ProbabilityTrue Randomness

One could argue that tossing a coin really isn’t random at all – it is chaotic. That means that the underlying physical principles are so complex that even tiny changes to the starting conditions (speed, angle) can have a dramatic effect on the final outcome. We can use coins in games and gambling not because they are random, but because it is so incredibly difficult (and for practical purposes impossible) to predict the result.

The same principle applies to many other “random” events in life, including dice and roulette wheels. They are not really random, we simply don’t have the tools to do the mathematical calculations accurately enough to predict the outcome.

But true randomness does exists – at the very foundations of matter. A block of radioactive material consists of billions of atoms which decay over time: they fall apart into smaller atoms while emitting dangerous radiation.

Radioactive decay of atoms is caused by forces which act at much smaller scales within atoms, and which can be explained using Quantum mechanics. During the last century, physicists like Max Planck and Paul Dirac discovered that fundamental particles have a mind-blowing property: they can be in multiple different places at the same time. They don’t have a fixed position, but instead a probability distribution (also called wave function) which tells us how likely it is that we’ll find them at a particular position.

This incredible property is used by Quantum computers. Conventional computers can only ever do one computation at a time. Quantum computers can use the properties of subatomic particles to do many calculations at the same time – and that makes them significantly faster.

We can’t really understand or explain quantum mechanics – we just have to accept that it is what is predicted by mathematical theory and confirmed by physical observations. The curious quantum effects have only ever been observed on tiny scales of a few atoms, and it is not clear how they affect us in everyday life. But it is the only known effect in nature that produces true randomness.