Spy’s-eye View

Google Earth and its rival programs offer (civilians) a new way to look at the world

As best I can figure, I have spent 35,000 to 40,000 hours of my life sitting at a computer. This knowledge does not improve my mood or self-esteem. But it brings into sharp relief the handful of moments at the keyboard I can distinctly remember, each involving a time when I realized that the computer had just done something important and new.

In the late 1970s, I marveled at the discovery that I could use my very first computer (a Processor Technology SOL-20) to save something I had drafted, then change it later on without having to retype the whole thing. In the early 1980s, I watched a message I had written go to its destination electronically, through a 300-baud modem I clamped onto a telephone handset.

In 1993, I tried a program called Mosaic, one of the very first browsers, and was amazed to see pictures and documents stored on someone else’s computer show up on my own screen. In 1995, I entered a few words into a search box and within seconds got back some more-or-less relevant information, via the early search engine AltaVista.

That was it for truly memorable moments, until last year when I first tried Google Earth.

The addictive nature of this pro­gram stems from three ele­ments. One is a set of satellite and aerial photos of the globe’s entire surface, which Google has acquired from a variety of public and private sources. These vary greatly in resolution, but the sharp ones, which already cover most major populated areas and are steadily expanding in range, are unnervingly clear. I now take it for granted that I can pick out every building—homes, schools, offices—I care about in the United States. But I can also see the tiny house where my family lived outside Tokyo, complete with ten-foot-square “back yard,” and the red-roofed colonial bungalow we rented in Kuala Lumpur, which now sits in the shadow of the Petronas Towers, two of the world’s tallest buildings. The village where my wife and I once worked in Ghana, on the other hand, is just a green blur.

The next element is Google Earth’s viewing system, which lets you “fly” from point to point. This sounds trivial, but I think it can profoundly reorient people’s sense of geography. We are used to thinking of places as being arrayed along roads or rail lines, or linked by airline routes. Taking a Google Earth “flight” is like driving through a city you knew only through subways, and seeing the surprising ways the pieces fit together.

Finally, the program has an imperfect but tantalizing 3D feature. The contours of terrain and, in certain cities, the heights of downtown structures are built into the database. Although the program’s standard view is straight down from overhead, you can tilt the perspective, until you’re looking from a low altitude or even ground level. This gives a dramatic sense of how, say, a ski resort fits into the surrounding mountains, or how the fjords of Greenland would look if you approached from the sea. You can’t count on the program to have enough accurate data to make this feature work everyplace—those Petronas Towers, when seen at a tilt, look no taller than my former house—but where it works it’s great.

The basic version of the program, which does everything described in this article, is free (it requires a broadband connection). For now, it runs only on PCs, but its creator, John Hanke, says that a Mac version is about to appear. Hanke and others developed the program at a small company called Keyhole, which Google bought two years ago. (Microsoft has released its counterpart program, Virtual Earth, at its Windows Live site, http://local.live.com. This program doesn’t have the flying or 3D features of Google Earth, but it does have superior close-up shots of many U.S. cities, including “bird’s-eye” views of about a dozen cities so breathtakingly detailed that in some cases you can see the individual panes in the windows. You can also see some structures that have been blurred out of Google Earth—for instance, the vice president’s home in Washington.)

Together these elements make Google Earth fascinating. What makes the program important is the trait it shares with other big steps forward in computing, like the previous ones I recall so sharply. It is not an end in itself but a beginning of new opportunities for innovation by others, based on the new tools it provides.

A huge theme in recent discussions of the Internet’s future is the growing importance of “user-created content.” In the old-media days of the twentieth century, small groups of specialists produced books, newspapers, or broadcasts that larger public audiences could consume. Now millions of people publish their views over the Internet, by producing blogs, or rating products or services online, or posting pictures and Webcasts for others to view, or creating networks of like-minded people who can share recommendations about vacation sites or bikes or restaurants.

The tools that have thus democratized publishing—or that have en­abled user-created content, if you prefer—are many and varied. But they rest upon the fundamental units of all modern Internet activity: URLs, links, and words. A URL (uniform resource locator) directs a browser to a particular set of files on a particular computer somewhere on Earth (each Web “page” is really a collection of files). Links take users from one set of files to another. The words in a file, indexed by search engines or catalogued as “tags,” serve as a guide to Web page content.

Google Earth of course employs links and URLs. Its basic unit of classification, however, is not a word but a set of global positioning system (GPS) coordinates, pinpointing a location on the Earth with uncanny precision. The Google Earth view of my neighborhood in Washington shows a red truck parked down the street. The front bumper of that truck has a different GPS address from the windshield. And in the same way that a “traditional” blog, if we can use that term, might have links pointing to a particular news item or posting, Google Earth allows the equivalent of bloggers to attach annotations to specific geographical points. These overlays consist of pictures, written descriptions, Internet links, or other data tied to the GPS coordinates of a particular place. When a Google Earth user zooms in on that place, the link to the information appears, usually as a clickable icon or button.

