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As mentioned later in this article, pointing devices have different possible states. Examples for these states are out of range, tracking or dragging. Examples. a computer mouse is an indirect, relative, isotonic, position-control, translational input device with two degrees of freedom (x, y position) and two states (tracking, dragging).
Action describes energy summed up over the time a process lasts (time integral over energy). Its dimension is the same as that of an angular momentum.. A phototube provides a voltage measurement which permits the calculation of the quantized action (Planck constant) of light.
The device had rotary dials that rotated in accordance with the selected numbers; with gears, drums, and clever engineering, it was capable of addition, subtraction, multiplication and division (using 9's constant). A stylus was used to turn the dials. Later devices of this type include the Arithmometer, in the 1860s; and the Addiator, in 1920. [5]
Like other pointing devices such as mice, touchpads or trackballs, operating system software translates manipulation of the device into movements of the pointer on the computer screen. Unlike other pointing devices, it reacts to sustained force or strain rather than to gross movement, so it is called an "isometric" [ 1 ] pointing device.
Logitech Cordless TrackMan Wheel trackball mose The original version of the Kensington Expert Mouse can use a standard American pool ball as a trackball. [citation needed]A trackball is a pointing device consisting of a ball held by a socket containing sensors to detect a rotation of the ball about two axes—like an upside-down ball mouse with an exposed protruding ball. [1]
A light pen is a computer input device in the form of a light-sensitive wand used in conjunction with a computer's cathode-ray tube (CRT) display. It allows the user to point to displayed objects or draw on the screen in a similar way to a touchscreen but with greater positional accuracy.
The most rigorous definition of this abstract tool is the "collapsing compass"; having drawn a circle from a given point with a given radius, it disappears; it cannot simply be moved to another point and used to draw another circle of equal radius (unlike a real pair of compasses).
Historically, the definition of a scientific instrument has varied, based on usage, laws, and historical time period. [1] [2] [3] Before the mid-nineteenth century such tools were referred to as "natural philosophical" or "philosophical" apparatus and instruments, and older tools from antiquity to the Middle Ages (such as the astrolabe and pendulum clock) defy a more modern definition of "a ...