Because of the charming, interesting and colorful effects that can be generated by light, there has been a long history of developing research on light, trying to find ways to first define it and explore it further. Reflection, refraction, and diffraction are all light behaviors of the light (Khan, 2000). In the scientific definition, light refers to all the electromagnetic waves. Edensor (2015) states that light is an electromagnetic wave that can be accepted by the naked eye. Light consists of basic particles called photons, with the attributes of particles and volatility. Light can be spread in a vacuum, air, water and other transparent media.
 

The understanding of the nature of light was basically centered on two kinds of models: the particle model and, the wave model (Rossing and Chiaverina, 1999). The particle model considers light as ‘a stream of corpuscles or particles carrying energy’ (ibid.), this model was advocated by Isaac Newton during the eighteenth century. Newton claims that after light gets reflected, it moves in perfectly straight lines which can demonstrate the particle nature of light since it is only particles that could travel in such straight lines (Buchwald, 1989). The other, alternative wave model was championed by Christiaan Huygens, from the same generation of scientists like Newton. Huygens suggested that light is an electromagnetic wave, transported through an invisible substance called ether. In the nineteenth century, ‘The Double Slit Experiment’ led by Thomas Young established the validity of the wave model, putting the particle model aside. However, Albert Einstein used the particle model to demonstrate the photoelectric effect in the twentieth century and nowadays, the light is viewed as a phenomenon of a dual nature (ibid.).

The wave-particle duality means that all elementary particles or quantum can be described not only in terms of particles but also, partially, in terms of waves. This means that the classic concepts of the particle and the wave lose the ability to fully describe the physical behavior within the quantum range (Meads, 2015). Einstein describes this phenomenon in this way, ‘It seems that sometimes we have to use a set of theories, and sometimes we must use another set of theories to describe the behavior of these particles, and sometimes both must be used. New difficulties that force us to describe reality with two contradictory perspectives, both of which cannot completely explain the phenomenon of light alone, but together with it’ (Bazavov et al., 2013). In 1924, de Broglie proposed the material wave hypothesis and believed that light and all things are characterized by a wave-particle duality.

Because of its wave-particle duality, light can present various colorful effects such as reflection, chromatic dispersion, and refraction. This nature made light and material interaction a key factor in this discussion. Visible light is an electromagnetic wave with a wave length from 400nm to 700nm,and a corresponding photon energy somewhere between 3.1eV~1.8eV (Panero, 2001). The materials have three possible behaviors for the visible light that are manifested on their surface: transmission, absorption, and reflection (Birnbaum, 2013). Therefore, the material can be divided into different categories according to its light penetrating ability: full transparency, which means there is almost no reflection or absorption of the light (Belmonte, 2013), no transparency, which means completely absorbed or reflected light, and is semi-transparency (Nilforoushan, 2011). The electronic energy gap of the material will absorb the corresponding light in the visible energy range. Of course, there are two extreme situations, if the material’s surface is white, it will completely reflect the light, but if the material’s surface is black it will completely absorb the light. Therefore, it is profound how the difference in the material can totally transform the light effect.

1.2 Thesis project overview

Light and the deployment of different media can create a variety of interactive moments, by producing different visual effects, and offer people diverse special experiences. The influence of the light environment itself is further affected by the personality of each person that is susceptible to light. Therefore, the light will impact on the psychology and physiology of people (Whatley, 1999). In addition, a light environment not only affects the visual nerves, but it also affects the heart, endocrine function, and activity of the central nervous system.

The main purpose of this project is to create an art installation in space that can bring together the feelings of reality and unreality through the deployment light and different media. The installation will interact with people according to their behavior. This report focuses on the study of the light effect and the experience of the installation. The effect of light is related to what kind of media is being used,therefore, the main question of this report can be attributed to what combination of light and material is suitable for the development of a range of light experiences?

This can be divided into three more specific questions:

1. How can light construct the experience of the ‘real’ and the ‘unreal’ and, what sort of light sources and selection of materials are required for these experiences?

2. What is the difference among the light effects generated by different materials and what are the advantages and disadvantages of them towards creating different experiences?

