Laser Interferometer Gravitational-Wave Observatory (LIGO)

Why in news?

The Union Cabinet has cleared Rs 2,600-crore project to construct and set up a Laser Interferometer Gravitational Wave Observatory- India (LIGO-India), which is likely to be completed by 2030.

What are Gravitational waves?

• Gravitational wave - A gravitational wave is an invisible yet incredibly fast ripple in space.
• Their existence was initially predicted by Albert Einstein in 1916 in his general theory of relativity.
• Properties - Gravitational waves travel at the speed of light.
• The waves can squeeze and stretch anything in their path as they pass by.
• Causes - The gravitational waves are caused
  • When a star explodes asymmetrically (supernova)
  • When two big stars orbit each other
  • When two black holes orbit each other and merge
  • When neutron star collide each other
• The objects that create gravitational waves are far away and sometimes, these events only cause small, weak gravitational waves making them hard to detect.

What is LIGO?

• LIGO - LIGO stands for "Laser Interferometer Gravitational-wave Observatory”.
• It is the world's largest gravitational wave observatory.
• It is an ambitious project by U.S to detect the faintest ripples from cosmic explosions millions of light years away.
• LIGO exploits the physical properties of light and of space itself to detect and understand the origins of gravitational waves (GW).
• LIGO Comprises two large observatories located 3000 kilometers apart - at Hanford in the State of Washington, and at Livingston in Louisiana.

• Working - Each LIGO observatories consists of two arms of laser interferometers that can merge two or more sources of light to create an interference pattern.
• The interference patterns generated by interferometers contain information about the object or phenomenon being studied.
• A passing gravitational wave causes the length of the arms to change slightly.
• LIGO's interferometers are designed to measure a distance 1/10,000th the width of a proton.
• LIGO cannot detect electromagnetic radiation such as visible light, radio waves and microwaves because gravitational waves are not a part of the electromagnetic spectrum.
• First detection - In 2015, LIGO physically sensed gravitational waves generated by two colliding black holes 1.3 billion light-years away.

What is LIGO India?

• The LIGO India [roject is an international collaboration between the LIGO Laboratory and three Indian lead institutions.
• The project is piloted by the Department of Atomic Energy (DAE) and Department of Science and Technology (DST).
• Aim - To improve the detectors’ collective ability to pinpoint sources of gravitational waves in the sky.
• It is to be located in Hingoli district, Maharashtra, India.
• LIGO India will consist of a detector (3^rd detector) to be built in the image of the twin LIGO instruments already operational in the U.S.

What are the opportunities for India?

• India could become a global site of gravitational physics research.
• Training and the handling of precision technologies could improve the current status.
• Big Science projects could be increased.
• It has the potential to provide employment opportunities.
• Indian society’s relationship with science could take a new dimension.

References

1. The Hindu│LIGO India
2. LIGO│ About LIGO
3. LIGO│ India About LIGO India
4. LIGO│Other Detectors