Quantum physics
The science beneath it all: the origins of quantum theory, the physicists who built it, and the ideas from superposition to entanglement.
17 entries
- Albert EinsteinAlbert Einstein (1879 to 1955) explained the photoelectric effect with light quanta in 1905 and later challenged the completeness of quantum mechanics.
- Bell's theoremBell's theorem proves that no local hidden-variable theory can reproduce all quantum predictions, a result confirmed by experiments and the 2022 Nobel Prize.
- Double-slit experimentThe double-slit experiment shows single particles building up an interference pattern, and demonstrates that which-path information destroys that pattern.
- Erwin SchrodingerErwin Schrodinger (1887 to 1961) wrote the 1926 wave equation of quantum mechanics and devised the Schrodinger's cat thought experiment in 1935.
- History of quantum mechanicsThe history of quantum mechanics runs from Planck's 1900 quantum through the 1925 and 1926 formulations by Heisenberg, Schrodinger, Born, and Dirac.
- Max PlanckMax Planck (1858 to 1947) originated quantum theory in 1900, proposing that energy is emitted in discrete quanta and defining Planck's constant h.
- Niels BohrNiels Bohr (1885 to 1962) built the 1913 quantized model of the atom and shaped the Copenhagen interpretation of quantum mechanics.
- Quantum entanglementQuantum entanglement is a correlation between quantum systems whose joint state cannot be described independently, producing nonlocal but non-signaling links.
- Quantum field theoryQuantum field theory unites quantum mechanics with special relativity, treating particles as excitations of fields, and underpins the Standard Model.
- Quantum mechanicsQuantum mechanics is the physical theory of matter and energy at atomic and subatomic scales, built on quantization, superposition, and probability.
- Quantum realmThe quantum realm is the scale, roughly atomic and smaller, at which quantum effects dominate; the term is also used loosely in popular culture.
- Richard FeynmanRichard Feynman (1918 to 1988) co-developed quantum electrodynamics and the path integral, and in 1981 proposed simulating physics with quantum computers.
- Schrodinger's catSchrodinger's cat is a 1935 thought experiment in which a cat is placed in a superposition of alive and dead to expose the quantum measurement problem.
- The measurement problemThe measurement problem asks why quantum superpositions yield single definite outcomes, the question that divides the interpretations of quantum mechanics.
- Uncertainty principleThe uncertainty principle states that conjugate quantities such as position and momentum cannot both have precisely defined values at the same time.
- Wave-particle dualityWave-particle duality is the quantum principle that matter and light each show both wave-like and particle-like behavior depending on the experiment.
- Werner HeisenbergWerner Heisenberg (1901 to 1976) created matrix mechanics in 1925, the first complete quantum theory, and stated the uncertainty principle in 1927.