8th Lecture — Abstract

Perceptual Realisation of Space

Movement – a Criterion

Let’s try to find out how humans orient themselves in space. Given that we evaluate space primarily in terms of distances (sizes), we need to discover which properties of “distance” we use in simple examples. If we proceed by referring only to these properties and “zero” to the nature of the elements we are working with, the findings will automatically apply to any given space and any “distance” that has certain key properties. This means that the system should be based primarily on the elements of space.

 

Let’s ask ourselves two questions

1

How does the (apparent) relationship between a pair of wall sections or a pair of bodies and a human vary?

2

How is the change in this ratio, which is in any way perceptible to a human being in the course of movement, characteristic of movement along a particular path?

In the simplest terms, movement along a path consists of moving towards goals. These are important landscape features and points of attention that are approached, passed, or represent the final stop along the way. They are used to measure progress and to set expectations (Figure 1).

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Fig. 1: Moving along a path consists of moving towards the goals. These are important landscape features and points of interest that we approach, pass by or represent our final stop along the way. They are used to measure progress and set expectations.

While we are directly approaching our goals, we are also orienting ourselves in the environment by discovering important phenomena and our own position in relation to them. This is partly a practical, partly aesthetic activity.

The sense of movement consists of the movement of ourselves, the apparent movement of our surroundings and the shape of the space through which we move. All these factors are intertwined. The sense of movement is given by what we see; apparent movement is based on external objects (Figure 2). We interpret movement itself as moving according to the shape of the surrounding space. We interpret the apparent motion of surrounding objects, which we know are really at rest, as our own motion. We feel space as a continuous spatial image (sequence).

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Fig. 2: What we see gives us a sense of movement; apparent movement is based on external objects. We interpret the movement itself as moving according to the shape of the surrounding space. 

We interpret the visual field not only as a series of distant views or a collection of objects in motion, but also as a space, a void through which we can move physically or just by looking.

The basic experience of space in motion is of boundedness and the scale of boundedness. This experience can be modified in many ways: by changing the shape of the space and its proportions, by the character of the peripheral elements or objects in the space, by the position of the observer… The observer can be low down, high up… The space can be narrow or wide, its boundaries can be clear or less clear. The view may be forward or sideways.

Formal parameters of movement through space

The term motion is used to denote change and movement of any kind. It can be the physical movement of a person through space, or just the apparent movement of surrounding objects, while in reality it is the part of the environment that one is observing at a given moment that is changing, as Appleyard sensibly distinguishes in his book. One could even say that movement is changing (changing) the environment in a certain way.

When we speak of motion as such, we distinguish two forms:

Topological motion

is movement/movement (mobilis). We necessarily speak of speed in connection with it. Topological motion is the external, physical, quantitative aspect of motion in space.

Structural motion

is movement/change (motus). In connection with it we necessarily also speak of variability of organisation (degradation). Structural movement is the internal, qualitative aspect of movement in space. The two forms of movement are interrelated, although they appear to be completely separate and independent.

The two forms of movement are interlinked.
In terms of human movement through space, there are three forms:

Last movement

human movement through space practically means overcoming distance and (continuously) changing one’s own standing position, thus also moving the coordinate origin. It happens in real space.

We interpret the apparent motion of surrounding objects, which we know are really at rest, as our own motion. It looks as if the surroundings are moving relative to a coordinate origin that is fixed. It happens in perceptual space.

Movement due to changing direction of gaze

is practically apparent motion, except that here the coordinate origin is really at rest.

These three types of motion are not clearly distinguished from each other. For example, we always experience apparent motion alongside our own motion.

