Nobel prize in Physics, 2017: Detectors of ripples in space-time:

Nobel prize in Physics, 2017: Detectors of ripples in space-time:

Context

• Nobel Physics Prize 2017 has been awarded to 3 scientists for discoveries in gravitational waves.  
• Last year, Nobel Foundation honoured theoretical work in the topology of matter, ignoring the Laser Interferometer Gravitational-Wave Observatory (Ligo), which had detected gravitational waves 12 months before the ceremony
• This year, the Royal Swedish Academy of Sciences has made amends by honouring the Ligo leadership — Rainer Weiss, who designed the most sensitive instrument ever made by the human race, Kip S Thorne, who narrowed down the signals and frequencies it was designed to seek, and Barry C Barish, who built the project hands-on.

What is Ligo’s exemplary contribution?

• It detected the signature of the first gravity wave on September 15, 2015, which was translated into a sound that was between a chirp and a ping.

What exactly did Ligo see or hear?

• It heard the collision of two massive black holes that had spun around each other at maniacal velocities and then collided 1.3 billion years ago, when life on earth had barely begun
• The cosmic incident was not visible, since light cannot escape the event horizon of a black hole, but it can be inferred by radiation in the vicinity of the maelstrom of matter and energy
• It also spread gravitational waves, ripples propagating at the speed of light across the fabric of space-time

Background

• When the first Homo sapiens walked the plains of Africa millennia ago, the waves were sweeping through the Magellanic Cloud, and they reached Earth in September 2015, producing tiny disturbances at Ligo’s laser interferometers in Louisiana and Washington state, apart from the Virgo instrument in Italy.
• It produced a tiny chirp that shook the world of quantum physics.

What remained unattended?

• The Higgs boson was the last element of the standard model of physics which remained unobserved in the wild.
• With the discovery of the Higgs boson, the laboratory caught up and theory was vindicated.
• However, the century-old prediction of gravitational waves remained untested — actually, it dates back to Henri Poincare’s postulate of 1905.

What is Ligo’s contribution with regard to the untested gravitational waves?

• Now, Ligo has provided yet another assurance of the patency of the standard model.

Why gravitational wave astronomy is so significant?

• Gravitational wave astronomy will give humanity access to parts of space and time which have remained invisible.
• Unlike electromagnetic radiation like light, which traverses space-time, they are ripples within the very fabric of space-time.
• They are not scattered by matter, and will allow instruments to peer impossibly far into the gulfs of space — and correspondingly far back in time.
• Parts of the universe which have remained dark to optical and radio telescopes will now become visible.
• Black holes and neutron stars — bodies so dense that a spoonful of their substance would weigh as much as the earth — will yield up secrets never seen before.

How are gravitational waves formed?

• Anything with mass produces gravitational waves when it accelerates.
• We produce scads of gravitational waves every time you dance, but they are not strong enough to be picked up by instruments.
• But anything with a gigantic mass, like a black hole or a neutron star, would generate measurable waves, rendering hitherto hidden phenomena visible.