I’m of the view that this is a semantic question where we have a word, “pile”, that describes a general amount but doesn’t have a specified quantity to it, and so the only way we can determine the amount of units required to constitute a pile at the bare minimum, is through public consensus on the most commonly shared idea we generally have when we think of a pile.
I also think it’s possible for there to be a “range of graduation” between a non-pile and a pile, so for example “a non-pile becomes a pile somewhere between x grains and x grains” (depending on what most people think this range is), and if a given number of grains falls below this range, it would necessarily be only a minority of people that would still accept it to be a pile.
So I plan to count the answers here and see if we can come to some kind of consensus or at least most common or average opinion. For sake of not skewing the results, I won’t suggest my opinion on what I think the number or range of grains is upon which a non-pile becomes a pile. What do you think it is?
I don’t think there is a specific number of grains where something becomes a pile. The state of being a pile is determined by qualities that are correlated but not strictly proportional to the number of grains.
In this way, two sets of sand grains could have the same number of grains, but not both be considered a “pile”, depending on their arrangement etc. Similarly, you could take a pile of sand grains and make it no longer a pile by changing its configuration (while keeping the grain count constant).
You could still ask what the minimum number of grains would be for something to ever be considered a pile. This is only measurable empirically, and is subjective.