While we judge the motion of ourselves by the apparent motion of surrounding objects, this motion is also a pleasure in itself. As we move forward, the objects in front of us and to the side break into two groups and slide sideways past us or turn around. The apparent movement becomes particularly interesting when we look at objects in groups. Landscape highlights may move relative to the background or foreground, they may be caught in a moving frame… The whole field of view may appear generally calmer as close objects move in front of a more distant background. If the surrounding objects are far away, few in number, or seem unimportant, we have the sensation of floating or hovering, similar to riding in an aeroplane (Figure 1). Conversely, if the surrounding objects are close and if there are many accents in the environment, we can get a feeling of high speed even when we are actually travelling very slowly. Occasionally, when we make a sharp turn (Fig. 3) or when the field of view is overcrowded (Fig. 4), we can get a sense of great dynamism because the pace of change of the surroundings increases greatly: rotation, rush or growth. The most static of all is the view of objects that are in the direction of the path but at the same time too far away to be able to grow at a reasonable rate as you approach.

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Fig. 3:
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Fig. 4: When we make a sharp turn or when the field of view is pinched, we can get a sense of great dynamism because the rate of change of the surroundings increases greatly. 

Two thirds of all the things and events we perceive are right in front of us. The other third is still in front rather than to the side perpendicular to the direction of motion.

Defining the factors by which we judge motion

Object

Humans detect motion by noting changes in the relationships between objects and themselves. It judges the speed of its own motion by how quickly the changes occur. We are talking about a change in perceived size (scale), a change in shape and a change in the distance of the person to the object.

In the chapter Elements of Space we have established that we perceive the specific features of space only through objects, and that in our case it is reasonable to consider as space only the formations that follow directly from the relations between objects. Since we also detect movement in space through the surrounding objects (i.e., through the bodies that define space), we will define space, as we did before, by the signs of the bodies.

One judges one’s own movement by the elements that constitute space. The factors of the quality of the object and the speed together determine the singularity (peculiarity) of the movement through a given space. Therefore, I can conclude that the experience of movement depends on the quality of the objects along the way.

Elements of a path

Any part of a path in a given space is characterised by some change. Once evaluated, its value can be determined with respect to the change in the link (lane) relationships. This value expresses the specificity of a given path segment in space. It is easy to say that the value depends on the observed spatial elements of the path segment.

We have already established earlier that man values space in relation to himself. In particular, the rate at which the magnitude of the distance between him and a pair of cuttings changes is important, which could be called the intensity of the movement. By analogy, we can conclude that the characteristics of the change in man’s relationship to the perimeter of space are already determined by the path (by the placement of objects along the path). So the change in intensity is a function of the “change” in the quality of the object.

Evaluation of movement

First, we will process the factors determining the change in the quality of an object, describe and define them. We will describe factors that are geometric in nature, such as scale, distance and shape. These will be followed by factors that affect the change in the perception of the surroundings, together with speed. Finally, we will describe the meaning factor. The values of the first three will be defined in terms of qualities, and the values of the others in terms of additional values.

Movement quality factors

Measure

One of the most powerful visual experiences is the relationship between the observer and the wider surroundings, the feeling one has when “measuring” empty space. This parameter corresponds in its main features to the size parameter in the Elements of Space chapter.

As we move, the relationship (scale) of the human being to the elements of the objects seemingly changes, and we speak of a change (increment or deceleration) in quality.

Distance

There is an optimal viewing distance depending on the amount of detail desired. The optimal distance in a theatre determines the price of individual tickets. In a film, we see a dramatic story by the small distance between the actor and the camera. Depending on what we want to say, we choose between close-ups and long focal lengths. The same applies to the design of a road space, where “everything” depends on the distance from the road. In particular, we pay attention to close objects, which seem to move faster, rather than more distant objects, which seem static (Figure 5).

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Fig. 5: We are particularly attentive to nearby objects that seem to be moving faster than to more distant objects that seem static.

As we move, the distance between humans and the elements of objects changes. Therefore, we speak of a change (increment or deceleration) in quality which is inversely equal to the change in distance.

This parameter also represents the distance travelled by a human being.

Direction of movement

A journey can be made in any direction (it is reversible). It is like watching a movie the same way if you played it forwards or backwards. Therefore, in a traffic environment, we cannot practically talk about front and back in an absolute sense, but only in a relative sense to the current orientation of the person.

Mathematically speaking, direction indicates a quality. In fact, if the sign is +, we are moving closer to the object, and conversely, we are moving away from it when the sign is -.

