The study by Nair et al. investigates the optical transparency and dynamic conductivity of suspended graphene, finding that these properties are defined by the fine structure constant, \(\alpha = e^2/hc\). Despite being only one atom thick, graphene absorbs a significant fraction of incident white light, with an opacity of \(2.3\%\) (\(\pi \alpha\)). This absorption is a result of graphene's unique electronic structure, which is described by the theory of ideal two-dimensional (2D) Dirac fermions. The dynamic conductivity \(G\) of graphene is found to be close to the universal value \(e^2/4h\), within a few percent accuracy. The authors also demonstrate that the optical properties of graphene are independent of material parameters and are solely determined by fundamental constants. The findings highlight the universal nature of graphene's optical behavior and its potential for metrological applications.The study by Nair et al. investigates the optical transparency and dynamic conductivity of suspended graphene, finding that these properties are defined by the fine structure constant, \(\alpha = e^2/hc\). Despite being only one atom thick, graphene absorbs a significant fraction of incident white light, with an opacity of \(2.3\%\) (\(\pi \alpha\)). This absorption is a result of graphene's unique electronic structure, which is described by the theory of ideal two-dimensional (2D) Dirac fermions. The dynamic conductivity \(G\) of graphene is found to be close to the universal value \(e^2/4h\), within a few percent accuracy. The authors also demonstrate that the optical properties of graphene are independent of material parameters and are solely determined by fundamental constants. The findings highlight the universal nature of graphene's optical behavior and its potential for metrological applications.