. 24/7 Space News .
TIME AND SPACE
A billion tiny pendulums could detect the universe's missing mass
by Staff Writers
Washington DC (SPX) Oct 15, 2020

Dark matter, the hidden stuff of our universe, is notoriously difficult to detect. In search of direct evidence, NIST researchers have proposed using a 3D array of pendulums as force detectors, which could detect the gravitational influence of passing dark matter particles.

Researchers at the National Institute of Standards and Technology (NIST) and their colleagues have proposed a novel method for finding dark matter, the cosmos' mystery material that has eluded detection for decades. Dark matter makes up about 27% of the universe; ordinary matter, such as the stuff that builds stars and planets, accounts for just 5% of the cosmos. (A mysterious entity called dark energy accounts for the other 68%.)

According to cosmologists, all the visible material in the universe is merely floating in a vast sea of dark matter - particles that are invisible but nonetheless have mass and exert a gravitational force. Dark matter's gravity would provide the missing glue that keeps galaxies from falling apart and account for how matter clumped together to form the universe's rich galactic tapestry.

The proposed experiment, in which a billion millimeter-sized pendulums would act as dark matter sensors, would be the first to hunt for dark matter solely through its gravitational interaction with visible matter. The experiment would be one of the few to search for dark matter particles with a mass as great as that of a grain of salt, a scale rarely explored and never studied by sensors capable of recording tiny gravitational forces.

Previous experiments have sought dark matter by looking for nongravitational signs of interactions between the invisible particles and certain kinds of ordinary matter. That's been the case for searches for a hypothetical type of dark matter called the WIMP (weakly interacting massive particles), which was a leading candidate for the unseen material for more than two decades. Physicists looked for evidence that when WIMPs occasionally collide with chemical substances in a detector, they emit light or kick out electric charge.

Researchers hunting for WIMPs in this way have either come up empty-handed or garnered inconclusive results; the particles are too light (theorized to range in mass between that of an electron and a proton) to detect through their gravitational tug.

With the search for WIMPs seemingly on its last legs, researchers at NIST and their colleagues are now considering a more direct method to look for dark matter particles that have a heftier mass and therefore wield a gravitational force large enough to be detected.

"Our proposal relies purely on the gravitational coupling, the only coupling we know for sure that exists between dark matter and ordinary luminous matter," said study co-author Daniel Carney, a theoretical physicist jointly affiliated with NIST, the Joint Quantum Institute (JQI) and the Joint Center for Quantum Information and Computer Science (QuICS) at the University of Maryland in College Park, and the Fermi National Accelerator Laboratory.

The researchers, who also include Jacob Taylor of NIST, JQI and QuICS; Sohitri Ghosh of JQI and QuICS; and Gordan Krnjaic of the Fermi National Accelerator Laboratory, calculate that their method can search for dark matter particles with a minimum mass about half that of a grain of salt, or about a billion billion times the mass of a proton. The scientists report their findings in Physical Review D.

Because the only unknown in the experiment is the mass of the dark matter particle, not how it couples to ordinary matter, "if someone builds the experiment we suggest, they either find dark matter or rule out all dark matter candidates over a wide range of possible masses," said Carney. The experiment would be sensitive to particles ranging from about 1/5,000 of a milligram to a few milligrams.

That mass scale is particularly interesting because it covers the so-called Planck mass, a quantity of mass determined solely by three fundamental constants of nature and equivalent to about 1/5,000 of a gram.

Carney, Taylor and their colleagues propose two schemes for their gravitational dark matter experiment. Both involve tiny, millimeter-size mechanical devices acting as exquisitely sensitive gravitational detectors.

The sensors would be cooled to temperatures just above absolute zero to minimize heat-related electrical noise and shielded from cosmic rays and other sources of radioactivity. In one scenario, a myriad of highly sensitive pendulums would each deflect slightly in response to the tug of a passing dark matter particle.

Similar devices (with much larger dimensions) have already been employed in the recent Nobel-prize-winning detection of gravitational waves, ripples in the fabric of space-time predicted by Einstein's theory of gravity. Carefully suspended mirrors, which act like pendulums, move less than the length of an atom in response to a passing gravitational wave.

In another strategy, the researchers propose using spheres levitated by a magnetic field or beads levitated by laser light. In this scheme, the levitation is switched off as the experiment begins, so that the spheres or beads are in free fall. The gravity of a passing dark matter particle would ever so slightly disturb the path of the free-falling objects.

