The Economist   In an article published in 2012 John Preskill, a theoretical physicist, posed a question: “Is controlling large-scale quantum systems merely really, really hard, or is it ridiculously hard?” Seven years later the answer is in: it is merely really, re

The Economist   “Nature isn’t classical, dammit, and if you want to make a simulation of nature you’d better make it quantum mechanical, and by golly, it’s a wonderful problem because it doesn’t look easy.” With those words, in 1981, Richard Feynman, an American phy