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Original question on worldbuilding.stackexchange by Daron
Fran is on holidays to planet Earth. She is having difficulty coping with the local geometry.
At this second Fran is thirsty. She can see a lemonade stand nearby. She knows a human would have no difficulty getting there. But sheâs worried of making a fool of herself or getting lost on the way. You see the lemonade stand is neither in front of or behind her. The lemonade stand is in one of the other directions.
According to the guidebook, humans have a bizarre extra-sensory direction-seeking power. Their cities are built with this power in mind, and that makes them very tricky for people like Fran to navigate.
Well, sheâll look more a fool just standing around like this. Fran takes the first step...
Drat! Whereâs the lemonade stand gone? Fran canât see it any more.
She looks around. Oh, itâs behind me!
Fran turns around and makes her way to the stand.
Phew! That wasnât quite so bad after all.
Fran is no longer thirsty. But sheâs dreading having to make it back to the hotel before nightfall....
Fran, and every member of her species, evolved with no ability to tell left from right. Suppose she was facing North. She can easily find and move towards things to the North or South. She can tell is something is East-West of her. But she cannot tell which is which. Likewise she cannot tell the difference between North-East and North-West.
Franâs holiday was fascinating but exhausting. She cannot fathom how Humans carry around so much extra information upstairs without going mad! Sheâs glad to be back in her home city.
Question: What does Franâs home city look like? In particular how are streets and corridors laid out to avoid people getting lost? How are roads laid out to prevent collisions?
Some Details: Fran is typical of her species. She has the following attributes:
Maybe every member of the species is the same size with the same number of arms and legs. Maybe there is huge variation between individuals. Feel free to modify the species as suits your answer. For example do you think there would be a difference if they has two left-right arms rather than the two arms being arranged one on top of another? Or would a species make sense to have only one big eye rather than pairs?
More Info: Some humans have a similar condition where they are unable to distinguish left and right. One countermeasure they take is to remember âleftâ as the side their wedding ring is on, and use that to navigate. Fran cannot by her nature use such a trick. She would certainly be aware that one side of her body has a ring. But since she cannot tell which side is which, it wouldnât help her judge which side to turn towards. If she tried she would just as likely end up facing the wrong way.
Fran is a naturally subterranean boring worm-like creature. Her cilia enable her to move forward and rotate.
On her homeworld, the tunnels are bored with ridges or grooves that serve as affordances for forward locomotion, allowing her species to progress along the intended direction of the tunnel (forward) more easily (and conversely, making it more difficult to walk backwards).
Fran walking forward along the floor ridges
Because the species finds linear forward motion comfortable, their settlements, structures, and rooms are arranged in intersecting rings. Wherever two rings intersect, the being can either choose to continue moving forward along their current ring, or turn off into the adjoining ring. They donât need to decide whether to turn left or right (or up or down, as the case may be) to enter the adjoining ring, since their tunnels all have a natural "forward" direction determined by the ridges in the floors/walls.
Cross-tunnel tracks at the junction of two rings might serve as natural indicators of which way to go if the being wants to switch rings. This keeps the decision to a binary (keep going or change rings) instead of a potentially confusing choice between the left tunnel and right tunnel or forward. (Hat tip to @Yakk for exploring this idea in the comments!)
The ring-tunnels can be quite broad to accommodate multiple beings concurrently moving together, but should not be so large as to be confusing. Long, wide rings might serve as rooms for storage, recreation, and labor, activities which may at times require the beings to rotate or turn around as they undertake their tasks, but the important consideration here is that they **always** can tell whether they are facing forward or backward based on the design of the tunnel. **Forward and backward are the only two cardinal directions**. This limited directional sense could be further exacerbated by minimizing the effects of gravity on Franâs homeworld, so even up and down become less relevant.
Extensive three-dimensional intersecting networks of rings compose the underground cities and streets of Franâs people. A human moving along such a network would be utterly confused by the homogeneity of each intersection and the overall structureâs inability to conform to a rectangular coordinate system, but Franâs species has both an extremely good kinesthetic sense of forward progress and a knack for remembering the relationships and spacing between rings, allowing them to recall which rings intersect with each other, which entrances belong to which rings, and where they are at a given moment within the ring network.
Ring network diagram of a settlement
Note that Fran and her fellows donât need an accurate mental map of the networkâs layout *in physical space* to navigate the network; they instead need an accurate mental map of the connections between rings, which would look more like a tree structure or hierarchy diagram than a traditional map.
