api: YAML JSON TOON Database version: 1.0.0 format: json dataset: id: 68 slug: quantum-mechanics-basics title: "Quantum Mechanics: Core Principles and Phenomena" description: "Foundations of quantum mechanics: wave-particle duality, Schrödinger equation, Heisenberg uncertainty, quantum superposition, entanglement, and measurement problem." summary: "The central principles of quantum mechanics and the phenomena that illustrate them: wave-particle duality, the Schrodinger equation, the uncertainty principle, superposition, entanglement and measurement, each with key experiments, a formula and its significance." use_when[2]: You need an accurate one-paragraph statement of a quantum principle.,You are connecting a principle to the experiment that demonstrated it. caveats[2]: Quantum mechanics is mathematically settled but its interpretation (what measurement means) is still debated.,Popular descriptions of superposition and entanglement often overstate what they imply; prefer the formal statement. related[3]: classical-mechanics,electromagnetism-basics,optics-fundamentals category: Physics category_slug: physics tags: "physics,quantum-mechanics,schrodinger,heisenberg,superposition,entanglement,wave-particle-duality" view_count: 0 created_at: 1778695229 updated_at: 1778695229 entry_count: 7 fields[11]{section,field,type,example}: principles,name,string,Wave-Particle Duality principles,description,string,Matter and light exhibit both wave and particle… principles,key_experiments,array,"[3 items]" principles,formula,string,"de Broglie wavelength: λ = h/p" principles,significance,string,Fundamental departure from classical physics; a… principles,interpretation,string,|ψ(x)|² gives probability density of finding pa… principles,implications,string,Explains atomic stability (electron can't colla… principles,famous_example,string,Schrödinger's cat thought experiment (cat simul… principles,experimental_verification,string,Aspect experiment (1982) confirmed Bell inequal… principles,interpretations,array,"[3 items]" principles,applies_to,string,"Fermions (electrons, protons, neutrons, quarks)…" data: principles[7]: - name: Wave-Particle Duality description: Matter and light exhibit both wave and particle properties depending on experimental setup key_experiments[3]: Double-slit experiment (interference pattern for electrons/photons),Photoelectric effect (light as particles/photons),Davisson-Germer experiment (electron diffraction) formula: "de Broglie wavelength: λ = h/p" significance: Fundamental departure from classical physics; all matter has wave nature - name: Schrödinger Equation description: Fundamental equation of non-relativistic quantum mechanics; describes evolution of quantum state formula: iℏ ∂ψ/∂t = Ĥψ (time-dependent); Ĥψ = Eψ (time-independent) significance: Predicts probability amplitudes; solutions (wavefunctions) give energy levels and spatial distributions interpretation: |ψ(x)|² gives probability density of finding particle at position x - name: Heisenberg Uncertainty Principle description: Fundamental limit on simultaneous precision of complementary observables formula: Δx · Δp ≥ ℏ/2; ΔE · Δt ≥ ℏ/2 significance: Not a measurement limitation but intrinsic property of quantum systems; conjugate variables cannot be simultaneously sharp implications: "Explains atomic stability (electron can't collapse into nucleus), zero-point energy" - name: Quantum Superposition description: Quantum system exists in all possible states simultaneously until measured formula: |ψ⟩ = α|0⟩ + β|1⟩ where |α|² + |β|² = 1 significance: Basis of quantum computing (qubits); demonstrated by double-slit interference famous_example: Schrödinger's cat thought experiment (cat simultaneously alive and dead) - name: Quantum Entanglement description: Two or more particles share a quantum state; measurement of one instantaneously affects the other regardless of distance formula: |ψ⟩ = (|00⟩ + |11⟩)/√2 (Bell state) significance: Violates local realism (Bell's theorem); basis for quantum cryptography and teleportation experimental_verification: Aspect experiment (1982) confirmed Bell inequality violation; 2022 Nobel Prize - name: Quantum Measurement (Collapse) description: Measurement causes wavefunction to collapse to an eigenstate of the measured observable interpretations[3]{name,description}: Copenhagen,Collapse is fundamental; measurement creates reality Many-Worlds,No collapse; all outcomes realized in branching universes Decoherence,Apparent collapse due to entanglement with environment significance: Measurement problem remains unresolved; central mystery of quantum foundations - name: Pauli Exclusion Principle description: No two identical fermions can occupy the same quantum state simultaneously formula: "ψ(r₁,r₂) = -ψ(r₂,r₁) (antisymmetric wavefunction for fermions)" significance: "Explains electron shell structure, periodic table, stability of matter, neutron star degeneracy pressure" applies_to: "Fermions (electrons, protons, neutrons, quarks); not bosons (photons, gluons)"