The first message sent by Morse code’s dots and dashes across a long distance traveled from Washington, D.C., to Baltimore on Friday, May 24, 1844 – 175 years ago. It signaled the first time in human history that complex thoughts could be communicated at long distances almost instantaneously. Until then, people had to have face-to-face conversations; send coded messages through drums, smoke signals and semaphore systems; or read printed words.
Thanks to Samuel F.B. Morse, communication changed rapidly, and has been changing ever faster since. He invented the electric telegraph in 1832. It took six more years for him to standardize a code for communicating over telegraph wires. In 1843, Congress gave him US$30,000 to string wires between the nation’s capital and nearby Baltimore. When the line was completed, he conducted a public demonstration of long-distance communication.
Morse wasn’t the only one working to develop a means of communicating over the telegraph, but his is the one that has survived. The wires, magnets and keys used in the initial demonstration have given way to smartphones’ on-screen keyboards, but Morse code has remained fundamentally the same, and is still – perhaps surprisingly – relevant in the 21st century. Although I have learned, and relearned, it many times as a Boy Scout, an amateur radio operator and a pilot, I continue to admire it and strive to master it.
Easy sending
Morse’s key insight in constructing the code was considering how frequently each letter is used in English. The most commonly used letters have shorter symbols: “E,” which appears most often, is signified by a single “dot.” By contrast, “Z,” the least used letter in English, was signified by the much longer and more complex “dot-dot-dot (pause) dot.”
In 1865, the International Telecommunications Union changed the code to account for different character frequencies in other languages. There have been other tweaks since, but “E” is still “dot,” though “Z” is now “dash-dash-dot-dot.”
The reference to letter frequency makes for extremely efficient communications: Simple words with common letters can be transmitted very quickly. Longer words can still be sent, but they take more time.