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Ten Weirdest Types of Computers

ScuttleMonkey posted more than 6 years ago | from the fringe-computing dept.

Science 163

An anonymous reader writes to mention that New Scientist has a quick round-up of what they consider to be the ten weirdest types of computers. The list includes everything from quantum computers, to slime molds, to pails of water. "Perhaps the most unlikely place to see computing power is in the ripples in a tank of water. Using a ripple tank and an overhead camera, Chrisantha Fernando and Sampsa Sojakka at the University of Sussex, used wave patterns to make a type of logic gate called an "exclusive OR gate", or XOR gate."

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163 comments

SLASHDOT SUX0RZ (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23041006)

_0_
\''\
'=o='
.|!|
.| |
what type of logic gate is this [goatse.ch]

It ain't ... (5, Funny)

Anonymous Coward | more than 6 years ago | (#23041010)

a computer if I can't get pr0n.

Re:It ain't ... (2, Insightful)

Anonymous Coward | more than 6 years ago | (#23041502)

OK editors, forget this is /.? Do you really think you have to explain the words behind XOR?

Re:It ain't ... (0, Troll)

Anonymous Coward | more than 6 years ago | (#23041996)

For the great majority of Slashdot's readers these days, if you gave them a pencil and paper and asked them to demonstrate an xor of two numbers, say 6 and 12, they wouldn't know where to start. Time was when this wasn't so, and not coincidentally, Slashdot was a far more interesting place.

Now we just have a majority of opinionated, non-technical idiots and children who once installed Linux screaming about technology they know absolutely nothing about.

For a while there, though, it was great.

Re:It ain't ... (1)

uglyduckling (103926) | more than 6 years ago | (#23042366)

Well... uh... imagine this piece of paper is the universe, and this pencil is a quantum singularity in n-th dimensional space. No, better still, imagaine that this salt cellar is the universe and this napkin is a small black hole - uh, no, that doesn't work... in fact, *thunk*.

Re:It ain't ... (-1, Troll)

billcopc (196330) | more than 6 years ago | (#23042472)

Then why are we still here ? /. died the day it was sold off, just about when Zonk and Jon Katz showed up with their special brand of navel-gazing drivel.

All that's left now is trolls and republicans.

Re:It ain't ... (1)

Schlage (195535) | more than 6 years ago | (#23042798)

What a time to not have mod points... -1 Troll, and +1 Ironic, to parent if I did. ;-)

Re:It ain't ... (1)

lattyware (934246) | more than 6 years ago | (#23042530)

Now we just have a majority of opinionated, non-technical idiots and children who once installed Linux screaming about technology they know absolutely nothing about.
And those guys who whine about how shit things are, and yet still manage to post.

Re:It ain't ... (1)

TwistedOne151 (1160593) | more than 6 years ago | (#23043076)

6 XOR 12=10 (in binary, 0110 XOR 1100 = 1010).

Re:It ain't ... (0)

Anonymous Coward | more than 6 years ago | (#23042916)

And sense when is an XOR gate a type of computer? That's a stretch.

What about the weirdest computer of all? (5, Insightful)

MaDMvD (1148691) | more than 6 years ago | (#23041012)

The brain.

Re:What about the weirdest computer of all? (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23041068)

whatever. people with high uids should be allowed to post anymore. why does every moron come along and think themselves witty?

this is the kind of crap they say on the science channel... the science channel is about on par with 5th grade thinking.

Re:What about the weirdest computer of all? (0)

Anonymous Coward | more than 6 years ago | (#23041094)

this is the kind of crap they say on the science channel... the science channel is about on par with 5th grade thinking.

So that brings up an important question -- is MaDMvD smarter than a fifth grader?

Re:What about the weirdest computer of all? (-1, Flamebait)

Anonymous Coward | more than 6 years ago | (#23042734)

No, but YoMaMa is fatter than a ... something.

