Gravitational Wave Background: A Very Simple Explanation
Recently, the gravitational wave background of the universe has been detected for the first time. Gravitational waves or gravitational waves (GW) are ripples in the structure of space-time.
These waves are generated by the most energetic phenomena in the universe (such as the merger of two black holes and the collision of a neutron star). First of all, Einstein had predicted about them in his ‘Theory of Relativity’.
They were first discovered in 2015. However, so far these waves have only been detected in the shortest range of wavelengths. When gravitational waves pass through a medium, there is a slight stretching or contraction of that medium. To find evidence of this stretching or contraction, astronomers observe the pulsar.
Pulsars are rapidly rotating stars. They emit beams of radiation at very precise intervals. Pulsars practically act as cosmic lighthouses (used as clocks that tell the exact time).
Now, scientists have discovered a “background hum” resonating throughout the universe. This confirms the presence of low-frequency (long-wavelength) gravitational waves. It is said that it keeps moving continuously in cosmic noise.
Cosmic or Space Noise It is also called Galactic Radio Noise. It is not actually a sound, but a phenomenon occurring outside the Earth’s atmosphere. These waves are also important for studying the nature of gravity.
The Pune-based Giant Meterwave Radio Telescope (GMRT) is one of the six large telescopes in the world that has played a key role in providing evidence of the Gravitational Wave Background. Five other telescopes are located in Germany, the United Kingdom, France, Italy and the Netherlands.
Detection of Gravitational Waves with Pulsars-
- Gravitational waves produced by the merger of supermassive black holes in distant galaxies subtly change the position of the Earth.
- Telescopes on Earth measure tiny differences in the arrival times of radio bursts caused by collisions.
- Measuring the effect on pulsars increases the likelihood of detecting gravitational waves.
Source – Indian Express
