The aim of the project was to transport an idea into reality, and that, despite any obstacles. The idea was simple: to bring light where previously was shadow. A simple apparatus – an automatic mirror – would bypass the existing distribution of light as well as divert the rays of the sun. The mirror should be robust and easy to maintain, it should be simple to install and be so inexpensive to manufacture, that those who live in the darkest of dwellings could also afford it.
There are two ways of looking at light: light from the sun which illuminates things, which in turn reflect an image that impresses itself on the retina; and conversely, light – in the sense of enlightenment – that originates in the eyes, and is the ability to see and to differentiate things. A sun mirror functions in both these directions and is thus a reflecting apparatus in a double sense: it reflects the light of the sun and further, it brings the distribution of light into consciousness.


Inventions are not simply found among the plentitude of possibilities, but rather become available as solutions through the process of identifying a problem. The prerequisite for identifying a problem, in turn, is a vision to want to change something. Thus patent offices are actually museums of visions.
At the patent office, independent private inventors can be seen researching alongside employees of major companies. These are perhaps the last utopists, who imagine a world that has been enriched and transformed by their small or large invention. In the reference halls of patent offices they search anxiously for earlier patents that might obstruct their own patent application, and thus their vision. In patent office jargon they are called "artists."
The visions of the "artists," that is, of the private inventors in the patent office, are simultaneously always also personal utopias. The inventors dream of their invention enjoying worldwide distribution, and of the wealth and recognition garnered from the multiplication of royalties. With few exceptions this is not the case. The investment made towards the "invention" of a product is usually much less than the costs of its insertion into the market. Technological development is thus defined more through market demands than through the potential for societal benefit.

SAD – Seasonal Affective Disorder

Melatonin is a hormone of the pineal gland, which drives seasonal rhythms in animals and people. It is secreted at night, and only suppressed through daylight. Scientists assume that the neural pathways involved in the production of melatonin travel through the part of the brain that is responsible for the control of the many bodily functions which, in the case of depression, can get out of balance, such as eating, sleeping, weight control, sexual activity, etc.
It was first in the 1980s that winter depression as a result of light deficiency appeared on the agenda of medical researchers as the illness SAD (Seasonal Affective Disorder). Since then, light therapy has proven itself in the acute treatment of winter depression. SAD is not a rare disorder. In the USA, where the symptoms are more widely acknowledged in medicine than in Europe, one assumes that approximately 5 percent of the population suffers from regularly occurring winter depression.
The influence of light on mood and productivity is perceived to varying extent by those affected. Many of those who suffer from SAD are first inclined to blame themselves for their lethargy or depression, or on external situations, before coming to the realization that it is a lack of sunlight which depletes them of any energy to change their situation. It is has been documented that especially unemployed people, who spend long periods of time inside indoors, have an increased need for sleep.
Not all, but the majority of SAD-stricken are pulled out of their depression by means of light therapy with white light in a matter of three or four days: two hours before a light box with 2,500 lux, especially in the morning, or 40 minutes in front of a brighter lamp of 10,000 lux. If this is done properly, light therapy helps gently and without the side affects of antidepressants. Only a few with SAD go from one extreme at the beginning of the therapy to the other extreme: from depression to a hypermania.

Geographical Situation

Berlin lies at the 53rd latitude and has about 100 sunny days a year. In comparison, Freiburg in Breisgau, situated at the 48th latitude, has 220. The gray Berlin winter months are infamous for their short days. Already at the turn of the last century, a certain form of rickets, which was traced back to vitamin D insufficiency – that is, lack of sunlight – was christened the "Berlin Disease."
According to a North American study, the occurrence of SAD is contingent upon geographical latitude and thus on the duration of daylight. In Florida, only 4 percent suffer from SAD; in New York, 17 percent; in Alaska, 28. This North-South gradient, however, is not linear. Obviously other factors also play a role, not least of all the intensity with which people in certain cultural circles expose themselves to daylight.
In Scandinavia, several light cafés have opened in the last years, in which people come to "tank up" on light during the dark season. The cafés are furnished with full-spectrum light bulbs, which are also used in light therapy. Scientists believe that in the past, northern ethnic groups such as the Inuit, could only psychologically survive the long winter through regular consumption of fish cod and halibut liver oil, in which vitamin D is stored. Today, arctic dwellers help themselves with the corresponding tablets.