Physical 2D map vs network hierarchy diagram
(I hope you like my MS Paint doodles)
As a final thought on this concept, since a troglodytic lifestyle doesnât necessarily lend itself to the evolution of great eyesight, Franâs species might have a dependency on olfactory markers for subterranean navigation, much like the pheromonal signaling used by ants or the territorial musk/urine marking employed by some mammals. The relative absence or overabundance of scents in an open-air city would add an extra level of navigational confusion for poor Fran.
I suggest rings.
As I understand, you want a solution that does not depend on the anatomy of the creature. Although I am taking some assumptions that I hope you find reasonable:
The intelligence is the hardest part. I can assume that they can recognize symbols, so they can read numbers, so they can have street numbers... but if they can recognize symbols, they may put symbols for left and right and navigate using that. Therefore, I am ruling out systemic abstract symbols. Yet, I am allowing them to recognize their peers and common objects.
Note: There will amounts of items that the creatures will be able to distinguish at a glance (for example you know that âAAAâ are three âAâ, you do not have to count them â did I just trigger you to ask how to develop a society where people cannot count?). Yet, as I said, I am being conservative on my assumption about the intelligence of these creatures.
First prototype: Have a big tower in the center of town and build rings around. In each ring, it does not matter if you have to go left or right because you can always walk any direction and still pass each house in the ring.
The problem with this solution is that it requires street numbers. The creature would look at the tower from an intersection (a connection between rings), there would be number signs and the creature would decide if it has to go to an inner ring (going forward) or an outer ring (going backward) based on the numbers.
As I said, if you can do that, you can have signs for left and right.
Therefore, we conclude that a single ring is ok, but multiple concentric rings probably not.
Second prototype: Create separate rings, each with a central tower. In the tower, you can place symbolsâ». This time you do not have to know what symbol comes first or second.
â» Perhaps just use colors. Alternatively, Make rings dedicated to certain things, for example, a ring for restaurants can have a symbol for restaurants. As long as we do not use any symbols that have an inherent ordering that the people need to know which come first. Otherwise you are telling these creature canât tell objects apparts, Iâm not going there.
What you need to do is this: First to look at the tower of the ring you are. If you are on the right ring, walk around it, in any direction, until you find the destination. If you arenât, go to the tower, from the tower you can see the other towers, find the one you need, and walk in that direction.
The above would require the tower to have an elevated (but not necesarily at the top), freely accessible from any direction, open area, from where you can see above the houses in the ring.
After you have seen the tower you need, you walk in that direction. To prevent the creatures to lose their sense of direction, the access points to the center area would need to be abundant. Or even better, design the houses so that you can walk over them.
Perhaps on your way there, you lose sight of the tower; in that case, you will end up in a different ring. Repeat the process until you get there.
Another problem is how to arrange the rings in space so that they do not block the view of other rings...
Nature has already solved this problem. It is similar to the problem of how to arrange leaves in such way that they minimize the light they block to the leaves below. More generally how to distribute items in such way that they do not eclipse resources to other items. The solution is the spiral pattern we see in sunflowers:
Pattern of dots in a sunflower behind a spoiler wall to mitigate eye stress.
Observe that in the pattern, from any given spot, the center of the other spot do not align perfectly. It is not a uniform tessellation. Instead they arrange spiral arms. Thus, if you imagine each spot as a ring, with a tower at the center, that tower will not eclipse the view of the other towers (well, unless the tower is too wide, there will be a maximum width given the spacing of the rings).
How about the rationality of object persistence? She doesnât have to know left from right; she knows the lemonade stand exists and will continue to exist if it is out of her sight. Infants know this within a few months. Thus: Turn. Left or right, randomly chosen, does not matter. If the lemonade stand is no longer visible; rationality tells you it is behind you; and that is a direction you know. Turn around. If the lemonade stand is still visible, approach until this procedure must be repeated.
Franâs City
Off hand, the easiest way to lay out a city is with one-way spiraling streets and one-way radial arms (freeways are side-by-side one-way paths; my city is roughly laid out this way: circles around, about 3 bisecting highways in different directions). Idealized, the species doesnât have to choose left or right, it is chosen for them as the only way to go.
So for example; where the inward spiral turns in, you can only go straight or turn: You happen to be turning LEFT and merging with traffic on the RIGHT, but you donât have to know you are making a left turn, it is the only turn, and you donât have to know you are merging right, there is no other choice. When you exit you choose to turn again: You donât have to realize it is a RIGHT exit, you have no other choice for an exit: follow the turn path, or do not follow it. That is how you make it to an inner ring.
I am presuming, of course, that evolutionarily speaking, no species develops that can literally walk only forward or backward; and this situation is more similar to some form of dyslexia; like not being able to tell lowercase âbâ from âdâ. But dyslexics do not have trouble when there is no choice or the images are symmetrical: âAâ, âOâ, âXâ, etc. So I think the trick may be to eliminate choices that depend on knowing your left from your right.
Turn towards the thing you want. If you donât see it, keep turning, youâll see it eventually.
Now, itâs in front of you. No problem. Walk forward.
A species like this would constantly be orienting itself towards the things it wants. There would be constant spinning. Perhaps even an evolutionary tendency towards pirouetting in place, until they see what they want to get.
So what would the streets look like on her planet? They would look like a circle rather than an axis.
Constant guides, like arrows, would let them know what direction to go in. They can find anything on a street, they just have to keep going around. To get to the next street, you keep going around until you see the entrance to the next street, from one circle to the next. There might be straightways from one to the next, and there might be some things on it, but they would be clearly marked.
I would think that there would be special orienting places where the spinning was allowed in order to chose a forward direction, which would be like turning.
Landmarks will be a big deal. Directions would sound like this: Go to Jasper Circle. Spin towards the clock tower. In front of the clock tower spin until you see the side sign for the grocers. Once you can no longer see the grocers spin until you can see the red street. Follow that until Market Circle. Use the go around there to find the Lemonade Stand. Once you see the sign directly in front of you, spin until you see it.
There will be no choice between left and right, the species is just forced to go a specific direction.
How does this evolve? Well, nature has to be laid out this way. There has to be an evolutionary pressure that makes omnidirectional choices a bad, bad idea, and always facing front a good idea.
EDIT: You said we should be free to redesign your species, so instead of the whole body spinning in place, why not just the head? (ignoring spinal difficulties with this, of course) They spin the head all the way towards what they want, then orient the body and go in that direction.
Fran doesnât have any sense of direction and canât distinguish right from left or north from east etc.. To compensate that she however has developed a perfect sense of height. She always knows at which altitude she is.
Their city is built in a spiral that goes from ground floor on the outside the top in the middle. So that the city looks like the tower of babel.
Whereever she is in the city she always knows at which height she is and to which height she wants to go to. So she turns to go up the spiral or down the spiral. And if she turned the wrong way she always knows that she only has to turn around to go back down/up.
Every answer I see here violate, in some manner, the question being asked. Fran is stated as not being able to tell East from West as well as Left from Right. That is, if Fran is pointed East she is unable to distinguish this from being pointed West (other than what is directly in front or behind, due to some concept of âvisionâ).
Ergo I think I know what Fran is.
She is a being that has precisely two light-sensing patches on her: one fore, one aft.
These vision patches are not capable of distinguishing objects. Theyâre closer to being a laser range finder. She can tell the color, distance, and material of an object in front of her and behind her. But she cannot distinguish anything else. A red dixie cup would be indistinguishable from any other piece of red plastic.
Furthermore these two vision patches cannot move independently. They are inextricably linked in a form of hard structural rigidity with both each other and her locomotive system. Additionally her locomotive system has no concept of âno, turn the other way.â Turning is turning. There is no, âI see it, I see it, I see it, now I donât, go backâ order that she can give to her locomotive system in order to reverse direction.
Which means... she can only turn in one direction. So not only can she not tell which direction sheâs rotating in she has no control over it in order to turn around. She only has three commands as it were for movement: forward, backward, and turn. [1]
At this point Iâve decided that thereâs no way this species would survive to sentience. Even a snail can tell that nope, that way is bad, turn the other way.
Fran would have to be completely cylindrical (symmetrical around the up-down axis, the other two are irrelevant), for if she were not, she would get stuck up against a rock or a tree, unable to turn away from it, and then starve to death (or get eaten, or...) and rapidly go extinct.
I have no idea what a city built by her people would even look like. Simple things like hinges would boggle their minds, because hinges would have to bend in a non-uniform way. We also have to do away with gears because those rotate non-uniformly when meshing with each other. At this point you have to basically discount every possible piece of technology above the stone age.
Fran does not live in a city. Sheâs a barely cognizant animal living on a vast rolling plane of grass with no carnivorous animals (or her species reproduces too quickly for it to matter). Sheâs basically blind, deaf, canât move quickly (or at all), and almost certainly either an herbivore or a composter (i.e. feeds off rotting organic matter).[2]
[1] Even this violates the uniformity of movement: turning while moving forward and turning while moving backwards are not mirrors of each other. That is, if an object moves forward 1 unit and rotates local-left 1 unit and repeats this pattern, it will move in a counter-clockwise circle. If it moves backwards 1 unit and rotates left 1 unit, it will move in a counter-clockwise circle. This is important because it does not retrace the path, ergo moving forward and turning and moving backward and turning get you to different places and imply a directionality difference of left and right!