"We are using the motion of objects as our signal," said Taylor. "This is different from essentially every particle physics detector out there."

The researchers calculate that an array of about a billion tiny mechanical sensors distributed over a cubic meter is required to differentiate a true dark matter particle from an ordinary particle or spurious random electrical signals or "noise" triggering a false alarm in the sensors.

Ordinary subatomic particles such as neutrons (interacting through a nongravitational force) would stop dead in a single detector. In contrast, scientists expect a dark matter particle, whizzing past the array like a miniature asteroid, would gravitationally jiggle every detector in its path, one after the other.

Noise would cause individual detectors to move randomly and independently rather than sequentially, as a dark matter particle would. As a bonus, the coordinated motion of the billion detectors would reveal the direction the dark matter particle was headed as it zoomed through the array.

To fabricate so many tiny sensors, the team suggests that researchers may want to borrow techniques that the smartphone and automotive industries already use to produce large numbers of mechanical detectors.

Thanks to the sensitivity of the individual detectors, researchers employing the technology needn't confine themselves to the dark side. A smaller-scale version of the same experiment could detect the weak forces from distant seismic waves as well as that from the passage of ordinary subatomic particles, such as neutrinos and single, low-energy photons (particles of light).

The smaller-scale experiment could even hunt for dark matter particles - if they impart a large enough kick to the detectors through a nongravitational force, as some models predict, Carney said.

"We are setting the ambitious target of building a gravitational dark matter detector, but the R and D needed to achieve that would open the door for many other detection and metrology measurements," said Carney.

Research Report: Gravitational Direct Detection of Dark Matter


Related Links
National Institute Of Standards And Technology (NIST)
Understanding Time and Space


Thanks for being there;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Monthly Supporter
$5+ Billed Monthly


paypal only
SpaceDaily Contributor
$5 Billed Once


credit card or paypal


TIME AND SPACE
New measurements of the solar spectrum verify Einstein's theory of General Relativity
Washington DC (SPX) Oct 09, 2020
This work, which verifies one of the predictions of Einstein's General Relativity, is to be published in the journal Astronomy and Astrophysics. The General Theory of Relativity, published by Albert Einstein between 1911 and 1916, introduced a new concept of space and time, by showing that massive objects cause a distortion in space-time which is felt as gravity. In this way, Einstein's theory predicts, for example, that light travels in curved paths near massive objects, and one consequence is th ... read more

Comment using your Disqus, Facebook, Google or Twitter login.



Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

TIME AND SPACE
European Service Module structure for Moon landing arrives in Bremen

Thomas prepares for Time in space

Fresh crew docks at ISS after record journey

Abort and attitude control motors to support six crewed Artemis missions

TIME AND SPACE
Blue Origin launches, lands NASA moon landing sensor experiment

Arianespace offers new shared smallsat payload opportunities on its Vega launcher

Final hot firing proves P120C booster for Ariane 6

Asteroid sampling technology tested on Blue Origin's suborbital rocket

TIME AND SPACE
This transforming rover can explore the toughest terrain

Airbus to bring first Mars samples to Earth

NASA, JAXA to Send Sampling Technology to Moon and Phobos

China's Mars probe completes deep-space maneuver

TIME AND SPACE
China's Xichang launch center to carry out 10 missions by end of March

Eighteen new astronauts chosen for China's space station mission

NASA chief warns Congress about Chinese space station

China's new carrier rocket available for public view

TIME AND SPACE
Iridium says consumers staying connected when off-the-Grid during COVID-19 pandemic

Cobham SATCOM and Kepler Communications achieve excellent results for maritime terminals over LEO network

Space agency leaders call for greater international cooperation

RBC Signals to Host Swarm Antennas Supporting Global Connectivity Constellation

TIME AND SPACE
GESTRA space radar ready to begin operations

Natural fibres threaded into satellites for safer missions

The current state of Space Debris

Northrop Grumman's next generation digital antenna passes key milestone

TIME AND SPACE
Earth-like planets often come with a bodyguard

No social distancing at the beginning of life

Vaporized metal in the air of an exoplanet

Massive stars are factories for ingredients to life

TIME AND SPACE
The mountains of Pluto are snowcapped, but not for the same reasons as on Earth

Arrokoth: Flattening of a snowman

SwRI study describes discovery of close binary trans-Neptunian object

JPL meets unique challenge, delivers radar hardware for Jupiter Mission









The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.