“Computers generate truly random numbers”

Many people assume that when a computer generates a "random" number for anything from a video game to a cryptographic key, it's truly unpredictable. This common misconception often arises because the output *appears* random, without any obvious patterns, leading to the belief that the machine is capable of spontaneous, unpredictable number generation. The term "random number generator" itself can be misleading, implying a level of true unpredictability that standard computer processes don't inherently possess.

However, the scientific truth is that standard computers are deterministic machines, meaning they operate based on precise instructions and inputs. They generate what are known as pseudorandom numbers using algorithms called Pseudorandom Number Generators (PRNGs). These algorithms start with an initial value, or "seed," and then apply complex mathematical formulas to produce a sequence of numbers. While these sequences can pass statistical tests for randomness and appear random, they are entirely predictable if you know the initial seed and the algorithm used. True randomness, in contrast (Review), comes from unpredictable physical phenomena like atmospheric noise, thermal noise, or radioactive decay, which specialized hardware random number generators (TRNGs) can harness.

The reason this myth persists is largely due to the effectiveness of pseudorandom numbers for most everyday tasks. For applications such as shuffling music, creating varied enemy behaviors in games, or running simulations, the "random enough" quality of PRNGs is perfectly sufficient and indistinguishable from true randomness to the average user. Without a deep dive into the underlying computer science, it's easy to mistake a highly complex, seemingly chaotic, but ultimately predictable sequence for genuine unpredictability.