, weapons, and medical imaging.

Optics

• Optics studies light behavior and interaction with matter, covering infrared, ultraviolet, and visible light.

Particle Physics

• Particle physics studies matter/radiation's basic constituents and interactions between particles.

Plasma Physics

• Plasma physics studies plasma properties. Plasma is ionized gas.

Polymer Physics

• Polymer physics studies physical properties of polymer molecules.

Thermodynamics

• Thermodynamics studies temperature, pressure, and volume changes in physical systems.
• Applications include heat engines, refrigerators, and air conditioners.