Introduction to Physics

• Physics is a natural science concerning the study of matter, its fundamental parts, motion and behavior through space and time, and related entities of energy and force
• A primary scientific discipline, physics seeks to understand the behavior of the universe
• The scientific method is used in physics to create and test hypotheses based on observations from experiments
• The development of physical theories falls under physics
• Physics is closely linked to other natural sciences, most notably chemistry
• Physics is generally split into classical and modern physics

Classical Physics

• Classical physics encompasses traditional branches and topics recognized and developed before the 20th century
• Classical mechanics is the study of motion in macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, and stars
• Thermodynamics involves the study of heat, work, and energy and the relationships between them
• The properties of matter in bulk, in addition to the laws of thermodynamics, fall under thermodynamics
• Electromagnetism is the study of electricity, magnetism, and light
• The behavior and properties of light, including interactions with matter and instrument construction, fall under optics
• Acoustics is the study of sound, including how sound is produced, spread, and received

Modern Physics

• Modern physics includes the developments that started in the early 20th century, primarily quantum mechanics and relativity
• Quantum mechanics studies the behavior of matter and energy at the atomic and subatomic levels
• The behavior of space, time, and gravity are studied in relativity

Related Fields

• Astrophysics uses the laws of physics on astronomical objects and phenomena
• Biophysics involves study of the physical principles of living organisms and systems
• Chemical physics studies the physical processes behind chemical phenomena
• The physical properties and processes of the Earth are studied in geophysics
• Engineering uses physics principles to design and build technologies
• Physics is used to understand the properties of materials within materials science
• Meteorology applies physics to the study of the atmosphere and weather forecasting

Physics is a natural science that studies matter, energy, and their interactions. It seeks to understand the fundamental principles governing the universe through the scientific method. Physics is broadly divided into classical and modern physics.