By Jillian Jennett
In 1916, Albert Einstein postulated that massive objects create spacetime ripples, better known as gravitational waves. In 2016, scientists confirmed that he was right.
Gravitational waves are, in essence, distortions in the fabric of spacetime caused by massive universal events. What is spacetime? It loosely means any model combining space and time in the same interwoven continuum. This means that space and time are dynamic and are able to be stretched and shrunk and moved around. Supernovae, the collapse and explosion of a supergiant star, colliding black holes, the birth of the universe itself are some examples of massive universal events. Other terrifying, existential panic-inducing things better not included in this article.
Two massive black holes collided approximately 1.3 billion years ago, merging together, and created gravitational waves that were first detected in September 2015. This discovery was kept secret for months until Feb. 11 at a press conference when the Laser Interferometer Gravitational-Wave Observatory (LIGO) executive director at the California Institute of Technology announced, “We did it!” The discovery would not have been possible without a team of nearly a thousand physicists working at LIGO for the past forty years.
How did LIGO discover the evidence for gravitational waves? The short answer is lots and lots of lasers. The long answer, not surprisingly, is much more complicated than that.
With two observatories, one in Louisiana and one in Washington, the team attempted to find the waves that are practically undetectable. The two observatories housed two four-kilometer corridors with a series of mirrors that would reflect a laser into a sensor. This sensor would check for any variance in wavelength.
Most of the time, the sensor detected nothing. But then it did.
Despite all of this, in 1980, Joseph Taylor and Russell Hulse won the 1993 Nobel Prize in Physics for discovering a new type of pulsar and the “decaying” orbits of two pulsars losing energy, the emissions being gravitational waves. Pulsars are spinning neutron stars that emit radio pulses at regular, unchanging intervals. Without this foundation of knowledge, this discovery would never have been possible.
Why is this discovery such a big deal? Well, it confirms the last piece of Einstein’s general theory of relativity. Also, the work of hundreds of scientists who dedicated their lives to this somewhat ridiculous and wonderful theory is worth it. So take a moment today to relish the total awesome nature of the universe and try not to think about black holes for too long.