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.
The user interface or humanâmachine interface is the part of the machine that handles the humanâmachine interaction. Membrane switches, rubber keypads and touchscreens are examples of the physical part of the Human Machine Interface which we can see and touch.