Since last June, when Google released the program and its toolkit for creating these overlays, many people have gotten to work. As with online book reviews at Amazon.com or entries on Wikipedia (the online encyclopedia in which anyone can write or edit an entry), the information supplied can range from authoritative to bogus. But nearly all of it is interesting.

The easiest way to see what’s on offer is through sites like Ogle­earth.com and Gearthblog.com. They have news and screenshots, and links to files that create the overlays for Google Earth. You click to download overlays to your computer. Then, when Google Earth is running, you choose the overlays you want displayed. John Hanke of Goo­gle showed me a few examples, which ranged from the fanciful to the highly practical.

On the practical side is an overlay from Caltrans, the agency responsible for California’s freeways. When you display this data within Google Earth, it shows congestion conditions every mile or so along freeways in the state’s major cities. Clusters of red, orange, yellow, or green dots show you where traffic is moving and where it is jammed; any dot you click on tells the average speed of cars passing that point. A WiFi overlay shows the nearest available commercial hot spots. On a skiing overlay, you can click a blue snowflake symbol by major resorts and get detailed slope information and a link to the mountain’s Web site. An aviation site called FBOWeb.com offers a free demonstration showing the tra­jec­tories airliners are taking toward several major airports; by using the tilted view you can “watch” planes as they descend over Boston Harbor or through the Los Angeles basin for landing. You can display as many of these varied overlays as you choose, clicking on a check box to turn them on or off.

Less practical, but often more delightful, creations continue to proliferate. An overlay from Blogwise.com shows who is writing a blog in your city—or in Buenos Aires or Beijing—with a link to each blog. Another shows bird migration patterns. One called South 3.1 shows the route of Ernest Shackleton’s doomed Endurance mission to Antarctica, with pho­­tos and log entries matched to their locations. Another, covering the Mount Everest area, maps the course of a 2003 Everest expedition with aerial photos so sharp you can see individual tents. The Google Earth Community overlay has Wikipedia-style notes on interesting buildings and historic sites.

Perhaps the most open-ended potential involves Google Earth’s interaction with Flickr, the photo-sharing site run by Yahoo. More than 75 million photos have been stored at Flickr, many of them tagged by location—“Paris, Arc de Triomphe”—or “geotagged” with GPS coordinates. People pay to post these pictures, as a handy way to store files that can clog hard drives and to keep them all in one place; viewing access is generally free. Using the Flickr overlay, which works through a site called Geobloggers, you can see any available photos of the place you’re looking at. For instance, when displayed in addition to the Everest overlay, Flickr brings up pictures people have taken at the summit. When I’m looking at my neighborhood, I see Flickr photos of trees that were blown down two years ago in a hurricane. New shots pour into Flickr each day, and to similar sites like Panoramio.com, founded by two young Spaniards, which lets users easily link their photos to specific sites.

Google Earth is far less powerful than “geographic information systems,” or GIS. These are complex and often expensive programs that match economic, demographic, environmental, and other data to satellite views of particular locations. A county government might use GIS to combine data on population density, fire risks, and traffic patterns to find the right location for a firehouse. Businesses use it to decide where to place distribution centers or new stores. Scientists use it to track environmental trends.

But according to Jack Dangermond, founder and president of the world’s leading GIS company, ESRI of Redlands, California, the free services available under Google Earth will increase the public’s use of geographically linked information, for-pay and free alike. “There’s no way to connect a professional data set to Google Earth, so in a sense it is pretty thin,” he said. “But because it is spellbinding to customers, it can only build awareness of geography. And if this exposure makes citizens more spatially literate, they can accept more of their information this way and visualize more about their local situations.” Many governments already use GIS to let citizens see public data, from the residences of registered sex offenders to the tax assessments of buildings, homes, and lots. Within a year or two, he said, standard Web browsers will allow citizens to “fly” through this data or see it in 3D, using features like Google Earth’s.

“Honestly, I have no idea where this is going in the long run,” John Hanke of Google told me. “Ten years ago, this technology was the exclusive province of the U.S. intelligence community. Five years ago, it cost $14,000 for a single satellite image. Now there’s free, global high-resolution imagery.” The most significant use of the technology so far, he said, has been to provide “maps for places where they had no previous maps.” He read from a newspaper story about the headman of a Kurdish village who was using a Google Earth printout to plan the village’s rebuilding. “This is really inspiring to me,” Hanke said. “It’s the sort of thing that we thought might happen as this information is released and democratized.”

Fooling around with this program and its overlays has put a few more hours on my computer total. These hours seem better spent than most.