3. What are the parameters that can control and adjust light effects that are led by light and material combinations?

By exploring the combination of different materials and light sources, this thesis explores the light effects that these produce and studies the relationship between the light effect and people’s experience. A design project is developed alongside these studies that determine the final use of materials and the form of installation.

2. Light experience, the ‘real’ and the ‘unreal’

2.1 What is the ‘real’ and what is the ‘unreal’?

The ‘Real’ and ‘unreal’ in this report are related to people’s perception and feelings. People first imagine, guess, believe and then they understand the world. The ‘real’ and ‘unreal’ can be distinguished by people according to their own perception and cognition (Stephen, 1997).

According to the ‘Allegory of the cave’, people’s understanding of the environment has an inseparable relationship to what they consider is ‘real’ and ‘unreal’ (Ferguson, 1922). Prisoners in the cave, due to their limited scope of activities, they can only see the moving shadows on the wall. Therefore, based on their understanding, these moving shadows on the wall are for them the ‘real’. After a prisoner is liberated, he develops an understanding of the overall environment, realizing that what he saw as moving shadows were created due to a fire at the other side of the wall that illuminates several moving objects and projects their shadow son the wall. As such, he learns and understands that the shadow he used to recognize as the ‘real’ which is a light projection (Plato, 2008). Therefore, people’s criteria of ‘real’ and ‘unreal’ are based on their understanding of the overall environment, object or a scene.

The experience of the ‘real’ and the ‘unreal’ can be demonstrated by the difference between the human states of dreaming and being awake. The experience in a dream seems to be real. However, when one wakes up, it can be discovered that the reality in the dream is an illusion since the scene in the dream has disappeared. Then how can people tell that objects in a dream are not real? After people seeing these objects, they try to get closer or find these objects, and they are not there. The disappearing of the objects is what makes people judge the substance as ‘unreal’. Changes in the state of the object will make people feel that the object is unreal (Spira, 2017). Relatively, people know when they are awake because, in the waking state, they can touch an object they see. Objects in a ‘real’ experience are in a changeless state.

In this report, the word ‘real’ refers to the state when people see a changeless object or scene and judge the scene they see as true. To be more specific, ‘real’ not only means the objective and real substance, but it also means that people judge what they see is true according to their feelings, such as the prisoners in the cave.Likewise, the word ‘unreal’refersto the state of experience when people see an object or scene they are uncertain about its authenticity and judge the scene as illusory. For example, when people see the reflection of the moon in the water, they have the experience of the ‘unreal’. It is because despite from the fact that the reflection in the water is ‘real’ and can be seen, common sense tells people it’s not the real moon at that position, so people will judge what they see is not true, or ‘unreal’.

2.2 How can different light effects create different experiences?

Light is an important part of our environment and has a certain impact on people’s feelings. Gander (2016) states that ‘Light certainly has a physiological impact on people.’ In our daily life, recreational activities, military activities, and other fields have a variety of light conditions that affect people’s psychology and emotions. Light is a strong driver for visual performance (Grangaard, 1995), regulating various physical processes such as sleep and alertness (Knez, 1995; Wright et al., 2004; Takasu et al., 2002), critical to cognition and emotion (Veitch & McColl, 2001). A recent study suggests that either the positive or the negative emotions of a human are experienced more intensely under bright lights (Ellis, 2014). An example of this can be seen in the criminal review. The examiner often positions the criminals under bright light and ‘to get’the truth out of them. Compare to a normal light environment, a strong light environment makes criminals more likely, to tell the truth. Thus, the light and the experience of people in the environment are closely linked, since different light effects directly influence this experience.

Many projects have studied the light effect and its experience. One of them is the ‘Light in Movement’ of Julio Le Parc. Julio Le Parc is an artist who focuses on optical art and kinetic art, by using light as his main material in his late career. The ‘Light in Movement’ is a piece of sensory artwork. It does not aim to be narratively as same as other works of Julio Le Parc, but it focuses on the ‘visual experience and omits the anecdotal‘(Leyva, 2011).

