The artist Olafur Eliasson--probably best known for installating four 90-foot artifical waterfalls on New York's rivers--is out with his newest work, Multiple Shadow House. It's a doozy.
On view (for free) at the Tonya Bonakdar Gallery  through March 20, it consists of a simple series of rooms, each one lit by a bank of lights. Here's the optical trick: The individual lights are all different colors, but the create white light when they all blend on a single wall. As visitors walk in front of the light sources, that hides certain colors--thus freeing the rest to reveal themselves as colored shadows.
You'd think something like this would only be reserved for CGI--but it's amazing to interact with:
Eliasson is a polymath who's designed everything from bridges (which we covered here ) to cars (which we covered here). But this piece is where his true skills lie--that is, using optical effects and light to create spell binding, immersive works, such as these two:
The piece that made Eliasson famous was a gigantic indoor sun and mirrored ceiling that he installed in the cavernous main hall of London's Tate Modern:
But before that, he worked on a smaller scale, though the works were just as amazing, such as the fantastically beautiful and nearly impossible-to-photograph Beauty, which consists simply of a misting mechanism, a spotlight, and a darkened room . When you're inside it, it seems like you're walking through a rainbow-colored ghost: