Who Started Quantum Mechanics? Planck, Bohr and Heisenberg

Ask who “started” quantum mechanics and you will get three different honest answers, depending on what you mean by started. Max Planck introduced energy quanta in 1900. Niels Bohr built a working quantum atom in 1913. Werner Heisenberg wrote the first full quantum mechanics in 1925 and stated the uncertainty principle in 1927. None of them alone is the whole story. Our stickers of Max Planck and Niels Bohr, and tees like Lady Uncertainty, mark those three turns.

What did Max Planck do in 1900?

Classical physics could not explain the spectrum of light from a hot body (black-body radiation). Planck found that the data fit if the oscillators in the wall exchanged energy only in packets

E = hν

with h a new constant (now Planck’s constant) and ν the frequency. His detailed account of the energy-distribution law appeared in the Annalen der Physik in 1901 (Planck 1901^[1]). That was not yet “quantum mechanics” in the modern sense — there was no wavefunction, no matrix, no uncertainty relation — but it was the first successful use of energy quanta in physics.

The Nobel Prize in Physics for 1918 was awarded to Planck “in recognition of the services he rendered to the advancement of Physics by his discovery of energy quanta” (NobelPrize.org, Planck facts^[2]). (The prize year is 1918; it was presented in 1919.)

What did Niels Bohr do in 1913?

Rutherford’s nuclear atom needed a rule for why electrons did not simply spiral into the nucleus. Bohr’s three-part 1913 paper in the Philosophical Magazine postulated stationary orbits with angular momentum quantized in units of ħ = h/2π, and radiation only when an electron jumped between orbits (Bohr 1913^[3]). The model predicted the hydrogen spectral lines and made the Rydberg constant emerge from e, m, h and c.

Bohr’s atom is still a hybrid: classical orbits plus quantum rules. It is not Heisenberg’s or Schrödinger’s quantum mechanics. It is the bridge that made atomic spectra calculable. The Nobel Prize in Physics 1922 went to Bohr “for his services in the investigation of the structure of atoms and of the radiation emanating from them” (NobelPrize.org, Bohr facts^[4]).

What did Heisenberg do in 1925 and 1927?

1925: matrix mechanics

In 1925 Heisenberg replaced classical position and momentum with arrays of transition amplitudes — what Born and Jordan soon recognized as matrices. His paper “Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen” founded matrix mechanics (Heisenberg 1925^[5]). Schrödinger’s wave mechanics (1926) gave an equivalent picture; Dirac and others showed the two formalisms were the same theory.

1927: the uncertainty principle

In 1927 Heisenberg argued that conjugate quantities such as position and momentum cannot both be known with arbitrary precision. In modern textbook form,

Δx · Δp ≥ ħ/2

His original paper is “Über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik” (Heisenberg 1927^[6]). How to interpret the inequality — disturbance by measurement, preparation of states, or something else — is still debated; the Stanford Encyclopedia of Philosophy surveys those readings (SEP, Uncertainty Principle^[7]). What is not open is that the relation is part of standard quantum theory.

The Nobel Prize in Physics 1932 was awarded to Heisenberg “for the creation of quantum mechanics, the application of which has, inter alia, led to the discovery of the allotropic forms of hydrogen” (NobelPrize.org, Heisenberg facts^[8]).

So who “started” quantum mechanics?

• Planck (1900/1901) started quantum theory as energy quanta — Nobel year 1918.
• Bohr (1913) started the quantum atom — Nobel year 1922.
• Heisenberg (1925) started quantum mechanics as a general dynamical theory; the 1927 uncertainty paper is part of that creation — Nobel year 1932.

Einstein’s 1905 light-quantum paper and de Broglie’s matter waves also belong in any longer history; they are not the three names in this queue entry’s title. Schrödinger, Born, Dirac and Pauli finished the formal structure in the mid-1920s. For how measurement fits into that structure, see our pillar What Is Quantum Measurement? and the supporting post Does Observation Change a Particle?.

Wear the founders

Besides Planck and Bohr, Heisenberg’s limit shows up on Indeterminax and δx the Heisenberg Runner. Browse the Quantum collection and the Physicist Stickers.

Where do Einstein and Schrödinger fit?

Einstein’s 1905 light-quantum paper treated radiation itself as quantized; it is part of quantum theory’s birth but not the 1925 mechanics package named in Heisenberg’s Nobel. Schrödinger’s 1926 wave equation gave the ψ that most students meet first; Born’s probability interpretation (also 1926) said |ψ|² is a probability density. Those steps sit between Bohr’s atom and the mature formalism. Measurement language — collapse, decoherence, many-worlds — is still contested; our pillar What Is Quantum Measurement? and the Stanford measurement entry (SEP, Measurement in Quantum Theory^[9]) keep that debate labelled open rather than settled.

A short timeline keeps the credit clean:

• 1900–1901: Planck’s energy quanta for black-body radiation (Planck 1901^[1]) — Nobel year 1918.
• 1913: Bohr’s quantum atom (Bohr 1913^[3]) — Nobel year 1922.
• 1925: Heisenberg’s matrix mechanics (Heisenberg 1925^[5]).
• 1927: Heisenberg’s uncertainty paper (Heisenberg 1927^[6]; SEP^[7]) — Nobel year for creating quantum mechanics 1932.

Feynman’s opening quantum lecture remains a readable modern tour of the experimental facts that force the theory (Feynman Lectures Vol. III, Ch. 1^[10]).

What was actually new in each step?

Planck’s novelty was discrete energy exchange with constant h — not a full atomic theory. Bohr’s novelty was stationary states and frequency condition ν = ΔE/h for spectra — still with classical orbits. Heisenberg’s novelty was dropping unobservable orbital pictures and quantising the kinematics themselves, so that commutators such as [x, p] = iħ replace classical Poisson brackets. Uncertainty then bounds how sharp those incompatible quantities can be simultaneously. The three layers answer different questions: spectra of heat, spectra of atoms, and the algebra of observables.

FAQ

Did Planck invent quantum mechanics?

No. He introduced energy quanta (1900/1901). Quantum mechanics as a general theory dates to 1925–26 (Heisenberg, Schrödinger, Dirac and others).

When was the uncertainty principle published?

1927, in Zeitschrift für Physik. Heisenberg’s Nobel (1932) was for creating quantum mechanics, not for the uncertainty paper alone.

Is Bohr’s atom still “correct”?

It is a historically crucial model that gets hydrogen’s spectrum right for the wrong dynamical reasons. Modern quantum mechanics replaces fixed orbits with stationary states of the Schrödinger (or Dirac) equation.

References

1. M. Planck (1901), “Ueber das Gesetz der Energieverteilung im Normalspectrum,” Ann. Phys. 309, 553. https://doi.org/10.1002/andp.19013090310
2. NobelPrize.org, Max Planck, Physics 1918, facts. https://www.nobelprize.org/prizes/physics/1918/planck/facts/
3. N. Bohr (1913), “On the constitution of atoms and molecules,” Phil. Mag. 26, 1. https://doi.org/10.1080/14786441308634955
4. NobelPrize.org, Niels Bohr, Physics 1922, facts. https://www.nobelprize.org/prizes/physics/1922/bohr/facts/
5. W. Heisenberg (1925), “Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen,” Z. Phys. 33, 879. https://doi.org/10.1007/BF01328377
6. W. Heisenberg (1927), “Über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik,” Z. Phys. 43, 172. https://doi.org/10.1007/BF01397280
7. Stanford Encyclopedia of Philosophy, “The Uncertainty Principle”. https://plato.stanford.edu/entries/qt-uncertainty/
8. NobelPrize.org, Werner Heisenberg, Physics 1932, facts. https://www.nobelprize.org/prizes/physics/1932/heisenberg/facts/
9. Stanford Encyclopedia of Philosophy, “Measurement in Quantum Theory”. https://plato.stanford.edu/entries/qt-measurement/
10. Feynman Lectures on Physics, Vol. III, Ch. 1: Quantum Behavior. https://www.feynmanlectures.caltech.edu/III_01.html

Written by Pixelated Physics. Every factual claim is linked to the source we checked; points that are still debated are labelled open.