Introduction

This blog is both a hobby and an experiment.

A favorite hobby of mine is to explore the history of New York. New York is much younger than the great cities in Europe and Asia. The lack of length, though, is balanced by the density of available information. There is plenty of pictorial and photographic material to visually document how New York has changed (or not) over time. Unlike cities in the Old World, we have plenty of visual documentation to see the city through the eyes of people that lived here many generations back. Sometimes it is shocking to see how much a place has changed, sometimes it is shocking to see that the place is the same for more than a hundred years.

In this blog, I will post series of photos that depict the same place, across different time periods. Of course, I am not the first to come up with this idea. The links on the side can point you to various other projects, including the "New York Changing" book, the New York Time series "Then and Now", or the "Invincible Cities" project documenting the recent changes in Harlem.
The digital collections of the Library of Congress and of the New York Public Library are irreplaceable sources of material for old New York. The only thing needed is to match these old photos with modern ones.

So, what is the experiment?

People that read my "professional" blog know that I have used Mechanical Turk extensively for research. In this blog, I use Mechanical Turk slightly differently. I asked Turkers to find matching photos that depict the same spot of New York both in the past and now. An impossibly difficult task for a computer; a task that many Turkers found incredibly enjoyable.

So, all the sets of photos in the blog entries (and actually many of the links) are contributed by workers on Amazon Mechanical Turk. The quality of the workers there is amazing. Despite the low payment, many workers contributed not just one but multiple sets of photos. Other sent links to useful websites, and told me about the projects that I mentioned earlier. In fact, most of the material that you see in the blog would not have been discovered without the help of Mechanical Turk!

My role in this blog is to simply select which of the discovered photos to post. I decided to post everything in sepia, to abstract away the effect color and let the viewer focus on the content of the scene. I will also post only photos for which it is possible to download a high resolution copy, or for which at least high-quality prints are available. I would personally like to have physical copies of the photos and display them side by side and I assume that many others would like to do the same.

Many of these photos are best enjoyed offline and preferably standing at the very same spot.