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Modern physics refers to the post-Newtonian concepts in physics, primarily dealing with the behaviors and interactions of matter and energy at atomic and subatomic levels. This field covers theories and principles such as quantum mechanics, special relativity, and general relativity.
The development of modern physics began in the late 19th century and continued into the 20th century, marked by significant discoveries and theories. Key milestones include:
1. **Quantum Mechanics** - Studies the behavior of particles at atomic scales.
2. **Relativity** - Encompasses Einstein's theories of special and general relativity.
3. **Thermodynamics** - Focuses on heat, work, temperature, and the statistical nature of matter.
4. **Nuclear Physics** - Examines atomic nuclei and their interactions.
5. **Particle Physics** - Investigates the fundamental particles of the universe and their interactions.
| Feature | Quantum Mechanics | Classical Mechanics |
|-----------------------------|-------------------------------------------|----------------------------------------|
| Scale | Atomic and subatomic | Macroscopic |
| Nature of Objects | Particles exhibit wave-particle duality | Objects follow deterministic paths |
| Measurement | Probabilistic outcomes | Predictable outcomes |
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Quantum Mechanics - The branch of physics that deals with the behavior of matter and light on the atomic and subatomic scale.
Photoelectric Effect - The emission of electrons when light shines on a material, demonstrating the particle nature of light (Einstein, 1905).
Wave-Particle Duality - The concept that every particle or quantum entity exhibits both wave and particle properties.
Uncertainty Principle - Formulated by Heisenberg, stating that the position and momentum of a particle cannot both be precisely determined at the same time.
Nuclear Fission - The process of splitting a heavy nucleus into lighter nuclei, accompanied by the release of energy.
Nuclear Fusion - The process of combining two light nuclei to form a heavier nucleus, releasing significant energy (as in stars).
Radioactivity - The spontaneous emission of radiation by an unstable atomic nucleus.
Half-Life - The time required for half of the radioactive nuclei in a sample to decay.
Fission and Fusion - F for Fission (split), F for Fusion (combined)
Superposition, Entanglement, Uncertainty - SEU (Sounds like 'see you')
E = mc² and Photoelectric Effect - E for Energy, E for Effect