Moreover, it is not necessary to always go the whole way. We can also start and exit at intermediate points. Therefore, the spatial picture must be discontinuous.

Angle (shape – position)

We interpret motion itself as moving according to the shape of the surrounding space. When we see an object at the same angle all the time, we conclude that we are moving in a straight line. But when that angle changes, we conclude that we are moving around.
If we were to agree in which direction we measure the angle , we could also talk about direction here; in which direction one moves around the object.

Speed

Experience varies with the speed of movement. Moving at a certain speed can be a way of establishing a new relationship with the environment. An opening may be clearly legible at high speed while it is shapeless at slow speed, or the same opening may appear small at high speed while it is appropriately large at low speed.

As speed increases, the field of view narrows. Nearer objects “pass” us more quickly and the view stops on slightly calmer (more distant) objects.

Speed can neutralise the mismatch between a person and their surroundings. The opposite experience happens when our car breaks down on the motorway and we have to keep walking. Then the scale is completely lost. So speed affects the perception of the scale in such a way that the result of the perception is not the same as the result of the measurement.

Rhythm

Tempo and rhythm are the core of any spatial image. The tempo of attention, it seems, is an indicator of the quality of the path. Where the tempo is fast, we are more focused on the path itself, and where it is slow, we have time to look left and right and to pay attention to more distant objects. The former is an experience of haste, forced attention and tension, the latter of slow “floating”.

Colour – lighting, texture, optical tightness (transparency)

A spatial image is created by many elements. We pay most attention to the path itself; to the colour and texture of the ground surface itself, to the shape and rhythm of the objects at the very edge of the path. The ground and the sky fill most of the field of vision. The details that are close to us along the path are also very important: the texture of the surfaces, the rhythms and the change in the surface of the ground. All of these increase the sense of speed of movement in relation to proximity or distance and frequency. The quality of the light directly determines the intensity of seeing colour, texture, movements, contours, etc. Looking towards the sun emphasises the silhouettes and is quite different from the sun shining from the side; then textures and details become visible. Artificial light can be used to direct attention, to change the apparent shape of a space. Light alone can be used to create spatial images. At night, otherwise important landscape accents and events can disappear, giving the whole a look of soothing unity. Or even a whole new world of light can be created.

These effects are captured by the surface quality factors of the building element. They further influence the perception of speed by affecting the optical change in the size of the surface, or by their alternation creating a rhythm.

Colour and texture affect the perception of velocity through the optical change in size and distance. Optical tightness (transparency), on the other hand, affects the perception of velocity through the change in the size of space.

Meaning

It is also necessary to consider those environmental set states that cannot be expressed by the visible surroundings alone. They are, however, recalled by our general ability to complete each partial perception or cognition into a whole when we recall the missing ones from memory.

Finally, the traveller wants to find meanings of the things he sees; he wants to connect the objects he sees with the knowledge and meanings in his mind. Tourists see their surroundings with fresh eyes and do not overly associate them with personal feelings and meanings because they are preoccupied with orientation. The everyday traveller, on the other hand, is not so attentive to the wider environment (landscape) because he is already familiar with it. His or her gaze only takes in the narrow angle straight ahead and is focused mainly on the events on the route itself.

If there are many objects in the surroundings that we recognise as important, the perceived speed is greater. It could be said that the perceived speed depends on the “density” of meanings in the environment.

If we apply all these factors, the main creative problem of path design is the design of the individual spatial images themselves. The main thing is to keep continuity within the developing, contrasting material. The path itself is quite a guarantee of continuity, but it must be supported by a sequence of spaces, movements, orientations and meanings that must appear as parts of a coherent whole.

There seems to be an optimal order of magnitude for the time interval between possible impressions, because long intervals lead to boredom and short intervals to tension and confusion. So the path must have a basic pulse, a real frequency.

If we were to join similar rhythms of attention and an optimal order of magnitude to similar paths, the traveller would know when to expect something. Expectation or non-expectation is compositionally (creatively) one of the key factors. Expectation is order (anticipation), security; but also boredom and monotony. Conversely, unexpectedness is disorder, surprise, confusion; but also interest and excitement.

