LIGO detects whispering Gravitational Waves Einstein predicted 100 years ago
"Don't underestimate the power of the dark side"- Darth Vader had cautioned his son Luke in a Star Wars film.
Had Darth Vader been an astrophysicist, he would have been accurate, as the newest discovery of the existence of gravitational waves by the advanced Laser Interferometer Gravitational Wave Observatory or LIGO has taken up the world by storm.
For the scientific community this is definitely a much sought-after milestone, one that scientists have been inching closer to, ever since Albert Einstein gave the Theory of Relativity a century ago.
We all have heard and read about the Big Bang Theory and how it led to the origin of life. The faint tone detected by LIGO, physicists say, are the first direct evidence of the ripples created by gravitational waves in the space-time continuum.
What makes the discovery even more thrilling for us Indian is the significant contribution of a group of Indian scientists, from top research centers and labs in Mumbai, Pune and Bengaluru who provided crucial research for the worldwide experiment.
Historic detection of gravitational waves opens up new frontier for understanding of universe!
— Narendra Modi (@narendramodi) February 11, 2016
Hope to move forward to make even bigger contribution with an advanced gravitational wave detector in the country.
— Narendra Modi (@narendramodi) February 11, 2016
According to news reports a team led by Bala Iyer at the Raman Research Institute in collaboration with scientists in France, had developed the mathematical calculations used to model gravitational wave signals from orbiting black holes and neutron stars. [Read here]
Sanjeev Dhurandhar at IUCAA led another group that had carried out stellar work related to developing data analysis techniques to detect these weak gravitational wave signals buried in the detector noise.
Many are watching a webcast from Washington at #UF about LIGO's efforts to detect gravitational waves. @WUFTNews pic.twitter.com/9ndoFnn8ne
— James Torrez (@jimmytinthemorn) February 11, 2016
Distortion of spacetime seen in both #LIGO detectors (in Louisiana and Washington) on Sept. 14, 2015 pic.twitter.com/vE14ZhWqmO
— Kathryn Jepsen (@grimkat) February 11, 2016
'We can now listen to the stars', claim scientists
What are gravitational waves?
Gravitational waves are freely propagating oscillations in space-time, as put forward by Albert Einstein in his General Theory of Relativity which predicts that accelerating masses produce gravitational waves.
During various astrophysical phenomena, like the collision and merger of two black holes, gravitational waves are released, which carry enormous amount of energy with them.However, the interaction of these waves with matter is extremely feeble and hence the challenge was to detect them through experiments.
Although gravitational waves were not directly detected earlier, observation of the orbital decay of binary neutron stars (pulsars) had provided indirect evidence of their existence.
Space-time and continuum
In
1906,
soon
after
Albert
Einstein
announced
his
special
theory
of
relativity,
his
former
college
teacher
in
mathematics,
Hermann
Minkowski,
developed
a
new
theory
related
to
the
physical
constructs
of
space
and
time.
According
to
Minkowski,
space
and
time
have
to
be
combined
into
a
new
mathematical
entity
called
'space-time',
because
the
equations
of
relativity
show
that
both
the
space
and
time
coordinates
of
any
event
must
be
combined
mathematically
in
order
to
accurately
describe
what
we
see.
Also, he had said that as space consists of 3 dimensions, and time is 1-dimensional, space-time must, therefore, be a 4-dimensional object.
The term 'continuum' refers to the fact that there are no missing points in space or instants in time. Hence, physicists now routinely refer to the world, present in a 4-dimensional Space-Time continuum, and all events, places, moments in history, are referred to in terms of their location in Space-Time.
How the waves are found now with collision of black holes?
The phenomenon that the LIGO experiment detected was the collision of two black holes, colliding a billion light years away.
Using the world's most sophisticated detector built connecting two observatories in Louisiana and Washington, the scientists listened for 20 thousandths of a second as the two giant black holes, one 35 times the mass of the sun, the other slightly smaller, circled around each other and finally collapsed releasing energy.
'Hear' the #gravitationalwave! ... @LIGO Announcement Chirp https://t.co/8v9GVkRUyg
— Amit Paranjape (@aparanjape) February 12, 2016
Last year in September, the space disturbance that was generated after the black holes collided was picked up by some of the world's most sophisticated machines, as mentioned in media reports. These were the LIGO detectors used earlier.[Read here]
However, strong signals were captured when the new advanced LIGO detectors were brought into operation for their first observing run.
Congrats to the #LIGO team! Here's a pic of LIGO Louisiana—"the most precise measuring device ever built"—from space pic.twitter.com/AIINRx5eq4
— Planet Labs (@planetlabs) February 11, 2016
Future course of action:
The gravitational-wave observations have opened up a fundamentally new astronomical window to the Universe in the near future.
Astronomers had not only their eyes but also ears on the space for listening to the echo of the celestial merger of the two black holes, colliding a billion light-years away in the past.
A similar facility is being planned in India in a direction opposite to the two American observatories in Louisiana and Washington.
"We need detectors in many more directions so that the exact route of the gravitational wave can be traced... hence, the proposal to set up an observatory in India," said Somak Raychaudhury Raychaudhury, Director of Pune's Inter-University Centre for Astronomy and Astrophysics (IUCAA). [Read here]
This revelation will help in tracking Supernovas, which are explosion of a giant star, ahead of time. It will also help to track major celestial phenomenon as well as the noise created by gravitational bodies travelling in space.