Planck's law In 1880, André-Prosper-Paul Crova published a diagram of the three-dimensional appearance of the graph of the strength of thermal radiation as a function of wavelength and temperature. He determined the spectral variable by use of prisms. He analyzed the surface through what he called "isothermal" curves, sections for a single temperature, with a spectral variable on the abscissa and a power variable on the ordinate. He put smooth curves through his experimental data points. They had one peak at a spectral value characteristic for the temperature, and fell either side of it towards the horizontal axis. Such spectral sections are
Bit-paired keyboard Bit-paired keyboard A bit-paired keyboard is a keyboard where the layout of shifted keys corresponds to columns in the ASCII (1963) table, archetypally the Teletype Model 33 (1963) keyboard. This was later contrasted with a typewriter-paired keyboard, where the layout of shifted keys corresponds to "electric" typewriter layouts, notably the IBM Selectric (1961). The difference is most visible in the digits row (top row): compared with mechanical typewriters, bit-paired keyboards remove the _ character from 6 and shift the remaining &*() from 7890 to 6789, while typewriter-paired keyboards replace 3 characters: from " to @ from _ to ^ and