Re:What about the weirdest computer of all? (1, Insightful)

MaDMvD (1148691) | more than 6 years ago | (#23041152)

So I gather you disagree, from your semi-intelligible response? Did we (collective humanity) or did we not create the computer you are reading this on? Did we not bring about the technological advances that are stated in the very article you are replying (hardly) to? If so, then are we not the ultimate computer? Equipped w/ the highest resolution video, audio, CPU/logic, etc?

Re:What about the weirdest computer of all? (4, Insightful)

c6gunner (950153) | more than 6 years ago | (#23041756)

So I gather you disagree, from your semi-intelligible response? Did we (collective humanity) or did we not create the computer you are reading this on? Did we not bring about the technological advances that are stated in the very article you are replying (hardly) to? If so, then are we not the ultimate computer? Equipped w/ the highest resolution video, audio, CPU/logic, etc?
Nope. We also created the nuclear bomb, but we're not the ultimate explosion.

Your logic is faulty because there is no rule which states that extremely complex systems have to be created by even more complex systems. This is the same logical fallacy which creationists often advance in order to "prove" the existence of God: the idea that because humans are complex, there must be an even more complex being which created us. In reality, it is quite possible for complex systems to be created as a product of random chance, or natural selection.

As for humans being equipped with "the highest resolution video, audio, CPU/logic, etc", that's just plain silly. Computers can detect and display video at resolutions (and in light spectrums) which are undetectable by the human eye. They can detect and produce sounds which would be inaudible to us. And when it comes to raw number-crunching ability....well, don't be silly. I'd like to see you sit down and brute-force an NT LM hash in your head. Hell, I'll be generous and let you use a pen and paper!

BTW, the guy you were responding to was clearly making a joke. Lighten up.

Re:What about the weirdest computer of all? (1)

edumacator (910819) | more than 6 years ago | (#23041950)

I think the underlying principle the original post was trying to make remains valid. And c6gunner, I think you made the leap in inference when you think he's saying complex things have to come from other complex things. I think he was implying that the human wetworks are pretty impressive to have dreamed up taking ones and zeros and making them into such marvelous things. You have to give him that right.

And to the resolution point. I think you're thinking too literally. Show me a computer that can discern a great masterpiece from a technically proficient work. Show me a computer that can tell what that woman isn't fine, when she says she is. Show me a computer that can identify irony in text. Once I see those things, I will willingly welcome our binary overlords.

Re:What about the weirdest computer of all? (1, Insightful)

CustomDesigned (250089) | more than 6 years ago | (#23042354)

Your logic is faulty because there is no rule which states that extremely complex systems have to be created by even more complex systems. This is the same logical fallacy which creationists often advance in order to "prove" the existence of God.
You are correct when talking strictly about complexity. Intelligent Design people, however, are talking about "chosen" or "specified" complexity. For instance, the number Boggle arrangements is its complexity, but when a person selects a particular arrangement (as opposed to tossing the cubes), that is specified complexity. If an arrangement forms an English sentence, then your judgment of the likelyhood that this was a random roll or selected by an English speaking person would revolve around the Total English Boggle Combinations / Total Boggle Combinations.

This kind of specified complexity is the mirror of entropy - it can only decrease (the message is gradually eroded), with a proof similar to the laws of thermodynamics. No amount of chance plus natural selection will expand the message to reveal more of what the author intended to say.

The philosophical problem comes with detecting design by non-human intelligence, possibly not even part of this universe. There are a ton of presuppositions as to how to recognize a message vs noise. The SETI project has to assume that the hoped for aliens think like us in certain aspects. And you run smack against the anthropic principal as an all purpose alternative for the philosophical materialist.

The materialist basically says that the Boggle cubes all come up in English because the universe has an English filter that is more likely to destroy combinations that are less like English. It is not surprising to the materialist that the universe has this property (that survival would produce intelligence). It is just the nature of the universe. And if it wasn't that way, we wouldn't be here to talk about it.

