This is kind of silly... this is really a problem with the human obsession with creating taxonomies and classifications of natural phenomena, when natural pheno

This is kind of silly... this is really a problem with the human obsession with creating taxonomies and classifications of natural phenomena, when natural phenomena are basically collections of atoms that have very fuzzy boundaries. Clustering algorithms are, in general, very subjective, and it's no surprise that our scientific efforts to "cluster" everything often produce counter-intuitive or undesirable results at certain boundary cases. It's the same problem with biological taxonomies - is a lungfish a fish or an amphibian? The reality is it doesn't matter apart from the artificial taxonomy we impose on it so that our brains can better cope with the complexity of the Universe. Perhaps a better (but more annoying) way of classifying everything would be to use hierarchically clustered taxonomies for everything, so that we could make statements like "Earth is considered a planet if we cut the dendrogram at level 5, but a dwarf planet if we cut at level 4, etc".