Why does the universe exist? Why is there anything instead of nothing? This is the very ultimate question of our existence and for some it might be philosophical and deep but for the other half it might be too childish. We have progressed exponentially in science yet we are not close to unveil the mystery of where we come from. This puzzle of existence is by far the most disturbing and intriguing idea which has surrounded us for thousands of years. It has obsessed eminent thinkers from our past but still science has not reached a provable answer YET.
An extremely common answer to this question is that God created this all. He created everything from sheer nothingness. That's how powerful God is. He doesn't need any pre existing materials to fashion a world out of nothing and this is what most of the population believes. There is no mystery for them, ‘God made it all’ is what they state and believe. Putting this in equation, it would be:
God + nothingness = the world.
Maybe you don't believe in God and are a scientific atheist or an unscientific one and might be unsatisfied with this equation. Whatever it is, if you look closely at the first part of the equation you might realize there is something wrong. There is God existing in the first place and if we are to resolve the very ultimate question of why anything exists then we might also have to hover over the question of why even God exists in the first place. There are many arguments to how God exists like God does not exist by logic alone or God is nothing but energy and there is even an ontology argument which states that God exists independent of anything and is the creator of all. But for those who might want to take their epigrams from a scientific point of view would like to know the scientific aspects of this question.
A controversial answer is that the entire universe, from the fireball of the Big Bang to the star-studded cosmos we now inhabit, came into existence from nothing at all.
This idea may sound bizarre or just another fanciful creation story. But physicists argue that it follows naturally from science's two most powerful and successful theories: quantum mechanics and general relativity.
Quantum mechanics states, there is no such thing as empty space. Even the most perfect vacuum is actually filled by particles and antiparticles, which flare into existence and almost instantaneously fade back into nothingness. The reason why we can't observe them is that they don't last enough to be perceived, but we know they do exist because of their effects.
The universe including the huge galaxies, stars, planets are best defined by Einstein's beautiful “theory of relativity.” Relativity is very different from Quantum Physics and till now no one has been able to unify both the laws though there are theories like “string theory” trying to combine both the laws but they cannot be trusted since they are still unproved.
Stephen Hawking, in an attempt to explain this very fundamental question of existence, once said “when quantum theory is applied to space at the smallest possible scale, space itself becomes unstable. Rather than remaining perfectly smooth and continuous, space and time destabilize, churning and frothing into a foam of space-time bubbles.If space and time are quantized, they can fluctuate. So you can create virtual space-times just as you can create virtual particles.”
Put differently he meant that it is not just particles and antiparticles that can snap in and out of nothingness: bubbles of space-time can do the same. And since then this bubble has evolved into billions of galaxies giving birth to planets, stars and other cosmological bodies. It's an extremely convincing idea, however, given our current scientific and technological reaches we are still not close to prove this theory and showcase it to the world.
These galaxies, planets have all been very mysterious to human minds and as the days are passing by we are inching towards a theory to define our universe’s existence and unveil its mysterious mask even though we don't know what lies beneath. We might be successful or unsuccessful but whatever it is, it cannot stop us from questioning and dwelling over these ideas, after all we are humans.