What is Gravitational Waves: India To Establish Lab To Study Gravitational Waves

What is Gravitational Waves: India To Establish Lab To Study Gravitational Waves

  • India has decided to establish a Laser Interferometer Gravitational-Wave Observatory (LIGO) where gravitational waves can be studied, Prime Minister Narendra Modi announced on Sunday.What is Gravitational Waves: India To Establish Lab To Study Gravitational Waves
  • In his monthly radio programme Mann ki Baat, Prime Minister Modi said Indian scientists were also in the research team that studied gravitational waves.
  • The laboratory will be third of its kind in the world after Hanford in Washington and Livingston in Louisiana, both in the US.
  • “Recently the Gravitational Waves have been discovered by the scientific community of the world, which is indeed a major achievement. We should be proud of the fact that Indian scientists were also part of it. Keeping this in mind, we have taken a decision to open a LIGO (Laser Interferometer Gravitational-Wave Observatory) in India,” said Prime Minister Modi.
  • LIGO is a national facility for gravitational-wave research, providing opportunities for the broader scientific community to participate in detector development, observation, and data analysis.
  • The Prime Minister announced that within its limited resources India will also participate and contribute in the research through the LIGO.

What are Gravitational Waves?

A gravitational wave* is a concept predicted by Einstein’s theory of general relativity. General relativity states that mass distorts both space and time in the same way a heavy bowling ball will distort a trampoline.

When an object accelerates, it creates ripples in space-time, just like a boat causes ripples in a pond (and also similarly an accelerating electrical charge produces an electromagnetic wave). These space-time ripples are gravitational waves. They are extremely weak so are very difficult to detect. Missions like LISA or LIGO hope to spot gravitation waves detecting small changes in the distances between objects at set distances; satellites for LISA and mirrors for LIGO. As the strength of the wave depends on the mass of the object our best hope of detecting gravitational waves comes from detecting two black holes or pulsars collapsing into each other.

Gravitational waves have been inferred from watching two pulsars spinning and noticing they are slowing down, due to losing energy from emitting gravitational waves.

Gravitational waves are important in telling us about the early universe. The cosmic microwave background gives us a snapshot of the universe about 380,000 years after the start of the universe. Looking very closely at the cosmic microwave background there are patterns seen which can are also be measured in the large scale structure of the universe (so galaxies and clusters) today. These patterns in the cosmic microwave background were caused by very tiny random perturbations from the time when the universe expanded rapidly, known as inflation.

Inflation should also generate gravitational waves. These waves affect the polarisation (the way the wave oscillates) of the cosmic microwave background. Measuring the strength of the polarisation due to gravitational waves gives us a ballpark figure of the amount of energy involved at the time of inflation and helps pin down when inflation occurred.

*Not to be confused with a gravity wave (which is a wave driven by the force of gravity).

Source- Physics.org