The recently discovered gravitational waves are to date the biggest news in universe physics. This discovery gives scientists a new way to listen in to what is happening in the universe and proves right Albert Einstein genius.
This article is a recap of some of the most important bits of information regarding this discovery.
WHAT ARE GRAVITATIONAL WAVES?
Gravitational waves are spacetime ripples that travel outwards from the source and propagate as waves. The existence of gravitational waves was predicted in 1916 by Albert Einstein, based on his general relativity theory. Gravitational waves carry energy as gravitational radiation. The Newtonian gravity theory does not allow the existence of gravity waves since it postulates that physical interactions propagate at infinite speed. Possible sources of gravitational waves include binary star systems that are made up of black holes, neutron stars, or white dwarfs. On 11th February 2016, the LIGO Scientific Collaboration and Virgo Collaboration teams revealed that using Advanced LIGO detectors, they had for the first time detected gravitational waves from two merging black holes.
HOW THE LIGO SYSTEM WORKS
- A single beam of laser is divided and directed into two identically similar tubes, each of which is 4km long.
- Mirrors are used to reflect the now twin beams back to the detector.
- Inside this detector, the two laser beams will arrive as perfectly aligned.
- They are recombined so that they can cancel each other out.
Detecting Gravity Waves Using LIGO
- When spacetime is distorted/altered by gravity waves, the lengths of the two tubes will change. One stretches while the other contacts progressively till the wave has passed.
- As the distances change the troughs and peaks of the returning beams of laser move in and out of alignment.
- Once recombined, the laser beams won’t cancel each other out. Thus, the light will reach the detector, which can then measure the gravity wave.
THE FEBRUARY 11TH FINDING
The new finding completes the scientific cycle of predicting, discovering, and confirming. At first, the research teams conducted calculations to establish what they should be able to detect, then made a decision regarding what the evidence ought to look like. The third step involved devising an experiment that could provide proof. Following the announcement of the discovery of gravitational waves on Thursday, February 11, 2016, scientists around the world hailed the experiment as another profound confirmation of the ‘standard model’ of the cosmos. This notable milestone is also scened as the start of a new era of discovery. In the past, astronomers have already been able to exploit visible light, ultraviolet and infrared radio waves, x-ray, and gamma-rays in attempts to better understand the makings and mechanics of stars, how galaxies evolve, and the expansion of the universal after that initial big bang over 13 billion years ago. Even before the Advanced Ligo in the United States reopened for operation towards the end of 2015, scientists were confident that detection was impending. The discovery came following months of speculation, and decades of hard theoretical and practical work that brought together a network of over 1000 scientists from the US, the UK, Europe, and other parts of the world.