SWhat changed
An electrical conductor can produce measurable random voltage even when no signal is being sent through it. Johnson measured this thermal noise and investigated how it depends on resistance, temperature and the measuring circuit. Nyquist gave an equilibrium explanation: in the classical regime, a resistor has voltage mean-square contribution 4kTR per unit ordinary-frequency bandwidth. The two separate papers connect an observed limit of sensitive electronics with thermal statistical physics.
Scientific scope
An electrical conductor can produce measurable random voltage even when no signal is being sent through it. Johnson measured this thermal noise and investigated how it depends on resistance, temperature and the measuring circuit. Nyquist gave an equilibrium explanation: in the classical regime, a resistor has voltage mean-square contribution 4kTR per unit ordinary-frequency bandwidth. The two separate papers connect an observed limit of sensitive electronics with thermal statistical physics. This is one observation-and-explanation family with two original bylines, not a joint paper. Equilibrium, dissipative impedance, bandwidth, filtering and one-sided versus angular-frequency conventions matter. The originals exclude unqualified material independence for non-ohmic, thermionic and photoelectric devices. Johnson measured a historical Boltzmann estimate with substantial uncertainty, not the modern exact SI value. Nyquist original quantum correction uses hf/(exp(hf/kT)-1), not a later zero-point/coth convention. Schottky earlier suggestion and acknowledged criticism and measurement assistance remain distinct. No general statement about all noise or every zero-temperature observable follows.
Evidence
The linked original works support the scoped statement and contribution attribution. WRS has not independently replayed experiments or reconstructed a full mathematical proof. This is one observation-and-explanation family with two original bylines, not a joint paper. Equilibrium, dissipative impedance, bandwidth, filtering and one-sided versus angular-frequency conventions matter. The originals exclude unqualified material independence for non-ohmic, thermionic and photoelectric devices. Johnson measured a historical Boltzmann estimate with substantial uncertainty, not the modern exact SI value. Nyquist original quantum correction uses hf/(exp(hf/kT)-1), not a later zero-point/coth convention. Schottky earlier suggestion and acknowledged criticism and measurement assistance remain distinct. No general statement about all noise or every zero-temperature observable follows.
Contributors
- The named authors in the research record · SCIENCE: Source-listed authors for the exact contribution; experimental subjects are not autonomous scientific authors. Source support and predecessor work retain separate roles. Individual effort shares and unresolved identities are not inferred.
Provisional WRS assessment, edition 2026-10-23.5. Independent expert calibration is pending. This grade does not certify correctness or assign ownership.
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