Morse code is method of sending text information as a series of tones, lights, or clicks that can be directly understood by a skilled listener without any equipment. Numbers, letters and other symbols are mapped into series of dots (short tone or flash) and dashes (long tone or flash). In the properly transmitted code, the duration of dash is equal to the three dots, space between parts in the same letter is equal to one dot, words are separated by pauses equal to three dots and sentences are separated by pauses of seven dots. Where it is not possible to vary the duration of the signal (like hitting the rock), the pause between signals can be varied to transmit the Morse code. The provided translation applet follows all these rules.
Morse code has been in use for more than 160 years, longer than any other electronic encoding system. It is now less important than it was in the past as evolving technologies allow to replace it by direct speech via sound capable channels. However it is still popular (while not required) between radio amateurs and is used in various navigational stations and beacons to emit they short id.
As Morse code may be transferred under circumstances when speech transferring is not possible, knowing it may help or even save life in various unusual situations. The most widely known Morse signal is likely SOS signal for calling help ("· · · — — — · · ·"). In other situations, Morse code can be transmitted by flashing lights, repeatedly hitting wall or rock, blinking with eyes (when speech is not possible or not allowed) and various other unusual means. Hence it may be interesting to learn even without the need to use it in daily work.