Its going Metaphysical!
In my experience everything in the universe can be broken down into two groups: is it a pie or a cake? "How can I tell?" you may ask. Well the answer is very simple. It comes down to the consistancies of the masses through the object. If it is roughly the same consistancy all the way through then it is a Cake. If there are varying level of toughness through the object then it is a Pie. Both Pies and Cakes can have smaller objects inside them that add texture (apple chunks and cherries) these aren't considered and can be ignored if the total space in the object if far greater that of the smaller texture granting object.
Examples: The UNIVERSE = Cake (filled with lots of little things but roughly the same density all the way through)
Humans = Pie (No matter where you go through there are multiple densities)