People have invented devices, such as paper and ink, engraved plastic disks, and magnetic tapes, for recording information. Communication technologies make it possible to send and receive information more and more reliably, quickly, and cheaply over long distances. Students explore their ability to discriminate between sounds, by dropping objects into a drop chamber and identifying each object by the property of its sound. Students develop a code by assigning letters to a selection of the objects and send messages to one another by using their drop code. Further activities encourage the students to create codes to communicate with members of their groups.
Some programs stay permanently in the machine but most are coded on disks.
Computers can be programmed to store, retrieve, and perform operations on information. These operations include mathematical calculations, word processing, diagram drawing, and the modeling of complex events. Mistakes can occur when people enter programs or data into a computer. Computers themselves can make errors in information processing because of defects in their hardware or software. Tools, such as thermometers and x-ray machines, provide us clues about what is happening inside the body.