LIGO project and Gravitational waves are in news .......there are a lot of technical terms involved ...which make it difficult for people from non SCIENCE background to understand it....so herez an ARTICLE which I am making to make THINGS easy !
First of all what are gravitational waves?
- Ripples in spacetime, a bit like ripples on a pond, that propagate out at the speed of light.
- Throw something really big into the stillness of space – like two black holes colliding, or two pulsars merging – and gravitational waves created by the event should spread not just across the galaxy, but ultimately through all of spacetime.
|Two Black holes ek dusre ko takraate hai ...aur ripple waves dete hai jise hum gravitational waves kehte hai|
nahi samja ? ..thik hai phir samajte hai !
- A gravitational wave is a ripple in space-time.
- By this we mean that when a gravitational wave passes by us, all the distances appear to oscillate.
- If it passes between me and you, the distance between us would grow, then shrink again, and so on, oscillating until the wave had passed.
- We never see this because the gravitational waves that reach earth are so tiny.
- But if we did have a strong gravitational wave pass through us we would really see this oscillating distance, and it would look really weird!
avhi nahi samje toh yeh video dekho !
Ok, incase u dont know what Black holes are ?
A black hole is a place in space where gravity pulls so much that even light can not get out. The gravity is so strong because matter has been squeezed into a tiny space. This can happen when a star is dying. Because no light can get out, people can't see black holes. They are invisible. Space telescopes with special tools can help find black holes. The special tools can see how stars that are very close to black holes act differently than other stars.
Ok, why are Gravitational waves in news ?
- At a press conference on Thursday, physicists from the Laser Interferometer Gravitational-wave Observatory (LIGO) revealed that they had detected gravitational waves.
Why did we think they exist?
- Gravitational waves were predicted by Albert Einstein’s general theory of relativity, 100 years ago.
- Almost everything the theory predicted has been confirmed by observation or experiment, except gravitational waves.
toh usase kya hua ? Gravitational waves detect huye toh ?
- Everything we currently know about astrophysics and cosmology arose from observations of electromagnetic waves.
- Gravitational waves give us a new and entirely different source of information.
- perhaps the main reason the discovery is important is that it opens a new window onto the stars.
- Gravitational wave detectors are a new kind of telescope that will allow us to learn a great deal more about the universe than we ever could otherwise.
accha phir ye LIGO project walon ne kaise detect kiya ?
- First they built two detectors, one in Washington and one in Louisiana, and required that both detectors see the same signal at (almost) exactly the same time.
- This greatly cuts down on the chance that the signal is just coming from random noise.
- There are very few things besides a gravitational wave that are going to hit both detectors at basically the same time with the same signal.
- They also work very hard to make sure that each detector has as little noise as possible, and that the level of the noise is well understood.
- For example, the earth vibrates all the time at a small level and this is a noise source for LIGO so they use impressive mechanical systems, a bit like shock absorbers, to keep their mirrors from feeling these vibrations as much as possible.
- Even the best laser is not perfect, and will have some noise in it. So they build two baselines in each detector to allow them to subtract off the laser noise that will be comment to both baselines. This is just a small fraction of the number of different noise sources they have considered, calculated carefully, and worked hard to understand and reduce as much as possible.
- They also use blind analysis techniques to help them make sure that they are not fooling themselves and are estimating their uncertainties correctly.
- And they spend a long time understanding their detector and the noise in it after they turn it on.
So basically scientists heard these GRAVITATIONAL waves?
A: Scientists mostly use the word "hear" when describing gravitational waves, and the data does, in fact, arrive in audio form. The researchers can don headphones and listen to the detectors' output if they want. On Thursday, to prove they found a gravitational wave, the researchers played a recording of what they called a chirp.
Ok , now thoda factual data about LIGO Project
- The LIGO study of the gravitational waves is being done as part of a joint project which involves over a thousand scientists from the United States and 14 other countries, including Russia.
- The twin LIGO detectors are located in Livingston, Louisiana, and Hanford, Washington.
- The LIGO observatories are funded by the US National Science Foundation (NSF), and were conceived, built and are operated by Caltech and MIT.
What was role of Indian scientist in LIGO project ?
- Indian scientists have, over 30 years, contributed substantially to the gravitational wave discovery that was announced last week. C.V. Vishveshwara and Bala Iyer, formerly of the Raman Research Institute, Bengaluru, were among the first to solve Einstein’s equations to derive a mathematical model to explain how colliding blackholes would look and what tell-tale signals they emitted.
- In later years, Anand Sengupta of the Indian Institute of Technology, Gandhinagar, developed methods to ensure that both the LIGO detectors — separated by 3,000 kilometres — have caught the same gravitational wave, and Sanjib Mitra of the IUCAA, has found ways to tell apart gravitational waves from various exotic stars.
(inke baare me mainstream MEDIA me gunn nahi gaaye jaate...bas deshdrohiyo ki vakalat hoti hai )
Ok, Indian government kuch kar raha hai ki nahi ?
INDIGO, or IndIGO (Indian Initiative in Gravitational-wave Observations) is a consortium of Indian gravitational-wave physicists. This is an initiative to set up advanced experimental facilities for a multi-institutional observatory project in gravitational-wave astronomy. Since 2009, the IndIGO Consortium has been involved in constructing the Indian roadmap for gravitational-wave astronomy and a phased strategy towards Indian participation in realizing a gravitational-wave observatory in the Asia-Pacific region. IndIGO is the Indian partner (along with the LIGO Laboratory in USA) in planning the proposed LIGO-India project.
- Days after the discovery of gravitational waves, the government today gave an "in-principle approval" for establishing a state-of-the-art LIGO (Laser Interferometer Gravitational-wave Observatory) project in the country.
- The project will bring unprecedented opportunities for scientists and engineers to dig deeper into the realm of gravitational wave and take global leadership in this new astronomical frontier.
- The LIGO-India project will also bring considerable opportunities in cutting-edge technology for the Indian industry which will be engaged in the construction of the eight-km long beam tube at ultra-high vacuum on a levelled terrain.
Moral of the Story !!
This is the opening of a new era in our ability to learn about the universe. People have always wondered what else is out there beyond our planet. We have learned a great deal from observing electromagnetic waves. Gravitational waves have the potential to reveal even more. Possibly, in the future, this could even include looking back to some of the earliest moments after the birth of the universe.