Schist Disc is very cool. Firstly, the fact that it’s a stone piece is super important, because so many observe the many stone vases and imagine some kind of tricky lathe work with mysterious diamond bit tools and then plod around the concept of the implied tool strength necessary to carve out the insides. But the Schist disc kills that idea mostly because of the impossible thin outer ring, and forces the inevitable conclusion of yet another example of ‘stone softening technology’. A leap to many, but such fine and delicate stone work like this completely destroys any modern day tool tech approaches and forces this idea that I see so much at least circumstantial evidence of around the world. But I digress..
The main focus of this thread is about its purpose, so I’d love to address what’s been discussed first.
I’m not into the fully submerged water analysis so much. Its interesting for sure, but looking at the flap shapes, there’s a concavity on the upper outer surface of the flaps, (on the actual disc, but not as much on the model), that would create a low pressure point and turbulence on the outside of those flaps that seems to me to be an effect that would only create flow dynamic inefficiency if it were intended to spin submerged. It seems the most important surface is inside the flap folds rather than the outside because of this, just as a hunch based conclusion.
I’m also in agreement with Audry that because of its fragile vulnerability, I have to assume it wouldn’t fair well with the pressure of water flow and the possibility of particulates and debris.
Scott’s idea of it being a particulate divider or essentially a fancy sprinkler head works in form alone, but again the material strength kills that idea.
Cladkings theory is cool, but I can’t help imagining a far less complicated vessel shape to achieve that function, (oil lamp worker indicator light), so it feels unnecessary to me.
Jon’s catch of the radius match of the inner flap tangent circle and the outer flap arcs was very cool. And from observations like that, I begin to imagine it being a cog in a complex machine, but the fact that its shape is less precise and more organic in form when you get up close and personal in the small measurements, makes that idea dissolve a bit.
Just on initial observation, the center cylinder screams ‘axis’ to me. If not a central point around which it spins, it might as well be that other stone pentagon plate linked further down the string, (which I see as more of an artistic piece much like the vases). But as Jon mentioned, I can’t see the intention of that spin being a high velocity. Too much unintended vibration from the imperfections.
So from my assumptions, if it spins, and the key surface areas are the inside of the flaps, then it certainly does seem to be something that is intended to disburse something that is directed into it. But if I widen the scope of possibilities into wave forms like light, sound, electricity, etc. then I suspect it wouldn’t be necessary for it to spin.
The angular momentum and friction would be key elements to a spinning Schist disc if it were interacting with physical materials like water or air, but wave forms would impact in instantaneous moments fast enough that a slow spinning disc would have no additional distribution effects, so the whole spinning thing falls apart.
I had fancy ideas of the disc spinning at a perfect speed with a stationary wagon wheel effect and then directed waves of some cymatic shape to match it is directed into this ‘sprinkler head’ of sound, turning it into the axis of a sonic circular saw, but I just don’t buy it.
It could very well be the head attachment of a low flowing decorative pond fountain that makes a pretty spiral dome shaped water effect. Who knows. The only thing I think I can presume is regardless of the interesting form, I believe it was made of stone because they had cool tech to manipulate stone density and they did it as easily as if it were made of clay, just because they could. If it were more precise, I might dwell a bit longer, but that slight organic imperfection kind of demystifies it for me.