“My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting.”
That Tweet from Arizona State Univ. theoretical physicist Lawrence M. Krauss was all it took to make the science world’s heart flutter. The wave-making rumor focuses on the possibility that the Laser Interferometer Gravitational-Wave Observatory (LIGO), which is operated by the California Institute of Technology and the Massachusetts Institute of Technology, has discovered gravitational waves.
While Krauss has no affiliation with LIGO, he apparently got wind of LIGO scientists writing a paper about gravitational waves discovered using U.S. equipment.
The discovery of gravitational waves would fill in a missing component of Albert Einstein’s general theory of relativity. Predicted in 1916, gravitational waves are “ripples in the fabric of space-time.” Large amounts of energy or mass distort space-time causing it to warp, what we observe as gravity. When large masses move suddenly, like during a violent cosmic explosion, some of the space-time curvature ripples outwards. “When two dense objects such as neutron stars or black holes orbit each other, space-time is stirred by their motion and gravitational energy ripples throughout the universe,” according to MIT.
The discovery of gravitational waves could tell scientists more about the Bing Bang and other cosmic events, such as black hole collisions and supernovae explosions. It opens up a new way to observe the cosmos.
LIGO scientists are keeping mum. “The LIGO instruments are still taking data today, and it takes us time to analyze, interpret and review the results, so we don’t have any results to share yet,” said Prof. Gabriela González, who teaches physics and astronomy at Louisiana State Univ. and is LIGO’s spokesperson, to The Guardian. “We take pride in reviewing our results carefully before submitting them for publication—and for important results, we plan to ask for our papers to be peer reviewed before we announce results.”
LIGO uses an instrument called an interferometer to detect gravitational waves. The instrument splits a laser beam into two, and sends one beam in a perpendicular direction while the other continues along its originally track. After traveling an equal distance, they bounce back on mirrors and return, merging into a single beam.
According to LIGO, “If the two beams travel exactly the same distance (i.e. the arms were exactly the same length) before recombining, the photodetector will either see a beam as bright as the pre-split beam or nothing at all.”
A gravitational wave passing through would change the length of the interferometer’s arm, but only by a small amount. The LIGO was designed to measure distances 1/10,000th the width of a proton.
LIGO wasn’t successful during its search for gravitational waves between 2002 and 2010. A more sensitive instrument dubbed the Advanced LIGO started taking data in September 2015.
Gonzalez told New Scientist the team expects to have the results within the next few months. The first data run ended Jan. 12.