Light and Space

The provision of rooms with sunlight has a large influence on the existential condition of the people who live or work in them. Many biological rhythms are managed through the perception of light and dark, as day turns into night. In its spectral composition, sunlight transfers a cornucopia of information to the body about the atmosphere, air pressure and humidity, amount of dust or smoke. Changes in the sky's brightness, when clouds pass by, are also subconsciously perceived and processed.
Sunlight is thus a unifying medium between the inner world of a room and its surroundings. Artificial light sources can never completely replace direct sunlight. Dark or artificially lit office spaces reduce the motivation and the creativity of the employees working in them. Work efficiency sinks.
In many urban spaces the amount of solar irradiation per square meter would theoretically suffice, even in winter. Unfortunately, sunlight does not reach the level of the streets, where public life actually occurs. Vertical building blocks the path of the low-angled winter sun.

Solar Architecture

Long before luxurious penthouse apartments became popular in the 1960s, access to light has been a contributing factor to the urban social gradient.
In Berlin, the boom in densely built late 19th century-style architecture, with its hallmark cramped courtyards introduced shadow as problematic. Most desirable in the front houses, where the upper middle class lived, was the "Belle Étage" on the first floor, with its large windows, open to the broad sunny street. In the cramped back courtyards where the worker families lived, people were drawn to the uppermost floors, towards the light.
In the garden cities of the 1920s, a social reform concept was realized to increase worker productivity through sunny living spaces in an artificial village-like environment. This was also supposed to increase the birth rate. It was assumed that lack of light in the cramped city dwellings drove the workers into the bars at night.
Le Corbusier planned in the "Unité d'Habitation," in addition to huge windows and balconies, a communal rooftop for all apartment dwellers. The limited ground area, and thus the exposure to sunlight, was to be used collectively. In New York, whoever wants to build a high-rise must "purchase" the sun from those who will as a result be left in the dark. And mirrored high-rise facades in the narrow downtown streets are not merely supposed to be representative, but actually do reflect and disperse the precious light.
Today, ambitious architects develop complex technical light systems for prestigious construction projects. The largest percent of urban buildings is still comprised of old apartment buildings.


Sunflower seedlings make so-called nutational movements, such that the later emerging petal surface of the flower stands in a right angle to the rays of the sun; only at night do they for a short time stand horizontally. The young blossoms thus follow the passage of the sun (heliotropism). With time, the nutations stop, and the mature sunflowers rest pointing in the same direction: to the south.
The sun mirror must serve a technology that just as simply and confidently follows the path of the sun, like the heliotropic plants.


A sun mirror that rotates on two axes is mounted to a wall of the building, or mast, which is exposed to the sun. Now there are two decisive directions: the one is the direction from which the sun comes, and is variable; and the second is that in which the light is to be reflected – this always remains the same. According to the Law of Reflection, that "the angle of incidence equals the angle of reflection," the mirror must, in order to meet its target, remain so that the vertical axis of the mirror surface equals the spatial angle bisecting the direction of the sun and of the target direction.
The bisecting angle of a rotating axis in relation to its support allows itself, technically seen, to be realized through a gear with a reduction of 2:1. Heliostats are common in photovoltaic technology. In the simplest case they are equipped with two light sensitive sensors and a shadow-making "nose" in between them. If the sensor pointing towards the sun measures a light beam stronger than the sensor in the shade, then the motor receives an impulse to turn the apparatus in the direction of the sun beam, until the amount of light perceived is equalized on both sides again. The device follows thus the path of the sun.
This is the rudimentary concept for a sun mirror, as an automatic self-correcting system that is simple and sufficient for sustained continuous operation. It must be adjusted only once upon installation, and then accommodates itself to the sun path automatically. On the other hand, computer-driven systems must be programmed with all necessary cosmological data, with the geographical position and the time of day; and then execute the calculated necessary angle to the target surface with an extravagant and costly mechanism.

Satellite Dishes

The beginning of the 1990s witnessed the introduction of a new architectonic element: the satellite dish. It was a grassroots technology, popularized through the individual desire for access to the multitude of available television channels, rather than through the usual advertising campaigns. As an architectonic element, the satellite dish is a symbol for the common orientation of people living next to one another in their living units: the television. The satellite dishes are all directed towards the same point in space, where the satellite hovers invisibly above the earth. It is possible to orient oneself in the city according to them: they all point south.