Showing posts with label Effects of Passing Gravitational Wave. Show all posts
Showing posts with label Effects of Passing Gravitational Wave. Show all posts

Wednesday, October 25, 2017

Gravitational Waves Arrive in Europe

Gravitational Waves

Race of Detecting Gravitation Wave

One of the most amazing discoveries of 2015 done by the US gravitational waves observatory LIGO of a distant chirp from death-spiral comprising of two black holes had been an incredible logical, scientific and engineering achievement. Thereafter, other black hole mergers – GW151226 and GW170104 had been recognised. Now mapping out the universe of Einstein together with discovering the most extreme gravitational physics possible – the coalescence of black holes, is a new breed of `gravitational wave astronomers’. The fourth burst of gravitational waves had been announced recently and for the first time, Virgo detector of Europe had taken the initiative.

 The race of detecting gravitational waves could have `won’ them the LIGO observatory of US way back in 2015. However, in an amazing display of scientific cooperation with two of the global scientific superpowers namely, Europe and US, Virgo gravitational waves observatory of Europe tends to operate in close cooperation with the LIGO Scientific collaboration in order to monitor the sky for gravitational wave `generates’. It is said that the scientists and engineers of Australia are part of the LIGO Collaboration through the Australian Research Council together with its new Centre of Excellence OzGray.

Characteristic `Chirp’

At precisely 10:30:43 on August 14, 2016, two of the LIGO detectors one based in the US while the other Virgo detector based in Europe had felt the characteristic `chirp’ of passing gravitational waves. The black holes at this point of time had been around 30 and 25 times the mass of the Sun and nearly 2 billion light years away at the time of mergers. In several areas of scientific attempt, competition has become severe together with hundreds of telescopes distributed all over the world,often a rivalryarises to beat the competition to astronomical encounter which is not always appealing to observe. Considering this, gravitational waves astronomy is quite unique since it does not make much sense in competing.

Besides, gravitational waves, contrasting from light tend to travel through the Earth and therefore do not matter where the Earth is pointed during the time of events. Hence irrespective of where your gravitational wave detector is build, it could be part of a global network. Moreover there are some good dividends which could be earned.

Error Box 

In contrast to the first three gravitational waves identified, the delay this time between the arrival time of the waves at every three detectors could be utilised to `triangulate’the location on the sky’. At first the wave hit the LIGO Livingston detector, thereafter 8 milliseconds the Hanford detector saw the wave and after 14 milliseconds the wave reached Europe much to the happiness of the Europeans.

The existence of the third gravitational wave detector immensely reduced the `error box’ of the origin of the wave wherein the potential sky localisation reached from more than 1,000 to just 60 square degrees.The vagueness in the origin of the gravitational waves for the four events was detected.

Minus the European detector Virgo the error box tends to be quite huge that at times it is not clear which hemisphere it had originated from. The error box for GW170814 is adequately small to perform detailed searches at the other wavelengths.

Saturday, June 7, 2014

Gravitational Waves – Ripples in Space-time Continuum

Gravitational Waves – Ripples in Space-time Continuum

Gravitational waves are ripples in space time continuum which was seen by Albert Einstein in his general theory of relativity. These are ripples that carry energy across the universe and were predicted to exist as a consequence of Einstein General Theory of Relativity in 1916.

Though there is a strong evidence of its existence, gravitational waves has not been directly detected earlier since they are minuscule which is a million times smaller than an atom.

Ripples in Space-time Continuum

They seem like tiny waves on a lake far away and the lake’s surface looks glassy smooth and the details of the surface can be seen only when very close to it.Einstein, in the year 1916, discovered a mathematical way to explain gravity and called it his general theory of relativity.

This theory relied on a set of coordinates which described the combination of space and time known as the space time continuum.

Warping of Matter and Energy – Force of Gravity

Since matter and energy warp the space time continuum like heavy weight on a mattress, the warping thus creates the force of gravity and gravitational waves are ripples in the space time continuum.

General relativity shows us how gravity can affect time which should be taken into account by satnav to inform where you are. A telescope at the South Pole known as Bicep – Background Imaging of Cosmic Extragalactic Polarisation, has been looking out for evidence of gravitational waves by detecting subtle property of the cosmic microwave background radiation.

The radiation which was produced in the big bang was originally discovered by American scientist in the year 1964 with the help of radio telescope and has been called as the `echo’, of the big bang. The large scale polarisation of this microwave had been measured by Bicep. Primordial gravitational waves only can imprint such pattern if they have been amplified by inflation.

Curvature of Space-time 

Curvature of Space- Time
According to Einstein’s theory of general relativity, gravity has been treated as a phenomenon, the outcome of the curvature of space time and this curvature is the result of the presence of mass. The more mass that is contained within a volume of space, the greater is the curvature of space-time at the boundary of the volume.

When the objects with mass move around in space-time, the curvature also changes to reflect the changed location of these objects.

In some situations, accelerating objects may generate changes in this curvature propagating outwards at the speed of light like a wave and these propagating situations are known to be gravitational waves.

Effects of Passing Gravitational Wave

Effects of Passing Gravitational Wave
As these gravitational wave passes far away, an observer will find space-time distorted due to the effects of strain and the distance between free objects may increase and decrease rhythmically as the wave may pass at a frequency which corresponds to the wave despite free objects not being subjected to an unbalanced force.

 The effect of the magnitude decreases inversely with distance from the source. Effects of passing gravitational wave can be seen by imagining a flat region of space-time with that of a group of motionless test particle lying in a plane and as the gravitational wave passes through the particles along a line which is perpendicular to the plane of the particles, the particles tend to follow the distortion in space-time.