Let’s pretend we are in science class for a moment. When a plane is traveling at the speed of sound, it is literally compressing the air at the front of the wing and leaving an area of negative pressure in the plane’s wake. What results is actually two sonic booms that are oftentimes experienced as a single sound. The sonic boom is a cool effect, but it’s not so good for people who live on flight paths, nor is it likely all that good for the wildlife in the area either. But we want to travel at that speed. So, researchers at MIT and Stanford University have come up with a biplane design that effectively eliminates this problem. If you look lengthwise at the wings, you get a couple of triangles pointed at eachother with flat edges on the outside. In effect, the shockwaves get reflected, canceling out the sonic boom effect altogether.
The problem with this design, which was originally conceived by Adolf Busemann in the 1930s, is that it doesn’t generate enough lift at sub-supersonic speeds. The new design by MIT and Stanford allows for the wings to change shape over the course of the flight, giving you the best of both worlds. Shown here is one example as produced by Tohoku University in Japan. Ground level shock waves are reduced by 85 percent. It’s still a work in progress, but this could be the future of commercial flight.[Source]