And once you assume that the universe selects for intelligence, it is no longer surprising that the low level systems supporting that intelligence (cell biology) also appear to be designed. A materialist scientist would even act like an ID scientist and look for "evolutionary strategies" as if there were a Designer, because a universe that selects for intelligence is effectively that.

In fact, textbooks talk about how Evolution did this and Evolution did that, and Evolution found an amazing solution to this problem. (Without actually detailing the step by step evolution of this or that.) The text is just as informative if "Flying Spaghetti Monster" or "God" is substituted for "Evolution".

The war between philosophical materialism and and intelligent design is essentially a religious war, and has very little to do with science.

Random chance cannot create complex systems (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23042590)

You're saying things like a watch can be created by accident?

Give me just one example of a complex system that was created by chance.

Re:Random chance cannot create complex systems (1)

yada21 (1042762) | more than 6 years ago | (#23042764)

The economy. A lobster.

Re:Random chance cannot create complex systems (5, Funny)

jd (1658) | more than 6 years ago | (#23043156)

Give me just one example of a complex system that was created by chance.

Earth. Jupiter. Saturn. Alpha Geminorum. The Andromeda galaxy. The United States tax system.

Re:What about the weirdest computer of all? (1)

Aetuneo (1130295) | more than 6 years ago | (#23042692)

Wait, there are 90 Megapixel sensors for computers now? Why did no one tell me about this?

Re:What about the weirdest computer of all? (1)

geekboy642 (799087) | more than 6 years ago | (#23041490)

Hi, oh Anonymous Coward. You may have forgotten something, seeing as you've been posting on Slashdot since before CmdrTaco registered, but "Anonymous Coward" isn't exactly a "low uid". In point of fact, I'd say you rank at just about a 12-digit UID.

Go troll Digg, that's a good place for idiots who have nothing better to do than spew pointless venom.

Re:What about the weirdest computer of all? (1, Interesting)

CRCulver (715279) | more than 6 years ago | (#23041114)

In his early Known Space stories collected in Tales of Known Space [amazon.com] Larry Niven forsaw a future 1975 (ha) where the brains of people managled in car accidents are integrated into spacecraft for guidance, allowing them to continue contributing to society even if their bodies are gone. This entire idea of "brain in a jar" science fiction seems to have faded out with the 1970s.

Re:What about the weirdest computer of all? (2, Informative)

Anonymous Coward | more than 6 years ago | (#23041212)

except, of course, for "Krang" in Teenage Mutant Ninja Turtles, the historical characters in Futurama, etc...

Re:What about the weirdest computer of all? (4, Interesting)

Naughty Bob (1004174) | more than 6 years ago | (#23041314)

You'd be interested to know that rat's brain cells have already [newscientist.com] (the linked article is from 2004) been harnessed to fly a virtual F-22.

The singularity, as the man said, is near.

Re:What about the weirdest computer of all? (1)

Daimanta (1140543) | more than 6 years ago | (#23041462)

The singularity, as the man said, is near.
And I still don't have my flying car!

Re:What about the weirdest computer of all? (1)

truthsearch (249536) | more than 6 years ago | (#23041504)

No, but apparently you do now have your flying rats... oh, wait...

Re:What about the weirdest computer of all? (1)

The Great Pretender (975978) | more than 6 years ago | (#23041526)

FTA - "Ferdinando Mussa-Ivaldi of Northwestern University in Chicago has shown how a few brain cells from a lamprey, a primitive eel-like vertebrate can be used to control a robot."

I would like to be the first to welcome our robot controlling, primitive eel-like vertebrate Overlords and welcome them to harness the power of our captive rat brain cells for virtual war.

Re:What about the weirdest computer of all? (1)

geekoid (135745) | more than 6 years ago | (#23041732)

Singularity is a myth perpetuated by people with no imagination.

Re:What about the weirdest computer of all? (1)

Naughty Bob (1004174) | more than 6 years ago | (#23041828)

Singularity is a myth perpetuated by people with no imagination.
So when, mighty imaginer, will computing power plateau?

