Abstract
Based on Planck's blackbody equation it 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 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 concluded that entropy under certain conditions is information.
Keywords. Information theory, Second law, Entropy.
JEL. D83, L96, Q40.
SDGs. SDG7, SDG9.