Physics: Relativity and Quantum Mechanics

Special Relativity
- Developed by Albert Einstein in 1905.
- Key concepts:
  - The speed of light is constant in all inertial frames.
  - Time dilation: Moving clocks tick slower relative to stationary observers.
  - Length contraction: Objects shorten in the direction of motion as they approach the speed of light.
General Relativity
- Extended in 1915, describing gravitation.
- Gravity is not a force but a curvature of spacetime caused by mass.
- Predictions include:
  - Light bending around massive objects.
  - Time running slower in stronger gravitational fields (gravitational time dilation).

Fundamental Principles
- Describes the behavior of matter and energy at atomic and subatomic scales.
- Wave-particle duality: Particles exhibit both wave-like and particle-like properties.
Key Concepts
- Heisenberg Uncertainty Principle: Cannot know both the position and momentum of a particle precisely.
- Quantum Superposition: Particles can exist in multiple states simultaneously until measured.
- Quantum Entanglement: Particles can become correlated, affecting each other instantly over distances.

Basic Principles
- Describes the interactions between electric charges and magnetic fields.
- Governed by Maxwell's equations.
Key Concepts
- Electric Field: The influence exerted by charged particles.
- Magnetic Field: Created by moving charges (currents).
- Electromagnetic Waves: Propagate at the speed of light; includes radio waves, X-rays, etc.

Core Principles
- Analyzes the motion of macroscopic objects.
- Newton’s Laws of Motion:
  - First: An object at rest stays at rest; an object in motion stays in motion unless acted upon.
  - Second: F=ma (force equals mass times acceleration).
  - Third: For every action, there is an equal and opposite reaction.
Conservation Laws
- Conservation of energy: Total energy remains constant in an isolated system.
- Conservation of momentum: Total momentum remains constant in a closed system.

Laws of Thermodynamics
- First Law: Energy cannot be created or destroyed; it can only change forms (conservation of energy).
- Second Law: The entropy of an isolated system always increases; heat flows from hot to cold.
- Third Law: As temperature approaches absolute zero, the entropy of a perfect crystal approaches zero.
Key Concepts
- Heat Transfer: Conduction, convection, and radiation.
- Thermodynamic Systems: Open, closed, and isolated systems.
- State Functions: Variables such as temperature, pressure, and volume that describe the state of a system.

Special Relativity describes the relationship between space and time.
Developed in 1905 by Albert Einstein, it is based on two postulates:
- The speed of light is constant for all observers in uniform motion.
- The laws of physics are the same for all observers in uniform motion
Key Concepts:
- Time Dilation: Moving clocks tick slower than stationary ones.
- Length Contraction: Objects appear shorter in the direction of motion as they approach the speed of light.
General Relativity extends the theory of Special Relativity
Proposed in 1915, it describes gravitation.
Key Concepts:
- Gravity is not a force, but a curvature in spacetime caused by mass and energy.
- Black Holes: Objects so dense that their gravity prevents anything, even light, from escaping.
- Gravitational Waves: Ripples in spacetime caused by accelerating massive objects like merging black holes.

Basic Principles:
- Wave-Particle Duality: Particles can behave like waves and waves can behave like particles.
- Quantum Superposition: A particle can exist in multiple states simultaneously until it is measured.
- Quantum Entanglement: Two entangled particles can be correlated and influence each other instantly even when separated by large distances.
Key Concepts:
- Uncertainty Principle: States that it is impossible to know both the position and momentum of a particle with absolute certainty .
- Quantum Tunneling: A particle can pass through a potential barrier even if it doesn't have enough energy to do so classically.

Describes the interaction between electric charges and magnetic fields.
Key Concepts:
- Electric Field: Created by a charged particle, influences other charged particles.
- Magnetic Field: Created by moving charges and is responsible for the attraction and repulsion of magnets.
- Electromagnetic Waves: Propagate at the speed of light and include radio waves, X-rays, and visible light.

Fundamental Theory of the relationship between heat and other forms of energy.
Laws of Thermodynamics:
- First Law: Energy cannot be created or destroyed, only transformed from one form to another.
- Second Law: The entropy of an isolated system always increases over time, heat flows from hotter objects to colder objects.
- Third Law: The entropy of a perfect crystal approaches zero as the temperature approaches absolute zero.
Key Concepts:
- Heat Transfer: The movement of thermal energy between objects or systems at different temperatures. Includes conduction, convection, and radiation.
- Thermodynamic Systems: Open, closed, and isolated systems.
- State Functions: Variables like pressure, temperature, and volume that describe the state of a system.