WTF IS QUANTUM

YOU'VE HEARD A LOT ABOUT IT. DO YOU TRULY UNDERSTAND IT? WE'RE GUESSING NO. ONCE AND FOR ALL, A CLEAR AND COMPREHENSIVE PRIMER ON THE NEXT COMPUTING REVOLUTION.

- Harry McCracken

COMPUTING REVOLUTIONS ARE SURPRISINGLY RARE. DESPITE EXTRAORDINARY TECHNOLOGICAL PROGRESS FROM THE FIRST GENERAL-PURPOSE DIGITAL COMPUTER- 1945'S ENIAC- TO THE SMARTPHONE IN YOUR POCKET, BOTH MACHINES WORK THE SAME FUNDAMENTAL WAY: BY BOILING DOWN EVERY TASK INTO A SIMPLE MATHEMATICAL SYSTEM OF ONES AND ZEROS. FOR DECADES, SO DID EVERY OTHER COMPUTING DEVICE ON THE PLANET.

Then there are quantum computers—the first ground-up reimagining of how computing works since it was invented. Quantum is not about processing ones and zeros faster. Instead, it runs on qubits—more on those later—and embraces advanced physics to take computation places it's never been before. The results could one day have a profound impact on medicine, energy, finance, and beyond—maybe, perhaps not soon, and only if the sector's greatest expectations play out.

The field's origins trace to a 1981 conference near Boston cohosted by MIT and IBM called Physics of Computation. There, legendary physicist Richard Feynman proposed building a computer based on the principles of quantum mechanics, pioneered in the early 20th century by Max Planck, Albert Einstein, and Niels Bohr, among others. By the century's end—following seminal research at MIT, IBM, and elsewhere, including Caltech and Bell Labs—tech giants and startups alike joined the effort. It remains one of the industry's longest slogs, and much of the work lies ahead.