This work is consisting of stainless steel, mirror, nylon thread and two spotlights and it is inside a dark semi-circular corridor through which both reflection and refraction can be experienced. Viewers will stand below this artwork and observe twinkling light above them which is created by mirror and steel and see the light projection on the wall. The moving, changing point and linear light effect in the space created by this installation can keep the light environment changing, and make viewers feel like they are in an illusory space. Due to the kinetic and colorless light effect of this installation, it can make viewers have an experience of being in an unreal space, and encourage the interaction between the viewer and the installation (Preciado, 2011).

According to the people’s experience of ‘real’ and ‘unreal’,people distinguish‘real’ and ‘unreal’ is distinguished by observing if the existing state changes, so light effect can deliver this experience by changing the state of the light effect itself. If the light can reflect the object truly and objectively, it may offer people a ‘real’ experience of light, such as the daily light environment. If the light effect and environment is uncertain and keeps changing when people explore it, it can offer people an ‘unreal’ experience. Thus, in order to create this experience, light effect needs to be shifting between these two contradictory states.

3. Different materials and ‘real’ and ‘unreal’ light effect

3.1 What light effect can be generated by liquid, film and solid materials?

The experiment is used to explore the relationship between light effect and different materials. By testing the combination of different materials and different light sources, we can see what kind of light effects can be created,and experiment trying to find an appropriate material as a transport media for light to create a light effect for the ‘real’ and ‘unreal’ experiences. Three kinds of materials have been tested, from hard to soft, solid, film, and liquid materials.

3.1.1 Solid materials and its effect

 

 

 

 

 

 

 

 

 

For solid materials, different shapes of prisms and convex lenses have been tested. Prisms and lenses can produce refraction of light. When the wave propagates from one medium to another from any angle other than normal 0°, the refraction is most often observed. The refraction of light means that light interacts with two different materials. Snell’s law states that ‘the ratio of the sines of the angles of incidence and refraction is equivalent to the ratio of phase velocities in the two media, or equivalent to the reciprocal of the ratio of the indices of refraction:

θ as the angle measured from the normal of the boundary, v as the velocity of light in the respective medium, λ as the wavelength of light in the respective medium and n as the refractive index of the respective medium(Wolf,1995).

Differently shaped prisms will make the light produce a different refraction effect. Dispersion is also a kind of light refraction phenomenon. With reflection and refraction, light through a triangular prism will transmit at least two rays of light.

After changing the incident angle of light, the position and number of light transmitted will also change. When using point light as a light source, it is difficult to cause dispersion. It needs to use the mirror to change point light source into the parallel light source. For the prism to cause the dispersion, a dark light environment is also needed, and the dispersion effect in this condition is very weak, as Figure 5 shows. Dispersion is more likely to occur when sunlight or parallel light is used as a light source as shown in Figure 6. Experiments show that the dispersion phenomenon needs a certain incident angle of light.

The second prism tested is a dichroic prism. A dichroic prism is a prism that changes one beam of light into two different wavelengths or colors of light. It is usually made up of one or more prisms depending on the wavelength selectivity of the light or the reflection and refraction of the optical coating to choose the needed wavelength.

 

 

 

 

 

 

 

 

 

 

 

The dichroic prism used in our experiments is a cube- dichroic prism consisting of four right- angled triangular prisms. When the incident angle of light is perpendicular to the edge of the colored prism, the other three sides of the prism will emit three different colors of light separately as shown in Figure 7. When the angle between the incident angle of light and the color prism is 45 degrees, the dichroic prism will emit two different colors of light from the direction perpendicular to the light source as shown in Figure 8. When the light source is incident from other angles, the dichroic prism will disperse the light into four different colors of light.

