So how does gravity work in Einstein’s theory of relativity. Interested?

New York, Feb 12 (IANS) Yes, Albert Einstein was right and the gravitational waves predicted by his general theory of relativity 100 years back have been detected directly in what is dubbed as breakthrough of the century.

But for a layman and for those who were never got on to the science bandwagon, the theory is one hell of a question.

Before Einstein came into the picture, Sir Isaac Newton quantified the force of force of attraction exerted between two bodies known as “gravity” but Newton never went into looking what is the source of it.

According to Space.com, in 1905, Einstein determined that the laws of physics are the same for all non-accelerating observers, and that the speed of light in a vacuum was independent of the motion of all observers.

“Einstein then spent 10 years trying to include acceleration in the theory and published his theory of general relativity in 1915. In it, he determined that massive objects cause a distortion in space-time, which is felt as gravity,” the report added.

So gravity is the force tugging between two bodies depends on how massive each one is and how far apart the two lie.

The latest analysis of the gravitational waves – ripples in the fabric of spacetime – suggests they originated from a system of two black holes, each with the mass of about 30 Suns, that gravitationally drew closer to each other.

The dense objects whipped up to nearly half the speed of light before colliding and merging, sending out a stupendous release of gravitational wave energy that eventually reached the Earth, 1.2 billion light years away.

“For this binary black hole system, it made a distinctive, rising ‘whoooop!’ sound,” said one of the researchers Matthew Evans from Massachusetts Institute of Technology’s Kavli Institute for Astrophysics and Space Research (MKI).

Simply put, even as the centre of the Earth is pulling you toward it, your centre of mass is pulling back at the Earth.

“But the more massive body barely feels the tug from you, while with your much smaller mass you find yourself firmly rooted thanks to that same force. Yet Newton’s laws assume that gravity is an innate force of an object that can act over a distance,” Space.com added.

As Einstein worked out the equations for his general theory of relativity, he realised that massive objects caused a distortion in space-time.

Imagine setting a large body in the center of a trampoline. The body would press down into the fabric, causing it to dimple.

“A marble rolled around the edge would spiral inward toward the body, pulled in much the same way that the gravity of a planet pulls at rocks in space,” the report added.

Gravitational waves — a major prediction of Einstein’s 1915 general theory of relativity — that carry information about their dramatic origins and about the nature of gravity that cannot be obtained from elsewhere, were detected on September 14, 2015 by both of the twin (LIGO) detectors, located in Livingston, Louisiana, and Hanford, Washington, DC.

The LIGO observatories were conceived, built and are operated by the California Institute of Technology (Caltech) and the Massachusetts Institute of Technology (MIT).

The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration and the Virgo Collaboration using data from the two LIGO detectors.

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