An equally detailed vision of a virtual earth was laid out in another book from the same era, David Gelernter’s Mirror Worlds: Or the Day Software Puts the Universe in a Shoebox … How It Will Happen and What It Will Mean. “The software model of your city, once it’s set up, will be available (like a public park) to however many people are interested,” Gelernter predicted. “It will sustain a million different views. … Each visitor will zoom in and pan around and roam through the model as he chooses.” Institutions such as universities and city governments would nourish the mirror world with a constant flow of data. The latest information on traffic jams, stock prices, or water quality would appear exactly where expected–overlaid on virtual roads and stock exchanges and water mains. But just as important, mirror worlds would function as social spaces, where people seeking similar information would frequently cross paths and share ideas. They would be “beer halls and grand piazzas, natural gathering places for information hunters and insight searchers.”
On page 203 of Mirror Worlds is a striking architectural drawing showing a bird’s-eye view of a fictional city distinguished by elegant skyscrapers, broad avenues, and abundant parkland. Superimposed on the view are several blank white boxes where, in Gelernter’s hypothetical mirror world, information about the streets and buildings would be displayed. The caption describes the drawing as “an abstract sketch, merely the general idea” of what a mirror-world interface might look like.
If the sketch looks familiar today, it’s because thousands of views like it can be found using Google Earth or Microsoft Virtual Earth, complete with 3-D buildings and white pop-up info boxes. There are superficial differences: the Google and Microsoft cityscapes, for example, are photorealistic, at least in the limited areas where buildings are covered with “skins” based on photographs of the real structures (like the virtual Amsterdam in Second Life). But Gelernter anticipated so many features of today’s virtual-globe software that these programs could readily serve today as the windows on a mirror world as he imagined it. In fact, Google Earth users can access a growing library of public and personal data, from national borders to Starbucks locations, jogging routes, and vacation photos–in effect, any kind of information that’s been “geocoded.”
Open geocoding standards allow anyone to contribute to the Google Earth mirror world. Just as Web browsers depend on HTML to figure out how and where to display text and images on a Web page, Google Earth depends on a standard called KML, the keyhole markup language, to tell it where geographic data should be placed on the underlying latitude-longitude grid. If you know how to assemble a KML file, you can make your own geographical data appear as a new “layer” on your computer’s copy of Google Earth; and if you publish that KML file on the Web, other people can download the layer and display it on their own computers.
This layering capability transforms Google Earth from a mere digital globe into something more like a 3-D Wikipedia of the planet. The results can be unexpectedly arresting. In one recent example, the U.S. Holocaust Memorial Museum worked with Google to create a layer highlighting the locations of 1,600 villages ravaged by the Sudanese government’s ongoing campaign to wipe out non-Arab tribes in the Darfur region. By zooming in on these locations, a user can see the remnants of the actual settlements destroyed by the Janjaweed, the government’s proxy militia. The closest views reveal that house after house has been reduced to a crumbling wreck–roofs burned away, contents apparently looted. Pop-up boxes contain testimony from survivors, statistics on the displaced populations, and dramatic, often grisly photographs taken in the field or at refugee camps [Google Earth link].
This evidence of genocide is attached to the same digital earth where most U.S. residents can quickly zoom and pan to North America and look down upon their own houses or their children’s schools. With the barrier of distance dissolved, it’s hard not to feel a greater sense of connectedness to tragedies abroad. Which is exactly what the Holocaust museum intends: “We hope this important initiative with Google will make it that much harder for the world to ignore those who need us the most,” museum director Sara Bloomfield said. (The Sudanese themselves cannot download Google Earth, owing to U.S. restrictions on software exports.)