There are only two ways to fix this:
Lets assume #2.
[2] Dear god, sheâs a pre-Uplift Traeki.
Update 5-29-17
As some folks have expressed derision over whether or not mirrored vision is able to sense direction, I built a quick application to test that theory. The compiled executable is not very stable, but if you wish to try it out for yourself, you can find it here (Windows executable, you assume the risks of running arbitrary internet code yourself).
Draco18sâ demonstration of Fran vision
In mirror vision you can navigate although identifying which direction is objectively left may not be possible, but it can be distinguished from objective right and a creature with this sort of vision would have no trouble tracking down a lemonade stand.
You can watch me navigate the simple maze in this video
and aside from some orientation and forgetfulness over which key I need to press next (i.e. moving backwards instead of forwards), you can easily identify when I turn the wrong way briefly before correcting to turn the correct way. There are a few places were I made a decision based on knowing the actual layout of the maze (not having to investigate dead ends) but I think that it is sufficient proof that navigation under this mode of vision is possible and that leftness and rightness can be understood as distinct, even if not readily identifiable (that is, if the world were flipped left to right and the controls were flipped left to right, I would be unable to tell).
That is, given this perfectly centered view,
it is impossible to tell if the branch path is to the left or to the right. But by rotating
you can see that in one case the branch is farther away from center and in the other, itâs closer. And closer to center is "forward" and if thatâs the direction you want to go, then having it be forward is desirable, ergo the two rotations are distinct and can be labeled as such.
On the other hand this is just meaningless and contains no directional information at all
(standard view of the same scene at the same point in space and time).
Not understanding left and right is different from not seeing left and right. We can infer from the OP text that she can, indeed, see the lemonade stand on her left. So her vision is not just one color and she can distinguish objects. Also, she cannot have eyes in the back of her head: When she turns the wrong way, she cannot see the Lemonade stand behind her. So fixed eyes in front, period. We have humans that can see perfectly but not comprehend, e.g The Man That Mistook His Wife For a Hat. So she sees left and right but mentally cannot tag objects as âleftâ or ârightâ. âAmadeus
She can see things to her left and she can see things to her right. She just cannot tell which is which. âDaron
@Daron I know that youâre trying to say that, but what Iâm saying is that its a fundamentally unsound premise. Let me phrase it a different way, as a question: if Fran looks at a swinging pendulum (so that its movement is to her left and right), can she tell that it is moving back and forth? I.e. that at one point in time it is on one side and that at another point in time it is on another side? If yes, she can infer leftness from rightness. If not, then she cannot have complex vision. âDraco18s no longer trusts SE
Imagine a pendulum that starts high up on the right. It sweeps down to its lowest point then miraculously and instantly changes direction while maintaining speed. It sweeps back up to its starting point and hovers there for a moment before descending again. It repeats forever. A human would find this strange but Fran would experience an identical sensation to that from a normal pendulum. âDaron
@Amadeus Having no evolutionary pressure to distinguish between left and right would imply a complete lack of any sort of danger in any form. "Donât go that way, youâll fall off the cliff" comes to mind. As well as a lack for a need to hunt (food source is plentiful all the time and generally found in all directions). Both of these things are the sorts of pressures that evolved the complex eye. By removing directionality from the list of concepts this creature understands, youâre altering something so fundamental that the end result is incompatible with the question. âDraco18s no longer trusts SE
Fran is of a rather pitiful species that has been under a lot of specialized evolutionary pressure by an apex predator. In response, her species has developed the gift of 360° vision and total awareness that we humans can only understand, if proficient in artificial neural networks:
See, there are perceptive neural networks that can tell you everything thatâs in a picture but not its location. Place a banana on your car, take a picture, feed the picture to such a neural network and it will instantly tell you âbananaâ and âcarâ are in the picture. It canât however determine where these items are. The fast processing comes at the cost of information about location, both of which are inherent features of the neural networkâs design.
