Thermal Physics

Thermal physics is the branch of physics that studies the nature of heat, temperature, and their relationship to energy, work, radiation, and the macroscopic properties of matter. It seeks to explain these large-scale phenomena by examining the collective motion and statistical behavior of their microscopic constituents, such as atoms and molecules. The entire field is fundamentally governed by the laws of thermodynamics, which describe how energy is transferred and transformed, and introduce the crucial concept of entropy as a measure of disorder within a system.

1. Introduction to Thermal Physics
   1. Fundamental Concepts
      1. Macroscopic vs. Microscopic Viewpoints
         1. Macroscopic Variables and Measurements
         2. Microscopic Description of Matter
         3. Connection Between Macroscopic and Microscopic Descriptions
      2. Systems, Surroundings, and Boundaries
         1. Types of Systems
            1. Isolated Systems
            2. Closed Systems
            3. Open Systems
         2. Types of Boundaries
            1. Fixed Boundaries
            2. Movable Boundaries
            3. Permeable Boundaries
            4. Impermeable Boundaries
         3. System-Surroundings Interactions
      3. Thermodynamic State and State Variables
         1. Definition of Thermodynamic State
         2. State Variables
            1. Pressure
            2. Volume
            3. Temperature
            4. Composition
            5. Density
         3. Extensive and Intensive Properties
            1. Definition of Extensive Properties
            2. Definition of Intensive Properties
            3. Examples and Distinctions
            4. Mathematical Relationships
      4. Thermodynamic Equilibrium
         1. Definition of Equilibrium
         2. Types of Equilibrium
            1. Thermal Equilibrium
            2. Mechanical Equilibrium
            3. Chemical Equilibrium
            4. Phase Equilibrium
         3. Criteria for Equilibrium
         4. Local vs. Global Equilibrium
   2. Temperature and the Zeroth Law of Thermodynamics
      1. The Zeroth Law of Thermodynamics
         1. Statement and Significance
         2. Transitive Property of Thermal Equilibrium
         3. Implications for Temperature Measurement
      2. Concept of Temperature
         1. Physical Meaning of Temperature
         2. Temperature as a State Variable
         3. Empirical vs. Thermodynamic Temperature
      3. Temperature Scales
         1. Celsius Scale
            1. Definition and Reference Points
            2. Historical Development
         2. Fahrenheit Scale
            1. Definition and Reference Points
            2. Conversion Formulas
         3. Kelvin Scale and Absolute Zero
            1. Definition of Kelvin Scale
            2. Absolute Zero Concept
            3. Conversion Between Scales
         4. Rankine Scale
      4. Thermometers and Thermometry
         1. Principles of Thermometry
         2. Types of Thermometers
            1. Constant-Volume Gas Thermometer
               1. Construction and Operation
               2. Advantages and Limitations
               3. Ideal Gas Extrapolation
            2. Resistance Thermometer
               1. Principle of Operation
               2. Temperature Coefficient of Resistance
            3. Thermocouple
               1. Seebeck Effect
               2. Uses and Calibration
               3. Reference Junction Compensation
            4. Liquid-in-Glass Thermometers
            5. Bimetallic Thermometers
            6. Optical Pyrometers
         3. Calibration of Thermometers
         4. Fixed Points and Standards
   3. Thermal Expansion
      1. Linear Expansion
         1. Coefficient of Linear Expansion
         2. Mathematical Expression
         3. Temperature Dependence
         4. Applications and Examples
      2. Area Expansion
         1. Coefficient of Area Expansion
         2. Mathematical Expression
         3. Relationship to Linear Expansion
      3. Volume Expansion
         1. Coefficient of Volume Expansion
         2. Mathematical Expression
         3. Relationship to Linear Expansion
      4. Thermal Expansion of Solids
         1. Crystalline Structure Effects
         2. Anisotropic Expansion
      5. Thermal Expansion of Liquids
         1. Apparent vs. Real Expansion
         2. Container Effects
      6. Thermal Expansion of Water
         1. Anomalous Expansion of Water
         2. Maximum Density at 4°C
         3. Significance in Nature and Technology
      7. Applications and Consequences
         1. Engineering Applications
         2. Thermal Stress
         3. Compensation Techniques