What Does a Lotus Root Teach Us About Topology, Humans, and Nezha?

The film Nezha 2 begins by reshaping Nezha’s body using a lotus root, prompting the question why not use mud, sand, or metal. The resulting Nezha looks smooth and supple.

One reason a lotus root can reshape a body is its biological property – the root’s fibers remain connected when cut, giving it extraordinary toughness.

Beyond the analogy, the lotus root resembles the human body in its “topological structure”.

In simple terms, a human can be seen as a seven‑hole “lotus”. The seven main openings are:

The digestive tract from mouth to rectum, forming one continuous passage.

The tear ducts, two in total, one for each eye.

The two nostrils.

Note that “blind holes” such as ear canals or the navel are not counted because they do not fully traverse the body.

Topology studies properties that remain unchanged under continuous deformation, especially the number of holes and connectivity.

Homeomorphism in Topology

Two objects are homeomorphic if one can be continuously deformed into the other without tearing or gluing. For example, a donut and a coffee cup are homeomorphic because each has a single hole.

The bowls, cups, and plates shown below are all homeomorphic.

Now we trace the topological transformation from the seven‑hole lotus to Nezha’s body:

First, the seven‑hole lotus:

Then, a seven‑hole donut:

Further three‑dimensional shaping:

Perspective view:

Through topological deformation we obtain:

Another important topological transformation follows:

Approaching a human‑like shape:

Expanding the “tube walls”:

Overall view:

Finally:

Even though Nezha’s body looks very different from a lotus root, they share the same number of holes and connectivity; continuous stretching and compression can transform one into the other without tearing or gluing.

Euler’s contributions to topology are foundational; his work on Eulerian paths and circuits underpins our understanding of shape deformation and connectivity.

For readers interested in topology, the popular science book “Euler’s Gem” is recommended.

Reference video: How many holes does a human have? – Vsauce, November 1 2017, YouTube.