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RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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Alexander Graham Bell's Audio Recordings Heard 130 Years Later (Title)
you had to guess, what would you say this image represents? Part of a printed spiral inductor? How about a printed
antenna for near field communications (NFC)? Need a hint? OK, the object is part of a project that Alexander
Graham Bell, his cousin Chichester Bell, and Charles Sumner Tainter worked on in their Volta Laboratory Associates
labs. No, it's not a neatly wound coil of telephone cable. It is a section of an audio recording etched on a glass
platter in November of 1884. After being stored at the Smithsonian Museum for 130 years, this and a few other
recording media was lent to the scientists at Lawrence Berkeley National Laboratory with hopes that they could
apply newly invented noninvasive, non-contact techniques to scan the disc and use software algorithms to recover
the data. Thomas Edison had introduced his phonograph to the world in 1877, after which many people attempted to
improve on his system both for recording and playback. About 200 of the Volta Lab recordings are in the
Smithsonian's collection of around 400 of the earliest recordings ever made on a variety of materials.
Per National Museum of American History curator Carlene Stephens, "These recordings were made using a variety of methods and materials such as rubber, beeswax, glass, tin foil and brass, as the inventors tried to find a material that would hold sound. We don't know what is recorded, except for a few cryptic inscriptions on some of the discs and cylinders or vague notes on old catalog cards written by a Smithsonian curator decades ago."
What took so long for work to begin on this and other archived recordings? Mainly it was the lack of a process for recovering the embedded data without risking damage to or destruction of the often fragile media. Berkeley Lab's approach creates a high-resolution digital map of the disc or cylinder. This map is then processed to remove evidence of wear or damage (e.g., scratches and skips). Finally, software calculates the motion of a stylus moving through the disc or cylinder’s grooves, reproducing the audio content and producing a standard digital sound file. If you look closely at the glass disc, you can see jagged edges in the spiral pattern that represent the complex voice print that was extracted for processing. For more information, visit www.irene.lbl.gov.
So, what message did Messrs. Bell, Bell, and Tainter consider important enough to place on this one-of-a-kind recording? Was it a secret password revealed only to 33rd-degree Freemasons, the key to accessing an underground treasure chamber containing the National Treasure, or maybe the code for President Chester Arthur's nuclear football1? Maybe... but only if that word - yes, a single word - was "barometer." Barometer. That's it. All that work for "barometer." If you say that word on the phone or in an e-mail, know that the NSA's ECHELON program will be watching you forevermore.
Listen to it here:
The National Museum of American History collects, preserves and displays American heritage in the areas of social, political, cultural, scientific and military history. To learn more about the museum, visit http://americanhistory.si.edu. For Smithsonian information, the public may call (202) 633-1000, (202) 633-5285 (TTY).
1. If you believe the government's story of the atom bomb not being invented until 1945, you probably also believe that it wasn't Islamic terrorists who brought down the Twin Towers.
These items are an archive of past Topical Smorgasbord items that have appeared on the RF Cafe homepage. In keeping with the "cafe" genre, these tidbits of information are truly a smorgasbord of topics. They all pertain to topics that are related to the general engineering and science theme of RF Cafe. Note: There is also a huge collection of my 'Factoids' (aka 'Kirt's Cogitations') that might interest you as well.
Posted December 15, 2011