Historypin.com — "Build a better time machine"

Below, excerpts from Peter Wayner's September 5, 2012 New York Times story about the rise of websites which marry technology and history.

Caption for the photo above, which accompanied the Times article: "Jon Voss posed for a photo at the Jefferson Memorial last year, right, recreating a photo of his father, Joe, from decades earlier. He shared it on the site historypin.com."

Jon Voss went to Washington last year with a very specific plan: to pose for a photo at the Jefferson Memorial with the Washington Monument in the background.

He wanted that particular photo because his father, Joe, was photographed in that spot while living in Washington between 1948 and 1952.

The younger Voss wanted to recreate the photo right down to standing on the same block of marble.

Mr. Voss had a good reason for his meticulous recreation. Once he got the shot, he shared it with the world on Historypin.com, a Web site with ambitions to create a large collection of historical photos cataloged by location and date.

The two photos are now part of the Web site's collection of photos taken at the Jefferson Memorial. If a viewer clicks on one, a slider allows that person to transition between the photos of the younger and older Vosses, blurring the two moments in time.

"That’s what I set out to do with this project: build a better time machine," Mr. Voss said.

As more digital cameras — and smartphone apps as well — automatically attach location and date information to photographs, our ability to organize the photos in revealing new ways is being expanded. It is a new concept for many sites with archives of old photos, but it is beginning to catch on.

Many smartphones, equipped with GPS chips, now include location information in the metadata of the photographs taken by the phone’s camera. These include the latitude and longitude in a set of attached numbers called the EXIF (Exchangeable Image File Format) values. It also contains the make and model of the camera, the shutter speed and the aperture.

Regular digital cameras with SD memory card slots can also add location information automatically if the photographer uses an Eye-Fi card. By triangulating known Wi-Fi hot spots in the vicinity of where the picture was taken, the card records an approximate location with the photo. The Eye-Fi card works well in dense urban environments where there are many Wi-Fi hot spots.

A number of photo-sharing sites are being transformed from places to look at pictures into tools to connect historical documents and give more people a sense of history.

Historypin.com is clearly one of the most ambitious of these sites. It is aggressively courting local historical societies to encourage them to upload their archives to the site. Already, several hundred institutions have used the site's bulk uploading tools to add thousands of photographs.

The public is also encouraged to upload photos and add any narratives that go along with the pictures. The site offers a unique tool that helps align the historical image with the current picture of the location available from Google Maps’ Street View. This provides a current image for comparison in many cities.