All Videos & Illustrations Credit & Copyright: National Science Foundation (NSF) & Caltech/MIT LIGO. All information that I provide is via the NSF announcement video and the Caltech/MIT LIGO press release.
As this is still a fluid and ongoing moment of discovery that I, myself am still trying to learn more about in detail, I wanted to at least provide you with a short writeup courtesy of the information provided by the NSF and the Caltech/MIT LIGO team. Although I already understood what gravity waves are, how they’re propagated etc., the event in question that let to discovery was a mystery to me as it was for everyone not in the loop until Thursday morning. The main purpose of this post is to take this journey of discovery with you as I will provide a large quantity of information in the form of videos and illustrations as well as links to highly reputable sources for further learning. I hope you find this, if not exciting, at least enjoyable.
On September 14, 2015, both Laser Interferometer Gravitational-wave Observatories (LIGO), one in Hannaford, Washington, and the other in Livingston, Louisiana, detected a “chirp” at roughly the same moment emanating from a generalized location in the Southern Hemisphere. The video and images below provide the sound of the “chirp” and shows the plot for what scientists predicted a gravity wave to look live vs. what they received. The second image actually points out the general direction on the sky that the wave arrived from.
That chirp, we would come to find out in this week’s (February 11, 2016) press conference, was the actual detection of the long sought, gravitational waves and affirming one of the last major untested pieces in Einstein’s now 100 year old Theory of General Relativity. The source; a pair of black holes 1.3 billion light years away, one being 29 solar masses and the other 36 solar masses in orbit around one another when 1.3 billion years ago they finally collided at nearly half the speed of light and merged into one.
The massive energies involved in the merger converted three solar masses worth of energy into a gravitational wave which was detected here on Earth last September just days after being turned back on after upgrades. LIGO is the most sensitive scientific instrument ever created to date. It can directly detect changes in distance to one thousandth of the diameter of a proton.
The first video illustrates what two black holes in orbit would look like throughout the process of merging. The second short clip shows the same but with emphasis of showing what the gravitational waves would look like supposing you could see them. The third clip explains the entire process from wave emanation to detection as well as the LIGO interferometry process and the just unbelievably tiny amount of movement that is actually detected.
So what are these gravitational waves? They’re literal distortions in spacetime. The more mass something has, the deeper its gravity well. You know; the old bowling ball on the bed sheet visualization. The problem is that gravity is very weak and detecting things like impacts on, say, Mars is nearly impossible at this time in technology. To detect gravity waves you need a ridiculous amount of mass moving at mind numbing speeds to generate a signal high enough to be detected. Orbiting or colliding neutron stars and black holes fit that bill wonderfully. As these waves pass by you, the distance between you and say, a particular object actually changes slightly before returning to normal. Trust me this movement in well, reality, is very small and to human senses completely undetectable. And that’s what was detected and recorded in this event.
It’s truly amazing that Einstein was never awarded the Nobel Prize for General or Special Relativity. I mean, these writings have, and continue to revolutionize the world and how we see the universe. Not to be completely robbed, he did receive one Nobel Prize for his discovery of the Photoelectric Effect. One thing is certain, someone involved in this project will most be awarded that prize and deservedly so.
Caltech LIGO press release: https://www.ligo.caltech.edu/news/ligo20160211
NSF press release: http://www.nsf.gov/news/news_summ.jsp?cntn_id=137628
MIT press release regarding this event: http://space.mit.edu/scientists-make-first-direct-detection-gravitational-waves
Sean Carroll’s blog, Preposterous Universe, “Gravitational Waves at Last” regarding this event (great read): http://www.preposterousuniverse.com/blog/2016/02/11/gravitational-waves-at-last/
APS Journal, Physical Review Letters page regarding the science of this event: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.116.061102
Lawrence Krauss article “Finding Beauty in Darkness” in the NY Times regarding this event: http://www.nytimes.com/2016/02/14/opinion/sunday/finding-beauty-in-the-darkness.html?action=click&pgtype=Homepage&clickSource=story-heading&module=opinion-c-col-left-region®ion=opinion-c-col-left-region&WT.nav=opinion-c-col-left-region&_r=0
Piled Higher and Deeper (PHD Comics) video on gravitational waves.