Quantum navigation systems are being tested in Britain. Last month there was a successful test flight of an aviation system, and a system is being tested on test trains on the London Underground. (It’s not clear to me whether these systems are related, but the U.K. has apparently been making a big push into quantum tech lately.) Quantum navigation is essentially quantum mechanics applied to dead reckoning, using the properties of supercool atoms to measure change of position. The advantage of the system is that it’s self-contained: it doesn’t require a GPS signal or navigation beacon to triangulate from, which makes it resistant to jamming or spoofing—and considering how essential real-time location data has become, and how easy it is to disrupt location signals, the appeal of a self-contained solution is self-evident.