30 June 2021

A black hole devouring a neutron star: - The first ever collision detected.

The US Laser Interferometer Gravitational-Wave Observatory (Ligo) detected the first collision, dubbed GW200105, on January 5, 2020, and the wave suggested that a neutron star bigger than our Sun had been sucked in by a black hole. The black hole had a mass equal to that of nine suns.

  • Gravitational waves are 'ripples' in space caused by some of the most violent and energetic processes in the Universe. These cosmic ripples would travel at the speed of light, carrying with them information about their origins, as well as clues to the nature of gravity itself. The speed, wavelength, and frequency of a gravitational wave are related by the equation c = λ f, just like the equation for a light wave. The frequencies of gravitational wave are much lower than those of the electromagnetic spectrum, less than a hertz to a few thousand hertz at most and have much larger wavelengths – ranging from hundreds of kilometres to potentially the span of the Universe, but surprisingly they travel at the speed of light.  Gravitational waves appear as 'ripples' of low frequency space waves, ranging between a fractions of a Hertz to a few Kilo Hertz, unusually travelling at the speed of electromagnetic waves, obviously due to its medium is space. It also appears that for a 150,000 Kilometre (Km) wavelength of a Gravitational wave, its frequency would be just a little less than 2 Hertz (Hz). 


  • 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 point. This can happen when a massive star dies. A black hole forms when the centre of a very massive star collapses in upon itself. Because no light can get out, people can't see black holes. They are invisible.
  • Neutron stars are dead stars that are incredibly dense. A teaspoonful of material from a neutron star is estimated to weigh around four billion tonnes. Both objects are cosmological monsters, but black holes are considerably more massive than neutron stars. Since neutron stars are dead stars and incredibly dense, when a black hole engulfs a neutron star, the collision creates ripples in the fabric of space called gravitational waves.
  • For sound waves in air, the speed of sound is 343 m/s (no comparison with C). The wavelengths of sound frequencies audible to the human ear (20 Hz–20 kHz) are thus between approximately 17 m and 17 mm respectively. However, radio waves travel at the speed of 299,792,458 m/s in space.

    • It appears that for a just 100 Hertz (Hz) frequency of a sound wave (unmodulated), its wavelength would be 3.43 Metre (m) and its speed would be 343 m/s on Air at 20°C.
    • It also appears that for a just 100 Hertz (Hz) frequency of a Gravitational wave, its wavelength would be 2,998 Kilometre (Km) and its speed would be 299,792,458 m/s in space.
    • It appears that only the waves those can also travel in space travels at C (f.λ = C).

#neutronstar #blackhole #GravitationalWaves


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