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Just as anyone can create a new layer for Google Earth, anyone with basic 3-D modeling skills can add buildings, bridges, and other objects to it. Google Earth uses the open Collada 3-D modeling format, which was originally created by Sony as a way to speed the development of video-game worlds for the Playstation Portable and the Playstation 3. Using a Google program called SketchUp, amateur architects have built thousands of Collada models and uploaded them to the Google 3D Warehouse, a free library of signature buildings and other 3-D models. Larger organizations around the world now have terabytes of Collada-formatted virtual objects in storage and can easily transform them into data layers for Google Earth. That’s what the city government of Berlin did in March, when it published a KML layer containing a meticulous 3-D model of the city, prepared as part of a new digital infrastructure for city management and economic development [Google Earth link]. The model is so finely detailed that a deft user of the Google Earth navigation controls can steer the camera through the front door of the newly renovated Reichstag and into the chambers of the German parliament.

But a true mirror world shouldn’t be static, as the Berlin model and the Darfur layer are; it should reflect all the hubbub of the real world, in real time. As it turns out, KML also supports direct, real-time exchanges over the Internet using the hypertext transfer protocol (HTTP), the basic communications protocol of the Web. One hypnotic example is the 3-D flight tracker developed by, a company that offers online flight-planning tools for general-aviation pilots and enthusiasts. Download the KML layer for one of the eight major U.S. airports that Fboweb covers so far, and tiny airplane icons representing all the commercial aircraft heading toward that airport at that moment will be displayed at the appropriate altitude in Google Earth [Google Earth link]. As time passes, each flight leaves a purple trail recording every ascent, turn, and descent, all the way down to the runway. It’s a plane-spotter’s dream.

Microsoft, as one might expect, isn’t far behind Google in its effort to bridge map worlds and the real world. Scientists at Microsoft Research are perfecting a system called ­SensorMap that collects live data from any location and publishes it in Windows Live Local (the latest name for Microsoft’s online 2-D maps) or Microsoft Virtual Earth. Researchers at Harvard University and BBN Technologies in Cambridge, MA, won a grant from Microsoft this spring to create a SensorMap interface for “CitySense,” a network of 100 Wi‑Fi-connected weather and pollution sensors they’re installing in Cambridge. Other scientists, however, are already using Google Earth to monitor live sensor networks. At the Center for Embedded Networked Sensing at the University of California, Los Angeles, researchers have connected a network of wireless climate sensors and webcams in the James Reserve, a wilderness area in California’s San Jacinto Mountains, to a public KML layer in Google Earth. Click on an icon in Google Earth representing one of the reserve’s nest boxes, and you get a readout of the temperature and humidity inside the nest, as well as a live webcam picture showing whether any birds are at home [Google Earth link].

“Google Earth itself is really neat,” comments Jamais Cascio, the Metaverse Roadmap coauthor. “But Google Earth coupled with millions of sensors around the world, offering you real-time visuals, real-time atmospheric data, and so on–that’s transformative.”

Indeed, it’s important to remember that alongside the construction of the Metaverse, a complementary and equally ambitious infrastructure project is under way. It’s the wiring of the entire world, without the wires: tiny ­radio-­connected sensor chips are being attached to everything worth moni­toring, including bridges, ventilation systems, light fixtures, mousetraps, shipping pallets, battlefield equipment, even the human body. To be of any use, the vast amounts of data these sensors generate must be organized and displayed in forms that diagnosticians or decision makers can understand; “reality mining” is the term researchers from Accenture Technology Labs, the MIT Media Lab, and other organizations are using for this emerging specialty. And what better place to mine reality than in virtual space, where getting underneath, around, and inside data-rich representations of real-world objects is effortless?

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