In our time, GPS is a vital navigation technology, but it is also extremely fragile. Leaving aside the possibility of coverage, if a satellite fails to provide a signal or if a Denial of Service attack occurs, GPS is useless. But now, scientists may have invented a very good solution to this problem. It is a quantum accelerometer, which could provide navigation without GPS or other technology that requires the use of a satellite. The device uses lasers to cool atomic particles to extremely low temperatures and then measure the quantum wave properties of those particles as they respond to acceleration.
The result is an extremely sensitive device that is also much more reliable than conventional accelerometers. While existing hardware can help determine position to some extent by measuring velocity, it quickly fails without help from a satellite.
This new quantum "compass" isn't ready to replace the accelerometer in your phone yet, due to its bulk. For now, it's possible to use it in ships, trains, and other large vehicles where size and power requirements aren't a major factor. With it, public transportation networks could continue to operate even if GPS didn't work at all. The researchers also expect that the basic concepts used for the technology will help in scientific studies, such as the search for gravitational waves.