The lens is a device that polymerizes or disperses light, usually made of a piece of glass. The convex lens is a lens with a thicker center and a thinner edge. The convex lens is divided into flat and other forms of convex. The convex lens can converge the light (Pliny the Elder, 2004). In the experiment in this report, the convex used has two sides of the lens made of glass in 6cm diameter.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

When the light passes through the convex lens at different incident angles, the luminous effect of the convex lens projection will compress in the horizontal and vertical directions and exhibit different shapes. When the convex lens is on the same horizontal line as the light source, the convex lens is rotated on the vertical axis, the projected light effect will change from circular to horizontal. When the convex lens is rotated horizontally, the light and shadow become a long strip in the vertical direction. Through this experiment, it can be observed that the larger the angle between the convex lens and the projection plane becomes, the smaller the light and shadow shape will be.

When the light source is a plurality of point light sources on the same straight line, the light effect shape of the convex lens projected on its vertical-horizontal plane is the feathery light effect that diverges from the same starting point as shown in Figure 11. When the convex lens is rotated on the vertical axis, the length of the two side of the light effect will change. The length of the light effect far from the side of the light source will become longer and the other side will be the opposite. Under the same light conditions, when the one convex lens changes into two convex lenses in the same line to the light source, adjusting the angle of the lens, then the light effect changes in the same way as in the experiment with the one convex lens.

Based on these single prism and lens experiments, a prototype of the combination of multiple prisms is built with servo, prisms and a mechanical robotic arm. This prototype and through the servo, it rotates simultaneously multiple prisms and uses the robotic arm to adjust the incident angle of the light source. The illuminated light source effect will project on the wall and the level plane. This prototype shows that the rotation of the prism will cause the light projected on the wall to rotate together. The shape of the light effect projected on the wall is rectangular or similar to the shape of a rectangle. When the position of the light source is fixed, the rotation of the prism does not change the size of the light effect on the vertical axis; it only changes the horizontal size of the light effect. While the prism is rotating and the light source moves, the light effect cast on the wall will change both position and shape.

In these solid material experiments, it can be seen that the shape of the light effect produced by the solid material has a certain relationship to the shape of the material itself. There is only a little change in the light effect, while the shape is relatively fixed. The light effect generated by solid materials produces a solid block light effect with no texture inside and has clearly defined boundaries.

3.1.2 Film materials and its effect.

There are three different film material tests for this project.The first one uses one-way mirror film, the second one uses iridescent film and the third, Aurora mirror film. One-way mirror film can make light penetrate from one side and reflect the light from the other side. This feature depends on the intensity of the light on both sides of the film. The iridescent film can present different colors when changing the angle of the view or illumination. The Aurora mirror film creates a similar effect of the iridescent film, where the color changes according to the viewpoint and illuminates angles, but it is opaque.

 

 

 

 

 

 

 

 

 

The one-way mirror film was attached to a piece of acrylic sheet. Carton was used to hold the acrylic sheet in the middle of it and a textured gypsum board was placed behind it. By changing the light source position,the light intensity changes on both sides of one-way mirror film. When the light is stronger in the front of the film, the film will reflect the image in front of it, like a mirror (as shown in Figure 14 left). When the light is stronger at the back of the film, it is able to see the texture of gypsum board through the film (as shown in Figure 14 right).If the one-way mirror is placed in a natural light environment, it will reflect images like a mirror. However, if we just illuminate the one-way mirror film, it cannot give a light effect projection like other materials by itself.

When the incident light enters two or more layers of translucent structure, multiple reflections of light are formed inside this structure. The phase shift and mutual interference of these reflected rays result in the enhancement or attenuation of some wavelengths, forming the iridescence phenomenon. The iridescent film is using the same principle (Srinivasarao, 1999).

The iridescent film is rolled into a cylindrical end that allows it to stand on the table. We illuminate the iridescent film from above, and it forms a fan-shaped colored light effect on the horizontal plane. Moving the light source vertically changes the radius of the light effect. The closer the light source is to the iridescent film, the larger the radius of the light effect on the horizontal plane will be. When the light source is moving far from the film, the light effect becomes smaller.

If we place the iridescent film tiling onto a horizontal plane, with the light source and the horizontal angle of 15 degrees to illuminate the iridescent film, then the light will go through the iridescent film and project a circular light effect on the wall in front of it. We adjust the incident direction of the light source, and the arc length and position of the light effect will change depending on the direction of the light source. When the direction of the light source moves from left to right, the light effect on the wall will move accordingly from left to right and along the shape of the arc.

