Is randomness a lack of complete information? Can the entire state of the universe be explained through cause and effect? Or is it possible for an uncaused cause to exist?

Randomness is defined as the absence of structure or pattern. Randomness is when effects occur that could never be traced to any cause. True randomness is sought after by many because of its importance in communications, cryptography, sampling, statistics and experimental sciences.

Let’s take an example of rolling a dice. A dice roll depends on several factors including the die's mass and shape, the initial position of the die, the speed and angle at which it is thrown, the texture of the surface etc. Can we represent all these factors into a mathematical equation and predict the dice roll? Difficult, yes; Impossible, no. The outcome of the roll is essentially deterministic. If we could calculate all the factors involved in rolling a dice, we could predict the outcome.

Humans cannot think randomly. Humans have evolved to find and think in patterns. So when humans try to create randomness they do so by following a pattern. A simple experiment is to have two persons produce a list of 20 heads and tails results in order. One person will flip a coin 20 times and other will imagine flipping a coin 20 times. The ‘wow’ moment comes when you look over the results and its obvious which is which. The person making up the coin toss will avoid long chains like 5 heads in a row because it doesn’t seem random. However, a true randomness has no memory of previous flips and long chains does happen.

Computers cannot create true randomness as well. Computers rely on pseudo-random number generators to generate random numbers. They are given a seed that is passed to an equation programmed. These are called 'pseudo random numbers'. Since these random number generators needs to be programmed which suggests someone who understood the program completely could predict the outcome.

A lack of randomness is a huge problem. While pseudorandom numbers generated by computers are acceptable for majority of use cases, there are places which needs truly random numbers. Germans believed their Enigma machine were unbreakable with 159 quintillion combinations yet it was broken in few years. Attacks in cryptographic hash functions such as SHA-1, DES, WEP are all possible due to lack of true randomness. Randomness is a very important principle in everything we do, from sampling, cryptography, deep learning to understanding evolution.

Everything that happens in this universe has a pattern and can be modeled. We might not understand it completely, but we can’t deny there isn’t one. Given enough information and computation, anything can be predicted.