The awe of science … and a pastor’s take on the Big Story.
Two years ago, after a major upgrade LIGO, the Laser Interferometer Gravitational-Wave Observatory, came back online and immediately detected gravity waves emanating from the collapse of of two black holes into one more than a billion years ago. Two interferometers with arms 2.5 miles long, one in Louisiana and the other in Washington State saw the clear signature 7 milliseconds apart. This was the culmination of decades of hard work … and the beginning of a new era of astronomical observatories. I know some of the people involved in this project and heard a talk about it just last week.
Since the first observation there have been at least three more events observed, the latest in August of this year, August 14 at 10:30:43 UTC. The LA Times story on the observation is here. This latest observation involved three observatories as the VIRGO observatory in Italy was operational along with the two LIGO observatories. The signal was observed in Louisiana, 8 milliseconds later in Washington and 6 milliseconds after that in Europe. Comparison of the latest signals allows a much more precise evaluation of the event – the collapse of two black holes 1.8 billion light years away. The LIGO website contains a wealth of information as well as some of the images used here. (Image Credit: LIGO/Caltech/MIT/LSC)
Gravitational waves are ripples in the fabric of space-time caused by events like the collapse of two black holes or two neutron stars merging into one. These waves travel at the speed of light and can be detected by the minute effect they have on the relative lengths of two arms of an interferometer. This image is reproduced from Wikipedia (here). A coherent laser beam is split into two and travels down the arms of the interferometer. They meet at the detector giving a baseline signal. When a gravity wave passes through the interferometer (illustrated in yellow) it will have a different gravitational…