Comment by Gravyness

Would it be possible to develop a computer from linear transformations? Suppose registers, op codes and their parameters were represented as images, and at each clock a led grid is turned on with the current computer state, the light propagating into a sequence of diffractive surfaces to generate the next state through linear transformations, which is picked up and its result is used to change the led grid in the right places. Even if such a thing could be turing complete I guess the current computing problem is memory retrieval time and not internal cpu processing time...