The compass is one of the oldest technologies in the world rather than the latest. The first ever compasses, based on an iron needle that aligns itself to the Earth’s magnetic North and South Poles, are believed to date from around the 2nd century BC and originated from Hang Dynasty China. According to the History of Compass website, the devices were initially used for a variety of alternative purposes such as divination, fortune-telling and geomancy, for finding precious gems and in Feng Shui before it was discovered that their real value was in navigation and orientation.
Over the millennia since compasses have been used to safely guide travels over land and sea, the basic technology has barely changed. However, in recent years use of the trusty compass has fallen out of favour, replaced by GPS technology, which works by bouncing signals off a global network of around 30 satellites. Locations are pinpointed based on their relationship to the position of these satellites, at least four of which are ‘visible’ from any given point on the Earth’s surface unless obstructed by large buildings or geographical features.
The technology that the Global Positioning System (GPS) is based on was initially developed by the U.S. military and has since developed into the de facto global navigation system. However, GPS’s reliance on satellite signals is a weakness and means that it can be blocked, intercepted or masked. When this is done deliberately, it can be a major security issue.
However, British scientists, backed by funding from the UK’s Ministry of Defence, have now developed a ‘quantum compass’ that, completely self-contained and independent of the need for external signals, may solve that vulnerability. The device’s official name is a quantum accelerometer and it works by measuring changes to an object’s velocity over a given period of time. It does so by measuring the movement of atoms at a temperature close to absolute zero. Maintained at this ultra-low temperature the atoms, which give the quantum to the quantum accelerometer, care manipulated and controlled by a powerful laser, custom designed and built by Glasgow-based MSquared over almost three years.
The quantum compass’s most obvious use will be by the military in stealth ships and submarines, allowing them to travel over long distances in unknown environments without the need to use GPS signals, which could alert to their presence. However, the technology will also be valuable in commercial shipping with pirates having learned to interfere with GPS navigation systems in order to direct vessels off course and into their clutches. Other possible uses include during caving or in any other subterranean or above ground environment that limits access to GPS signals such in isolated mountain regions.