GoKawiilMay 2026
The Futility of Lava Lamps: What Random Really Means
Cloudflare brags about using lava lamps to “help with internet encryption”. They have this impressive wall of lava lamps, one hundred of them, standing witnesses of their commitment to security, dutifully generating entropy to make the internet a safer place.
It’s not just one wall of lava lamps. They have double pendulums, wave motion (my personal favourite), mesmerising mobiles… different setups, same core principle: unpredictability before your very eyes, at a non-trivial cost. You can see how serious Cloudflare is about your safety.
That’s all marketing. Security theatre. Cloudflare stops shy of openly lying, but the impression they give that lava lamps significantly contributes to their security is false. They don’t. They’re worse in fact than more mundane alternatives, and Cloudflare almost certainly knows it.
To understand why though, we need to know what randomness actually is.
Probability is in the mind
Take a look at this program:
int getRandomNumber () getRandomNumber { return 4 ; // chosen by fair dice roll. // guaranteed to be random. }
Does this function return a random number? Most people would look at you funny if you asked them with a straight face: the thing returns 4 every time, fair dice roll or no, that’s obviously not random at all.
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