Lightning strikes, lasting less than a half-millionth of a second, often scorch the skin but don't cause internal burns. Just as crucial, most of the electricity in a lightning bolt does not pass through the body. Rather, it dissipates over the skin in what's known as a flashover. Vernon Cooray, a lightning scientist at Uppsala University in Sweden, explains the phenomenon by contrasting the ways a human body and a tree react when struck.
Human-computer interaction (HCI) is the study and planned design of human and computer activities. HCI uses productivity, safety and entertainment to support and fulfill human-computer activities and is applied to various types of computer systems, including air traffic control, nuclear processing, offices and computer gaming.
A computer mouse is an input device that is most often used with a personal computer. Moving a mouse along a flat surface can move the on-screen cursor to different items on the screen. Items can be moved or selected by pressing the mouse buttons (called clicking).