The human body is an extremely complex structure with many passages and exits. But how many holes does each person have? Portal livescience.com found it in the question uses mathematics and topology.
Before counting, we need to clarify the definition – that is, what can be considered a “loss” in general. For example, mathematicians understand holes and holes as single entities—for example, the hole in a donut. A hole goes through the entire object and ends on the other side.
But if you dig a “hole” on the beach, chances are you're not trying to dig a tunnel to the other side of the planet. Many people believe that a hole is just a depression in a solid object, but mathematics says that a hole is not a hole if it has an end point. In the same way, topologists only consider holes through holes as holes: for example, underground tunnels.
However, this logic also has nuances. If you ask someone how many holes there are in a regular straw, you might get a variety of answers: one, two, or even zero. And it's all because there are so many ways to explain the concept of a hole.
To put an end to the question once and for all, it is necessary to turn once again to the field of topology. From the topologist's point of view, the shape of objects is not so important – this science is more concerned with the basic properties of these shapes and how objects are connected in space. Following the logic of topology, objects can be grouped according to the number of holes they possess. There is no difference between golf balls, baseballs, and frisbees based on this criterion. Their shape can be changed regardless of the material without changing the number of holes.
That said, the objects above are fundamentally different from a pretzel, a donut, or a basketball hoop—because they have a hole in the middle. Likewise, the shape of an 8 with two holes is not the same as a pretzel with three holes; they are considered different topological objects.
Perhaps people sometimes say that a straw has two holes because of its shape – it is long and thin, and the holes are relatively far apart. But to a topologist, bagels, basketball hoops, and doughnuts are the functional equivalent of a tube with a hole.
Now, armed with the topological definition of hole/hole, we can return to the problem of the human body. The first step is to count all the clear segments. Mouth, urethra, anus, nostrils, ears; in women – milk ducts in the nipples and vagina.
But there are four more, not so obvious holes that everyone has in the corners of their eyes – four lacrimal holes, through which tears flow into the sinuses. And if you zoom in, you can classify skin pores as inconspicuous. This adds up to millions of potential “vulnerabilities”… But can they be considered vulnerabilities?
There is another way to look at the question. Think about it, is it possible to thread a very thin thread through all these holes? If you take a thread with a thickness of 60 microns (60 millionths of a meter), then yes, perhaps such a thread can penetrate. But the important thing is that it cannot get through because blood vessel cells will block its path. That is, the pores function more like pits.
This way of thinking allows you to immediately eliminate all pores, milk ducts and urethra. The same goes for the ear canals – they are separated by the eardrum. Technically, the mouth, anus, and nostrils form the through holes, but tear ducts must also be added to them.
And for women there is another nuance, because the vagina leads to the uterus, which then leads to the fallopian tubes. They open at the distal end and lead into the abdominal cavity next to the ovary, and in medicine there are cases where eggs released by the ovary on one side are captured by the tube on the other side. Thus, a hypothetical thin wire could pass all the way through a woman's reproductive tract.
