What’s up (or maybe down?) with gravitational waves? They’re suddenly (at least for many of us) in the news and generating a lot of excitement, noise, questions and rumors. Would Einstein be excited? I’m no Einstein but here’s my simple explanation of what’s going on.
First, what are gravitational waves? They’re ripples in the fabric of space-time predicted by Albert Einstein in 1915 in his theory of general relativity. If they exist (remember, Einstein only predicted them), the waves travel at the speed of light and are produced by massive bodies accelerating, colliding, exploding or all of the above. Despite that, the waves would be faint and tiny - physicists estimate them to be a billionth the diameter of an atom – and unable to be detected by today’s equipment.
Until now … maybe. The Laser Interferometer Gravitational-Wave Observatory (LIGO) – actually two observatories located in Louisiana and the state of Washington - was built in 2002 to detect gravitational waves. Nothing was found and LIGO was shut down for repairs in 2010. It reopened in September 2015 with more sensitive equipment and a rumor started spreading that gravitational waves had indeed been detected.
The source of that rumor was Arizona State University astrophysicist Lawrence Krauss – a highly reputable scientist (and author of “The Physics of Star Trek”). Krauss upped the noise level a notch with a tweet on January 11th stating:
My earlier rumor about LIGO has been confirmed by independent sources. Stay tuned! Gravitational waves may have been discovered!! Exciting.
Why is it exciting? Being able to observe, read, and interpret these space-time ripples would give scientists a fantastic new way to study distant objects that can’t be seen by conventional means. Think of them as gravitational fingerprints that can tell about an object's origin, life and possible demise. Krauss puts it this way:
… gravitational wave astronomy will be the astronomy of the 21st century.
Except … it’s still a rumor. Krauss has backed off on his initial tweet (is that REALLY the way to make announcements like this?) and admits he didn’t see the data himself and the signal detected by LIGO could have been false … in fact, it could have been deliberately placed in the data to test the researchers. Those practical-joking physicists!
No other scientists have confirmed the rumor. While there is considerable support in the LIGO community that the detection of gravitational waves will happen in 2016 due to the new equipment, they’d like to have time to confirm it before it reaches the Internet and beyond.
As I warned, this is a SIMPLE explanation. If you want more, ask an 11-year-old who's smarter than Einstein.