Having recently been to Mammoth Cave National Park, I've been considering the caves of my own worlds, and more specifically their formation. Now while not all caves are formed from limestone, it is the most common cave material, given that water seems to so readily dissolve it. The groundwater drills into the limestone--or other stone depending on the cave system--going where water does by taking the path of least resistance, or in other words, dissolving the less dense stone first, eventually forming what we recognize as caves after the water table recedes enough for the cave network to become more readily accessible. For a more visual representation, see this short, interactive simulation.
With that in mind, I would like to be able to simulate the formation of the cave networks in my own worlds, but I don't have massive slabs of limestone on hand nor the time it takes to see how water will form caves within them, which is why I'm looking for a small-scale solution preferably meeting the following requirements:
- Either digital or physical is fine, but physical simulations should have components that are easy enough to obtain
- Simulation should produce three-dimensional results or a representation of three-dimensional space
- The resulting model should be something one could easily split apart without disrupting the final results to look inside and see the final formations
- Simulation should have some way to allow for the density of the simulated limestone to be controlled to allow for more variety in cave formations
- The volume of the model should be able to be changed to allow for a wider area of effect on both the depth of the system and length of the tunnels overall
- Whether models represent stalactite/stalagmite formations is not real important overall, but models that do provide that type of insight are obviously appreciated.