Slime Mold, Tube Map and Urban Design

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We can't deny that we look at nature for inspiration, whether for science, engineering, or architecture. Biomimetic and biophilic principles imitate natural systems or integrate nature into the systems we design, whether for functionality or aesthetics. By doing so, we can create systems or spaces that have optimal functions and natural aesthetics. It is similar to how we design cities. We take into account nature in our plans. We work around it or find ways we can incorporate it into our designs. One vital feature of a city or town is well-defined roads the connect certain places within or to another city.

That is why I find it genius when Tube maps conceived. The tube map is not a literal map but a simplified representation of underground trails that first emerged in London. Back in the day, many attempted to create a simple map for the interconnecting railways in the city that we know where to take our ride. Several maps presented to be the solution but seemingly don't fit well. Most looks like an intertwine spaghetti, and it confuses the public more. People then needed a simple visual that points out the way at a glance. Where can we go? How to get there? It is more important than how well the map represents.

It was Harry Beck who gives as the Tube maps, a 29-year-old draftsman. It simple and contained only horizontal, vertical, and 45 degrees with different colors for different routes or trails and foregoes the traditional printing of distance in the map. Technically, it was not the map they used to have. He provided what they want. A map pointing them to the station from the station, and even with one eye close, they can perceive where they will go. But it was not one-time magic; it has flaws. We continually developed the map until it is what we saw today.

London Underground map - London tube diagram 1938

The map became the fundamental representation of a city or a town, and it what makes us perceive how well-designed it is. Beck's map inspired a generation of artists, designers, and even network theorists. It became the blueprint of what think of metro maps will look like in London, Tokyo, New York, or even Manila. The design of tube maps reflects focus and simplicity, but it reflects not close to how we planned roads and trails in our cities, especially in the Philippines. The urban design should have focus and simplicity. Focus more on functionality and not on the controversy and self-fish agenda.

The image of the city is not the chaotic and unplanned streets and alleys, but not all. The image must that we dream of speaks streamline but functional. When cities boom and expands, it is hard to plan out city routes while maintaining heritage and aesthetics without compromising functionality. Hence our world becomes interconnected not just within humanity but with nature itself; we can borrow a concept that will enable us to have sleek but functional layouts of trains and roads in cities.

I had read countless biomimetics and meta-heuristics papers that computational intelligence adapted. I ran into a particular concept that seems peculiar but seemingly ingenious, slime molds. Physarum polycephalum, in layman's term slime mold, has an intelligent behavior that it avoids retracing its path. The slime has spatial memory that enables it to navigate and design networks despite not having a brain. It can detect the areas it passed through. It learns and adapts to its environment and remembers what it learned through it. Does it seem science fiction, right? But it is not.


What peculiar with slime mold is they establish the shortest route and the most efficient with one aim in mind, to search and reach the food source. Quite clever, right? Slime mold is a single-cell primitive intelligence that is fictitious but real. Another thing about slime is it reacts to the trails left by others. One research maps the Tokyo subway system using slime molds. They placed oats align to the Tokyo subway routes, and in awe, slime successfully modeled the subway routes. Others tried the experiment with the slime mold and oats to map China, Canada, and Belgium. They even find which transportation network seems off and not optimal for the US and Africa. Maybe, this can solve the traffic woes in the Philippines and cut down our losses due to it.

Slime is a very crafty and intelligent organism. The slime's spatial memory is outstanding in that it can maps cities and even solve puzzles despite being primitive. It solved problems that architects, engineers, and urban planners faced in planning for the optimal routes in cities and towns. The slime took only hours to map what we design for decades. Also, it gives us a better outlook on how to optimize the design of routes in the cities we live.


Slime mold can form optimize network and can solve the traveling salesman problem with ease. The traveling salesman problem is a challenge in finding the shorted yet efficient routes to traverse a list of destinations. We can observe the slime to help us solve several of our real-world spatial problems like routing roads, railways, and pipelines. Slime can be a supercell that aids us in dynamic modeling. Urban designers can play with simulated models of a slime mold to find answers to road crashes and flooding mitigation. As mentioned earlier, slime retracts when it reached earlier so that it doesn't override. We reflect on it and have the traffic contingencies for our city plan.

Slime mold is the tube map of our contemporary society. The tube map signaled the rise of better mapping in urban spaces before, and slime molds now give us a better understanding of how we design routes and streams despite the topography constraints in cities and towns. It can map the most efficient path that accounts for all points optimally despite any restrictions. Several cities used slime to mapped an optimum network that includes Silk Road and global trade routes. Biomimetics is not new to us, and it always proves to us that it can do the work with optimality. If we want new city routes in our cities, we may sign a contract with the slimes.

Readings on Slime Modelling

  1. Robert H. Austin, A slime mold’s remembrance of things past, Proceedings of the National Academy of Sciences in the United State

  2. David Parr, Cities in motion: how slime mould can redraw our rail and road maps, The Guardian

  3. American Association for the Advancement of Science, Slime design mimics Tokyo's rail system: Efficient methods of a slime mold could inform human engineers, Science Daily

Photo (Video) Credit and Footnotes
(arranged in the same order of photo in the text)

  1. London Underground map in 1938 created by Harry Beck, which is a first Tube map. | Photo Credit: Mikeyashworth

  2. In the experiment, the slime mold spread from the first food source and invaded the remaining food sources. It eventually resolved into a network of tubes joining the food sources, similar to the Tokyo train system. | Photo Credit: Live Science

  3. When the researchers deposit food at cities on the map, the fungus works with them, spreading out to map many different configurations before withering away to highlight the shortest pathways between cities and the most efficient overall system map. | Video Credit: Harvard Magazine

  4. A slime mold mapped network, developed by Toshiyuki Nakagaki. | Photo Credit: Tim Tim

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