Why is discovery of gravitational waves a scientifical breakthrough

"It's not everyday you wake up and learn something completely new about the early universe." This really is an incredible discovery, a whole new era in physics and cosmology.

What is the Big Bang theory?

Apart from the ever so popular sitcom, the Big Bang theory is so far the most popular and possible model or explanation for how the universe developed from a really tiny and dense form into the present state. 

A common misconception of the theory is that big bang is the exact moment when the dense point containing all the matter and energy in the universe exploded, shooting stuff in all directions of the space - and so universe was born. But rather than a huge explosion, you have to look at the Big Bang as expansion of space - everything within the space is spreading apart from everything else.

Another great way to explain the big bang is, when we observe the night sky, we can see galaxies and between them huge areas of black empty space. In the very earliest stages of the universe, energy, matter and all the observable space was compressed to a single point with no volume but infinite density - this is called singularity.

What are Gravitational Waves? 

Imagine ripples full of energy travelling across the universe. There already were strong evidence of their existence, Albert Einstein predicted them in 1916 as a consequence of his theory of General Relativity,  but until recently they have not been actually discovered. The reason behind the "late" discovery lies in gravitational waves being really, really tiny and when I say tiny, I mean a million times smaller than an atom.

And the ones cosmologists are particularly interested in, are the so called primordial gravitational waves, which were created in the very first moments of the birth of the universe. These kind of waves are suppose to carry vital information about how everything begun. 

Yesterday March 17, scientists announced that they basically struck gold - after the press conference it is now pretty clear, that the first direct evidence of the early stage of the Big Bang has been detected. The leading role in this primordial gravitational waves detecting experiment was played by the microwave telescope called BICEP-2 (Background Imaging of Cosmic Extragalactic Polarization), situated at the South Pole (image bellow). This was not the first time gravitational waves have been detected, but what makes this discovery so incredible, is they found the already mentioned primordial gravitational waves.

Why do cosmologists say that this a game changing discovery?

The discovery of gravitational waves or the "first tremors of the Big Bang" as how they have been described, will open a brand new way of studying the Universe. It is also the best evidence yet that universe was starting to form when a super fast expansion - the Big Bang - started a process called inflation and as a result of this super fast inflation of space the universe as we "know it" was born.

Check out Stanford Professor Andrei Linde celebrating physics breakthrough: