I've long wondered if it would be possible to hear the speech of ancient peoples by scanning sequential imperfections in crystal formations of fire-side stones as they cooled down and solidified (for the last time before the people moved on), assuming that ambient sound waves would be strong enough to create detectable shifts in the molecular positions and assuming that the formation would otherwise be precisely linear.

It probably sounds like a crazy idea on first inspection, but I think there's something in this.

So, are the crystals that are formed as stone cools down always in a precise formation regardless, or could their positions (on the picometre scale) be shifted slightly off linear by external vibrations and then stay that way?

As heat leaves the stone, I assume there's an imaginary line travelling inwards marking the point where the crystalline structure goes from malleable to fixed. If this line takes 10 minutes to traverse a 100mm stone (I think for the US that would be a rock), and assuming a crystal size of 500pm (0.5nm), you'd have an effective sampling frequency of over 300kHz, if the technology could be developed to measure the positions of crystals.

I hope there's an answer to this other than "you're mad!"

  • 1
    $\begingroup$ No! You are not mad. It's an interesting question. Many scientific advances have origins in interesting questions that some initially thought were "strange" or "unconventional". Then again, many "strange" & "unconventional" ideas never lead to anything. The important thing is to have ideas & then investigate them. As to your question, I don't know. Irrespective of the outcome, keep thinking! $\endgroup$
    – Fred
    Commented Jan 30, 2022 at 23:23
  • $\begingroup$ Thanks, @Fred. There's no upvote button next to your comment, otherwise I'd click it. :) $\endgroup$
    – Spiritman
    Commented Jan 31, 2022 at 0:09
  • $\begingroup$ there is an upvote arrow beside the comments,it is there to bring the best comments to the top. $\endgroup$
    – trond hansen
    Commented Jan 31, 2022 at 4:53
  • $\begingroup$ @trondhansen I'm afraid there isn't. There's only a flag. Maybe it's a privilege I don't have yet. If someone upvotes my question I might get enough points to unlock it. 🤷‍♂️ $\endgroup$
    – Spiritman
    Commented Feb 1, 2022 at 0:47
  • $\begingroup$ @Spritman I recall someone speculating whether ancient Greek plaster walls contained the voices of the plasterers. The recording process would be rather like that of a phonograph with the plasterer's trowel acting both to gather the voice and to impress it into the wet plaster. I'm guessing the SNR is really really bad and much much worse than that for thermal recording of audio into rocks - but interesting question! $\endgroup$
    – Roger Wood
    Commented Feb 1, 2022 at 2:07

1 Answer 1


Yes, it would work. Though, you would have to have really precise instruments to measure that. You would also have to filter out the other things that might have caused imperfections in the crystal. Currently, this is far beyond our technological capabilities.


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