I first read about this in a Straight Dope-like column in a German paper: There could be sounds of days long gone recorded on ancient pottery, the rumor goes.
When the potter decorates his piece of art by engraving patterns with a needle into the wet clay on the wheel, surrounding sounds might cause the needle to vibrate, encoding the sound waves into the grooves. It basically becomes an Edisonian cylindric record, and you could “play”, say, what a Roman potter said to his wive two thousand years ago!
The column debunked this as a hoax, and since it mentions reports about allegedly successful playings of ancient vases circulating prior to WWII already, it certainly is. But would it at least theoretically work? I know that other effects, such as the potter’s trembling hand or the process of burning the clay afterwards will most likely outweigh the sound’s effect on the grooves. But microscopy combined with digital remastering and whatnot could probably filter out those effects (audio experts forgive me, total layman speaking here).
Related question: Why was sound recording invented so lately? The Greeks knew that sound is produced by vibrations, and causes other things to vibrate, so I think the leap to a primitive yet functionable record apparatus wouldn’t have been that hard.
That reminds me of an x-files episode. They found this thing called the lazarus bowl that supposedly had the power to reanimate the dead. The story goes that when Jesus raised Lazarus from the dead, there was a potter nearby who was in the process of making a bowl and who recorded the words that Jesus spoke in the bowl. They “played” the grooves in the bowl and a linguist was astonished that the words were in Aramaic, a dead language. And the bowl did actually raise the dead. But that was the X-files, and as for it actually being able to happen, I have no idea.
Last December, I saw a display at the Fleet Science Center in San Diego that had such a ‘recording’ rigged up. A clay pot turned, and a needle laying across it was purported to detect sounds being played back. I don’t know that it on the up and up, or wasn’t somehow enhanced.
It sounds very improbable to me. The vibrations in sound are miniscule and not likely to be actually recorded with any accuracy even assuming the clay kept a perfect form all these years. I doubt you could have even gotten a good recording you could play back back when it was made let alone years and years later after the surface has worn down.
The problem is not “the potter’s trembling hand”, it’s the opposite: that the potter’s hand is holding the stylus too steadily. In an all-acoustic recording, the recording stylus must be attached to something that is vibrating freely with the sound. Unless the potter’s hand weighs a few ounces, and has virtually no muscle strength to counter ambient vibrations, forget it.
Another problem is that compared to a fluid medium like wax, clay is extremely irregular in texture. The signal-to-noise ratio would be impossible to deal with.
The principles of what you propose are solid–vibrations from sound could be recorded in clay and then played back later. Unfortunately, the practical problems would overwhelm the task. As others have said, most clay would be too course to record anything much more than noise. You might get it to work with really loud noises like screaming.
Like Flash said…solid principle, but it wasn’t until 1857 that the phonautograph got it’s patent.
A phonautograph was a device for converting sound into visible traces. Usually this was accomplished by rigging up a needle or brush hair to a membrane and allowing the needle or hair to scratch smoked glass as the membrane vibrated.
http://www.150.si.edu/chap9/9horn.htm
The closest thing I’ve heard to this would be the Dropa Stones. However, it seems that most of the information about them is very questionable at best.
http://www.violations.dabsol.co.uk/weird/weirdpart3.htm
(Info is on the middle of the page. Starts beside the pic of the large, platter shaped rock with a hole in the middle on the right side of the page.)
So, I have my doubts…
Here’s the last thread that addressed this topic.
And, although I also mentioned it in that thread, I’ve just gotta point out that this would be cool to build and play with, even if you didn’t have any ancient pottery or old paintings at hand.
Here’s an interesting question: Can we posit ANY natural processes which might have recorded sound? Are there any good candidates for ‘prospecting for sound’? Perhaps even very loud sounds, like explosions?