Re:What about the weirdest computer of all? (0)

Anonymous Coward | more than 6 years ago | (#23042656)

The dummy plugs don't work!

Re:What about the weirdest computer of all? (0)

Anonymous Coward | more than 6 years ago | (#23042676)

bombidier to pilot target is at 12 oclock do we drop the load...Sir those look like well cats sir. Why are we bombing those poor animals sir? SQQUUUEEEEKKKK!

Re:What about the weirdest computer of all? (3, Informative)

knarfling (735361) | more than 6 years ago | (#23041412)

Actually, check out Anne McCaffrey's Brainships series. Although the first one, "The Ship Who Sang" was written in 1969, several others like "The Ship Who Searched", and "The City Who Fought" were written in the early 1990's. The last one that I know of, "The City and the Ship" came out in 2004.

I realize that the only one written only by Anne McCaffrey was the original, "The Ship Who Sang", and the others were co-written by other authors. (Usually that means written by other authors using McCaffrey's universe and published with her name and by her permission so as to get better sales.) However, that means that there are several other authors that like to write using the "brain in a [jar|box|ship]" theme.

Re:What about the weirdest computer of all? (1)

geekboy642 (799087) | more than 6 years ago | (#23041520)

I absolutely love that entire series. Then again, I'm definitely a McCaffrey fanboi, anything written in her universe makes me giddy.

Re:What about the weirdest computer of all? (0)

Anonymous Coward | more than 6 years ago | (#23043270)

Have not read Anne's books, frankly the dragon thing is a turn-off. But a similar ship-brain concept was explored in a book called The Star Wolves by Thorarrin Gunnarson (sp?) wherein outcasts of humanity -space pirates of a sort- with giant thinking computer spaceships had to raid a city run by computer which was formerly the brain of a ship. It alone remembered how to find Earth.

So the pirates broke in and stole it.

It was probably a stupid, simple scifi thing but I recall thinking it would have made an awesome TV show.

Re:What about the weirdest computer of all? (4, Funny)

c6gunner (950153) | more than 6 years ago | (#23041812)

In his early Known Space stories collected in Tales of Known Space [amazon.com] Larry Niven forsaw a future 1975 (ha) where the brains of people managled in car accidents are integrated into spacecraft for guidance, allowing them to continue contributing to society even if their bodies are gone.
Some idiot who can't even handle a car ends up causing a massive accident, and Niven wants to let him drive a spaceship? Great idea! What could possibly go wrong?

On the bright side, I hear collisions at relativistic velocities are rather painless....

Re:What about the weirdest computer of all? (1, Funny)

Anonymous Coward | more than 6 years ago | (#23043106)

On the bright side, I hear collisions at relativistic velocities are rather painless....

Are you sure? Thanks to time dilation, the moment of impact would take darn near forever!

Re:What about the weirdest computer of all? (2, Informative)

syukton (256348) | more than 6 years ago | (#23041400)

An analog asymmetric multiprocessing system complete with random-access memory and a variable-speed bus. Truly, quite weird.

Re:What about the weirdest computer of all? (1)

dfedfe (980539) | more than 6 years ago | (#23042516)

I take it you mean the brain, but my instinct is to say that brain memory should be considered content addressable (i.e. associative) rather than random-access, but perhaps they are not strictly opposites. Certainly, though, I can't think of any random access processes in the brain. On the other hand, sequential access is a reasonable claim, at least for procedural (performance of learned sequences of actions) and episodic memory (memory for personal events in a spatiotemporal context, implying the ability to recall "the next moment in time" given a starting point).

Re:What about the weirdest computer of all? (1)

syukton (256348) | more than 6 years ago | (#23042964)

The strange dreams people have would seem more random than associative, although they may indeed be associative on some level. Although the single best example I can think of is simple creativity. One's ability to create new things, come up with new ideas, look at things from a different perspective, those seem like random-ish processes.

