For December, we are delighted to publish our annual special issue, "World Changing Ideas," about innovations that can make a better world. The magazine features a stepped cover that allows two extra editorial covers to show through for readers. The three-cover treatment, developed with photographer Dan Saelinger, helps us realize some of the issue’s World Changing Ideas, many of which are all still in their formative stages, including the idea of "The Machine That Would Predict the Future" and "A Computer Chip That Thinks." For the innermost cover, we created a more general World Changing Ideas light bulb illustration that could work as a stand-alone cover in our many international markets. In the spirit of innovation and collaboration, we invite you to vote below on the cover that you prefer.