In the age of computer technology, most of the calculations in the design of equipment are fully automated, engineers can only enter the required parameters through a convenient interface.
XX century called differently. It was atomic, space, and informational. Aircraft designers improved the planes, and they turned from clumsy biplanes into swift supersonic MiGs, Mirages and Phantoms. Giant aircraft carriers and submarines began to plow the seas and oceans at all latitudes. An atomic bomb was tested in Los Alamos (New Mexico) , and the first nuclear power plant began to give energy in Obninsk near Moscow. Missiles soared upwards ...
How was the atomic bomb, rockets and jets calculated ?
Historical chronicles demonstrate the process of working on these achievements. Scientists and engineers in white coats, standing at the pans and sitting at the tables littered with drawings, make complex technical and scientific calculations on arithmometers. Sometimes in the hands of Tupolev, Kurchatov, or Teller, a thing suddenly unfamiliar to a modern young man - a slide rule. Photos of those whose youth passed in the post-war decades, right up to the 80s, also recorded this uncomplicated subject, which successfully replaced it with a calculator while studying at the institute or graduate school. And the dissertations were also considered on her, on dear.
What is the principle of a slide rule?
The main principle of operation of this wooden object, neatly pasted with celluloid white scales, is based on the logarithmic calculus, as the name implies. More precisely, on the decimal logarithm. After all, everyone who has studied higher mathematics knows that their sum is equal to the logarithm of the product, and, therefore, by correctly dividing by moving parts, it is possible to achieve that multiplication (and hence division), squaring (and extracting the root) become a simple matter.
The logarithmic line became popular back in the 19th century, when the main means for performing calculations were ordinary scores. This invention is a real find for the then scientists and engineers. Not immediately, they all figured out how to use this device. To learn all the tricks and reveal its capabilities to the full, fans of the new counting mechanism had to read special manuals, quite voluminous. But it was worth it.
Rulers are different, even round
Nevertheless, the main advantage that the ruler has is a logarithmic one - its simplicity, and therefore reliability. Compared to other calculation methods (there were no calculators yet), operations were performed much faster. But there are moments that should not be forgotten. Calculations can only be done with the mantissa, that is, the integer (up to nine) and fractional parts of the number, accurate to two (three, who have very good eyesight) decimal places. The order of the numbers needed to be kept in mind. There was another drawback. The logarithmic line, albeit small, is difficult to call it a pocket device - after all, 30 centimeters.
However, size did not become an obstacle to inquiring minds. For those who, by the nature of their activity, should always have a calculating device with them, a compact slide rule was invented. A dial with arrows gave it a resemblance to a watch, and some models of expensive chronometers contained it on their dial. Of course, the capabilities of this device and its accuracy were somewhat inferior to the corresponding parameters of the classic line, but it could always be carried in your pocket. Yes, and it looked more aesthetically pleasing!