Gravitational Waves

• An invisible, incredibly fast ripple in space- travel at the speed of light and squeeze and stretch anything in their path as they pass by.

• Albert Einstein’s prediction: When two bodies,
such as planets or stars, orbit each other- could cause ripples in space.

• Most powerful gravitational waves are created when objects move at very high speeds.

• Events that could cause a gravitational wave are:
 When a star explodes; When two big stars orbit each other; When two black holes orbit each other and merge.
• Sometimes, these events only cause small, weak
gravitational waves- hard to detect.

• 2015: Scientists detected gravitational waves
for the very first time- using LIGO.
 Happened when two black holes crashed
into one another- happened almost 1.3 billion years ago.

Laser Interferometer Gravitational-Wave
Observatory (LIGO)

• Made up of two observatories- one in Louisiana and one in Washington.

• Each observatory has two long “arms”: each more than 4 kilometres long.

• When a gravitational wave passes by Earth, it squeezes and stretches space- detected by LIGO.

• A passing gravitational wave causes the length of the arms to change slightly.

• Uses lasers, mirrors, and extremely sensitive instruments to detect these tiny changes.

IndIGO (Indian Initiative in Gravitational-wave
Observations)

• An initiative to set up advanced experimental
facilities, with appropriate theoretical and computational support, for a multi-institutional Indian national project in gravitational-wave astronomy.

• IndIGO plans on gravitational-wave astronomy related to the LIGO-India project.
LIGO-India Project.

• A planned advanced gravitational-wave detector to be located in India.
• To be built and operated in collaboration with the LIGO USA and its international partner Australia, Germany and the UK.

• Scheduled for completion in 2024- will be built in the Hingoli District of Maharashtra state in
western India.