When the iris film is folded into three layers tiling on the horizontal plane, and we illuminate it with a light source, it will generate similar light effects as it is tiling on a plane in one layer. However, the arc light effect will change from a single layer or part two layers to arc-shaped multi-layered and different colors of light effects. The light effect of the iridescent film in this form is more bright and colorful.

 

 

 

 

 

 

 

 

 

 

 

Aurora mirror film can also generate colored light effects. If we use a led torch to illuminate from above, it can reflect light into different colors. The present color is related to the distance between the light source and the film. There are mainly three kinds of colors. As the light source moves higher, the color will change from cool to warm.

 

From these film material experiments, it can be seen that the shape of the light effect generated by the film is related to the shape of the film. An advantage of the film material is that it can be attached to other materials. For the iridescent film, the color of the light effect depends on the indecent angle and direction of light,while the light effect of the film material, compared to the light effect of the solid material, is softer but at the same time, the effect is not equally controllable.

3.1.3 Liquid material and effects.

Liquid materials, such as water and ink, are soft and they can both reflect and refract light. As their flow characteristics and their wave patterns need to be seen, the liquid materials tested need to be transparent. Due to the fact that the density of the liquid can affect the light effects created, liquids with different densities were tested.

The density range of the liquids that have been tested are from 870kg/m3 to 1420kg/m3 and, they are oil, water, beer, and honey. By using a laser module and a led torch to light it, these liquids generate different light effects. When using the red laser module as the light source, the brightness of the light effect will raise with the increase of the density of the liquid and the line of the laser will be clearer.When we use a led torch as the light source, the light effect will be softer and less bright when the liquid density increases. In the liquids tested, the light effect of the water is clearer compared to the rest and, the range of the effect is bigger than in other liquids. Therefore, water becomes the chosen material to further develop the experiments.

When the shape of the container is fixed, the shape of the projected light effect will change with the change of the indecent angle. The size of the light effect is related to the distance between the material, the light source, and the projection plane. In order to research the relationship between the size of the projection, the shape of water and the height of the light source, the water is contained in a 16cm diameter transparent hemispherical container and that is illuminated by a led torch above it. If the light source illuminates it from the top, the shape of the light effect projection will be a circle block. If the angle between the water surface and the incident angle of light is smaller than 15 degrees, the shape of the light effect will change into a diamond shape with a bright line in the middle.

When the fixed distance between the container’s lowest point and the projection plane is 10cm, the light source is moved in a vertical direction and the size of the light effect will also change. When the light source is 40 cm above the container, the diameter of the light effect on the projection surface is about 11cm. The light effect on the projection surface will become bigger as the distance between the light source and the container decreases. When the light source is 1cm above the horizontal plane of the container, the light effect on the projection surface is about 130 cm in diameter.

One difference between liquid and solid materials is that the shape of liquid is not certain, it can be shaped into any form, so it can generate a different pattern. To see what kind of patterns we can generate by using water and what the differences between them are, there are three ways that have been deployed to trigger the wave pattern.

When we use the wind to blow water, water will generate waves according to the speed of the wind. When the water is static, the projection of the light effect has clear boundaries and no texture in it. When the speed of the wind changes from 3m/s to 8m/s, water will generate different waves that will affect the light projection. When the wind speed becomes faster, the ripples will be more intense enlarging the light effect. When the wind becomes faster, the boundaries of the light effect will become fierce and fuzzy because of the ripple.

Sound waves on the water can also cause water to generate a ripple. The wave generated by sound is a kind of Cymatics, which is ‘a subset of modal vibrational phenomena’ (Hans, 2001). The ripple pattern produced by the sound is relatively regular, following the principle of the wave pattern. As part of the experiment, we used a transparent, quadrangular container for the water and put it on a speaker, using led torch to illuminate it from the left side. As such, the light effect will be projected on the right side plane. When the sound frequency is 28Hz, the water starts to vibrate. The vibration stops when the frequency is approximately 120Hz. Between 28Hz and 90Hz, as the frequency increases, the corrugations of the light become larger and the speed it moves in becomes higher. From 90Hz to 120Hz, the light effect of the corrugations becomes slower and smaller.