Re:What about the weirdest computer of all? (1)

dfedfe (980539) | more than 6 years ago | (#23043028)

I more or less agree with those statements, but you've just swapped your use of the word random away from random access memory (which is what we were talking about and which doesn't mean items in memory must be retrieved at random) to talk of random processes.

Clearly elements in an associative memory can be retrieved at random by using noise as a retrieval key and that is more akin to the type of randomness you've just mentioned (and with which I tend to agree).

Re:What about the weirdest computer of all? (1)

Reziac (43301) | more than 6 years ago | (#23041480)

Worse -- MY brain!

[looking around the room]

Or possibly my computer, which has a mind of its own. ;)

Re:What about the weirdest computer of all? (2, Funny)

ppc_digger (961188) | more than 6 years ago | (#23041594)

I'm pretty sure Pinky is weirder.

Re:What about the weirdest computer of all? (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23041992)

brain != computer

Wetware (5, Informative)

Rassleholic (591097) | more than 6 years ago | (#23041088)

The one I find most facinating is MONIAC [wikipedia.org] . A cookie to whoever gets it to run linux.

Re:Wetware (1)

savorymedia (938523) | more than 6 years ago | (#23041418)

Knowing /., someone here will one up it and put BSD on it first.

Re:Wetware (1)

The 1st Truth (573818) | more than 6 years ago | (#23041510)

Interesting. I had wondered where Pratchett came up with the idea of the Igor created economy simulator/controller. Now I know, Thanks!

No Conway's Life? (4, Interesting)

pclminion (145572) | more than 6 years ago | (#23041090)

Conway's Life is Turing complete. I guess, to a computer scientist, it's not really surprising that an automaton could be Turing complete, but it's still pretty damn awesome to think that little cells replicating on the screen are capable of carrying out any arbitrary computation -- as well as self-reproduction.

I wonder, with a large enough simulation, if self-reproducing, intelligent entities could evolve out of just a few simple rules (and it's really only one rule, if you code it a certain way).

Re:No Conway's Life? (1)

frovingslosh (582462) | more than 6 years ago | (#23041410)

The article missed a lot, but certainly a serious candidate would be the Wireworld Computer, a cellular automaton computer that actually (slowly) computes prime numbers and displays them, done by implementing a digital computer as a cellular automaton. This is an amazing computer, only one op code, and you can watch the data as it flows through the computer, including the stack of 64 registers (a few unused in this program).

Re:No Conway's Life? (3, Interesting)

frovingslosh (582462) | more than 6 years ago | (#23041444)

The article missed a lot, but certainly a serious candidate would be the Wireworld Computer [quinapalus.com] , a cellular automaton computer that actually (slowly) computes prime numbers and displays them, done by implementing a digital computer as a cellular automaton. This is an amazing computer, only one op code, and you can watch the data as it flows through the computer, including the stack of 64 registers (a few unused in this program).

Sorry, due to a typo the link was lost in the previous post.

Re:No Conway's Life? (0)

Anonymous Coward | more than 6 years ago | (#23042310)

You may be interested in reading Greg Egan's book Permutation City ( http://gregegan.customer.netspace.net.au/PERMUTATION/Permutation.html ) which deals in part with evolution of life in a cellular automaton.

Wierdest computer of all? (-1, Troll)

Anonymous Coward | more than 6 years ago | (#23041098)

One that runs Micro$oft Winblowz.

Har har har!

Why are these weird? (1)

The Ancients (626689) | more than 6 years ago | (#23041136)

weird |wÉÉ(TM)d|

adjective

suggesting something supernatural; uncanny : the weird crying of a seal.

â informal very strange; bizarre : a weird coincidence | all sorts of weird and wonderful characters.

I don't really see them as 'weird' as such - different, and fascinating, and many seem to point a potential way forward for computing. I don't see why we should refer to technology moving forward as 'weird'.

Re:Why are these weird? (1)

Itninja (937614) | more than 6 years ago | (#23041620)

Yeah. The word weird comes from the olde tyme term 'wayward', meaning something unearthly or unnatural. These computers are maybe unusual, but certainly not weird.

Re:Why are these weird? (1)

tirerim (1108567) | more than 6 years ago | (#23041808)

I don't think that's right. 'Weird' comes from Old English 'wyrd', meaning 'destiny', or more specifically the power to control destiny, as in 'the weird sisters'. That grew into the 'unearthly' or 'unnatural' meanings, which then evolved to the modern meanings, but I don't think it ever had a form of 'wayward'.

Regardless, though, the word's etymology doens't have much bearing on what it means today, which certainly includes just 'strange' or 'unusual'. There are plenty of more extreme examples out there, like 'nice', which used to mean 'stupid' or 'ignorant', but its meaning changed enough over time (through several intermediate stages) that it got to what we use today.

Re:Why are these weird? (3, Funny)

value_added (719364) | more than 6 years ago | (#23041740)

weird |wÉÉ(TM)d|

Weird is trademarked?

I'm in trouble.

Re:Why are these weird? (1)

Dr. Cody (554864) | more than 6 years ago | (#23042536)

Don't try to out-weird me, three-eyes...

Re:Why are these weird? (1)

dfedfe (980539) | more than 6 years ago | (#23042564)

No, no, wee is trademarked.

You're in more trouble than you thought.

Pneumatic computer (4, Interesting)

Thelasko (1196535) | more than 6 years ago | (#23041162)

When I worked in manufacturing I would occasionally rig up some logic circuits using a series of pneumatic valves. If only a few conditions had to be met (like don't open door if bucket raised) it was cheaper and easier than installing a PLC.

Personal favourites (3, Interesting)

ozamosi (615254) | more than 6 years ago | (#23041166)

My personal favorites are computers built in Game of Life [rendell-attic.org] and a model railroad [rendell-attic.org] .

K'nex Computing. (2, Interesting)

KinkoBlast (922676) | more than 6 years ago | (#23041190)

You know, someone on Youtube showed off logic gates in K'nex. But it was only and, or, and not.

Has anyone figured out how to do an xor in k'nex without horrible permutations along the lines of (in scheme, since it's easy for me to think in today)

(define (xor a b) (and (not (and a b)) (or a b)))

?

Re:K'nex Computing. (1, Informative)

Anonymous Coward | more than 6 years ago | (#23041572)

Given that you can make any of the basic logic gates (NAND, NOR, NOT, XOR, XNOR, AND, OR) out of just NAND and/or NOR gates, there's definitely a way to do it. Whether it's "neat" or not is irrelevant. I think most stuff today uses NAND gates for everything because it's cheaper to make.

Re:K'nex Computing. (1)

Actually, I do RTFA (1058596) | more than 6 years ago | (#23041774)

NAND and/or NOR gates

Or XNOR...

The one at Unseen University (5, Funny)

TheWoozle (984500) | more than 6 years ago | (#23041222)

Hex [wikipedia.org]

Re:The one at Unseen University (1, Funny)

Anonymous Coward | more than 6 years ago | (#23041486)

+++ Divide By Cucumber Error. Please Reinstall Universe And Reboot +++

Some better examples (5, Interesting)

Animats (122034) | more than 6 years ago | (#23041232)

Some better examples:

  • The Great Brass Brain [jhu.edu] , an analog tide predictor. It was built in 1910, and used until 1966, for regular tide predictions.
  • The Bay Model [army.mil] , a working 1.5 acre model of water flow in San Francisco Bay. Built in 1956, in use until 2000. (You can still visit, but it's not used as a research tool any more.)
  • SCEPTRON [aip.org] , a mechanical filter bank of quartz fibres which could record and play spectra onto photographic film. This was trainable as a speech recognition system. Early 1960s.
  • The Iconarama. [ed-thelen.org] , the USAF's Etch-A-Sketch. This was one of the first large screen displays, basically a plotter/slide projector combo. It could write, but not erase selectively, so units were used in pairs, allowing a redraw by the unit not projecting, then a lamp switch. 1950s.

Re:Some better examples (1)

Intron (870560) | more than 6 years ago | (#23041962)

About 40 years ago one of the railroads built an analog computer for controlling switches and retarders in a gravity classification yard (hump yard). It used ball bearings rolling down tracks to model the rolling cars. Google didn't find anything online about it, so I don't have a link.

Well written (0)

Anonymous Coward | more than 6 years ago | (#23041242)

Quote:

But making something as powerful as a microprocessor this way would require acres of space â" unless your balls or dominoes are very small.

*snicker*

Don't forget most impractical computers (1)

davidwr (791652) | more than 6 years ago | (#23041270)

Students and others throughout the history of computers have come up with Rube Goldberg computer designs using anything from solid-object mechanics to fluids to sounds as computational objects. In WWII groups of human beings were "computers" that solved problems in a 1-person=1-subtask algorithmic manner.

Even some databases and other software packages are technically complete computers. I heard a rumor that EMACS was but don't quote me on that.

The Game of Life is Turing Complete (3, Interesting)

still_sick (585332) | more than 6 years ago | (#23041282)

http://en.wikipedia.org/wiki/Conway's_Game_of_Life [wikipedia.org]

It is possible for gliders to interact with other objects in interesting ways. For example, if two gliders are shot at a block in just the right way, the block will move closer to the source of the gliders. If three gliders are shot in just the right way, the block will move farther away. This "sliding block memory" can be used to simulate a counter. It is possible to construct logic gates such as AND, OR and NOT using gliders. It is possible to build a pattern that acts like a finite state machine connected to two counters. This has the same computational power as a universal Turing machine, so the Game of Life is as powerful as any computer with unlimited memory: it is Turing complete. Furthermore, a pattern can contain a collection of guns that combine to construct new objects, including copies of the original pattern. A "universal constructor" can be built which contains a Turing complete computer, and which can build many types of complex objects, including more copies of itself.[4]

homebrew purely optical computer (5, Interesting)

smellsofbikes (890263) | more than 6 years ago | (#23041300)

They're all impressed by using waves for building logic circuits.
Want to build your own cheap, brilliantly visual set of logic gates to show kids how digital computing works? Nightlights. Each one is a NOT gate. You put two close to a third's sensor and you have a NOR. Put them some distance away with some blocking material around them (this is fussy) and you can get a NAND. A little bit of thinking and combinatorial logic and you can build anything else from those. I've built stacked, carrying half-adders this way, and it's pretty cool to watch small binary numbers get added.
Two nightlights, each with its bulb by the other's sensor, are a flip-flop. Now you have memory.
For extra credit, you can build a ring oscillator by putting an odd number of nightlights in a ring, so each is seeing the next one's sensor, and use that to clock your half-adders and flipflops.
If I had a lot of money and time, it'd be fun to see how far this could be extended (before I had to start hiring kids as tube runners to keep the whole works going.)

Re:homebrew purely optical computer (0)

Anonymous Coward | more than 6 years ago | (#23041420)

So the monsters hiding under my daughters' bed will be replaced by engineers. Great...

(Cool stuff, BTW)

Re:homebrew purely optical computer (1)

harry666t (1062422) | more than 6 years ago | (#23042762)

Argh, damn mod points, never around when you need 'em. Imaginary +1, Interesting from me, sir.

Re:homebrew purely optical computer (1)

smellsofbikes (890263) | more than 6 years ago | (#23043060)

Well, don't mod me interesting -- go build one! Seriously. Nightlights cost like 2/$4 at BigLots! and similar places. The main problem is hooking them all up without potentially electrocuting yourself or going bankrupt buying cheap extension cords. (and for the ring oscillator use the same type of nightlights throughout because if you have different types, they'll often have different delays and sometimes it'll screw up the oscillation and you'll lose pulses.)

