Valdemar Poulsen’s 148th Birthday

Today’s Doodle celebrates Valdemar Poulsen, a Danish engineer whose innovations made magnetic sound recording and long-range radio transmission possible. Many modern conveniences, from telephone answering machines to cassettes, even VHS tapes and floppy disks, used the basic technology that he developed by stringing a steel piano wire at a slight angle between two walls. By sliding an electromagnet down the wire he was able to record sound using a microphone and play it back through a telephone earpiece.

Born in Copenhagen on this day in 1869, Poulsen studied medicine for a time before joining the Copenhagen Telephone Company as a technician. During his time he invented the telegraphone—or telegrafon in Danish–– and was awarded a patent. The cylindrical electromagnetic phonograph was capable of recording up to thirty minutes of speech. In 1900 he showed off his device at the Exposition Universelle in Paris, where he recorded the voice of Austrian emperor Francis Joseph—still the earliest surviving magnetic recording. After winning a Grand Prix in Paris, he founded the American Telegraphone Company, but sales were sluggish as the device was truly ahead of its time.

That same year brought another breakthrough, a “singing arc” radio that would transmit up to 150 miles. Subsequent improvements of this design, capable of reaching 2,500 miles, were eventually used by the U.S. Navy.

Although he dropped out of medical school, Poulsen was awarded an honorary doctorate from the University of Leipzig. He was also a Fellow of the Danish Academy of Technical Science and the Swedish Institute for Engineering Research, and won the Gold Medal of the Royal Danish Society of Science and the Danish Government Medal of Merit. A stamp was issued in his honor and the Danish Academy of Technical Sciences established an annual award in his name.

Happy Birthday, Valdemar Poulsen!