Slashdot Mirror
Rube-Goldberg Type Random Number Generators?
stercor asks: "I've been considering random number generators made with easily-available materials. Living in Oregon might suggest photoelectric cells and rain. Or something to do with slugs (generation rate IS a factor, however)
My question is what other off-the-wall shelf hare-brained brilliant ideas can other Slashdot readers come up with? Please limit ideas to ones that would actually work." When I was younger, I was always intrigued by the rigs used by most State Lotteries. You know the ones: dump balls into a chamber, throw in a fan/vacuum combination to agitate the balls and to allow a random one to shoot thru a tube when the button was pressed (basically, a high tech version of your average BINGO machine). Has anyone else seen or built a contraption that does something similar but in a weird, roundabout or weird and roundabout way?
I remeber the sgi page... but I always thought lava lamps were a little cumbersome for random number generation, firstly they take several minutes to warm up before there's any visible movement, they give off a lot of heat, and they aren't supposed to be on for more than 10 hours. I figure something like bits of styrofoam in a large clear tube with a fan at the bottom would be more efficient, as the styrofoam bits should fly around quite randomly.
Look it's being setup again, due in September, here.
It's got a picture of the old sgi setup.
I've yet to notice any coorelation between a topic and the number of troll/flamebait/offtopic responses, so just grab a topic, count the number of whatever responses and factor the result in whatever way you want.
:)
Hope this helps.
Everything in the Universe sucks: It's the law!
Chicken droppings on a grid.
How about a webcam that is aimed at a black backdrop, with an incense burner hidden just out of frame, below. You light some incense, turn the webcam on, every time you take a picture you get a random black and white image. Do some fancy pixel crunching to generate a number.
"And like that
That might not keep people from TRYING though...
Check out RoboDJ, made by just one of the really cool, really clueful people that hang out on Kuro5hin.org. RoboDJ replaces the default WinAmp randomness with a weighted random selector that promises to be better than the default.
--Robert
random: : a haphazard course
at random : without definite aim, direction, rule, or method
www.m-w.com
A button on a sidewalk somewhere. If people step on it/kids play with it, you're ensured a random number.
=================
Unix is very user friendly, it's just picky about who its friends are.
I've been vexed that the sound card plus CD-ROM drive combination always shows signal at around -50 dBVU in CoolEdit. So, just for grins, I decided to capture a few seconds of the noise and analyze the properties. I was astonished to see that the resulting signal is a white-noise pattern with a slight emphasis at the high end (when sampled at 44 kilosamples per second). In short, it looks like diode noise with a 4 kilohertz square wave thrown in.
That suggests to me that this would make a fair source of random samples, especially after you slot out the interfering signal.
How many computers don't have cheap sound cards and CD-ROM drives?
Or in a more techinical(within the scope of a random number generator) a random selection is a selection from a set where any element of the set has an equal likelyhood of being selected.
"as plurdled gabbleblotchits on a lurgid bee" - Prostetnic Vogon Jeltz. (One man's humorous is another mans flamebait)
I can't find my polarizers, so I can't test this, but I think you could rig something up with a cheap CCD webcam. If you look at a poorly lit image from a CCD there's an awful lot of noise, and the image sort of rides on top of this noise. If you took your cheap CCD webcam and kept reducing the light to it till you got mostly noise it'd be simple to capture and generate random data from. I was thinking of a shoebox with the sensor inside, USB cable coming through a small light-tight hole. Make a hole in front of the lens and stick a pair of polarizers in front of that hole. Rotate the polarizers to get a light intensity such that you get lots of noise.
If you snap a frame you'll get some random bits. Somebody could break the randomness by shining a really bright light through the polarizers, but as long as you can control access to the shoe box you'd be fine.
Chris Kuivenhoven is a thief, beware
Shred a bunch of junk mail with a confetti style (cross cut) shredder, dump the resulting pieces on a scanner, then run the capture through an OCR program.
"From my cold, dead hands you damn, dirty apes!" - CH
Shocked! Yes, shocked and dismayed I am to note that the SGI lava-lamp random number generator has not been mentioned! Unfortunately, it seems to be gone. It's too bad, really... it was a VERY cool combination of the physical world and computers.
http://lavarand.sgi.com used to tell you about an apparatus that SGI's researchers had set up to generate "truly random" numbers. It worked by using several (about 6?) lava lamps clamped in laboratory stands and placed very close together. A SGI camera (an IndyCam, IIRC) was pointed at the slowly roiling liquids, and they generated random numbers by the percentage of the frame that was occluded. (Transparent vs. opaque liquid)
Or something like that. It's been years since I looked at it, and it's gone now. Damn.
"...America's great minds of today, teaching America's great minds of tomorrow. Poor bastards." -- A Beautiful Min
> I doubt you could implement it at home
:-). Not necessary go get some additional source for a higher rate!
If you get a cheap Geiger-Mueller somwhere the natural activity around us should provide you with enough randomness for all your home-computing needs
i could just go around to the neighbors house, make a little noise, and count how many times the dog barks at me. perhaps, the number of barks in a minute.
the problam is, you wont get zero. you begin counting with the start of barking. and you are unlikely to get anything around one or two - dogs are like that.
still, it should be something kinda random.
Just get a Seismograph, and return the heigh of the last reading. Sensitive enough to measure footsteps across the room, so you shouldn't have a problem if you place it right.
I live near a freeway, so I have plenty of randomnees avaiable in the traffic going by my house.
Warning, with this, and many other schemes you need to normalize the data. Otherwise you will tend to get larger numbers during rush hour, and smaller ones during the night. Also a big snow fall (shuts down traffic) will change the values received. Be aware of these issues, if someone else finds out what you are using to generate random numbers they may use that to break your scheme. (Even if you numbers are random, just over a smaller range)
ye gods, 'loose one turn' is on the original, how racy... what do you have to be slutty for one turn or something?
or is it more like let loose the hounds? and turns come from everywhere and attack the players?
Need a Catering Connection
In a nutshell, they pointed a camera at a lava lamp and used an algorithm to reduce the image into random numbers.
The best definition of random I have ever seen is this:
A string whose complexity (or in other words, the length of an algorithm to generate that string) is equal to the length of the string plus a constant (the constant is there for some very specific reasons, but it is a bit complicated to go into here).
Random is very difficult to get a hold of. There are many mathematicians who would claim that randomness doesn't even exist!
The middle mind speaks!
... if you sample white noise from any source, you'll have a random value. Analogue synthesizers commonly use a reverse-biased diode of some sort to generate noise as it reaches the Zener region. You used to get special "noise diodes" - basically Zener diodes that were chosen because they were extremely noisy.
A good, simple white noise source is a reverse-biased transistor. Get an NPN transistor, connect the base to negative and the emitter to positive through a large (220k or so) resistor. Look at the voltage on the emitter - noise! Use an amplifier of some kind to get a useful voltage - you're not too bothered about hi-fi here, although theoretically distortion could skew the results (hint - what would clipping do to high and low values? What would crossover distortion do?)
SD
âoeWho knew something as harmless as willful ignorance could end up having real consequences?â
Terry Ritter offers us "Random Number Machines: A Literature Survey" which discusses random numbers from noise and other sources. Well worth a look.
Ritter expounds on Geiger counters:
Now they also offer canned software - a random number generator based on radioactive decay.
I hate call waitin`~+~~~
NO CARRIER