Using light as a shared shorthand within cities
By Jane Slade
When light-driven information technology jumped from the desktop into our hands, a new gestural language was born. We now utilize an entirely new way of communicating with technology through the gesture of our hands across screens. A small swipe down from the center, two fingers to zoom, and many other shorthand gestures create more ease and efficiency when communicating with technology.
With the development of smart controls, lighting also holds the potential for the creation of a gestural language based on movement and patterns of use. Yet when we default to shining light through the night at constant brightness, we not only create incalculable harm for humans and wildlife, but we also miss an incredible opportunity to communicate with one another and to be responsive to wildlife. In the interstitial space between light and darkness, there is an opportunity to create language, shared meaning, ritual, connection, and a more symbiotic way of illuminating at night.
The gestural use of light and darkness has already begun. Cities are starting to adjust lighting to symbiotically respond to the movement and migration of animals. Each year, light at night leads billions of birds astray, causing fatal strikes into buildings. This has contributed to a shocking overall decline of nearly 3 billion birds in North America since 1970. Yet we can now predict migration patterns better than ever with advances in predictive technology such as BirdCast, which uses radar to forecast real-time bird migration. To protect wildlife, many cities are utilizing this modern data and passing laws to turn lights out.
But the possibilities extend well beyond gestural responses to wildlife patterns. Indeed, light can also be used as a gestural language to share information within communities. Weather beacons are a good example of using light as a shorthand language. In Boston, the light on top of the old John Hancock building broadcasts the weather status to the city. As the old poem says:
Steady blue, clear view.
Flashing blue, clouds due.
Steady red, rain ahead.
Flashing red, snow instead.
The precedent of weather beacons lays the groundwork for combining city infrastructure with a more gestural way of communicating within communities. In comparison, billboards or screens tend to deliver visual information in words, images and video that is quite localized to downtown areas. Moreover, electric signage is a major contributor to light pollution. Yet the ubiquity of city streetlights is an opportunity to develop a new gestural language and medium for communication altogether, with infrastructure that can also be dark-sky friendly.
One of the distinctive aspects of gestural language is that it utilizes a shared shorthand instead of literal communication. Gesture efficiently communicates quick bursts of information while being intuitive and adaptive, with the possibility of getting smarter over time. When the Red Sox won the World Series, the top of the old Hancock flashed blue and red. This non-verbal gesture denotes a shared lore that generates a bond and a sense of community for Bostonians. It also inspired a new line to the coded poem: Flashing Blue and Red, when The Curse of the Bambino is dead!
Sharing a common shorthand knowledge elicits a much different feeling for residents than literal information. It is as if there is a secret form of communication and you have to be in the know. This interpretation of light also mimics the responsive relationship that wildlife takes from light cues. If we begin to use light in the form of non-verbal cues and gestures, then we also open up to new forms of connection and ritual.
This model of gestural communication with pulses of light and color could be applied much more broadly across the infrastructure of city light poles to transmit gestural information understood by a city’s residents, such as communicating the timing of civil dawn, civil dusk and potentially civil midnight, the start of selected time period for a community’s lowest light levels or Full Darkness Hours (FDH). Instead of tolling a bell, gestural light cues can silently indicate the timing of shared light within communities.
The creation of a gestural light language introduces a new medium to disseminate public information, allowing a forum and dialogue with the public about the shared use of light, including more transparency about the importance of natural darkness. For many communities, the conversation about light pollution has not yet taken place. Moreover, there is boundless creative potential to develop gestures and dialogue for other types of information, from weather, sports and lighting schedules, to information about bird migrations, meteor showers, as well as messaging during times of public emergencies.
Thus far, much of the gestural language of light in cities has focused upon façade lighting. Illuminating façades can be a beautiful form of gestural communication, yet there are more and more façade lighting projects taking place, turning cities into walls of light that contribute to increased illumination all over the planet.
The meaning of light diminishes significantly when it is used ubiquitously at night. In current lighting practices, light at night is used indiscriminately due to a lack of awareness about the importance of natural darkness for the health and well-being of all living things. The planet is experiencing exponential increases in light pollution as we struggle to find meaning through an unsustainable race to the brightest. In our blinded focus on light, we are overlooking the subtle powers of nuance, gesture and dialogue. Without the contrast of darkness, light is reduced into a weak and polluting tool of communication.
If we are to get the stars back, we will need to implement lighting and darkness plans that embrace natural, nightly darkness most of the calendar year, and consider light at night more judiciously.
Lighting controls offer unparalleled ability to reclaim darkness in order to have a more intentional conversation with light. Perhaps in the future, communities will enjoy light festivals that punctuate long periods of natural darkness; building façades will be allotted a total amount of Unnatural Lumen Hours (ULH) to use per year; communities will turn lights off when the human need subsides; modern data about wildlife will build more resilience into our designs; outdoor light levels will adjust to fluctuating ambient light levels based on the time of day, year, and weather; rapid experimentation with lighting controls will seek to maximize visual harmony and balance with the natural daylight cycle; gestural light language will enrich communities with new forms of connection and ritual.
Today, much of the discussion of light pollution focuses upon our disconnection from the stars, but massive disconnection is also taking place here on Earth. Light is everywhere; it has met us at every front of modern life. By pushing darkness out to the edges of existence, we have disconnected both humans and wildlife from the meaning of light. If we can regain control of light on the planet, the interstitial space between light and darkness holds great promise to develop a more symbiotic balance with the natural world, and a more inclusive, nuanced and gestural language with light.