Gravitational Waves / Physics Rejoicing


After decades of searching, scientists have succeeded in detecting gravitational waves from the violent merger of two massive black holes.

Physics must be rejoicing right about now, and Einstein would be smiling on us from above. The reason for such joy can be amounted to months of speculation, and decades of continuous effort and hard work, scientists at LIGO (Laser Interferometer Gravitational-Wave Observatory) have for the first time detected gravitational waves, or ripples in the fabric of space-time, confirming a prediction made by Albert Einstein 100 years ago and opening a new window to observe hitherto invisible exotic events in the universe.

Also remarkably, the waves were even powerful enough to break the Internet, bringing down both the LIGO and American Physical Society websites.

Until our servers are back online (we’re adding more capacity now) here is figure one from the paper #LIGO

"Ladies and gentlemen, we have detected gravitational waves. We did it," said David Reitze, executive director of LIGO, the Laser Interferometer Gravitational-Wave Observatory, which was created to do just what Reitze announced.

The detection was made on September 14, 2015. The ensuing months were spent in the arduous task of actually confirming a signal that was, at first, considered too good to be true.

“Looking for Proof”

“It was definitely not a blind injection,” said Gabriela González, spokeswoman for the LIGO Scientific Collaboration, referring to false signals occasionally injected into the data to ensure accurate detections.

The signals which led to the discovery of such elusive Gravitational Wabe, were emitted from somewhere in the southern celestial hemisphere, in the rough direction of the Magellanic clouds. Ultimately, they were emitted roughly 1.3 billion years ago (which means the source was located about 1.3 billion light years away). The waves resulted from the collision, and subsequent merger, of two black holes.

According to theoretical physicist Kip Thorne of Caltech, a co-founder of LIGO and pioneer in the field of gravitational wave detection, the colliding black holes “created a violent storm in the fabric of spacetime.”

This storm was very brief—lasting only 20 milliseconds—and unleashed an amount of energy equivalent to 50 times the total power output of all the stars in the universe. The two black holes merged to form a single, 62 solar mass black hole. 3 suns worth of gravitational energy was annihilated in the coalescence, releasing the gravitational waves that were detected last September.

The signals exactly matched predictions from Einstein’s General Theory of Relativity regarding what would happen when two black holes collide and merge. In fact, the nature of the event was made clear by running computer simulations and finding which ones produced a signal that coincided with the September 14 event.

Wait a minute, what is the general theory of relativity?

“Einstein would be beaming, wouldn’t he?” enthused France Córdova, Director of the National Science Foundation.

Now, the General Theory of Relativity, is a complex theory of the universe that Einstein put forward in November 1915. It demands some sophisticated mathematics, but essentially proposes that mass can distort space and time, just like a heavy load pushes down on a spring mattress. Space and time thus behave like a jelly-like substance that can stretch and bend under the influence of mass. (Hello Worm Holes!!)

The final question. What does this all mean?

The new discovery has enormous implications, many of which will require decades to be worked out.  It’s an astonishing independent confirmation of the fundamental truth and power of Einstein’s equations, but more importantly, it opens up to human understanding an entirely new dimension of astronomical observation.  Whereas before we were restricted to electromagnetic radiations alone, we can now observe the very ripples of spacetime itself.

Thorne expects that further gravitational wave detections will be made in the coming year; when the VIRGO instruments come online, astronomers will be able to pinpoint the sources with greater precision and accuracy.

And there are designs in the works for new detectors that can register gravitational waves with periods, not merely in the millisecond range (as with LIGO), but in the range of minutes to hours, years to decades, and even billions of years.

And there’s likely much more to come. Also I hope there will be movies and TV Shows exploiting the imaginative reach of this concept.

“As we open a new window in astronomy, we may see things we’ve never seen before,” David Reitze predicted.

You can read the paper, which was published in Physical Review Lettershere. In the event that the peer review article is not accessible, as the website may go down again, the results and abstract are copied below:

P.S. India’s role in the search for gravitational waves

Scientists from at least five academic institutions contributed to the global efforts of data analysis leading to the confirmation of the discovery. Indian scientists are also awaiting a government nod to build a third LIGO detector in India that will be crucial in the search for astronomical sources of gravitational waves.

Source: Phys Review Letters

This blog post is inspired by the blogging marathon hosted on IndiBlogger for the launch of the #Fantastico Zica from Tata Motors. You can apply for a test drive of the hatchback Zica today.