Gravitational Waves: An Introduction


The groundbreaking discovery of gravitational waves, by LIGO in Louisiana and Washington, confirmed an age-old theory that could provide exciting new advances in physics.

Over a century ago, Albert Einstein came up with his theory of general relativity, predicting that as a mass accelerated, it would radiate gravitational waves as it lost energy. This idea means that there should be a huge effect on the fabric that holds the universe together- a ripple effect that we should be able to sense on Earth.

The origin of gravitational waves was due to the merging of two black holes, which in turn created a more massive, spinning black hole. This huge mass that had been created was turned into gravitational waves that would radiate about 50 times as much energy as the entire visible Universe.


Around the world several countries have built gravitational wave detectors. In the United States the project was called LIGO (Laser Interferometer Gravitational-Wave Observatory). The purpose of the detector was to sense a stretching of matter across a distance of hundreds of yards.

On 11 February 2016, the executive director of LIGO, David Reitze, confirmed reports that researchers had detected gravitational waves.

But what does this mean and why was their discovery so important?

We need gravitational waves in order to prove once again that black holes really exist. Since they absorb all of the light around them, scientists can’t currently see them. They don’t emit any radiation that can be detected, so it is left to estimations of their existence, size and movement based on the impact to the ‘fabric’ around them. With this new detection of gravitational waves, it is now possible to ‘hear’ black holes.

So what next? There is a need to develop more sensitive detection equipment so that measurements can be more accurate and then from there, there is no telling what scientists will be able to do next. They may be able to measure the expansion of the Universe and how fast it is accelerating or even discover defects in space-time, which have happened since the time of the Big Bang.

There is one thing that we can be certain of though. This monumental discovery has really caused a stir in the science community. Some people are even comparing it to have had as much of an impact as when telescopes were first able to confirm planets or when Sir Isaac Newton defined gravity.



Images used with Creative Commons thanks to Wikimedia Commons


Online Manager 2016-17. Physics with Astronomy Student.

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