I have always had a soft spot for the philosophical dreamers among us, and the ancient alchemists are no exception. Maybe it is partly because, in eighth grade, I was a serious little person with a 100 average in my science class and a very proud member of an after-school club called the Alchemists. (Our main function seemed to be to bring order to the Bunsen burners and various flasks.) But I think, beyond that, I have always admired the raw ambition of trying to transform something that has little value (such as base metals) into something that has a great deal (such as silver and gold).

Of course, the process of science is the major tool today for shaping the world in material ways that help to improve human lives. And with an increasingly crowded, warming world, we are far less interested these days in transforming dross into precious metals than we are in developing solutions that allow us to create a sustainable future.

In this issue's cover story, “How Supercomputers Will Yield a Golden Age of Materials Science,” Gerbrand Cedar and Kristin Persson describe a modern take on alchemylike conjuring: the ability, as our authors explain it, to “design new materials from scratch using supercomputers and first-principle physics.” Manufacturers of cars, planes and other such equipment have been designing virtually for many years, they write. Now materials scientists are joining them, working at the level of quantum mechanics.

That feature article is part of our annual report on “World Changing Ideas.” We debuted this special section several years ago to recognize innovation that is ready to spring from the labs in a practical, significant way. Among this year's thought-provoking notions we offer “soft” robots, flexible smartphones, ways to treat illnesses by manipulating the genes in our gut microbes, toolbox-size labs to detect bad medicines, and snap-together bridges and planes.

Control over our world is hardly firm, of course. In fact, as you will see in “The Internet Has Become the External Hard Drive for Our Memories,” by Daniel M. Wegner and Adrian F. Ward, our own technologies are molding us in turn. In their article, you will learn how our increasing reliance on tools such as Internet search engines is actually diminishing our powers of recollection. At a recent corporate dinner, I saw it in evidence. Someone asked, “Who said, ‘Absolute power corrupts absolutely’?” I shouted the answer. After a pause, several people whipped out smartphones to check because nobody else could remember. If you can't either, now you can always look it up.