The result of movement – the journey

Movement in space practically means overcoming distance (it can only be apparent) and moving “from one spatial picture to another”. In doing so, one travels a distance equal to the change in distance between the person and the object.

The sensation of moving through space is made up of individual spatial images, like a sequence of slides. When they are arranged in sequence, we get some idea of our overall movement.

A person knows the overall value (feeling) of the space that has been imposed on him humanly, according to his personality and the circumstances of his movement in space. But each place of space is special. It is a reciprocal correlation of the changing action of several definitions (orientations) to one and the same standpoint. That is why, when we speak of stands, we always think only of spatial – specific stands. Each such standpoint is also the point where a person is located at a given moment in time.

The value (character) of our path is therefore the result of the specificity of parts of space. In order to get the relationships between the values of the individual valuations of the spatial parts, let us imagine a room full of people. Given the different individual reactions, we obtain simultaneously the impressions that an individual would get gradually when visiting all these different places.

The description of the route recorded by the navigator in the diary consists of the position at a given moment. Such a description gives only an approximation of the route, since the movement between the entries is not described. If we wanted to be precise, we would have to describe the movement at each moment. Such an accurate diary would have a record of the position of the person in the terrain for each moment in time during which the movement took place. This would be a perfect mapping of the time interval into a set of points on the surface over which the man moved.

We are only able to detect a limited number of spatial images in a given time (at a given speed). This means that we need time dt to perceive one spatial image. For example, we know that a human is able to perceive 18 colour stimuli per second. However, experiments could be carried out to find out what time it takes to perceive a normal spatial image in its entirety.

Since we are always dealing with distance, let us also try here to find out what distance, or rather the length of a journey, a human being has travelled. The navigator calculates the distance between pairs of individual points, and adds these distances together at the end. The denser the points, the better the calculation of the path length (“the distance between the starting and ending points of the path”). This means in practice, since we never move in a perfectly straight line, that the distance of a pair of points is always less than the actual path length between them.

Man interprets his own motion mainly by the apparent motion of the surroundings, i.e. by the apparent motion of the elements of the objects df. We have already said that the path s is equal to the change in the distance between man and object ld. So, instead of the points of our path (the track) itself, we could take reference points in the form of the elements of the objects. Thus, we would equate the length of our path with the “distance” travelled between the objects. This is, practically speaking, also the distance we want to cover. Movement (traffic) originates from the objects and ultimately flows to (into) the objects.

Orientation in space

Space begins in front of the body (the human being). Although we are aware of the space behind us, having previously evaluated and remembered it, it only affects us mentally at any given moment. If we want to change these two values in terms of one and the same basic direction, we have to turn the body 180°.

Knowing the peculiarities of the human definition of space is crucial both in the objective definition of space and in the corresponding compensations in the corrections of space.

First, we divide the space into parts; initially, we do not yet take height into account. Divide the space into foreground and background and left and right sides. Projecting these two divisions over each other gives a floor plan of the room which has already been evaluated. Valued because the foreground, background and left and right sides are real values. In addition, we also distinguish in the space the centre between the foreground and the background and the centre between the left and right sides. Thus, we have also introduced mean values. These mean values alone give (for now) the plan (median) cross. But when we introduce a measure (scale), we get a kind of Cartesian coordinate system. At this point I would like to draw attention to two special cases of floor plans: the longitudinal and the transversal floor plan. In the first case, the centre between the front and the back is missing, and in the second case, the centre between the left and right sides is missing. Therefore, in these two cases, we speak of ‘one-dimensional’ spaces.

In order to orientate ourselves in the room, we have laid a grid across the floor plan, separating the front from the back and the left from the right. And when we introduced a centre, we got a central cross. Practically speaking, however, space is defined only by man when he determines the directions in space: man projects a spatial raster into space, starting from his own standpoint. Here it is necessary to distinguish between the absolute (general) definition of space and the human (actual) definition in space. For example: when looking at a car from the rear, the rear is in the foreground and the front is in the background. In terms of the general definition, the front is always the front.