This may seem confusing to humans:
Child play books that let you search for stuff in a picture are plain boring for Fran. One look and she knows everything thatâs in the picture like she had a mental list. However this ability helps in triggering the flight reflex early enough for Franâs species to evade the apex predator of her home planet. It is very much like the eyesight of flies with their faceted eyes. When Fran checked for the lemonade stand, she closed all her eyes (in contrast to a fly she is able to do that) in rapid succession and noticed itâs location, when for a short moment it vanished from her mental list of things that are around her. So she can only check for direction, if she is willingly losing sight of what sheâs searching for. At the same time she feels like something isnât there, which she should know to be there on a whole different level than humans do. This position check is a voluntarily triggered action that employs multiple uncontrolled reflexes: One for each eye.
From all the above the design of a city is obvious:
Narrow and zigzagging passageways that only allow for few things to be seen at any given time. These passageways donât need to be underground, but ceilings help limiting the view to above.
If youâre walking along a passageway (which you navigate by touch of your antennae) and something pops up on your mental list, it will simply be further along the passage. That is, if itâs not another traveler, who may be going faster than you, catching up from behind. It is therefore common courtesy to recite all that you see upon meeting someone. By the way, thatâs a lot more helpful, than stating the already obvious time of the day like humans do, when saying âgood morningâ. It tells you not only, if the other one is coming from front (because he tells you something new) or behind (because he tells you thing that just vanished from sight) but also at least one of you will learn whatâs up ahead.
Franâs species are a communal burrowing species, but more importantly theyâre solar navigators which is why she has to be back at the hotel by nightfall or sheâd be completely lost. Their two key directions are âtowards the lightâ and âaway from the lightâ *.
Their cities are built along a straight line with a large artificial light at one end. Individual âbuildingsâ are burrows dug straight down from the main route. Passing another person on the street is done by the one going away from the light going over the top of the one going towards the light. Overtaking someone moving more slowly is done much the same way, personal space is not a thing.
Prior to their becoming a technological species they were mostly active in the cool of sunset and sunrise and remained in their burrows during the heat of the day and dark of the night, the cities were orientated East (sunrise) to West (sunset).
Her Earth hotel is specially adapted for her species, having a large light at the top to aid navigation and burrows at ground level for accommodation.
[*] These directions translate generally to âtowardsâ and âawayâ, for example, âtowards the foodâ and âaway from the predatorâ.
Great answers so far.
Iâd propose cities with a simple hierarchical layout, where all cities are build on the following principles:
For an addressing system, they use a simple hierarchical reference, starting at the origin point for the city, and then numbering every road that must be taken to arrive to the destination. For example:
City maps would appear to have a leaf-like structure:
The question seems to boil down to finding a realistic one-dimensional environment for animals still embodied in a fundamentally three-dimensional universe. I think itâs impossible for an animal to evolve to have no conception of all three dimensions while living in the same universe as Earth. Thereâs just too much of an evolutionary advantage to fuller navigation. But I think Thriggleâs is the best approach to imagining how an animal might be biased to 1D motion. The structure of the underground city wouldnât have to be rings in particularâjust a network of 1D pipes. One justification for this might be that tunneling forward or backward is easy, but left and right or up and down (all in the animalâs local reference frame) is hard or impossible.
This is analogous to how we surface-dwelling creatures tend to think in terms of 2D maps. Navigating up and down is less common for us, but very far from impossible. I imagine (but have no proof) that animals who donât jump or meaningfully climb (like beetles or turtles) feel this bias more strongly. But they still need to be aware of of predators (or prey?) who are more mobile!
One side effect of this might be an even greater tendency to sort things along a single axis, ignoring multiple dimensions of variation. There is evidence that we tend to employ a 2D conceptual grid for more than just navigation. I bet their politics would be even less nuanced than ours, which sounds frightening.
At the same time, optimization in multiple dimensions (of which the unicellular chemotaxic food-finding alluded to by John is one example) can be sped up considerably by dimension reduction. This is why algorithms like Newtonâs method or gradient descent work. If the choices at hand truly do come from a one-dimensional submanifold of the ambient 2+ dimensional space, then it makes sense to treat left/right (and up/down) as equivalent. But, in the adversarial setting of evolution, as soon as you make this optimization and sacrifice distinguishing power in the transverse directions (e.g., small krill to eat are at the oceanâs surface; protection from surface predators is down), some other creature will take advantage of your disability and outcompete you (just go around the stupid up-down whale).
But you never did say the creature had to evolve this way naturally. This question reminded me of the company QBotixâto save money on solar panel rotation motors, they make a robot that travels along a linear track, rotating each solar panel in an array individually. It only needs to deal with motion along a single axis, simplifying the problems of navigation and control considerably. Maybe Fran is a designed "organism" and the original design spec (say, autonomously navigating a Dyson ring for maintenance) had no requirement for freer movement.
