2. The Problem: Associating Information with Places

Atoms in Places: Consider the fundamental problem of how to associate useful information with a place. An everyday solution to this problem is to put up a sign. Signs provide useful information about places, and can be found wherever people go: names of streets, billboards along highways, addresses on buildings, directories in buildings, and numbers on doors. Beyond simple signs there are more complex ways of providing messages in places: notes posted on bulletin boards, instructions placed on machinery, menus outside restaurants, exhibit information at museums, audio messages on subways, and TV monitors in airports. Going one step beyond non-interactive signs and messages, people can get information associated with a place using computer kiosks, courtesy telephones, and of course real people at information desks. Access to the information associated with a place supports intelligent, efficient, coordinated human behavior. It may sound over blown, but civilization as we know it would not be possible without the humble sign! Signs, along with wrist watches and thousands of other everyday things, augment reality to make us smart [4]. And yet, we all value the time and places when we can shed our technological and cultural "artifact skin." Getting away from it all is an important design point.

To support and coordinate diverse activities we often need to associate information with places. Interestingly, humans are not the only creatures that do this. Nearly all species of ants rely on leaving molecular messages at places to coordinate activities such as gathering food, clearing waste, building structures, and defending the colony. Configurations of atoms (physical stuff) is one way to place useful information where it's needed.

Atoms on People in Places: Of course, associating useful information with a place does not necessarily require permanently placing signs, messages, people, kiosks, or telephones at locations. For many activities, people can simply remember the information they will need at a place or bring along the information in the form of guide books, instruction manuals, crib sheets, or even other people (colleagues, tour guides). Furthermore, given the availability of radios, cellular telephones, mobile computing devices, and wireless access to the World Wide Web, we now possess an even wider array of technological gadgets to serve up useful information at a place. These latter techniques exploit portable devices and do not require permanently placing atoms (physical stuff) at the places of interest. Nevertheless, because portable devices are used in many different places to access a great variety of information, people must search for the relevant information associated with the place of interest.

Atoms with Location Sense on People in Places: Given a mobile computing device with "location sense," it is sometimes possible to overcome the problem of manually searching for useful information associated with places. The term "location sense" was coined by Rao Machiraju to refer to a capability of a device that can ascertain its location. A device with location sense can automatically bring up information about its location. These devices often incorporate GPS (Global Positioning System) and/or INS (Inertial Navigation System) components to determine their locations. Alternative positioning techniques include: triangulation based on dead reckoning to known locations on a map, tracking stations that provide telemetry data, and beacons (physical stuff) placed near all locations of interest.

The Illusion of Bits in Places: Given wearable personal video systems with location sense wirelessly communicating with servers that index information by location, it becomes possible to create the illusion of bits in places. This particular integration of technologies is inevitable, and done on a planetary scale creates a WorldBoard SPECIES. The inevitability of this integration is most apparent when shopping at Fry's. Three separate aisles contain the wireless devices (cellular phones), positioning devices (car navigation, and hiker navigation), and personal viewing devices (video game glasses, and personal video displays). Each separate technology is generating increased competition, taking up more shelf space, as prices plummet. Their integration is inevitable, and the result will be a new SPECIES - a planetary augmented reality system referred to in this paper as WorldBoard. If the illusion of bits in places is "good enough," then our notion of place changes and we begin to think about not just atoms in places, but bits in places.