We’re suckers for the Fallout aesthetic, so anything with a post-apocalyptic vibe is sure to get our attention. With a mid-century look, Nixie tubes, a brushed metal faceplate, and just a touch of radioactivity, this quantum random number generator pushes a lot of design buttons, and it pushes them hard.
Charmingly named “Chernobyl Dice”, this little gadget comes to us from [Nathan Griffith], and appears to be one of those “Why not?” builds we love so much. The heart of any random number generator is a source of entropy, for which [Nathan] chose to use six slightly radioactive uranium glass marbles. Those feature prominently in the front panel of the device, occasionally made to fluoresce with a few UV LEDs just because it looks cool. A Geiger tube inside the case is used to look for decay events from the marbles every millisecond. After some adjustment for the bias toward zeroes due to the relative rarity of decay events, the accumulated bits are displayed on eight Nixies. The box can be set to generate a stream of random numbers up to 31 bits long and send it over a USB port, or make random throws of a die with a settable number of sides. And when it’s not doing random stuff, it can just be a cool Nixie clock.
There are lots of ways to generate the entropy needed for truly random number generation, from a wall of lava lamps to bubbles in a fish tank. They’ve all got style, but something about this one just works.
[via r/DIY]
power, why power are stil from wall ?
;)
My guess would be convenience in getting the required high voltage to drive the nixies, and the other voltages needed for the other electronics. Transformers are simple, cheap, and effective. Using wall power when you need multiple voltages for a project just makes sense, in my way of thinking.
What’s wrong with that?
Just read from /dev/urandom, it is cryptographically secure on all current linux machines.
https://xkcd.com/221/
Pretty sure /dev/urandom doesn’t have radioactive marbles of doom…
On an entropy-starved computer, /dev/urandom is not cryptographically secure because it may cause the system to hang. Hint: advice that begins with “just” is usually bad, there are always issues with complex systems.
/dev/random will block waiting for additional entropy (generally not an issue on any modern system), but /dev/urandom will never block (by design). Both methods are secure, but /dev/random’s potential for blocking makes it less convenient.
See https://www.2uo.de/myths-about-urandom/
“Just read from /dev/urandom,”
Oh sure! IF you want to do it the safe way,
This guy reads his from /dev/uranium
B^)
This is SO Dr Strangelove…. I even love the Dymo tape. What’s the half-life of the marbles?
4.468 billion years.
https://en.wikipedia.org/wiki/Uranium-238
Yea, I don’t care what it does I just love the look of it!
That’s cool.
No, it’s hot! (radioactive)
B^)
At a half life of 4.468 billion years, I’d call it lukewarm.
Nice build. I recall that John Walker’s hotbits quantum rng created for his retro-psychokinesis experiments uses the time delay between decay events (https://www.fourmilab.ch/hotbits/how3.html), and thereby produces a sequence sufficiently random to pass all the Marsaglia randomness tests. No debiasing hacks needed.
Walker’s website has been a great resource of interesting information for years.
Nice build! Going to have to do something similar now. One minor point, the tube that you list in the parts only detects beta and gamma radiation. Uranium is primarily an alpha emitter, which won’t get detected by the tube you are using. The clicks you hare are as likely background as from the uranium. If you had a tube with alpha sensitivity, then the count rate should be significantly higher.