I have never read about the peculiarities of dirt, its unsual dynamics, the mysterious physics associated with dirt, or the conservation of dirt matter, but after 15 years of planting and digging holes in dirt for all sorts of reasons I have discovered there are some weird qualities of dirt that do not fit the normal parameters of the physical universe as I understand them (which really isn't saying much).
Hasn't anyone dug a large hole in the ground and then later tried to fill it with the dirt one just dug out the hole? A scientific approach to this situation would have one naturally hypothesize that either one would have enough dirt to fill the hole to the level it was at before, or, more likely, have excess dirt thanks to the additional air and the natural process of entropy that would keep all the dirt from filling the hole as neatly and compactly as it was its condition before it was dug out. Yet that is not what one finds (at least in my experience). No matter how carefully one keeps track of the dirt one takes out of a hole in the ground, there is never enough dirt left to fill the hole even back to the level it was to begin with... where did the extra dirt go? I have dug thousands of holes over the last 15 years and often filled them with plants, including all the soil the plants came with... and then backfilled the rest of the hole with whatever dirt was still around... and even then I sometimes came up short. Does dug dirt enter some wormhole and end up at the opposite end of the universe somewhere? If so, there is enough dirt there just from the holes I have dug, to cover a two story building. Perhaps this dug dirt changes its chemical composition somehow and does one of those things that one doesn't intuitively expect (like to have water get bigger as it freezes into a solid structure... I would think it would get smaller... though I now completely understand this physical phenomenon. But what about dirt?). Does it run off while you're not looking (I sometimes look carefully and never see any go anywhere)?
You would think after having planted over a thousand plants on my dinky property that the soil levels would have risen significantly from all the imported dirt I have dragged in with these new plants over the years. I have even had multiple truck loads of dirt shipped in to fill planter boxes... yet all that dirt has continued to sink ever since. And who knows how many bags of potting soil and top dressing I have dragged home from the local garden outlet stores over the years- countless! At the current rate of dirt shrinkage in my yard I will be back to a flat piece of land in just another few years. Had I not brought all these plants in and planted them and had 2 huge truckloads of dirt shipped in, not to mention the hundreds of bags of potting soil I have purchased and spread about, I figure our house and yard would be sitting in a hole about 6' deep as we surely must be sinking gradually towards the center of the earth. Yet the yard next to ours, in which no holes have been dug, is still the same level it was 5 years ago.
I have never taken a class in soil science and perhaps the answer is discussed there. But no one seems to mention this bizarre phenomenon in the nursery trade- perhaps due to the embarrassment of not being able to explain it all? Maybe it's the worms- they are eating the dirt, digesting it, and turning it into some gaseous product that sails off into the upper atmosphere (greenhouse gases?). Is it a more complex reaction of dirt mixing with water and just making mud? That still wouldn't explain the missing-dirt-from-a-freshly-dug-hole phenomenon, though.
I will never look at dirt the same again. It sort of scares me now to dig holes as I assume I am upsetting some delicate balance in the universe, and that is why all the ‘extra' dirt is whisked away surreptitiously into some other dimension. Perhaps I will find it after I die. Just be sure when I do die, you bring extra dirt to fill the hole they put me in!