Keep what waves explain
Wave optics describes propagation and interference successfully. Einstein asks whether energy exchange with matter needs an additional, explicitly heuristic description.
Read · Light quanta: from entropy to an energy scale · Results
Follow all nine sections: the classical allocation problem, the Wien entropy calculation, independent configurations, the heuristic move, and three energy-transfer applications.
Newly authored explanatory preview in modern notation; editorial and physics review are pending. The introduction and all nine numbered sections have explanatory treatments below, but this is not a German transcription, an aligned English translation, or a complete critical edition. Source faces remain in preparation. The headings and argument units are editorial, not a verified paragraph-by-paragraph source inventory.
Wave optics describes propagation and interference successfully. Einstein asks whether energy exchange with matter needs an additional, explicitly heuristic description.
At a positive temperature, classical allocation assigns more energy as the frequency cutoff rises. Its all-frequency total has no finite value; the plotting cutoff is not a physical explanation.
Matching a spectral coefficient to classical thermal allocation constrains R/N. Quantized resonator energies and independently propagating light quanta are different claims.
At fixed volume and frequency, the entropy increase per added energy is 1/T. Inverting an admitted spectrum therefore determines an entropy derivative, but not yet its integration constant.
Inverting Wien’s law and integrating gives the entropy density plus a frequency-dependent constant. Requiring zero entropy density at zero radiation fixes that constant; it does not cancel automatically.
For the same energy and narrow frequency band, Wien radiation gains entropy logarithmically with accessible volume. Both endpoint states must remain in the admitted regime.
For n independent uniformly distributed points, the chance that all lie in a fraction f of a volume is fⁿ. Perfectly locked positions instead give f; the exponent is a statement about independence.
In the Wien regime, the radiation entropy coefficient has the form associated with independent elements. Reading an energy scale from that match is a heuristic inference, not a proof of every property of light.
With one absorbed quantum, no extra energy, and a single emitted quantum, the outgoing energy cannot exceed the incoming energy. Extra thermal energy or multiple-quantum input changes those premises.
In the one-quantum model, frequency sets the maximum electron energy after paying the escape cost. Increasing power at fixed frequency can increase the number emitted without increasing that maximum.
The ideal stopping-potential magnitude is Kmax divided by the positive elementary-charge magnitude. Partial transfer or internal losses produce an inequality rather than a larger endpoint energy.
Under a one-quantum ionization assumption, a quantum must meet the required ionization energy. Absorbed energy bounds the count; equality requires that every absorbed quantum causes exactly one counted ionization.