Image: Goddard physicist Babak Saif
NASA / Pat Izzo
Goddard physicist Babak Saif is part of a team from Stanford University and AOSense, Inc., a Sunnyvale, Calif.-based company, that has received NASA funding to use atom optics to detect theoretically predicted gravitational waves.
By Senior Writer
updated 10/22/2012 1:55:44 PM ET 2012-10-22T17:55:44

Albert Einstein predicted the existence of gravitational waves that ripple outward from moving celestial objects such as stars or black holes — but such waves are so weak by the time they reach Earth that the planet quivers by less than an atom's width in response. NASA wants to harness the spooky quantum behavior of atoms to help detect the gravitational waves.

The U.S. space agency has funded the possible solution, called atom interferometry, so that it might someday enable a mission consisting of three identical spacecraft flying in a triangle formation between 310 miles and 3,107 miles. If a gravitational wave swept through the area, the spacecraft interferometers would sense the tiny disturbances.

"The NASA funding is basically for a preliminary design study for what a gravitational wave detector would look like," said Mark Kasevich, a physicist at Stanford University.

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The technology would enable scientists to detect gravitational waves related to events such as a black hole or two stars merging in a distant star system. It could also lead to more sensitive sensors for steering U.S. military submarines or aircraft — Kasevich's Stanford lab has been working on gyroscopes, gravimeters, accelerometers and gravity gradiometers for the U.S. Department of Defense.

But for NASA, a gravitational wave detector is "probably a decade away," Kasevich told TechNewsDaily. An actual space mission would probably take even longer to launch.

Normal interferometry — a 200-year-old technique — gets accurate measurements by comparing light that has been split into two equal halves by a beam splitter. Scientists shine one of the beams through something they want to measure, and compare it to the other untouched beam by bouncing both off mirrors to reflect back onto a detector or camera. [ Space Quantum Experiment Has First Balloon Flight ]

The atomic interferometry funded by NASA's Innovative Advanced Concepts program takes advantage of quantum mechanics, the physics theory that describes how matter behaves at the tiniest scales. That effort is led by researchers at NASA's Goddard Space Flight Center in Greenbelt, Md.; Stanford University in California; and AOSense Inc., in Sunnyvale, Calif.

Researchers would first fire a laser to slow and cool the atoms down to a frigid temperature near absolute zero (minus 273.15 degrees Celsius), so that the atoms behave like waves rather than particles. Then they would fire more laser pulses that put the atoms into a " superposition of states," which allows them to exist in multiple states simultaneously.

The superposition means a single atom can split into different states that exist independently and go flying off on different trajectories like separate particles, before they recombine at a detector. If an atom's path is altered even a bit by a passing gravitational wave, the atom interferometer can detect the difference.

NASA's funding does not cover the full spacecraft mission just yet. First, the researchers plan to test the atomic interferometer at a 33-foot drop tower in the basement of a Stanford University physics laboratory — firing lasers at a cloud of falling rubidium atoms to cool them and then put them into their "spooky" quantum states. Successful testing could establish the foundation for making the space version of the technology.

You can follow TechNewsDaily Senior Writer Jeremy Hsu on Twitter @jeremyhsu. Follow TechNewsDaily on Twitter @TechNewsDaily , or on Facebook.

© 2012 TechNewsDaily

Photos: Month in Space: January 2014

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  1. Southern stargazing

    Stars, galaxies and nebulas dot the skies over the European Southern Observatory's La Silla Paranal Observatory in Chile, in a picture released on Jan. 7. This image also shows three of the four movable units that feed light into the Very Large Telescope Interferometer, the world's most advanced optical instrument. Combining to form one larger telescope, they are greater than the sum of their parts: They reveal details that would otherwise be visible only through a telescope as large as the distance between them. (Y. Beletsky / ESO) Back to slideshow navigation
  2. A balloon's view

    Cameras captured the Grandville High School RoboDawgs' balloon floating through Earth's upper atmosphere during its ascent on Dec. 28, 2013. The Grandville RoboDawgs’ first winter balloon launch reached an estimated altitude of 130,000 feet, or about 25 miles, according to coaches Mike Evele and Doug Hepfer. It skyrocketed past the team’s previous 100,000-feet record set in June. The RoboDawgs started with just one robotics team in 1998, but they've grown to support more than 30 teams at public schools in Grandville, Mich. (Kyle Moroney / AP) Back to slideshow navigation
  3. Spacemen at work