Usually, enclosures are important indicators (evaluations) of the objective size of the front-rear and left-right space. We have already said that the individual evaluates space according to the impression of distances. Linearly, we can distinguish four different sensations of distance. What we call the sense of space is the resultant of individual impressions guided by the reawakened traces of memory. Two of the four main forms of distance evaluation are pleasant and two are unpleasant. Enclosure and freedom of movement are pleasant, cramped and lost are unpleasant. If we potentiate enclosure, we arrive at a negative value, cramped, and if we exceed freedom of movement, we arrive at a negative value, lostness in space. We cannot give absolute values in the form of numbers because too many different factors (for example, climate) influence these impressions of value.

However, since space has height, we can add a fifth value, namely inaccessibility with the upper limbs.

Three basic directions in space

In both enclosed and open spaces, there are three basic directions: front-centre-back, left-centre-right and bottom-head-height-top.

Front-centre-centre-back

This is the main direction of progression. It is the most important for feeling and appreciating the distance at all. The distance between a person and the front wall is referred to as the critical spatial distance. In the animal world, forward movement is considered to be advancing and backward movement is considered to be retreating. “What moves reaches as much space as it leaves (loses)” (Leonardo da Vinci). When we occupy space, our gaze falls first on the rear. Even the eye, which is not yet adapted, is “set” at a distance.

We put our feet in the foreground, the foreground is often a bridge into space. From here we have an overview. In the foreground we decide whether to move forward or to turn around, while the background is passively closing or lost in the distance in the unseen. With this direction we often also think of the flow of time; for forward movement is also movement into the future. For some, such as Oswald Spengler, this is also the only true dimension of space.

Mid-left – centre – right

The sensory and visual functions are complementary in perception. The eyes look forward while the feet and hands are in direct contact with the surrounding surfaces. Left and right directions have different meanings depending on whether one is right- or left-handed, or what cultural environment one lives in. For example, a right-handed person, turning to the left, closes and withdraws, seeking protection, while a right-handed person, turning to the right, opens and acts. On the left he seeks cover because he is less agile on the left, while on the right he wants to be open so that he has enough space to act.

Diameter below – head height – above

Humans orient themselves in a bottom-up direction from eye level to floor and ceiling. Because of their upright posture, the distance from bottom to top is very important to them. It depends on the position of the body: lying, kneeling, squatting, sitting and standing change the distance between the floor and the head on the one hand, and the distance between the head and the ceiling on the other.

Shape of the room

The shape of a room depends on the size and position of the walls. If we extend the space in one direction only, we get typical spatial phenomena. If we extend it only in the foreground-middleground-background direction, we get the corridor phenomenon. If, on the other hand, it is extended in the direction left-hand side – centre – right-hand side, we get the phenomenon of a grandstand. When it is extended in the direction bottom – head height – top, we get the appearance of a shaft. In nature, we would speak of a boundary between a precipice and a globe.

The operation of these phenomena depends not only on the shape of the space itself, but above all on our position in the space or our movement through it. We experience the phenomenon of a corridor or change when we walk across a grandstand, and the phenomenon of a grandstand or precipice when we are leaning on a windowsill, on a balcony railing, or even just on a step. We experience the appearance of a shaft or globe when we are in a corner or close to a wall.

There is something very special about a round room, especially when it is covered by a dome. The horizontal dimensions become questionable and in a sense the vertical dimension becomes questionable. The perimeter walls are ignored by the observer and the vertical axis dominates because of the special importance of the central part of the space. In such a space, the observers position themselves in concentric circles, because the shape of the perimeter walls dictates it, and observe those in the centre. The man in the centre is left with only three options: to be watched by everyone, to show off and to think. Most of the time, nobody lasts long in the centre and sooner or later retreats to the margins.

Let us stress once again that the vask topos of space has an “objective” (independent of us) content, since it causes in the human body its own sensations (e.g. below, above, deep, upright, in front, in the middle, etc.). Of course, these elementary sensations may be valued differently in personal experience, humanly prefigured. But probably the areas of space do not quite “have the values (meanings) that each individual in the space gives them”.