You can see a video of the Cloudflare lava wall by [Tom Scott], below. If you don’t need a random number generator, maybe you could use a spectrum analyzer. Thanks to [Ptkwilliams] for the tip.

A quantum machine has used entangled qubits to generate a number certified as truly random for the first time, demonstrating ...

Of course, it is easy to create a very long pseudorandom sequence in software, but even the best PRNG (Pseudorandom Number Generator) needs a good random seed, as we don’t want to get the same ...