Wavenumber Wavenumber In the physical sciences, the wavenumber (also wave number or repetency) is the spatial frequency of a wave, measured in cycles per unit distance or radians per unit distance. Whereas temporal frequency can be thought of as the number of waves per unit time, wavenumber is the number of waves per unit distance. In multidimensional systems, the wavenumber is the magnitude of the wave vector. The space of wave vectors is called reciprocal space. Wave numbers and wave vectors play an essential role in optics and the physics of wave scattering, such as X-ray diffraction, neutron diffraction, and elementary
First Draft of a Report on the EDVAC two dimensions plus time will require the most memory, with three dimensions plus time being beyond what can be done using technology that was then available. He concludes that memory will be the largest subdivision of the system and he proposes 8,192 minor cycles (words) of 32-bits as a design goal, with 2,048 minor cycles still being useful. He estimates a few hundred minor cycles will suffice for storing the program. He proposes two kinds of fast memory, delay line and Iconoscope tube. Each minor cycle is to be addressed as a unit (word addressing, Sec. 12.8). Instructions are to