When using a stick to hit the water to generate the wave, the effect produced is similar to the one of the wind blowing water. The experiment connects the wooden stick to a servo and uses the servo to move the stick. When hitting the water in the vertical direction with a stick, the corrugated texture is divergent at the point of contact with the intensity of the ripple being proportional to the number of stops when the speed of the strike is constant. Meanwhile, the clarity of the pattern is inversely proportional to the number of touch points. Interestingly, when using the same method to slide water from a horizontal direction, the light effect of ripples is more intense.

These liquid experiments show that the light effect of water entails more possibilities to introduce controllable change in comparison to other materials. The effect depends on the moving pattern of water and the ways of fluctuating the liquid, with the shape of the liquid light effect being as well related to the incident angle of light and the shape of the container.

3.2 Brief summary of materials and effects.

Different materials can present different light effects in shape, following the change of position of the light source. Solid materials are the hardest class of materials in the three types of materials that have been tested. When using solid materials as media of light, it is easy to control the light effect generated by them. That is because the light effect boundary of the solid medium is clearer and the effect is a dot that does not have texture. The change of the light is predictable when changing the parameters that can influence it.

Film materials are softer than solid materials with a greater variability in shape. The main parameter that affects the shape of the light effect of the film material is the shape of the film itself. However, the ways in which the light effect produced by the film material will change when changing the parameters that influence it are less controllable. The light effect produced by the liquid material is changeable since the liquid is soft and can obtain a variety of shapes, generated various effects. The clarity of the boundary of the light effect can be adjusted by creating waves, and the shape of the light effect can be controlled by changing the illuminating incident angle and the shape of the container. Although the light effects of liquid materials are various, the requirement of the liquid container is chosen in relation to the needs of the light effect we wish to create.

According to the research of ‘real’ and ‘unreal’ experiences, in order to create a‘real’ experience we need a changeless state of the object. On the other hand, ‘unreal’ experiences require a changeable state of the object. If we are using the light effect to create these experiences, we need a light effect that can be both static and dynamic so as to correspond to the two different states of the object in ‘real’ and ‘unreal’ experiences. The solid material can change the position of the light source to create a mobile light effect and, develop ‘unreal’ experiences. The film material can create ‘unreal’ experiences by changing the light intensity or the shape to provoke a dynamic light effect. The liquid material can change the light effect state by generating waves to change from being in a static to a dynamic state.

4. Applications in project

4.1 Prototypes

Based on my research on human experience and experiments with the materials, two different prototypes were built. The aim was to use a different combination of materials to create and change the light effect in a mechanical way.In this way, we wanted to explore the interaction between the light effect and the prototype as well as the ways in which we could use the light effect to create ‘real’ and ‘unreal’ experiences.

The first prototype combines water with acrylic strips. It uses multiple acrylic strips to form four different arrays,with which it can reflect and refract light in a different way and generate different effects. These strips are at the bottom of a transparent square acrylic box that holds water inside it and at the bottom it has a mirror which can reflect the light effect on the wall. With the different heights of the acrylic strip and the water tension, when the strip is higher than the water level, the water will form several convex lenses; when the strip is lower than the water level, the water will form several concave lenses.

This box will be rotated by the servo in the horizontal axis. When the box is flat, the light effect project on the wall is clear and has an obvious contrast of light and shadow generated by the array of strips, which can construct a ‘real’ experience. When the box is tilted, the boundary of light and shadow will become fuzzy and the light effect will bring people an ‘unreal’ experience. The rotation of the box will also change the position of the light effect on the wall.

The second prototype is creating a pure light reflection effect. This prototype is built with four parts: the backplane is made of forest acrylic, the supporting structure is made of plywood, the rotating light that consists of the servo and led torch and, the moving part for changing the light effect that consists of a motor and the iridescent film. By using a curved reflective material, the light will form a curved line light effect at the backplane. When the servo rotates the light source, it will change the incident angle of light, resulting in a dynamic curved line light effect that moves along with the rotation of the light source. The moving part will drive a piece of the iridescent film to move along the edges of the prototype when the iridescent film is in the range of illumination of the light source. Therefore, the color of the light effect will change from white to multiple colors. Due to the light effect of the prototype 2 that appears to be rather uncertain and keeps changing, it can be used to construct and provide people with the experience of the ‘unreal’.

From these two prototypes, we found that in order to create a dynamic condition that develops into an experience of the ‘unreal’, the nature of the light effect needs to be dynamic and ever-changing. On the other hand, in order to express the feeling of a ‘real’ experience,a light effect needs to be not only static, but it also should have a clearly defined boundary or clear relationship between light and shadow.

 4.2 Proposal for final design

From both experiments and prototypes, it can be concluded that water is the most suitable material for creating a range of experiences of the ‘real’ and the ‘unreal’ due to the softness and the changeable light effect it can provide. Therefore, the proposal for the final design uses water as the main material to create a light effect. The design project attempts to make an art installation that uses water to generate mutative light effects in space and let people in that space interact with the light. In the experiment, the light effect of illuminated water from above and the projection effect on the ground is brighter and clearer than illuminating water from the side and through projection effects on the wall. Therefore, in the final design, water is illuminated projects its effects directly on the ground. There are multiple transparent hemispherical containers hanging from the ceiling that hold water inside them, and a LED light fixed at a 5cm height above each container. A servo connects with the container through a clear acrylic stick that is fixed on the side.

The interaction between people and the installation is related to the users’ movement and the light projection on the ground. The brightness of the LED light above the container and the movement of the servo are controlled by Arduino which connects with a Kinect that collects data of people’s movement. The intensity of the water fluctuations can be controlled through the speed of the stick; the faster the stick moves, the greater the degree of water fluctuation will be.

When there’re no people in the space,the light projection on the ground will appear randomly. When there are people in the space, the light effect will be changing in response to people’s position,motion and moving speed. The position of people defines which container generates ripples and, Arduino controls the servo of the nearest container to wipe the water and generate a wave. The specific motion of people will trigger an overall light effect within the space of the installation. The moving speed of people will control the fluctuation of water. The faster people move, the more intense the water fluctuates, and the light effect will be larger and vaguer. This changeable effect is trying to create the experience that when people move slowly, they can see the environment in a clearer way as the fluctuation of light is very small,with a clear boundary, and develops a ‘real’ experience. When people move fast, they cannot feel the environment in detail, since, their fast movement will make the fluctuation of water will become greater and will result in a light effect that moves strongly has a fuzzy boundary. That means that when people move faster, they will feel like entering an ‘unreal’ space and have an ‘unreal’ experience.

By relating people’s behavior to different light effects and states, the installation wishes to offer people an experience that their behavior can change. Therefore, the authenticity of the environment, the ‘real’ and the ‘unreal’, they can all shift and change by interacting with the installation that is driven by the use of water as a playful media that can allow for a variety of forms and experiences to be staged.

5. Conclusion

Light as an important part of people’s lives has a certain impact on the human emotions and cognition. Different light effects, conditions, and environments can offer diverse experiences while provoking varying feelings. Conditions that are characterized by a rather changeless state, can be, therefore, seen clearly by people and as such, they create a‘real’ experience. On the contrary, when the state of the light effect changes and has blurry boundaries, people will have a feeling that is assigned to the nature of the ‘unreal’.

The role of the materials within this discourse is key. That is to say that different materials as the media of light generate a different effect. As such,the resulting light effect is directly related to the nature and form of the material itself. The light effect generated by using a solid material as the medium, has a strong position variability, a shape that is relatively fixed according to the shape of the solid material itself, and therefore, the state of the light effect does not change much. On the other hand, the light effect that is being produced through the film material creates a form vulnerable to change, but the effect has a poor control ability. But, light effects generated by the use of a liquid material as the medium, are characterized by a strong variability of shape and form.

