2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/133664Based on Planck's blackbody equation it is argued that a single mode light pulse, with a large number of photons, carries one entropy unit. Similarly, an empty radiation mode carries no entropy. In this case, the calculated entropy that a coded sequence of light pulses is carrying is simply the Gibbs mixing entropy, which is identical to the logical Shannon information. This approach is supported by a demonstration that information transmission and amplification, by a sequence of light pulses in an optical fiber, is a classic Carnot machine comprising of two isothermals and two adiabatic. Therefore it is concluded that entropy under certain conditions is information.Information Theorytext