What will quantum computing actually look like?

The field of quantum computing, like qubits themselves, exists in a state of indeterminacy, with multiple companies making big claims about wildly different approaches. On Thursday, DARPA—the Defense Advanced Projects Research Agency—launched its latest effort to sort practical approaches from chimeras, handing contracts to 15 companies that will attempt to benchmark their work. So little is known about the field that there is no way—at least, not yet—to predict what