March 29, 2020

Moved by Gravitational Waves

Where history was made… LIGO Hanford.

Photo by the author.

By now, you’ve heard the news: Gravitational Waves have been detected by the Laser Interferometer Gravitational-wave Observatory (LIGO) for the very first time. We’re now in a post-gravitational wave detection phase of astronomy; as a species, we can now examine the universe in a mode completely separate from the electromagnetic spectrum.

Yay humanity. Thursday’s announcement involved a merger of a binary black hole pair 29 and 36 solar masses in size respectively, and 700 million to 1.6 billion light years distant. You could say that this signal has been headed towards Earth long before intelligent interferometer-building apes such as ourselves ever existed.

We’ve written lots about LIGO over the years, and have even managed to visit the detector in Livingston Louisiana and Hanford Washington. Scientists were just finishing up the commissioning phase for Advanced LIGO when we visited in late 2014. As fate would have it, the announcement came at exactly the wrong time for us to attend the press release at LIGO-Livingston in person. We had actually just departed Tallahassee on business a few days prior, and could’ve easily zipped over to Louisiana had the release been just 48 hours earlier.

What’s next for LIGO? Well, the Fermi gamma-ray observatory detected a possible tantalizing gamma-ray burst detection just 0.4 seconds after the LIGO event. Connected, perhaps? With two detectors, LIGO only gives a rough direction of the event in the sky… though that many soon change, as the European Virgo/GEO-600 and Japanese KAGRA detectors go online and reach comparable sensitivities. LIGO also has plans to establish a third detector in India.

What would it have looked like to sit a few dozen A.U. From the merger? Of course, you wouldn’t want to be to close, but the National Science Foundation released a pretty mind-blowing simulation of just such a black hole merger:

Remember, you are witnessing more energy from the event than all the stars in the universe released at that very moment.


How many other civilizations out there heard the din from GW150914? Was it their first, or just one of many in a long line of detections? Could civilizations of unimaginable power play cosmic billiards with black holes for fun?

Our thoughts on the LIGO detection: expect more to come. It’s rather telling that the September 14th, 2015 event was discovered shortly after Advanced LIGO was turned on and during its first observing run. Our hunch (and yes, scientists, like science writers, have hunches) is that such events are fairly common across the universe… but we’ve just now developed the ability to detect them.

And kudos to science journalists everywhere, for coming together on this historic discovery and, for the most part, getting the science right. Very few articles ran saying ‘gravity waves had been discovered’ by LIGO. Enhanced LIGO is the next phase, as scientists learn from the lessons of LIGO and Advanced LIGO. Farther out in space, the European Space Agency’s LISA Pathfinder mission is now testing the technology needed for a full-up LISA (the Laser Interferometer Space Antenna) observatory, taking to the skies in the 2030s. Let’s see, by then I’ll be…

Advanced LIGO is officially is the science phase of its mission!

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