    Russian cosmonauts Oleg Kotov, right, and Sergey Ryazanskiy perform maintenance on the International Space Station on Jan. 27. During the six-hour, eight-minute spacewalk, Kotov and Ryazanskiy completed the installation of a pair of high-fidelity cameras that experienced connectivity issues during a Dec. 27 spacewalk. The cosmonauts also retrieved scientific gear outside the station's Russian segment. (NASA) Back to slideshow navigation
  4. Special delivery

    The International Space Station's Canadian-built robotic arm moves toward Orbital Sciences Corp.'s Cygnus autonomous cargo craft as it approaches the station for a Jan. 12 delivery. The mountains below are the southwestern Alps. (NASA) Back to slideshow navigation
  5. Accidental art

    A piece of art? A time-lapse photo? A flickering light show? At first glance, this image looks nothing like the images we're used to seeing from the Hubble Space Telescope. But it's a genuine Hubble frame that was released on Jan. 27. Hubble's team suspects that the telescope's Fine Guidance System locked onto a bad guide star, potentially a double star or binary. This caused an error in the tracking system, resulting in a remarkable picture of brightly colored stellar streaks. The prominent red streaks are from stars in the globular cluster NGC 288. (NASA / ESA) Back to slideshow navigation
  6. Supersonic test flight

    A camera looking back over Virgin Galactic's SpaceShipTwo's fuselage shows the rocket burn with a Mojave Desert vista in the background during a test flight of the rocket plane on Jan. 10. Cameras were mounted on the exterior of SpaceShipTwo as well as its carrier airplane, WhiteKnightTwo, to monitor the rocket engine's performance. The test was aimed at setting the stage for honest-to-goodness flights into outer space later this year, and eventual commercial space tours.

    More about SpaceShipTwo on PhotoBlog (Virgin Galactic) Back to slideshow navigation
  7. Red lagoon

    The VLT Survey Telescope at the European Southern Observatory's Paranal Observatory in Chile captured this richly detailed new image of the Lagoon Nebula, released on Jan. 22. This giant cloud of gas and dust is creating intensely bright young stars, and is home to young stellar clusters. This image is a tiny part of just one of 11 public surveys of the sky now in progress using ESO telescopes. (ESO/VPHAS team) Back to slideshow navigation
  8. Fire on the mountain

    This image provided by NASA shows a satellite view of smoke from the Colby Fire, taken by the Multi-angle Imaging SpectroRadiometer aboard NASA's Terra spacecraft as it passed over Southern California on Jan. 16. The fire burned more than 1,863 acres and forced the evacuation of 3,700 people. (NASA via AP) Back to slideshow navigation
  9. Where stars are born

    An image captured by NASA's Spitzer Space Telescope shows the Orion Nebula, an immense stellar nursery some 1,500 light-years away. This false-color infrared view, released on Jan. 15, spans about 40 light-years across the region. The brightest portion of the nebula is centered on Orion's young, massive, hot stars, known as the Trapezium Cluster. But Spitzer also can detect stars still in the process of formation, seen here in red hues. (NASA / JPL-Caltech) Back to slideshow navigation
  10. Cygnus takes flight

    Orbital Sciences Corp.'s Antares rocket rises from NASA's Wallops Flight Facility on Wallops Island, Va, on Jan. 9. The rocket sent Orbital's Cygnus cargo capsule on its first official resupply mission to the International Space Station. (Chris Perry / NASA) Back to slideshow navigation
  11. A long, long time ago...

    This long-exposure picture from the Hubble Space Telescope, released Jan. 8, is the deepest image ever made of any cluster of galaxies. The cluster known as Abell 2744 appears in the foreground. It contains several hundred galaxies as they looked 3.5 billion years ago. Abell 2744 acts as a gravitational lens to warp space, brightening and magnifying images of nearly 3,000 distant background galaxies. The more distant galaxies appear as they did more than 12 billion years ago, not long after the Big Bang. (NASA / NASA via AFP - Getty Images) Back to slideshow navigation
  12. Frosty halo

    Sun dogs are bright spots that appear in the sky around the sun when light is refracted through ice crystals in the atmosphere. These sun dogs appeared on Jan. 5 amid brutally cold temperatures along Highway 83, north of Bismarck, N.D. The temperature was about 22 degrees below zero Fahrenheit, with a 50-below-zero wind chill.

    Slideshow: The Year in Space (Brian Peterson / The Bismarck Tribune via AP) Back to slideshow navigation
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