With the discovery of gravitational waves, ripples in the fabric of space-time, scientists have finally been able to provide convincing evidence for the existence of black holes and confirming an enigmatic part of Einstein’s theory of relativity. The discovery is one of the most important climaxes of the century and may finally provide the fundamental understanding of the formation of the Universe.
This article will not be related to gravitational waves fully, but will cover up another most important theory that has been the target of decades of study by physicists worldwide. If this idea is established, then the General Theory of Relativity can be combined with quantum mechanics eventually revolutionizing the field of subatomic particles.
Quantum gravity is a field of theoretical physics that deals with the force of gravity rendering to the principles of quantum mechanics, and where quantum effects cannot be ignored. Subatomic particles have different characteristics and some of them are quantized meaning they can only move or exist in particular whole number states. Many physicists believe gravitational waves are similarly quantized and are made up of individual quantum particles of gravity known as gravitons.
While there is no concrete proof of the existence of gravitons, quantized theories of matter may necessitate their existence. Some physicists believe that gravitons join together, forming gravitational waves that travel through space in the form of ripples. Like photons of light, gravitons are also considered massless and move at the speed of light.
In the center of black holes, effects of quantum gravity are predicted to be quite definite, however it is impossible to accumulate data from the events happening near a singularity. The scientists form LIGO (Laser Interferometer Gravitational Wave Observatory) used a set of instruments which was very sensitive, yet they could only identify a distortion in space-time, which is a thousandth the diameter of one atomic nucleus across a 4 km strip of laser-beam and mirror.
It is impossible for the LIGO detector or any advanced gravitational wave detector to detect a graviton in the space-time, leave alone proving the theory of relativity. But maybe in future a device so precisely modified is build, that it could finally detect the evidence of quantum gravity by examining the emission spectrum of energy surrounding the event horizons of black holes.
With LIGO , the astronomers have so far detected intangible ripples in space-time which is only the beginning of a new kind of physics. Further into the advancement of astronomical devices, they may come across other evidence of astrophysical theories such as cosmic strings, theoretical one-dimensional strings of energy, which may be there in the depth of space-time since the very beginning.
The recorded data of the gravitational waves may also give the physicists to analyze the ripples in order to finally examine some evidence of gravitons which will eventually solve the mysterious puzzle of relativity theory. If the existence of gravitons is established, it could change the way of understanding gravity. Such a finding could suggest that other notions of gravity, such as string theory, could prove to be the basis of future work on the nature of gravity.
But until that time comes, the existence of gravitons are strictly theoretical.