When you learn about massively cool things, like how researchers are now able to play a voice recorded in 1860. (Link leads to the StraightDope Message Board thread.)
Think about that: You can now hear a voice that was recorded in 1860. (Link leads to the project page where you can here an MP3 recording of a woman singing "Au Clair de la Lune" in French.) That's 17 years before the first play-backable recording made by Edison, although in Edison's case, "Mary Had a Little Lamb" got the honor of being recorded.
I mean, 1860 is the year Abraham Lincoln was elected president, and the year South Carolina got the U.S. Civil War ball rolling by seceding from the the Union (the U.S. Civil War itself hasn't even started yet). In Italy, Garibaldi is leading the troops in the Unification of Italy (or fighting the Second Italian War of Independence, whichever name you prefer). It's also the year that the first-ever in the world nursing school was founded in St. Thomas Infirmary in England.
The "phonautograph," which was invented by Frenchman Edouard-Leon Scott de Martinville, recorded his "Au Clair de la Lune" singer using a stylus that moved across a sheet of paper blackened by the smoke of an oil lamp. However — and this is the key — it was never designed to be played back once it was recorded. The general idea was to capture a physical representation of the soundwaves and then study the paper. To still give Edison his due, he was thinking "play back" with his phonograph, which resulted in people hearing for the first time mechanically reproduced sounds.
Until recently, "playing" the phonautograph "recordings" was impossible. But thanks to the march of computer and audio technology, not to mention an international team of researchers, you can now hear what Scott recorded. For reals.
If I were a poetic sort, I'd almost say that into smoke a singer's voice was recorded, and from smoke it was returned.
Or better yet, as one of the researchers put it, "It's like hearing a ghost."
To hear a 3:44 minute report on this fantastic find from National Public Radio's All Things Considered, and to hear "the ghost" herself, go here. (Warning: Audio Recording.)
To hear a 2:43 minute report from BBC News, including the ghostly recording, go here. (Warning: Audio recording.)
For additional information:
The New York Times has a detailed article on how Scott's recording was converted to sound using technology.
The FirstSounds.ORG Website, which is dedicated to detailing the process of converting all of Scott's recordings to sound can be found here.