The latest big discovery of Gravitational Waves is considered to be one of the most important topic regarding most of the PSU, IES and other UPSC exams ….
In 1916, one of the greatest scientists in the history of mankind, Albert Einstein, had proposed a theory, which was a sister to his famous Theory of Relativity. He depicted gravity as a distortion of space and time triggered by the presence of matter.
Scientists had found only indirect evidence of their existence.
On 11th February 2015, in a packed conference in Washington, California Institute of Technology physicist David Reitze announced that that his researchers and scientists have ‘detected’ Gravitational waves.
The scientists had detected the waves in September 14.
Here I would like to jot down all that we know in the simplest form possible.
- In Einstein’s theory of gravity, the basic concept of gravity is thought upon as distortion of space-time. (Space is a physical region, where events that occur can be located. Events also occur at a certain time. This combination is called Space-Time).
- Space-Time can be explained by imagining that space is a giant sheet of rubber. Suppose you drop a hard ball in this sheet of rubber. It dips down forming a depression of sorts along with certain circular creases. Now suppose you drop a marble in the rubber sheet and guide it to travel in a straight line along the path (Creases) formed because of the hard ball, you’ll find the marble actually moving in a circle instead of the straight line that you had initially started.
- The reason the earth goes around the sun is because, the sun is very massive, causing a big distortion of space around it. The earth invariably tends to take a circular part around the sun.
- This is exactly how orbits work. There is no actual force pulling the planets around. It’s just the bending of space.
- Now, Gravitational waves are produced, whenever masses accelerate, changing the distortion of space.
- Everything with mass and/or energy can make gravitational waves. Even if you and I started dancing around each other, we would create ripples in the fabric of space-time.
But these would be extremely small and practically undetectable.
- LIGO, which stands for Laser Interferometer Gravitational-wave Observatory, is a device, which has been used to detect these gravitational waves.
- In LIGO, a laser beam is split into two perpendicular beams that bounce between the two pair of mirrors. When a gravitational wave passes, it moves the mirror, which changes the length of the path of the laser beams. That minuscular change can be measured with all the optical instruments. This is very similar to the Michelson-Morley experiment, which motivated the theory of relativity.
Questions for which we might discover answers soon-
- Do Neutrinos have mass?
- Are there additional Dimensions?
- Where do ultrahigh-energy particles come from?
These unanswered questions may soon be brought to light.
Do you think you know everything to know about Gravitational Waves to answer all the General Awareness Questions? Attempt the quiz and check your knowledge