A British university has developed the world's first gravity sensor that can detect terrorist tunnels, bombs and archaeological treasures hidden beneath the ground.
The sensor, which was commissioned for the Ministry of Defence, works by dropping a cloud of cooled atoms over an area and measuring the tiny changes in gravity that occur as the particles are pulled by their surroundings.
Objects hidden below ground, such as a weapon or an ancient Roman vase, can be identified.
Gareth Brown, joint project technical authority for quantum sensing and senior principal scientist at the ministry's Defence Science and Technology Laboratory, says the sensor will open up new opportunities.
“For national defence and security, accurate and rapid measurements of variations in microgravity open up new opportunities to detect the otherwise undetectable and navigate more safely in challenging environments,” he said.
“As gravity-sensing technology matures, applications for underwater navigation and revealing the subterranean will become possible.”
Researchers from the University of Birmingham working at the UK National Quantum Technology Hub in Sensors and Timing have published their research in Nature.
The sensor has already discovered a tunnel in real-world conditions one metre below the surface of the ground.
Kai Bongs, head of cold atom physics at the University of Birmingham and principal investigator for the UK Quantum Technology Hub Sensors and Timing, described the technology as a major breakthrough.
“This is an ‘Edison moment’ in sensing that will transform society, human understanding and economies,” he said.
“With this breakthrough, we have the potential to end reliance on poor records and luck as we explore, build and repair.
“In addition, an underground map of what is currently invisible is now a significant step closer, ending a situation where we know more about Antarctica than what lies a few feet below our streets.”
The development will help reduce costs and delays for construction, rail and road projects, improve the predictions of natural phenomena such as volcanic eruptions, aid in the discovery of natural resources and unseen structures, and solve archaeological mysteries without damaging sites.
Current gravity sensors have been limited by a range of environmental factors, with a particular challenge being vibration.
Vibration had previously limited the measurement time of gravity sensors for survey applications.
With the new technology, surveys will be faster, more comprehensive and less expensive.
