Other scientists think that experimental research, such as wind tunnel testing, and computational research are both needed. Many times the results from a wind tunnel test are compared to the results predicted by the computer. If one set of values is very different from the other set, then we know that something is wrong. Scientists use computation tools to solve many different types of problems. Computers can predict how automobile engines mix air and fuel together, how rivers and oceans move water around the world, how blood is pumped through the human heart, or even how winds on one part of Earth can affect the weather somewhere else in the world.
Pilots sit in a simulator that looks just like the cockpit of a real airplane.
As the pilot moves the control stick, the entire simulator moves up, down, and around and the computer-generated scenery outside the windows changes, giving the pilot the feeling that he or she is actually flying. Flight sim is not just used during airplane design. New airline, combat, and even space shuttle pilots get trained in flight simluators before they fly the real thing. The world's largest motion-based simulator is the Vertical Motion Simulator at NASA Ames Research Center. Because it stays on the ground the whole time, the simulator has to provide different cues or signals to the pilot to make the experience as authentic as possible.