Rube-Goldberg Type Random Number Generators? 82
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?
Traffic Accidents (Score:1)
--MonMotha
SGI's Lava Lamp RNG (Score:1)
Re:SGI's Lava Lamp RNG (Score:2)
Re:SGI's Lava Lamp RNG (Score:2)
It's got a picture of the old sgi setup.
Re:SGI's Lava Lamp RNG (Score:1)
if anyone comes up with anything good (Score:1)
Re:if anyone comes up with anything good (Score:2, Informative)
--Robert
Resistors (Score:1, Interesting)
HotBits (Score:1)
Re:HotBits (Score:2)
Re:HotBits (Score:2)
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
Just use /. (Score:2, Interesting)
Hope this helps.
Re:Just use /. (Score:2)
Re:Just use /. (Score:2)
Re:Just use /. (Score:3, Funny)
here's one other:
Post a random comment.
the number of moderation points, given a suitable comment, will probably be completely random.
Re:Just use /. (Score:2)
I was cheated I tell ya, cheated! *grumble*
Re:Just use /. (Score:2)
hey, i'll mod you up next time i have some points, mm-kay?
it is karma, afterall. and what goes around comes around, yes?
Re:Just use /. (Score:2)
Only problem is, I'm a really lousy troll. Oh well, maybe I need to go to troll school or something. I'll check O-Reilly's and see if they have a "Trolling Slashdot in a Nutshell" or something similar.
Cheers,
ok (Score:1, Troll)
Yeah, I didn't think so...
Re:ok (Score:2, Funny)
at random : without definite aim, direction, rule, or method
www.m-w.com [m-w.com]
Re:ok (Score:1, Troll)
bzzt! Try again!
Re:ok (Score:2)
Re:ok (Score:1, Troll)
For a large enough series (or a small enough series divisible by 6) each item has an equal probability of being selected.
bzzzt! Try again.
Re:ok (Score:1)
Re:ok (Score:1, Troll)
Re:ok (Score:1)
A minimum requirement for a completely random selection is that the set of objects chosen from have an equal probability of being chosen. Otherwise, it is not fully random (ignoring the fact that very little is fully random in real life).
>Define what probability is. Do your best not to invoke the definition of random.
Doing your homework for you:
dictionary.com:
3a. The likelihood that a given event will occur.
3b. Statistics. A number expressing the likelihood that a specific event will occur, expressed as the ratio of the number of actual occurrences to the number of possible occurrences.
Oh, and while we're at it, let's look up random, too!
2. Mathematics & Statistics. Of or relating to a type of circumstance or event that is described by a probability distribution.
3. Of or relating to an event in which all outcomes are equally likely, as in the testing of a blood sample for the presence of a substance.
Equal probability. Every dictionary i could get my (literal or figurative) hands on all define random in terms of probability. So, now I fire a question back. You don't define random in terms of probability?
Re:ok (Score:2)
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!
Re:ok (Score:1)
The old standby: (Score:2, Funny)
Re:The old standby: (Score:2, Insightful)
Smoke (Score:3, Interesting)
Re:Smoke (Score:3, Informative)
to be honest, any similar sort of image will do. the image just needs to change *enough*. so like a webcam of a busy elevator or traffic intersection will do. or a webcam pointed at a television. or a dog kennel/chicken coop/horse stable. or just a picture of the person seeking the number (the human visage changes by subtle amounts all the time).
yeah, your version is a lot prettier. but i do think you'd need several chunks of incense, to make enough smoke.
Re:Smoke (Score:1)
Re:Smoke (Score:2)
Re:Smoke (Score:2)
Got that one from Applied Crypto.
Lotto machines... (Score:1)
How about this... (Score:2, Insightful)
OK, how about this boring idea? (Score:4, Interesting)
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?
Cheap CCD webcam (Score:3, Informative)
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.
Re:Cheap CCD webcam (Score:2)
Again, the idea is from Applied Cryptography.
Here's a goofy one (Score:2, Insightful)
Ah, to weep at the demise of LAVARAND (Score:2)
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.
Re:Ah, to weep at the demise of LAVARAND (Score:1)
Taking the obligatory look at the forever cached version [archive.org] of lavarand.sgi.com reveals a little information. Granted, the cool images are definitely not there. A pity.
However, checking the above link reveals that the digital photography technique did not involve such interesting processing as determining transparent vs. opaque. Quoting:
The technical description mentions the use of SHS-1 and then the Blum Blum Shub pseudo-random number generator. Not being familiar with such subjects, it does seem that this is even more Rube-Goldberg [rube-goldberg.com] like than a 'simple' image processing which determines opacity.
