Barriers are obstructing and intervening entities in buildings and outside in nature. Barriers through their configuration, position and occurrence affect things passing by, touching, or going through them. Barriers rarely operate on their own, so are distinguished by the context or the surroundings where they operate. Barriers operate as multi functional entity doing many intended and unintended things.
Barriers change the environment on both the sides. Barriers have a capacity to obstruct, absorb, filter and reflect, and so cause distinctly different conditions on the other side. However, barriers are often so extensive that the modified environment is not recognised, as the perceiver has no idea of, what the original (one beyond the barriers or without the barriers in position) experiences were. Barrier systems, as a result, are evident at the joints, thresholds, ends, edges, cut sections, or at the gaps.
Barriers are selectively opaque to transparent for various energies and objects. A lattice may allow a rat or insect to pass through but not a cat or dog. A membrane filter can allow gas but not any particulate matter. A barrier system, by deflecting, reflecting, by absorbing within its own body, does not let certain things to pass through them.
A barrier is a separator that not only divides an entity. It allows a new set of cultures to flourish on both the sides. However man-made barriers are not powerful enough to cause extensive changes in the environmental system within which they occur.
Natural barriers are like rivers, mountains, ridges, valleys or atmosphere. Natural barriers are very extensive in space, and long lasting in time. Natural barriers are territorial, affect macro or micro regions, and also temporal in terms of occurrence like, eternal, seasonal, diurnal, etc. The start and end of natural barriers are not always within the relevant time and space scale. Natural barriers start or become effective somewhere and imperceptibly end or become ineffective somewhere. Natural barriers as a result are often not experienced because the other side experience (without the barrier) is not possible due to their large spread. Natural barriers are overlapped by other natural barrier systems, so have no distinct definition.
ATMOSPHERIC BARRIERS SYSTEMS:
Atmospheric barrier systems are natural barriers formed by the constituents of the atmosphere such as: air, moisture, breeze, winds, radiation, temperature, etc. For example, air or its gases control the level of radiation penetration, the moisture checks the amount of dust in the air, and presence of dust and other particles helps distribution of illumination. The atmospheric barriers are very extensive, consisting of over lapping layers, and so do not have the sharp edge definition. Some of these barriers are very acute and causative, while others are mild and almost irrelevant. Atmospheric barriers are so common and omnipresent that we many times take them for granted. Some effects of the atmospheric barriers are so fast or short lived that it becomes very difficult to notice or learn any thing about them.
Man-made barriers are finite in size, designed for specific function and alterable. Man-made barriers occur as barricading elements such as: Curbs, embankments, Guard, Railing, Fender, Shield, Buffers, Balustrades, Fence, Parapet, Rampart, Bumpers, Cushions.
- Physical Barriers: Physical barriers are contrived structures (peculiarly shaped, sized and formed) that exploit conditions, properties of materials (strength, weight, bulk, ductility, etc.), and energy reactivity.
- Metaphysical Barriers: Metaphysical barriers are indicative and unreal, or Make-believe. A society by a tacit understanding accepts certain words, signs metaphors, and indications as allowable and non allowable actions (warnings, danger, caution, etc.). When such commonly acceptable norms are displayed, they function almost like a real barricade. Signs like Caution, Danger, ‘Do not trespass’, ‘keep off the grass’, etc. operate as barriers.
- Indicative Barriers: Indicative barricades occur as signs, signals, symbols etc. Unreal barriers arise as a response to our accumulated experiences, in the form of taboos, beliefs, customs etc. Indicative barriers are effective only for that class of beings, who not only know the meaning, but are willing to abide by it.
Make-believe barriers exploit the instinctive associations and conditioning of physiological and mental faculties. Man-made barrier systems are often unreal and metaphysical.
- Make-Believe Effects and Barriers: We are generally conditioned by predictable effects of the traditional or known materials. However, when we discover that any peculiar configuration or additional input creates an experience that is different from the one that is predictable, we get a tool for a make believe effect. Mirrors play a very important role in creation of duplicate spaces. Glasses provide a transparent wall compared with a nominally solid opaque structure. Rooms other than square or rectangular shape provide an unusual experience. Echoes and reverberation of sound provide predictable space dimensions, but different perception gives unusual experience of the space. Lights and shadows mould the visible space. Ionized air endows a garden like freshness in an otherwise stifled space.
- In real life we do use the stage like make-believe and indicative effects. We use these to create situations that are called ‘dramatic or melodramatic’. Discotheques, Night Clubs, Amusement Parks, etc., are places where such make-believe effects are extensively exploited. Make-believe effects occur because we are conditioned by certain predictable responses of materials, texture, colour, illumination frequency and schedules of occurrence etc. When these predictable effects fail to arrive in the nominal context, or arrive in spite of a different situation a delusion occurs. Make-believe effects are almost magical or ethereal, and defy logic or reason.
- Indian epic Maha Bharat mentions Lakshagriha, a palace where solid looking floors were water surfaces, and water surfaces were real floors. We perceive a dark space to be quiet and cold, but in a ‘maze’ of an amusement area, the reverse experience is provided. We usually perceive a load-bearing wall to be opaque, so a glass-wall seems different.
- Sensual Variations as Barriers: A non physical barrier could also occur through sensory variation. A subtle shift in texture, gradient, colour, illumination level, view, temperature, audio perception changes the behaviour of the user and can become an effective barrier.
- Visual Barriers: Visual barriers use colours in terms of their brightness and other optical qualities such as fluorescence, reflection and background-foreground contrasting. Visual barricades also include use of illumination or brightness, blinking (dynamic) lights, iridescence.
