How do we know that gravitational waves exist? In 2015, scientists detected gravitational waves for the very first time.
They used a very sensitive instrument called LIGO (Laser Interferometer Gravitational-Wave Observatory).
These first gravitational waves happened when two black holes crashed into one another..
The strongest gravitational waves are produced by cataclysmic events such as colliding black holes, supernovae (massive stars exploding at the end of their lifetimes), and colliding neutron stars..
“Gravitational waves are ripples in spacetime.
When objects move, the curvature of spacetime changes and these changes move outwards (like ripples on a pond) as gravitational waves.
A gravitational wave is a stretch and squash of space and so can be found by measuring the change in length between two objects.”.
In general, a gravitational wave is created any time a mass accelerates.
Traveling along a circular path is only one type of acceleration.
If an object with mass speeds up along a straight path, this is also a type of acceleration, and therefore it should create gravitational waves..
Gravitational waves are ripples in space-time (the fabled “fabric” of the Universe) caused by massive objects moving with extreme accelerations.
In outer space that means objects like neutron stars or black holes orbiting around each other at ever increasing rates, or stars that blow themselves up (supernovae)..
Gravitational waves are ripples in space-time, the fabric of the universe, that travel at the speed of light.
Gravitational waves are created when objects speed up, slow down, or change direction.
And just like light, they come in different wavelengths and frequencies..
Gravitational waves are ripples in space-time, the fabric of the universe, that travel at the speed of light.
Gravitational waves are created when objects speed up, slow down, or change direction.
And just like light, they come in different wavelengths and frequencies..
The strongest gravitational waves are produced by cataclysmic events such as colliding black holes, supernovae (massive stars exploding at the end of their lifetimes), and colliding neutron stars..
Albert Einstein's general theory of relativity predicted the existence of gravitational waves — distortions in spacetime — but assumed that they would be virtually impossible to detect from Earth..
The observation of primordial gravitational waves could provide a new and unique window on the earliest moments in the history of the universe and on possible new physics at energies many orders of magnitude beyond those accessible at particle accelerators.
Such a background will involve waves today whose wavelengths will extend all the way up to our present cosmological horizon (the distance out to which we can currently observe in principle) and that are likely to be well beyond the reach of any direct detectors for the foreseeable future.
The GW cosmological backgrounds are assumed typically to be unpolarised, as a consequence of the absence of a significant source of parity violation in the universe.
If the process sourcing the GWs is based on interactions that are symmetric under parity, the outcome is a GW background for which the two polarisations , are uncorrelated.
