Information can be carried by many media, including sound, light, and objects. In the 1900s, the ability to code information as electric currents in wires, electromagnetic waves in space, and light in glass fibers has made communication millions of times faster than mail or sound.
For Grades: 9-12
Learning Goal 1
Almost any information can be transformed into electrical signals. A weak electrical signal can be used to shape a stronger one, which can control other signals of light, sound, mechanical devices, or radio waves.
Learning Goal 2a
The quality of communication is determined by the strength of the signal in relation to the noise that tends to obscure it.