One hundred years after Albert Einstein predicted the existence of gravitational waves, could one have been detected?
The world will know Feb. 11 when the results are announced from the initial run after a complete overhaul and fine-tuning of the Laser Interferometer Gravitational-wave Observatory, or LIGO, north of Richland. A twin LIGO in Louisiana produced parallel data.
Rumors have been spreading across the Internet for several weeks that the run was successful, fueled by a Twitter post of a theoretical physicist in Arizona without firsthand knowledge of results.
LIGO officials have declined to respond to rumors. But now a press conference has been called to provide an update on efforts to detect gravitational waves.
It will be held Thursday morning in Washington, D.C. Scientists will be available after the announcement to answer media questions at the LIGO on Hanford land.
The Hanford LIGO operated from 2002-10 without detecting a gravitational wave from outer space. But extensive improvements to the scientific facility before a restart in 2015 increased the sensitivity of detection instruments by a factor of 10.
Einstein predicted the existence of gravitational waves, or traveling space warps, in his 1916 general theory of relativity
Previously, LIGO had the sensitivity to detect gravitational waves from 100 galaxies. That’s up to 100,000 galaxies with improved equipment operating in the latest run.
After five years of downtime, it officially began collecting information at 8 a.m. Sept. 18, running through 8 a.m. Jan. 12. But it also ran in engineering mode for a few weeks before the three-month planned run started and that’s when the discovery occurred, according to some rumors.
As it operated in 2015, astronomical observatories around the world were on standby to search the sky for light signals that could correspond to possible gravitational wave detection. Some information could have been released to astronomers during the run.
But as Science Magazine pointed out, not all information from the run may be valid. False signals are injected into data to test sensitivity of analysis techniques.
LIGO has been trying to detect vibrations, or ripples, through space caused by violent events. Neutron stars pulled together by gravity, the collision and merger of black holes or supernovae — exploding stars — could cause a gravitational wave.
A wave’s force is theoretically so great that as it passes through Earth, it would stretch objects lengthwise and cause them to compress sideways. A circle would become an ellipse.
Length of each Hanford LIGO steel vacuum tube stretching across the desert
However, the change would be extremely small. LIGO is attempting to detect a movement about one thousandth of a diameter of a proton, which is the nucleus of a hydrogen atom. It would take 10 trillion such movements to equal the width of a human hair.
LIGO Hanford is designed to detect the barest movements of mirrors suspended at the end of 2.5-mile-long tubes extending across the shrub-steppe landscape at Hanford. Data collected is compared with data at the Louisiana LIGO to verify results.
Einstein predicted the existence of gravitational waves, or traveling space warps, in his 1916 general theory of relativity. Evidence has been collected that strongly supports their existence, although they have never been directly detected.
If gravitational waves are detected and analyzed, a new way to learn about the universe could open up.
Historically, scientists have relied mostly on observations with electromagnetic radiation, such as visible light, X-rays and radio waves to learn about the universe.
Gravitational waves are a different phenomena that could advance knowledge of astronomy and physics, including about the nature of time and space.