Quantum Gravity Sensor Breakthrough Paves Way for Groundbreaking Map of World Under Earth’s Surface

Future Gravity Cartography

A perspective of future gravity cartography being used with 0.5 m spatial resolution over a region, at an uncertainty level of 20 E. Expected signal sizes for a range of applications are shown. Credit: Stray et al. 2022 Nature DOI: 10.1038/s41586-021-04315-3

An object hidden below ground has been located using quantum technology — a long-awaited milestone with profound implications for industry, human knowledge, and national security.

University of Birmingham researchers from the UK National Quantum Technology Hub in Sensors and Timing have reported their achievement in Nature. It is the first in the world for a quantum gravity gradiometer outside of laboratory conditions.

The quantum gravity gradiometer, which was developed under a contract for the Ministry of Defence and in the UKRI-funded Gravity Pioneer project, was used to find a tunnel buried outdoors in real-world conditions one meter below the ground surface. It wins an international race to take the technology outside.

The sensor works by detecting variations in microgravity using the principles of quantum physics, which is based on manipulating nature at the sub-molecular level.

The success opens a commercial path to significantly improved mapping of what exists below ground level.

This will mean:

  • Reduced costs and delays to construction, rail, and road projects.
  • Improved prediction of natural phenomena such as volcanic eruptions.
  • Discovery of hidden natural resources and built structures.
  • Understanding archaeological mysteries without damaging excavation.

Professor Kai Bongs, Head of Cold Atom Physics at the University of Birmingham and Principal Investigator of the UK Quantum Technology Hub Sensors and Timing, said: “This is an ‘Edison moment’ in sensing that will transform society, human understanding, and economies.

“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.”

Current gravity sensors are limited by a range of environmental factors. A particular challenge is vibration, which limits the measurement time of all gravity sensors for survey applications.  If these limitations can be addressed, surveys can become faster, more comprehensive, and lower cost.

How the quantum gravity sensor works

The quantum gravity sensor measures subtle changes in the pulling strength of gravitational fields when a cloud of atoms is dropped. The bigger the object and the greater the difference in density of the object from its surroundings, the stronger the measurable difference in pull. But vibration, instrument tilt and disruption from magnetic and thermal fields have made turning quantum theory into commercial reality challenging. The Birmingham quantum sensor breakthrough is the first to meet these real-world challenges and perform a high spatial resolution survey. The removal of noise due to vibration will unlock gravity mapping at high spatial resolution.

The sensor developed by Dr. Michael Holynski, Head of Atom Interferometry at Birmingham and lead author of the study, and his team at Birmingham is a gravity gradiometer. Their system overcomes vibration and a variety of other environmental challenges in order to successfully apply quantum technology in the field.

The successful detection, realized in collaboration with civil engineers led by Professor Nicole Metje of the School of Engineering, is the culmination of a long-term development program that has been closely linked to end-users from its outset.

This breakthrough will allow future gravity surveys to be cheaper, more reliable, and delivered 10 times faster, reducing the time needed for surveys from a month to a few days. It has the potential to open a range of new applications for gravity survey, providing a new lens into the underground.

Professor George Tuckwell, Director for Geoscience and Engineering at RSK, said: “Detection of ground conditions such as mine workings, tunnels, and unstable ground is fundamental to our ability to design, construct and maintain housing, industry, and infrastructure. The improved capability that this new technology represents could transform how we map the ground and deliver these projects”

Dr. Gareth Brown, joint Project Technical Authority for Quantum Sensing and Senior Principal Scientist at Dstl, said: “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. As gravity sensing technology matures, applications for underwater navigation and revealing the subterranean will become possible.”

Reference: “Quantum sensing for gravity cartography” by Ben Stray, Andrew Lamb, Aisha Kaushik, Jamie Vovrosh, Anthony Rodgers, Jonathan Winch, Farzad Hayati, Daniel Boddice, Artur Stabrawa, Alexander Niggebaum, Mehdi Langlois, Yu-Hung Lien, Samuel Lellouch, Sanaz Roshanmanesh, Kevin Ridley, Geoffrey de Villiers, Gareth Brown, Trevor Cross, George Tuckwell, Asaad Faramarzi, Nicole Metje, Kai Bongs and Michael Holynski, 23 February 2022, Nature.
DOI: 10.1038/s41586-021-04315-3

The breakthrough is a collaboration between the University of Birmingham, environmental, engineering and sustainability solutions provider RSK, Dstl (the Defence Science and Technology Laboratory, part of the UK Ministry of Defence), and technology company Teledyne e2v. The project is funded by UK Research and Innovation (UKRI) as part of the UK National Quantum Technologies Program and under contract from the Ministry of Defence.

8 Comments on "Quantum Gravity Sensor Breakthrough Paves Way for Groundbreaking Map of World Under Earth’s Surface"

  1. Very Nice.

    Extend to Earthquake Prediction to minimise Catostrophic Risks. Other Catostrophic Risk Detection because “Planet Earth Rocks”, can also be detected to save lives. A fe minutes early warning system can save millions of lives and get the poitician many votes in a democracy!!

    The entire Building Indusytry Can be revolutionised by developing genuine Eartquake resistant Structures using New Materials which cause less damage to lives and structures. The Insurance Industry can fun this program. They will be a major beneficiary!

    This is just one reimagined industry.

    The only limitation to revolutionising the world and makeit slightly better is self imposed.

    Like the Good Book in All Religions states, Build you8r Home on a Strong Foundation of Rock, rather than on Sand. Silicon (atomic Number 14) is not a Weak Element. Lots of potential for protecting Carbon Based Life Forms.

    However, because of Climate Change, it becomes imperative for us to invent new technologies at a increasingly rapid rate , which will handle all types of Scenarios which could emerge in a World where people are unwilling to change. Technology needs to be the answer for Human Stupidity and Greed.

    Veiews expressed are personal and not binding on Anyone.

  2. Not true. It is not the first one. US mintelkigencr satellites use quantum gravimetry for well over the decade now

  3. What is the difference between this and sonar?

  4. Sonar is a sound frequency wave unlike this new atom particle wave. Me thinks.

  5. Part of the caption for the image reads “uncertainty level of 20 E”. In the image we see apparently related items — (<20 E), (<30 E), (<40 E), (<100 E), (<150 E).

    What we don't see is any mention of what the devil these "E" labeled items are supposed to refer to. Is "E" supposed to be a time measurement? Length? Depth? Power needed to observe the subsurface features? Who the heck knows.

    There is no time to follow up on every interesting article that omits vital information. We have to rely on writers and editors to provide the needed details. And when you consider that most of the articles appearing here are items that have been copied/pasted and then edited for content, it sure seems that the editors are not being very thorough.

    Unfortunately, this has been happening more and more often here at SciTechDaily.

  6. If it is groundbreaking, and important as military tech, the UK will allow the sale of whatever the company spinoff is to the Chinese, like they did for critical tech for magnetic catapults…forcing the US to squander years and billions to get a workable catapult for the Ford Class Aircraft Carrier.

  7. Oak Island needs this!

  8. Hi there! This is some nice work.

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