Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Technology

What the Heck is Google Earth Doing to the Bridges of Our Fair Planet?

DiscoblogBy Veronique GreenwoodApril 14, 2011 6:17 PM

Newsletter

Sign up for our email newsletter for the latest science news

Perusing Google Earth’s quilt of aerial images is good for hours of stalkerish fun (Find your house! Find your ex’s house!). But every now and then, Google's geo toy can also bend the fabric of reality—literally:

60_millau-bridge-e1302722019462.jpg

Something’s wrong with this picture...

60_la2-e1302722188207.jpg

Get ready for a bumpy ride!

Artist and programmer Clement Valla

has discovered 60 strange, beautiful scenes

where Google Earth’s mapping has gone awry, as you may have seen in a post on Boing Boing

. So what's really happening in these pictures? Here’s Valla's explanation:

The images are the result of mapping a 2-dimensional image onto a 3-dimensional surface. Basically, the satellite images are flat representations in which you only see the topmost object—in this case you see the bridge, and not the landmass or water below the bridge. However, the 3D models in Google Earth contain only the information for the terrain--the landmass or the bottom of the ocean. When the flat image is projected onto this 3-dimensional surface, the bridges are projected down onto the terrain below the bridge. In other words, the bridge appears to follow the terrain that it actually goes over.

The view is further complicated by the shadows in the aerial images, which cue our brains to look for depth. When 2D images overlay nicely on the 3D terrain data, these cues help everything look normal. When they don't...fascinating disaster ensues.

60_deception-pass-e1302722247650.jpg

This one just screams for roller-coaster sound effects: WheeeOOOOOAAAAAAaaaah!

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.

Subscribe

Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%

Subscribe

Already a subscriber? Register or Log In