MAI PHYSICSModels. Measurements. Reproducibility.Research / Original papersFoundational papers / Volume 01
Twelve papers. Four research traditions.
Follow the idea back to its source.
What is observable? What is assumed? Which calculation connects the two? Read Feynman, Einstein, Bohm and Dirac through original visual studies that keep those questions open.
Begin with amplitudes →01 / Feynman
The formulation associates a phase with the action of a path. Alternatives contribute amplitudes; probabilities follow from the combined amplitude.
q.When do alternatives reinforce, and when do their phases cancel?
Space-Time Approach to Non-Relativistic Quantum Mechanics
DOI: 10.1103/RevModPhys.20.367
Original research by R. P. Feynman. Publisher access conditions may apply.
A = (1/7) Σ exp(ijδ), j = −3,…,3; relative intensity = |A|².
Space-time diagrams organise contributions to a quantum-electrodynamic calculation. Internal lines encode mathematical propagators, not directly observed tracks.
q.What does a diagram calculate—and what does it leave unobserved?
Space-Time Approach to Quantum Electrodynamics
DOI: 10.1103/PhysRev.76.769
Original research by R. P. Feynman. Publisher access conditions may apply.
Feynman examines the difficulty of simulating quantum systems with classical computers and motivates quantum-mechanical simulation.
q.Which resources must a simulator preserve to reproduce a physical system?
Simulating physics with computers
DOI: 10.1007/BF02650179
Original research by R. P. Feynman. Publisher access conditions may apply.
02 / Einstein
The light-quantum hypothesis connects radiation energy to frequency. The photoelectric relation provides one testable consequence; light also exhibits interference.
q.Which observation calls for a particle-like description of radiation?
On a Heuristic Point of View Concerning the Production and Transformation of Light
DOI: 10.1002/andp.19053220607
Original research by A. Einstein. Publisher access conditions may apply.
Brownian motion links statistical displacement to diffusion and molecular-scale thermal agitation. Ensemble spread grows even when the mean displacement is zero.
q.How can irregular motion provide quantitative evidence for molecules?
DOI: 10.1002/andp.19053220806
Original research by A. Einstein. Publisher access conditions may apply.
⟨x²⟩ = 2Dt (one dimension); zero mean displacement.
Special relativity connects inertial frames through the Lorentz transformation. Clock synchronisation and the invariant speed of light reshape simultaneity.
q.Which events are simultaneous—and according to which inertial frame?
On the Electrodynamics of Moving Bodies
DOI: 10.1002/andp.19053221004
Original research by A. Einstein. Publisher access conditions may apply.
03 / Bohm
Bohm develops a formulation with definite particle positions guided by the wavefunction. It is an interpretation with a specified dynamics, not a classical trajectory picture.
q.Which parts of a theory are observed, and which describe its ontology?
A Suggested Interpretation of the Quantum Theory in Terms of “Hidden” Variables. I
DOI: 10.1103/PhysRev.85.166
Original research by D. Bohm. Publisher access conditions may apply.
The second paper treats measurement and the relation to the usual quantum predictions. Agreement relies on the quantum-equilibrium distribution, not arbitrary hidden-variable states.
q.If predictions agree, what would distinguish interpretations experimentally?
A Suggested Interpretation of the Quantum Theory in Terms of “Hidden” Variables. II
DOI: 10.1103/PhysRev.85.180
Original research by D. Bohm. Publisher access conditions may apply.
The Aharonov–Bohm effect is a prediction of standard quantum mechanics, not unique evidence for Bohm’s interpretation. The relative phase of coherent alternatives can depend on enclosed magnetic flux even when the accessible paths lie in a field-free region.
q.What is physically testable when a potential depends on a gauge choice?
Significance of Electromagnetic Potentials in the Quantum Theory
DOI: 10.1103/PhysRev.115.485
Original research by Y. Aharonov & D. Bohm. Publisher access conditions may apply.
I(x) = 1 + cos(2πx + φ); equal coherent amplitudes, arbitrary intensity units.
04 / Dirac
Dirac treats emission and absorption using a quantum account of radiation and its interaction with matter. The sketch marks a transition, not a calculated rate.
q.What changes when radiation itself becomes part of the quantum system?
The Quantum Theory of the Emission and Absorption of Radiation
DOI: 10.1098/rspa.1927.0039
Original research by P. A. M. Dirac. Publisher access conditions may apply.
Dirac’s first-order matrix equation, H = cα·p + βmc², incorporates electron spin through its spinor structure. The dispersion relation shown here is relativistic but not unique to Dirac’s equation. Its energy structure has positive and negative branches; the later antiparticle interpretation is not a direct reading of this graph.
q.What additional structure is required when a wave equation is relativistic?
The Quantum Theory of the Electron
DOI: 10.1098/rspa.1928.0023
Original research by P. A. M. Dirac. Publisher access conditions may apply.
E±(p) = ±√(p² + m²), with c = 1.
Dirac explores how magnetic monopoles would constrain electric charge through quantum consistency. This is a theoretical condition, not evidence that monopoles have been detected.
q.Can a consistency requirement explain why an observable comes in discrete units?
Quantised Singularities in the Electromagnetic Field
DOI: 10.1098/rspa.1931.0130
Original research by P. A. M. Dirac. Publisher access conditions may apply.
Continue the inquiry
Move from a historical formulation to a bounded model: specify the assumptions, compute a reference, and identify what evidence would change your conclusion.
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