Introduction to Physics

• Physics is a natural science examining matter, its basic parts, motion, and behavior in space and time, along with energy and force.
• It's a core science aiming to explain the universe's behavior.
• Physics uses the scientific method to create and test ideas based on observations.
• It covers everything from tiny particles to huge galaxies.

Core Concepts

• Classical mechanics studies how large objects move, like machines and planets.
• Thermodynamics looks at heat, work, energy, and their connections.
• Electromagnetism explains how electric charges and magnetic fields interact.
• Quantum mechanics deals with how things act on the atomic level.
• Relativity, both types, explains space, time, gravity, and things moving very fast.

Branches of Physics

• Acoustics: Studies sound and mechanical waves in different materials.
• Astrophysics: Focuses on the physics of the universe, like stars and galaxies.
• Atomic Physics: studies the atom as an isolated system of electrons and a nucleus.
• Condensed Matter Physics: Examines the physical qualities of solids and liquids.
• Cosmology: Explores the universe's start, changes, and future.
• Electromagnetism: Studies the force between charged particles.
• Fluid Dynamics: Studies how liquids and gases move.
• Geophysics: Studies the Earth's physical features and actions.
• High-Energy Physics: Studies the most basic parts of matter and how they interact.
• Materials Science: A mix of fields studying what things are made of and what they're used for.
• Mechanics: Studies how things move when forces act on them.
• Nuclear Physics: Studies what makes up atomic nuclei and how they act.
• Optics: Studies light and what it does.
• Particle Physics: Studies the basic pieces of the universe and forces.
• Plasma Physics: Studies plasma, where gas is ionized.
• Thermodynamics: Studies heat, work, energy, and their links.

Key Principles and Laws

• Newton's Laws of Motion: Explain the link between forces on an object and its movement.
• Law of Conservation of Energy: Says energy in a closed system stays the same.
• Laws of Thermodynamics: Connect heat, work, and energy, and bring in the idea of increasing entropy.
• Maxwell's Equations: Describe how electric and magnetic fields act and connect.
• Schrödinger Equation: Shows how quantum systems change over time.
• Einstein's Theory of Relativity: Links space, time, gravity, and fast-moving objects.

Measurement and Units

• Accurate measurement of physical quantities is key.
• The International System of Units (SI) is the standard.
• SI base units: meter (m) for length, kilogram (kg) for mass, second (s) for time, ampere (A) for electric current, kelvin (K) for temperature, mole (mol) for amount of substance, and candela (cd) for luminous intensity.
• Derived units mix base units through multiplication or division.
• Scientific notation expresses very large or small numbers.
• Error analysis is needed to measure uncertainty in measurements and calculations.

Mathematical Tools

• Calculus describes constant change and motion.
• Linear algebra solves linear equations and shows changes in space.
• Differential equations model physical systems that evolve.
• Complex analysis studies waves and oscillations.
• Statistics and probability analyze data and predict outcomes.

Experimental Methods

• Controlled experiments test ideas and isolate variables.
• Data analysis uses statistics, fitting curves, and visuals.
• Instrumentation accurately measures physical quantities.
• Computer simulations model complex systems and test theories.

Physics and Technology

• Physics is the base for much of today's tech.
• Examples: electronics, telecommunications, medical imaging, and nuclear power.
• Physics advances often spark new technologies.

Open Questions

• Nature of Dark Matter and Dark Energy: Most of the universe is dark matter/energy, but we don't know what they are.
• Quantum Gravity: How to combine quantum mechanics and general relativity?
• Unification of Forces: Can the four forces be united into one theory?
• The Measurement Problem in Quantum Mechanics: How does measuring cause wave function collapse?
• Origin of the Universe: What caused the Big Bang and what was before?

Physics is a natural science that studies matter, energy, and their interactions. It seeks to understand the fundamental laws governing the universe, from subatomic particles to galaxies. Core concepts include classical mechanics, thermodynamics, electromagnetism, and quantum mechanics.