This is the first in a series of Did You Know? articles that uncover interesting historical, technical, and IEEE-related factoids. Here, we set the record straight on several misperceptions of technical history. Some have been repeated so often as to be taken as fact. We welcome submissions from readers debunking other misperceptions they know about.
(A version of this article is available on the IEEE Global History Network.)
EDISON’S FIRST LIGHTBULB
Thomas Edison did not invent the lightbulb, or even the first incandescent one. British scientist Warren De La Rue made a lightbulb in 1840 using a platinum filament, and the first demonstration of incandescence (making a wire glow by running electricity through it) was in 1802 by British chemist Humphry Davy. Learn more about the early history of lightbulbs on the IEEE Global History Network.
In 1879, Edison did invent the first incandescent lightbulb that was reliable, long lasting, and manufacturable. That bulb is not viewable in any museum, however. It was broken and taken apart in Edison’s laboratory to find out what had made it work so well.
HEINRICH HERTZ’S BURIAL PLACE
Heinrich Hertz is well known in the history of science and engineering, but his burial place has been wrongly reported.
Hertz was the first to experimentally produce and detect the electromagnetic waves predicted by James Clerk Maxwell. As a result, in his honor the unit of frequency—cycles per second—is named the hertz. In 1987, IEEE established an award in the field of electromagnetic waves and named it the IEEE Heinrich Hertz Medal.
Hertz was born in Hamburg in 1857 to a father from a wealthy, educated, and successful family that had converted from Judaism to Lutheranism a generation before. Hertz’s mother was the daughter of a Lutheran minister, so it is no surprise that when he died at the age of 36,* his body was returned to Hamburg and buried in the main Protestant cemetery, Ohlsdorf.
A figure as important as Hertz is of course well represented in online biographies. But when you Google his name you find that almost all sites that mention the disposition of his body claim he was buried in the Jewish cemetery in Hamburg—a cultural impossibility as well as just plain wrong. Several websites, including Wikipedia, do not even mention what happened after his death. Someone must have once posted the idea, and other sites blindly copied it without checking the facts. A trip to the library for an authoritative print biography would not have even been necessary. Clever use of the Web itself would have turned up the Ohlsdorf cemetery’s list of its famous occupants, which includes an entry for “Hertz, Prof. Heinrich Rudolf, 1857–1894.”
MORSE CODE ‘SOS’
The “SOS” in Morse code does not, as is popularly believed, stand for “save our ship.” The letters S-O-S were chosen in 1910 as the distress call to replace the previously used C-Q-D because the pattern of three short, three long, three short letters was more easily distinguishable against background noise. CQ originated from the “sécu” in the French word “sécurité” (security) followed by D, which signaled distress.
TITANIC'S DISTRESS CALLS
The sinking ship’s distress calls were not received by ham radio operators in the United States, as is commonly believed, because the Titanic’s transmitter range did not extend that far. What ham radio operators did pick up was the radio traffic relayed from ship to ship, and from ship-to-shore stations.
The ship’s state-of-the-art transmitter had an 800-kilometer range during the day, extending to 4800 km at night when the reflective character of the atmosphere changed. But that range constantly varied with the location of the ship, along with the atmospheric conditions. Although a ham radio with a good receiver and antenna could have heard Titanic’s distress calls on the East Coast of the United States, there is no confirmed report that happened. The only amateur radio operator to receive a signal directly was Welsh wireless operator Artie Moore.
*This article has been corrected from its original version