Mapping the Shadows of New York City

Midtown Manhattan in the winter.

From the winter shadows cast on the Hudson from One World Trade to the bright, sun-dappled street corners of Midtown Manhattan in spring ...  all of the shadows produced by thousands of buildings in New York City over the course of one day mapped.

A time-lapse view of Madison Square Park. Chang W. Lee/The New York Times

"Calculating the length and shape of a shadow cast from a simple object can be easily done with pen, paper and some basic math. But architects use a more sophisticated method known as ray tracing; it simulates the effects a ray of light can have on a building and its surroundings. Most analyses of shadows study just a few buildings at a time. What made it an interesting problem for the researchers at the Tandon School of Engineering at New York University was how to do it at a scale so you could quickly study whole neighborhoo
ds."

More: The New York Times