Halving
131Frieze group — A frieze group is a mathematical concept to classify designs on two dimensional surfaces which are repetitive in one direction, based on the symmetries in the pattern. Such patterns occur frequently in architecture and decorative art. The… …
132Diffraction-limited system — Memorial to Ernst Karl Abbe, who approximated the diffraction limit of a microscope as , where d is the resolvable feature size, λ is the wavelength of light, n is the index of refraction of the medium being imaged in, and θ (depicted as α in the …
