Most modern computing relies on digital technology, but this was not always the case. Early computing used analogue techniques, operating on continuous voltages and currents, to perform calculations.
Now, a report in Science describes a theoretical metamaterial that performs calculus on light waves that propagates through it. Apparently, the cross-sectional profile of the incident light is transformed into a new profile equal to the derivative of the original profile. This could have applications in image processing and even potentially enable further speed increases in particular applications of computing.