2. CONTENTS
• Introduction
• What are gravitational waves
• Sources and types of gravitational waves
• Types of gravitational waves
• Detection of Gravitational waves
• What is interferometer
• Why to detect gravitational waves
• LIGO-India: A Planned Joint India-US Detector
• References 2
3. Introduction
It all started with Einstein theory of general relativity, which
predicted the existence of gravitational waves in space time.
Einstein theory stated that objects cause the fabric of space-
time around them to curve. Moving objects should therefore
create ripples in space-time.
It predicted that the more massive the object, the larger the
gravitational waves it would create.
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4. What are gravitational waves
Gravitational waves are ripples in the
curvature of space time, generated in
certain gravitational interactions and
travelling outward from their source.
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5. Sourcesand types of gravitationalwaves
Any object with mass that accelerates (which in science means
changes position at a variable rate, and includes spinning and
orbiting objects) produces gravitational waves, including humans
and cars and airplanes etc.
The Universe is filled with incredibly massive objects that
undergo rapid accelerations (things like black holes, neutron
stars, and stars at the ends of their lives)., the gravitational waves
produced by these massive objects can be detected.
.
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6. Types of gravitational waves
In order to understand the types of gravitational waves these objects
may produce, LIGO scientists have defined four categories of
gravitational waves, they are:
1. Continuous Gravitational Waves
Produced by a single spinning massive object, like an extremely
dense star called a neutron star.
2. Compact Binary Inspiral Gravitational Waves
Produced by orbiting pairs of massive and dense (hence "compact")
objects like white dwarf stars, black holes, and neutron stars.
3. Stochastic Gravitational Waves
4. Burst Gravitational Waves
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7. Detectionof Gravitationalwaves
Gravitational waves were detected on 11th Feb. of this year.
Detection of gravitational waves has been carried out
successfully by LIGO.
LIGO stands for Laser Interferometer Gravitational-Wave
Observatory. It is the world's largest gravitational wave
observatory and a cutting edge physics experiment.
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Aerial views showing the locations and extents of the LIGO
Hanford and LIGO Livingston interferometers.
9. What is interferometer
Interferometers are investigative tools used in many fields of
science and engineering. They are called interferometers because
they work by merging two or more sources of light to create an
interference pattern, which can be measured and analyzed; hence
"Interfere-ometer". The interference patterns generated by
interferometers contain information about the object or
phenomenon being studied.
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10. Why to detect gravitational waves
• Gives us a newer meaning of universe
• Opens up a new window to study of universe
• Gravitational waves are not electromagnetic radiation. They
are a completely different phenomenon, carrying information
about cosmic objects and events that is not carried by
electromagnetic radiation
• Colliding black holes, for example, emit little or no
electromagnetic radiation, but the gravitational waves they
emit will carry information of them
• A better understanding of space time
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11. LIGO-India:A PlannedJointIndia-USDetector
LIGO India is a collaboration between the Laser Interferometer
Gravitational-wave Observatory (LIGO) Laboratory (operated by
Caltech and MIT) and three Institutes in India – the Raja
Ramanna Center for Advanced Technology (Indore), the Institute
for Plasma Research (Ahmedabad), and the Inter-University
Centre for Astronomy and Astrophysics (Pune). These three
institutions bring the complementary skills and resources
needed the success of the project.
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