The video linked below is located on YouTube.
A webpage duplicate of the video follows for those who would rather read than watch a video.
What is the basis of the Single Cylinder View of the Human body?
Some of the behaviors of the human body can be modeled by a single cylinder. That is a real world observable behavior that cannot be denied. Those undeniable observations are enough to justify the existence of the Single Cylinder View of the Human Body.
It seems reasonable that there must be some reason that some of the behaviors of the human body can be modeled by a single cylinder. Yes the human body can act like a single cylinder, but why?
Here is a comparison picture between a human being and a single cylinder
Aside from some general similarities such as a similar height and width, a human being looks nothing like a single cylinder. A single cylinder is a smooth featureless circular object. A human being changes shape constantly throughout it’s height, width and depth.
If a human being and a single cylinder looks nothing at all alike, why can some of the behaviors of the human body be modeled by a single cylinder?
The answer to that question can be provided by the human skeleton. Here is a front view of a human skeleton.
Here is a profile view of the human skeleton.
The rear view of the human skeleton.
And here is a comparison picture between the human skeleton and the single cylinder.
The skeleton does not look anymore like a single cylinder than the human body did. The single cylinder is a smooth featureless circular object while the skeleton changes shape and is constructed of many different single objects.
How can the human skeleton be used to show why some of the behaviors of the human body can be modeled by a single cylinder?
This picture shows the top view of the skeleton. The arms and the head have both been removed.
Some of the bones have been changed to a white color. These are the collar bones. The collar bones naturally form an elliptical or generally circular shape.
In the next picture, the single cylinder has been reduced in diameter until it will fit within the ellipse formed by the collar bones to show the similarity between the natural ellipse formed by the collarbones and the single cylinder of the Single Cylinder View of the Human Body.
This picture shows the same overhead view including the arms. The arms have been positioned to hold a circular shape in front of the body.
There is a natural circle formed by the rear collar bones and the extended arms. In the next picture, the single cylinder has been enlarged and repositioned so that it fits within the rear collar bones and the extended arms.
At this point it has been shown there is a natural circular space within the collarbones that generally match the single cylinder view of the body, and there is a natural circular space formed by the rear collar bones and the extended arms that generally matches the single cylinder view of the body.
Both of these circles are in the same vertical plane. That means that they are both at the approximately at the level of the shoulders. A circle that lays on one vertical plane is only a circle. A cylinder is a circle that exists in three dimensions. There needs to be a vertical component to the circles shown in the previous pictures to complete the comparison to the Single Cylinder View of the Human Body.
Here is an overhead view of only the bones of the ribcage.
The bones of the rib cage form a natural elliptical shape like the bones of the collarbone do. The next picture shows the ribcage with a cylinder located in the center.
The comparison is beginning to take shape in the picture below. This is a 3/4 view that shows the single cylinder within the ribcage.
The circle at the top of the red object can be seen and the red object has a vertical component. The red object is definitely a cylinder, and it fits within the space naturally created by the rib cage bones of the human body.
The human body experiences extremely strong forces during daily use. The rib cage and collar bones are a relatively small portion of the vertical height of the entire human body. It is difficult to accept that a cylinder such as the one shown above, encompassing only the rib cage and collar bones, could be responsible for the human body behaving like a single cylinder.
There is another reason that the explanation feels incomplete if the reader patiently considers what has been shown.
A human being walks on two legs. The majority of the movement of the human body during the day involves the legs. That would mean that a majority of the physical forces traveling through the human body would travel through the legs.
Yet the single cylinder in the example only encloses the rib cage and collar bones. Does it seem reasonable that the cylinder in the rib cage and collar bone area could influence the legs to behave like a single cylinder?
For this example, the answer will be no. The single cylinder in the rib cage and collarbone area is not influencing the legs.
Here is an overhead view of the lower part of the human skeleton.
The bones that are at the foreground are the pelvic bones. There is a circular shape within the pelvic bones that is not immediately obvious from this particular picture.
The next picture is a 3/4 view of the lower part of the skeleton and the single cylinder.
The cylinder is running through a natural circle within the pelvic bones. The cylinder located within this natural circle in the pelvis is almost exactly centered on the vertical center of the human body.
Here is a closeup of the hips bones with the single cylinder in the natural circular area in the pelvis.
Using this picture it is possible to compare the curve of the single cylinder to the curves of the surrounding bone of the pelvis. This makes it easier to visualize the circular shape formed by the pelvis bones.
The next picture shows the lower skeleton, the rib change and the hip bones with the single cylinder that is centered within the circular area of the pelvis.
The viewing angle, the skeleton and the cylinder are in exactly the same location as they were in the previous picture. The single cylinder, when located within the natural circular area of the pelvic, is naturally centered within the circular rib cage and the circular collarbones.
The picture below is the same as the one above except the cylinder has been shortened so it only includes the rib cage and the pelvis.
This picture provides much of the justification for the Single Cylinder View of the human body. The only difference between the picture above and the Single Cylinder View of the human body is the size of the cylinder.
There is a cylinder on both the human body and the skeleton. That cylinder is centered on the vertical center of the human body. The diameter of the cylinders on the skeleton and the human body make no difference to the comparison. Whatever the diameter of the cylinders, they will be cylinders and will behave according to the laws of physics for cylinders.