Probability is a term which is presumably known to all human beings. If you ask people about probability, chances are they will tell you about the ’50-50’ odds of a coin getting flipped to either side of head or tail. Asking further details will fetch you answers like ‘probability of Manchester United winning the league’ or ‘probability of scientists discovering extra-terrestrial life in the Universe ’.

If we closely analyze all the aforementioned answer we can predict that the governing rules of the probability are quite specific. Yet the exact meaning of the term is not dictionarized. When we toss a coin, how do we know that the coin is really fair? The obvious way is to get the answer is to toss it and measure the proportion of heads and tails. The laws of probability are then used to turn the measured proportion into a belief and install it in our conscious mind. Then we assume that the coin flipped is fair.

But is this definition of probability fair? I mean ‘probability has now become a sort of subjective belief rather than objective frequencies’. In 1920, one mathematician declared the non-existence of the term probability. The apparent lack of objectivity has led him to come to such a conclusion.

Imagine what if probability does not exist. Data Analysis becomes a matter of opinion. So to avoid these horrendous situation scientists advocated techniques for analyzing experimental results that offered to use an objective measure of probability called ‘p-value’.

But with the passage of time even the concept of ‘p-value’ started to fade away and gained the critics as a nonsensical theory. Newer methods such as Bayesian method has been suggested in the recent decades. This method is comparatively more robust and has a wider range of theoretical use. Despite the vast application of probability, the concept of probability still instills doubt among many renown scientists.

**How probable is our universe?**

But whatever anomalies the term ‘probability’ carries, it is still regarded as one of the most advanced analyzing tool in the field of science including the Universe. So let’s see how probable our Universe is by applying the theory of probability? We have a vague idea about the creation of the Universe. As Big Bang happened around 14 billion years ago, an external inflation expanded at near about nine times the speed of light. This external inflation hypothesizes the existence of quantum forces which created rapid- expanding regions of space and time, one of which became our Universe. Given on the above facts, we can imagine how immense of a geometrical structure the universe is. Yet to our surprises, it is in fact just one of the infinite number of the bubble like Universes which constitute the totality of existence, dubbed the Multi-verse.

Multiverse is an amazing proposal and may only be solved by applying the theories of probability. This situation is so difficult to imagine that some of the scientists don’t even want to believe the existence of multiverses. For example, using the standard definition of probability, which means dividing the total number of universes by the numbers making up the multiverses, a theorist can state the ‘probable outcome of our Universe’. But if the external inflation is happening from the very beginning, there will an infinite number of Universes like ours now. And the numbers making up the Multiverse is also infinite. Thus the whole situation of finding the probability of our universe is becoming infinite which is quite obsolete.

This part of astrophysics has been one of the most difficult conundra to break for many scientists. One way to solve the puzzle is to assume that the forces driving the bubble universes leads them to inflate at an even higher rate as they get larger. This stretches the very fabric of space and time within the Multi-verses. But then Einstein’s light-speed limit will become archaic along with the fact that these regions will become forever undetectable due to their faster speed. It will be very tough to find the exact answers to this kind of compelling questions, but theorists are still quarreling over the details and by applying the theory of cosmic probability calculation perhaps one day we may finally arrive at the answer to the very beginning of our Universe.