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eavesdripping

Eavesdripping is the design for an installation that uses water as both medium and display, rendering invisible communication visible.

The starting point for this project was an assignment at the Berlin University of the Arts: by enhancing a material electronically, make an intelligent surface intelligent and able to interact with the world around it. My initial approach was to experiment with physical displays that show computer generated information by a physical change of material. Related projects are the Wooden Mirror by Daniel Rozin as a physical representation, The Source by Greyworld as a volumetric display and Bitfall by Julius Popp as an approach to using natural effects as means of display.

The surface which I chose for my work is water - or more precisely, the visual effect of drops of water hitting a liquid surface. My goal was to construct a physical display which by raining on a surface could display simple information on it. Every splash would represent a white dot in the image on the ground, every absence of a splash, a black dot.

To achieve this, first there has to be a surface on the ground for the drops to hit and a water source above to create the drops. This was realized by building a matrix of magnetic nozzles that open a valve when current is applied. To add some controllability to the setup, a computer running Max-MSP/Jitter processes information and serially connects to two relay-boards. These then control the individual nozzles.

To increase the visibility of the splashes on the ground, the water surface sits in a container made of clear acrylic. From one side, light is being pumped in by an array of super-bright LEDs. Since the acrylic and also the surface of the water is subject to the effect of total reflection, the water stays perfectly black. However, when a drop of water breaks the surface, the light has the chance to escape, brightly lighting up the spot. As the waves subside, so does the light. Thank you very much Thomas Gardner for this idea. This effect could eventually also offer a way for constructing a grayscale display, as since the nozzles are controllable individually a change of frequency would also result in a change of brightness on the ground. The combination of these elements results in an installation with which you can, depending on the resolution, display a range of things: graphics, typography and even simple video.

eavesdripping demo-video (23mb MPEG4, QT required)

This way of displaying has some interesting properties that separate it from a regular projection or screen:

The image is created on the ground and has a very ephemeral character, the drops are only visible for a very short period of time then quickly disappear in the table of water.
The drops stay, depending on the height they are dropped from, in the air for quite some time and form a volume there with which other forms of displays are conceivable. The falling drops also have a temporal aspect, because the column upwards shows the future, for example of a moving image on the ground.
The display has got a certain diploarity because of the spatial separation between nozzles and surface. The glowing drops in the water seem as if they have been 'charged' on their way down.

For what kind of content could a water display be used? As you can see in the video, it is possible to display geometric forms and some basic typography with even a 16-drop display. Depending on the resolution, there could be more text and also moving image. A display with roughly 1000 drops has already been tested and used for the display of live video.

Since the display is very physically present, it would initially be best to use it to visualize an experience that is equally sensual, where the metaphor of the installation is to 'wash' something from the air and make it visible on the ground in front of you. The primary presentation took place in the digital media department of UdK where most people are using wireless internet connections to communicate, which is how the idea of visualizing these conversations emerged. For achieving this, the packages were successfully "sniffed" from the air, parsed to readable text, processed into the output form of 'drops' and then displayed on the ground for everyone to read. This setup makes the installation Eavesdripping, which typographically in water shows the contents of data packages on the local wireless-network. It's important that not only the amount of communication is being displayed, but also that real content which moves through the very same space is shown - messages from instant-messaging-chats, emails and websites. In highly networked environments, much of the communication is happening silently and is disembodied over the mentioned channels. Eavesdripping creates a space within the space, where the sent words in the data packages are removed from their codification and rendered public for a very short time.

Other applications of the technology are also possible, for example the use of live video input to create a visual representation in the water, or the analyzation of movement around the installation to be displayed by the water surface.



Sascha Pohflepp (cc)2004

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