Which of the following statements is correct? 1. Gravitational waves were predicted by Albert Einstein in 1916 on the basis of his theory of General Relativity 2. Gravitational waves do also exist in the Newtonian theory of Gravitation 3. Gravitational Waves are to be detected by very sensitive detectors known as Interferometes Select the correct answer using the code given below:

Albert Einstein predicted the existence of gravitational waves in 1916 as a consequence of his General Theory of Relativity, describing them as ripples in the fabric of spacetime [1]. Unlike General Relativity, Newtonian theory of gravitation does not allow for gravitational waves because it assumes gravity acts instantaneously across space, whereas gravitational waves travel at the speed of light. Statement 2 is therefore incorrect. To detect these minuscule distortions, scientists use extremely sensitive instruments known as laser interferometers, such as those at the Laser Interferometer Gravitational-Wave Observatory (LIGO) [2]. These detectors measure changes in distance much smaller than a proton by comparing the travel time of laser beams along perpendicular arms. The first direct detection of these waves occurred in 2015, confirming Einstein's century-old prediction [2].

Sources

1. [1] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 1: The Universe, The Big Bang Theory, Galaxies & Stellar Evolution > Gravitational Waves > p. 4
2. [2] Physical Geography by PMF IAS, Manjunath Thamminidi, PMF IAS (1st ed.) > Chapter 1: The Universe, The Big Bang Theory, Galaxies & Stellar Evolution > Gravitational Waves > p. 5