Nowadays, people become increasingly concerned with and interested in the different ways of experiencing light. By using water as the medium of light in the design of this interactive installation piece, we enhance the possibilities to create a space that could offer to both users and viewers a unique and authentic feeling. The softness of the water breaks the limits of materials that can only produce a fixed light effect, and it can create interesting light effects that can be altered both in state and form and thus, construct a series of experiences that successfully range from the degrees of the ‘real’ to the ‘unreal’.

6. Bibliography

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7. List of Figures

Figure 1. Thomas Young’s sketch of two-slit diffraction of waves. https://en.wikipedia.org/wiki/Wave—particle_duality

Figure 2. Light in movement of Julio Le Parc. http://brandonshigeta.com/blog/2011/01/01/suprasensorial-experiments-in-light-color-and-space/

Figure3. Refraction of light at the interface between two media of different refractive indices, with n2 > n1. https://en.wikipedia.org/wiki/Refraction
Figure4. Bian, S. (2017). Refraction and reflection of light in different prisms.

Figure 5. Bian & Chen (2017). Dispersion and refraction effect of triangular prism with point light source.

Figure 6. Bian & Chen (2017). Dispersion and refraction effect of triangular prism with sunlight.

Figure 7. c Dichroic prism experiment. Perpendicular incident angle

Figure 8. Bian & Chen & Sun(2017). Dichroic prism experiment. Incident angle in 45 degrees.

Figure 9. Bian, S. (2017). Rotating convex lens experiment. Vertical axis.

Figure 10. Bian, S. (2017). Rotating convex lens experiment. Horizontal axis.

Figure 11. Bian & Chen & Sun(2017). Convex lens experiment with multi-point light source

Figure 12. Bian, S. (2017). The consist of multiple prism prototype

Figure 13. Bian & Chen & Sun(2017). Effect of multiple prism prototype.

Figure 14. Bian & Sun(2017). One-way mirror experiment effect.

Figure 15. Bian & Chen & Sun(2017). Iridescent film experiment in rolled shape. Effect.

Figure 16. Bian, S. (2017). Iridescent film experiment in rolled shape. Experiment Setting.

Figure 17. Bian, S. (2017). Iridescent film experiment in tiling. Experiment setting.

Figure 18. Bian & Chen & Sun(2017). Iridescent film experiment in tiling. Effect.

Figure 19. Bian, S. (2017). Iridescent film experiment. Shaped in multi-layer. Experiment Setting.

Figure 20. Bian & Chen & Sun(2017). Iridescent film experiment. Shaped in multi-layer. Effect.

Figure 21. Bian, S. (2017). Aurora mirror film experiment. Relationship between color and height.

Figure 22. Bian & Sun(2017). Liquid experiment. Liquid density and light effect.

Figure 23. Bian & Chen (2017). Water experiment. Incident angle and shape of light projection

Figure 24. Bian, S. (2017). Water experiment. Projection size experiment setting.

Figure 25. Bian, S. (2017). Water experiment. Diagram of relationship between height and size.

Figure 26. Bian & Chen & Sun(2017). Water experiment with wind. Effect.

Figure 27. Bian & Sun(2017). Water experiment. Effect of sound vibrate.

Figure 28. Bian & Sun(2017). Water experiment. Effect of vertical direction hitting.

Figure 29. Bian & Sun(2017). Water experiment. Effect of horizontal direction hitting.

Figure 30. Experiments materials and light sources.

Figure 31. Sun, X(2017). Strip array of prototype 1.

Figure 32. Sun, X (2017). Light effect of prototype1. Relationship between box angle and light effect.

Figure 33. Sun, X (2017). Prototype1 and its light effect.

Figure 34. Bian, S. (2017). Structure of prototype 2.

Figure 35. Bian, S. (2017). Light effect of prototype 2.

Figure 36. Sun, X (2017). Space arrangement of proposal.

Figure 37. Bian, S. (2017). The relationship of proposal light effect and moving speed.
Figure 38. Bian, S. (2017). Interaction system of proposal.

Figure 39. Sun, X (2017). Proposal effect picture.