Airtexting is the visual transmission of text by moving a changing array of LEDs through the air. An airtexting array, also called an LED wand, operates similarly to the printhead of a dot matrix printer or a scrolling LED display of one light in width. However, the scrolling aspect must be provided by the viewer, in a simulation of the saccade, the rapid movement of the eye from and back to the object of focus, so that the successive one-pixel wide slices are read in space rather than superimposed. The psycho-perceptual illusion is similar to that experienced when writing letters in the air with a sparkler.
In 1980, physicist Bill Bell (b.1928) installed a piece titled "Lightstick I" at MIT, that demonstrated this principle. The work of his with which I am most familiar is set of twelve columns of LEDs at The Exploratorium in San Francisco along the high back wall of their exhibition hall. These columns are three LEDs wide, red, green, blue, and transmit patterns like sine-waves or sketches of an eye and the time of day. They are visible from nearly anywhere in the hall, with a slight dis-focus of the gaze and a pan of the head. It is also used for staff paging, as it takes a bit of experience to get used to reading. Bill Bell also produced the airtexting array on the exterior rear wall of The Temporary Contemporary annex of the L.A. Museum of Contemporary Art, a series of columns of LEDs that would flash "MOCA" so that drivers on Alameda Street could read the building’s name as they scanned traffic.
In the early-80s, a handheld keyboard and wand called the Sky Writer allowed that same sort of transmission of a message. It is still available, relegated to segments on late-night television shopping programs. In March 2003, Kyocera demonstrated a handheld device at CeBIT that included an airtexting array, a cellphone, a color display, a digital camera, an FM radio, and an MP3 player. An accessory shell will allow the Nokia 3220 Camera Phone to airtext, according to a press release from late May 2004. One wonders why we don't have these LED wands for the windshield wipers on cars.
References
Bill Bell’s website <www.subliminaryartworks.com/>
The Sky Writer <users2.ev1.net/~rik1138/Misc/IdealSkyWriter.htm>
Nokia’s press release <press.nokia.com/PR/200405/947495_5.html>
The Register’s review of the Nokia <www.theregister.co.uk/2004/06/02/nokia_shells_waving/>