- Barriers Consuming Energy: Barricades bar or control the exchange between its two faces. Barricades, themselves are variously affected by the exchange occurring through them. Some barricading systems use energy, to cause specific changes during the exchange process and also to revert to the nominal status. Barricading systems capable of using energy are machines, or a live beings, if additionally can reproduce or self sustain.
- Protective Barriers: Protective barricades are designed to resist the most unfavourable combination of imposed loads (impact, wind, etc.). Such barricades allow planned deflection and distortion, with or without a collapse. A noncollapsible barrier is resilient enough to revert to the original position, whereas the collapsible barrier at a predetermined stage becomes ineffective. These conditions are included through a structural configuration, material technologies and through machine devices (operating on feed forward and feed back).
- Soft Barriers: These recover after an impact, but do not bounce-back the striking object. Rubber flaps or plastic stripes on warehouses doors are flexible barriers.
- Hard Barriers: These are used to divert (bounce back) the force of the impact. On express highways the shape and height of the railings and curbs are so designed that a vehicle on striking slides along it rather than thrown-back into the fast-moving traffic.
- Transparent, Transluscent or Opaque Barriers: A glass barricade could be transparent for light but not for other objects. A large aperture grill could be ‘transparent' for light, air and view, ‘translucent' for an infant, pet etc., but ‘opaque' for a fat man. A vertical or horizontal Venetian blind could be ‘transparent' or ‘translucent' from a particular position and could be ‘opaque' from another position. A smoke glass is ‘opaque' for view from outside but ‘transparent' for view from inside. Fast-moving air in an ‘air curtain system’ is a transparent barricade.
- Notional Barriers: These are used for ceremonial purposes or as a representative form of a barrier . A wrought iron chain, a rope around a monument, podium, dais or rostrum, a red ribbons for inauguration, yellow tape of police investigation teams, are all notional barriers. Similarly signs and symbols (danger, do not enter, slow, stop) can also be used for barricading. If the users are knowledgeable, and are ready to accept a set social behavioural norm, than indicative (non physical) barriers are as effective as physical barriers. However, it should be possible for the user to recognize, feel and experience the presence of such barriers. Where such opportunities for recognition are not available, non physical barriers fail to be effective. Notional barriers are not recognised in a crowded area or in a chaotic situation. Similarly where barriers are required as protection against unknown elements, notional barriers are not effective.
- Need for Barriers: Barriers are required at all places of hazards such as: construction sites (for the safety of workers, visitors, and trespassers), works in public areas (such as trenches, excavations), place near electrical equipments (with exposed parts that could be live, and installations with voltage of over 440 volts), any area where explosives are used or stored, to define the radius of any cranes or such equipments, etc. Barricades serve as warning (through visual and other sensorial recognition) and also as a protective element. Barricades also denote territories, ownership and right of ways.
BARRERS FOR PHYSICALLY IMPAIRED PERSONS
Persons with physical deficiencies require barriers for: extra support to the body, as a facility to ease the movement and as a guidance for the route. The barricades however, must not create an exclusive route for the physically impaired. The barriers have distinguishing elements such as: shape, size (height, width), materials and their surfaces, nature of sensorial qualities available in the defined zones.
Barriers for visually impaired persons are required at two levels. The main barricade is like that required for a normal person. The barricade for the visually impaired persons should be continuous and have same texture, size, shape and feel throughout its spread. For the visually impaired person, a secondary set of barricade system is required at near the floor level to strike the walking stick. Even where, primary barricades are not ordinarily required due to the absence of a height-related hazard, a secondary barricade (at floor level) helps in directing a visually impaired person to a specific destination. Visually deficient persons require colour contrast from their background or neighbouring elements, Ramps or steps on passages must be indicated by colour, illumination and textural difference. A colour blind person may not read a colour but recognises the later two elements.
BARRIERS FOR PERFORMING ARTS
The best and perhaps the most imaginative use of non physical or indicative barrier systems occurs in the performing arts. Here a performer wishing to express different experiences on a stage or arena has limited time, space and means. As a result the performance space or the stage is extended beyond its physical limits by exploiting both, the real barriers and indicative barriers. Since it is not possible to accommodate the entire set of physical barriers, only the acute or important sections are highlighted through frames, outlines, edges, cleavages, thresholds.
The sets, stage property, curtains, side wings, lighting, audio-video effects, etc. are used for creating a variety of spaces (‘here’ and ‘beyond’). A cleavage in side wings or a gap between two stage properties could signify a door, window, opening, corridor or a passage. The Stage thus becomes a place where a multiplicity of spaces ‘Here’ and a series of connected spaces supposed to exist ‘Beyond’ occur. Whatever is lacking in such definitions is further reinforced by the actors. The acting makes the audience feel as if the actor is actually dealing with or reacting to a real barrier. Mime acts are such explorations with unreal barriers.
Stage set barriers are experienced by the audience from a limited and fixed angle view. Sage Bharat Muni in his treatise on Natya Shastra (Canons on Dramatics) says actor turning back to the audience is out of the scene or dead. Even in Roman Amphi theatres the actors on the front section are active and by retreating to the backside become inactive. Stage barriers serve a very limited purpose effective for a short period, and last only for a scene, dialogue or the expression. However, real life barriers are rather permanent or at least are longer lasting, seen or experienced dynamically, that is from all sides.
Next artricle: Barricades in Buildings and Nature