One of 100 billion nerve cells in the human brain, the neuron waits, ready. Suddenly, a neigh­bor releases signaling molecules with an attention-getting message, like the irresistible chatter of a next-door gossip who has a hot tidbit. The receiving cell, excited, experiences fluctuations in ion concentration, creating a small electric current flow. Then it, too, releases communication signals down the line. The cascade continues until a large region of the brain is buzzing with heightened processing. Imaging scans would reveal the additional blood flow and electrical activity as thousands of neurons flare in response.

A good idea can be like that—it stirs everything up—whether it is being shared throughout a network of cells in one person’s brain or in the world at large, through a community of people. Good ideas motivate us to action. They lead us to reflect on how to make things better. They spur us not to settle only for what is possible today.

That is why we are celebrating a set of innovative projects with our cover story for this issue, “World Changing Ideas.” In this new annual section, we detail 20 ways to push the frontiers in areas that are critical to improving modern life: energy, transportation, environment, electronics and robotics, and health and medicine. Some of the inventions are dazzlingly simple—such as how Solar­City, headquartered in California, removes the biggest obstacle to solar-panel installations by homeowners: their upfront cost. Some are head-thumpingly obvious in hindsight, such as employing zoning to thwart the currently nearly uninhibited resource depletion of the world’s oceans. (For more on that topic, see this month's Perspectives.) And some, such as Hewlett-Packard’s Central Nervous System for the Earth, a planned array of up to a trillion pushpin-size sensors for the globe, are mind-bendingly sophisticated in their scope and potential implications.

All the concepts in this section inspire hope that advances in science and technology will keep improving our lives in the years ahead. Read the article, then, for a look at the future.

One place where humanity’s creative problem-solving abilities are in high demand is in the battle against global climate change. While government policy leaders debate their countries’ responses to this phenomenon, it continues to disrupt ecosystems with unsettling speed. As Katey Walter Anthony describes in “Methane: A Menace Surfaces,” thawing Arctic permafrost is doing more than causing damage by heaving and cracking the foundations of buildings: it is also creating lakes that emit methane, a gas that, pound for pound, has more than 20 times the heat-trapping power of carbon dioxide. These new methane emissions could accelerate the process of global warming. Walter Anthony’s research serves as yet more evidence for the great need to address this problem. But will we act on our ideas in time?

Note: This article was originally printed with the title, "Wanted: Bright Ideas."