Re:Ah, to weep at the demise of LAVARAND (Score:2)
Good show, I'd forgotten about all the different archives out there. I noticed that Google didn't have a cache of it, and stopped there.
Looking at the page, I note they weren't using the IndyCam, but the O2Cam.
I think I remember the lava lamps being backlit, that would make for a relatively easy transparent/opaque determination. The O2Cam is a color system, so you use what amount of which color is covering what percentage of which section of the image... there are a lot of ways to get your "digital output of the image" from which the calculations start.
Interestingly, a 921,600-byte image works out to 640 by 480 at 24-bit color. Reading further, it looks like that was exactly what they were doing -- blobs of color in various places, never the same twice. Neat idea, available (at the time) as a "Professional Service." I wonder if they still offer it... I'm sure they would, for enough money.
The only reference to Lavarand I could find at SGI's site, by the way, was an entry in a list of their trademarks.
The Slashdot RNG (Score:1)
barking dog (Score:2)
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.
Re:barking dog (Score:1)
Re:barking dog (Score:2)
-a
Seismograph (Score:3, Insightful)
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)
Re:How about ... (Score:2)
or is it more like let loose the hounds? and turns come from everywhere and attack the players?
Re:How about ... (Score:1)
Re:How about ... (Score:1)
Cascades (Score:1)
The problem is that you'd need to be fairly precise, or you won't get true random numbers. This is the core problem.
Counting, say, the number of raindrops that fall in a certain time frame, or number of cars that go by your house with the bass turned up may be random, but the distribution won't be even. Either you're going to get a lot of rain, or no rain, and very seldomly somewhere in between -- and if you're like me, many many cars, but very few blissful, quiet nights.
SGI's random lava lamp (Score:4, Interesting)
In a nutshell, they pointed a camera at a lava lamp and used an algorithm to reduce the image into random numbers.
Re:SGI's random lava lamp (Score:1)
Isolate a single quantum dot, and measure the spin. +1/2, -1/2 for 1,0. The quantum world is purely random, unlike Lava Lamps that just look like it.
Lots of choices (Score:1)
Then, there's LAVALAMP randomness: LavaRND [lavarnd.org]
Oh, and you could connect a radio to a sparcstation, and use broadcast noise at: Random.org [random.org]
Hell, you could use a webcam pointing at a staticy TV.
Lots of possibilities. Amazing what you can find with
Code Red? (Score:1)
Random Numbers UK Style (Score:1, Interesting)
I could be wrong on this but the random number machine (called Ernie) was built by a firm called Logitec and used the noise from a neon bulb as a random number generator. Since this was a government project I assume that it worked right.
Regards
Ed Almos
Re:Random Numbers UK Style (Score:1)
Not really a contraption but... (Score:3, Informative)
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?)
lava lamp (Score:1)
Spam Random (Score:2)
SD
Webcam, "random" scene, & MD5 (Score:1)
The Tom Clancy Method (Score:1)
input to a sound card.
One random number generator.
Just line Tom thought up in Cardnal of the Kremilen.
Re:The Tom Clancy Method (Score:1)
Chip H.
Microphone input on soundcard (Score:1)
Just turn the gain up to the max and read the values. It's plenty noisy.
Geiger counter! (Score:2, Informative)
Terry Ritter offers us "Random Number Machines: A Literature Survey [ciphersbyritter.com]" which discusses random numbers from noise and other sources. Well worth a look.
Ritter expounds on Geiger counters: [ciphersbyritter.com]
Now they also offer canned software - a random number generator [aw-el.com] based on radioactive decay.
Some mentioned ONE radio station, why not ALL? (Score:1)
You have a radio receiver -- but you don't set it to ONE channel, but rather you receive all (or as many as practical) channels at once.
One radio station isn't completely random -- programs repeat, station IDs are said several times a day, the same commercials come on.
But the combination of ALL radio stations at any given time is 100% unique and probably will never occurr again as long as the planet is around (assuming a free press).
Taking the values of all stations simultaneously could result in a neat random seed that is never repeated twice.
Is this a stupid idea?!?
Phase 1: Get all radio waves on planet.
Phase 2: Reduce to a number with enough bits to always be unique (128? 256? 1024?)
Phase 3: ?
Phase 4: Profit
Re:Some mentioned ONE radio station, why not ALL? (Score:1)
Re:Some mentioned ONE radio station, why not ALL? (Score:1)