From lava lamps to quantum dice: how random numbers rule your life

The modern world relies on random numbers. We need them for secure communication, password protection, weather forecasting, scientific research, traffic management, quality control, and even to select winners for affordable housing. But it's not easy to produce reliably random numbers. In fact, as reported in this BBC article, "The search for the random numbers that run our lives," "you can never prove that something is truly random, only that it is indistinguishable from random, based on your best analysis."

The article begins with Mads Haahr's 1997 quest for a cheap transistor radio that would produce static as a source of random numbers for online gambling software. Haahr's online casino failed, but he ended up creating, which uses atmospheric noise for randomness.

From the article:

Sometimes people write to Mads Haahr, complaining that they have spotted what looks like a predictable sequence of numbers in the site's output. That's really just because humans are very bad at recognising randomness, he says. We seem predisposed to see patterns in everything. Haahr enjoys taking the time to reply and explain these concepts in more detail.

He might not have set out to create a resource like originally, but over time Haahr realised it was something he wanted to do. Perhaps, he suggests, it's because he is originally from Denmark – regularly ranked among the least corrupt countries in the world. Now, people use his website in order to convince their users, participants or audiences that they are tossing a fair coin. That whatever game or process they're running is an honest and just one – at least within the boundaries of randomness.

There would be, it must be noted, a rather large incentive for Haahr and his colleagues who collaborate on to manipulate the output of the website if it allowed them to rig the result of a lottery draw, for example. They would never do that, Haahr insists, as it's against everything they stand for. But it's a fair question because, as he freely admits, it is possible.

The article mentions several other methods to generate random numbers:

  • Lava Lamps: Cloudflare uses an innovative approach involving lava lamps. John Graham-Cumming of Cloudflare notes, "The motion of those lava lamps, the blobby, oily, waxy thing inside, is not predictable."

  • Network Traffic: Some systems use the unpredictability of network traffic as a source of randomness. Steven Murdoch, a professor at University College London and creator of the Tor browser, comments on this method: "We're pretty confident that that is secure."

  • Quantum Random Number Generators: The article discusses more advanced methods using quantum mechanics. Zhanet Zaharieva of Quantum Dice explains their approach: "What you end up having is a system that is a mixture of quantum entropy […] and classical noise."

  • Radioactive Decay: While not extensively discussed in the article, radioactive decay is mentioned as a quantum process considered to be truly random.

  • Computer Algorithms: The article notes that computers typically use algorithms to generate pseudorandom numbers, though these are not truly random.

  • Physical Methods: The article briefly mentions traditional methods like dice rolls and coin flips, though it points out that these are influenced by physical factors and are not truly random.

• How to roll an imaginary 6-sided die in your head