The throughput and containment of the object is the criteria for classification here.
Can the object passing through the hole be contained by the medium of the object that is subject to the "hole" classification? If yes, then the object has two holes, one which the passing object passes through to enter the object, and one which is passed through to exit the object.
If the object passing through the object being classified cannot be contained entirely within the classification object medium, then the classification object has one hole.
This kind of classification relies upon the context of the item's usage, and is in fact a "contextually dependent" classification!
Take the straw for example:
When a straw is being used for drinking bubble tea, the straw has two holes when a boba is passing through. The straw has two holes for each ice crystal or clump of crystals that passes through.
Does the straw have two holes for a liquid? Good question! This is also a contextually dependent classification criteria, though this time it is a matter of reference frame! Do you consider a liqiud to be a macro expression of the fluid dynamics of the molecules comprising the medium? Then it is a whole, though I would suggest that the "whole" of the liquid in the container from which it is being drawn to be one "whole" and the liquid which is drawn into the straw during the vacuum action (from the initiation of the "pull" through to its conclusion) to be a new and unique "part" separated from the source volume and comprises a new "whole".
Ok, so NOW if the newly separated volume of liquid being drawn into the straw is less than the total volume of the straw, the straw has two holes (one hole being drawn upon, and one hole into which the newly created liquid volume is being drawn into.
Are you very thirsty? Have you drawn more liquid through the straw than the volume of the straw itself? You could then say the straw only had one hole for the duration of that pull!
On the other hand, if you are defining each molecule within the liquid medium to be its own object, then the straw always has two holes.
I don't personally subscribe to the notion that a straw is a single hole, since, in the abstract, my gut reaction is to define a hole as an absence of something, rather than a property of something else. Tools used to make holes (a shovel, an auger, a 3 hole punch, a gravitational singularity, etc.) all remove a part of the initial object, rather than "adding an absence" (ground media, paper circles, or the physical constants of dimensional spacetime, respectively).
Now that I'm thinking about it though, a straw is constructed by extrusion. The straw media is forced through a mold which defines the initial hole (the initially extruded straw media, which, as side note, is almost certainly trimmed to be cleanly cut to present as clean and uniform tip) and then subsequently, each straw would be severed at standard intervals to make the straw object. While considering this, I feel like it provides even more support for the "two hole argument" as each end of each straw must be independently and intentionally "formed" during the process of manufacturing.
Thoughts?
