On 14 September 2015, the universe's gravitational waves were observed for the very first time.
The waves, which were predicted by Albert Einstein a hundred years ago, came from a collision
between two black holes. It took 1.3 billion years for the waves to arrive at the LIGO detector in
The signal was extremely weak when it reached Earth, but is already promising a revolution in
astrophysics. Gravitational waves are an entirely new way of observing the most violent events
in space and testing the limits of our knowledge.
LIGO, the Laser Interferometer Gravitational-Wave Observatory, is a collaborative project
with over one thousand researchers from more than twenty countries. Together, they have
realised a vision that is almost fifty years old. The 2017 Nobel Laureates have, with their
enthusiasm and determination, each been invaluable to the success of LIGO. Pioneers Rainer
Weiss and Kip S. Thorne, together with Barry C. Barish, the scientist and leader who brought
the project to completion, ensured that four decades of effort led to gravitational waves finally
In the mid-1970s, Rainer Weiss had already analysed possible sources of background noise that
would disturb measurements, and had also designed a detector, a laser-based interferometer,
which would overcome this noise. Early on, both Kip Thorne and Rainer Weiss were firmly
convinced that gravitational waves could be detected and bring about a revolution in our
knowledge of the universe.
Gravitational waves spread at the speed of light, filling the universe, as Albert Einstein described
in his general theory of relativity. They are always created when a mass accelerates, like when an
ice-skater pirouettes or a pair of black holes rotate around each other. Einstein was convinced it
would never be possible to measure them. The LIGO project's achievement was using a pair of
gigantic laser interferometers to measure a change thousands of times smaller than an atomic
nucleus, as the gravitational wave passed the Earth.
So far all sorts of electromagnetic radiation and particles, such as cosmic rays or neutrinos, have
been used to explore the universe. However, gravitational waves are direct testimony to
disruptions in spacetime itself. This is something completely new and different, opening up
unseen worlds. A wealth of discoveries awaits those who succeed in capturing the waves and
interpreting their message.
Source : Google
Submitted By : Chinmoy Dey Antu
Roll : #11911079