It is well known that electromagnetic waves can be emitted or received with the help of „sky threads“ (commonly known as „antennas“ in English). The Chinese word is made up of the characters 天 tiān „sky, day“ and 线 xiàn „wire, line, thread, beam.“ Incidentally, the English word is related to the Latin tendere or Greek teinein, which means „to stretch“ or „to tighten.“