Homepage photo credits: i. Vasiliy Vishnevskiy / 123RF. ii. Cropped version of "Fog (water particle) wind tunnel visualization of a NACA 4412 airfoil at a low-speed flow (Re=20.000)" distributed under the same license as the original. http://en.wikipedia.org/. Copyright © 2010 by Georgepehli. The image is released to the public domain courtesy of Smart Blade GmbH (www.smart-blade.com). License: CC BY-SA 3.0