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5 Reasons You Should Care About the Discovery of Gravitational Waves

The world of physics was abuzz last week with the historic announcement of the first ever detection of gravitational waves. But why is it such a big deal?

By
Sabrina Stierwalt, PhD
5-minute read
Episode #181

4. Hundreds of People Had to Take a Huge Risk to Make This Detection Possible

Einstein predicted the existence of gravitational waves 100 years ago but at the time, there was significant doubt that such weak signals could ever be detected. In 1992, LIGO became the largest investment the National Science Foundation had ever made. The investment was a risky one–the existence of gravitational waves was only theoretical, and their signal, even if they were real, would be impossible to detect without the construction of an instrument larger than any other measurement device previously built. In fact, the initial operations of LIGO between 2002 and 2010 came up empty-handed.

However, when the new and improved advanced LIGO came online with its increased sensitivity, it detected a signal that was so clear it could be seen by eye almost immediately.

5. With Our New Ears on the Universe, We Will Likely Make Discoveries We Haven’t Even Thought of Yet

Arguably the most exciting part of this new discovery is that it’s only the beginning! The ease with which LIGO detected the signal suggests that there will be many more to come and that we won’t have to wait long for them either. The LIGO detectors are not even at their full planned sensitivity yet and so detections will get easier.

The success of LIGO will also likely help other, similar projects get funded, and in fact it likely already has with the prime minister of India voicing support for LIGO India. Other efforts include KAGRA in Japan, VIRGO in Italy, and the already operational GEO600 in Germany. Using multiple detectors in concert will further help pinpoint the origin of the gravitational wave signals.

The LISA project (i.e., the Laser Interferometer Space Antenna), which has experienced funding woes since NASA bowed out in 2011 and the project was picked up entirely by European agencies, would also send gravitational wave detectors into space. This would open up the possibility of detecting  signals with much longer periods (on the order of minutes or hours rather than milliseconds) not currently possible with LIGO.

Gravitational waves are predicted to arise from co-orbiting black holes like the system detected in September 2015, but also from binary systems with other compact objects like neutron stars. But gravitational waves are also fundamentally different from the electromagnetic radiation that we know so well. So really, who knows what we will find?

Until next time, this is Sabrina Stierwalt with Ask Science’s Quick and Dirty Tips for helping you make sense of science. You can become a fan of Ask Science on Facebook or follow me on Twitter, where I’m @QDTeinstein. If you have a question that you’d like to see on a future episode, send me an email at everydayeinstein@quickanddirtytips.com

Image couresty of LIGO, NSF, and Aurore Simonnet.

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About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.