PORT ANGELES — Observations of a collision of black holes billions of years ago in a distant part of the universe will be presented at the Port Angeles Library at 6:30 p.m. Monday.
The observation of gravitational waves arriving at Earth from a cataclysmic event was the first of its kind ever made, said Dale Ingram, public outreach coordinator for the Laser Interferometer Gravitational-wave Hanford Observatory.
The free program will be in the Raymond Carver Room at the Port Angeles Library, 2210 S. Peabody St.
Also in Hadlock
During his visit to the North Olympic Peninsula, Ingram also will offer students at Port Angeles High and Stevens Middle schools a chance to learn about the observatory and give an encore presentation of his gravitational waves discussion at 6:30 p.m. Tuesday at the Jefferson County Library, 620 Cedar Ave., Port Hadlock.
Ingram works to connect students and the general public to the newly born field of gravitational wave astronomy.
At the observatory, Ingram coordinates a variety of outreach programs and activities, and participates in the monitoring of data that’s collected by the site’s numerous environmental sensors.
Scientific milestone
The observation of gravitational waves discussed by Ingram confirms a major prediction of Albert Einstein’s 1916 general theory of relativity and opens an unprecedented new window onto the cosmos, Ingram said.
Gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot otherwise be obtained, he said.
Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole.
This collision of two black holes had been predicted but never observed.
The gravitational waves were detected Sept. 14 by both of the twin Laser Interferometer Gravitational-wave Observatory detectors — located in Livingston, La., and Hanford.
The observatories — known by the acronym LIGO — are funded by the National Science Foundation and were conceived, were built and are operated by Caltech and MIT.
The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration — which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy — and the Virgo Collaboration using data from the two LIGO detectors.
Based on the observed signals, LIGO scientists estimate that the black holes for this event were about 29 and 36 times the mass of the sun, and that it took place about 1.3 billion years ago.
About three times the mass of the sun was converted into gravitational waves in a fraction of a second — with a peak power output about 50 times that of the whole visible universe, researchers said.
By looking at the time of arrival of the signals — the detector in Livingston recorded the event 7 milliseconds before the detector in Hanford — scientists can say the source was located in the southern hemisphere of the Milky Way.
For more information, see www.ligo.caltech.edu.
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Reporter Chris McDaniel can be reached at 360-452-2345, ext. 56650, or cmcdaniel@peninsuladailynews.com.
