Abstract For over a century, the fine-structure constant ( α ) has remained one of the most enigmatic dimensionless numbers in physics, often relegated to the realm of pure numerology. In this work, we provide a physical foundation based on the Fluctuation-Dissipation Theorem (FDT). By establishing an identity between the electromagnetic coupling strength and the reciprocal of the photon-number variance within a black-body cubic cavity, we demonstrate that these quantities correspond to a dynamic “line constant” rather than a static value. We show that the Sommerfeld value emerges as a resonance condition where the geometric confinement scale ( L = 3.3 cm) and the thermal energy of the emission fine-structure line (equivalent temperature of 0.516 K) satisfy a reciprocal duality between the field strength (stiffness) and the photon gas fluctuations (compliance). This statistical framework extends to the entire Mendeleev table of elements, suggesting that atomic properties are local manifestations of vacuum fluctuations of the photon gas.
- Stiffness and compliance of the electromagnetic field: A normalized mechanical analogy to introduce a line-structure constant
- L. Varani - Centre National de la Recherche ScientifiqueF. Intini - University of Modena and Reggio EmiliaL. Reggiani - University of Salento
- EPL - Europhysics Letters, Vol.155(3)
- 99260767509311
- IES - Institut d'Electronique et des Systèmes
- English
- Journal article
- hal-05684171