In 2010, Tokyo engineers used Slime Mold - a brainless fungus - to build an efficient transportation network. Why? Let’s find out.

What is Slime Mold:

Slime Mold is a brainless fungus with the ability to learn, remember, and find the most efficient path to food by spreading over a surface like a web. It’s a single cell with multiple nuclei growing without dividing.

Each strand travels outward “feeling” it’s environment for food. When it connects to food, the path reinforces itself by sending nutrients through the branch. Other paths get reabsorbed and sent in different directions. Most strands expand outwards to centimeter lengths, but others cover square meters. It optimizes for eating.

Tokyo’s Transportation Problem:

After many natural disasters, Tokyo’s transportation needed to be robust, efficient, and adaptable. They couldn’t develop a mathematical model to determine a specific solution, so they turned to nature.

By overlaying the Slime Mold over a map of Tokyo and using oat flakes to represent cities, the mold solved Tokyo's transportation problem within 26 hours. The design resembled Tokyo’s existing tunnel network and provided areas for improvement.

An Oxford professor Mark Fricker suggests using slime mold for creating networks that need to change over time, such as short-range wireless systems of sensors that would provide early warnings of fire or flood. At a deeper level, the slime mold optimizes path finding each day. We deal with path finding called The Traveling Salesman Problem.

The Traveling Salesman Problem

The Traveling Salesman problem that goes like this:

• Given a list of cities and the distances between each pair of cities, what is the shortest possible route that visits each city exactly once and returns to the starting city.

We use supercomputers to optimize the distance yet it’s slow and inefficient. Computer scientists call this an intractable problem- a problem with no efficient algorithm, yet a brainless, single-celled fungus solves it each day.

Other Applications:

After the experiments in Tokyo, other professions began studying the fungus and trying to understand its abilities and methods. Other professions began using its efficient path-finding ability in their work such as the following:

• Robotics & electronics

• Urban planning

• Self-Driving Cars

• Efficient short-range wireless systems of sensors

• Biology: How blood vessels grow to support tumors

Each of these fields are better off with the knowledge of Slime Mold efficiently solving problems than if they weren't. The TED Talk below covers more examples of Slime Mold used in different fields.