Weirdest storage. (4, Interesting)

argent (18001) | more than 6 years ago | (#23041346)

OK, let's go back a ways and look at the weirdest storage systems.

Mercury delay lines are a good one. Delay lines in general, actually. I recall readong once about a free-space delay line using a laser beam between Earth and a retroreflector on the moon.

CRT storage tubes are another.

An XOR gate? How banal. (1, Interesting)

Anonymous Coward | more than 6 years ago | (#23041366)

Using ripples in a container, you can do Fourier transforms and similar things.

In fact, the ear organ does exactly that (channeling waves through liquids in a properly wound casing and picking up the resulting vibrations at different locations corresponding to different frequencies).

An XOR gate is rather embarrassing...

Re:An XOR gate? How banal. (1)

NonSequor (230139) | more than 6 years ago | (#23041604)

I wasn't impressed with that one either. You could do it by setting up two ripple sources so that the wave peaks will be out of phase when they reach a certain point. If both or neither ripple source is turned on, the water will be calm at that point, but if only one is turned on the camera will see ripples at the point.

What about stochastic computers ? Robust, cheap... (4, Interesting)

franois-do (547649) | more than 6 years ago | (#23041386)

Stochastic computers represented any value between 0 and 1 (both included) by a probability. A set of random bits were sent according to that probability.

Multiplication, always a problem with analog computers at the time, was very simply, quickly and cheaply done by an AND chip (one of the inputs had to be decorrelated of the other by a delay line to avoid parasitic correlations). The addition was a little more tricky, but getting (p1+p2)/2 could be achived with just three basic circuits, if I remember well. Of course you had to remember that the value was scaled, well, exactly the same king of caution you had to observe with analog synthetizers at the very same time.

Details here for whoever is interested... and knows somebody reading French ;-)

http://fr.wikipedia.org/wiki/Calculateur_stochastique [wikipedia.org] The complexity of keeping trace of scaling, decorrelations and the like could be taken away by monitoring them from an associated PC, now that I am thinking about it. Try it ! You will like it ;-)

Puzzle computers (3, Interesting)

Bob Hearn (61879) | more than 6 years ago | (#23041438)

Conway's Life was mentioned, but that is still a deterministic computer.

Many puzzles have been shown to effectively be nondeterministic computers. E.g., you can make a sliding-block puzzle that is solvable if and only if a given traditional computation succeeds.

Science News story:

http://www.sciencenews.org/articles/20020817/bob10.asp [sciencenews.org]

Personal plug:

Games, Puzzles, and Computation [mit.edu]

They mentioned water computer but... (1)

Yold (473518) | more than 6 years ago | (#23041564)

they didn't mention MONIAC, which is the coolest analogue computers IMHO. http://en.wikipedia.org/wiki/MONIAC_Computer [wikipedia.org]

ah Man, is that what pratchet was talking about (1)

geekoid (135745) | more than 6 years ago | (#23041780)

in Making Money? Gee, I guess I'll 'have' to reread it, shucks~

How about an old one? (4, Interesting)

thatskinnyguy (1129515) | more than 6 years ago | (#23041614)

What about the Antikythera mechanism [wikipedia.org] ?

Computer #1 (0)

Anonymous Coward | more than 6 years ago | (#23041616)

Macintosh

More Weirdness (4, Interesting)

Purity Of Essence (1007601) | more than 6 years ago | (#23041726)

In A.K.Dewdney's Scientific American column (and subsequent books) he documents many unusual mechanical computing devices that solve a range of computationally expensive problems. In a chaptered entitled Analog Gadgets in the book The Armchair Universe he describes several mechanical computing devices that solve a number of many computationally expensive problems (with some caveats):

* a spaghetti powered sorting machine
* computing a convex hull using a board, nails and a rubber band
* finding the shortest path joining two nodes of a graph network using brass rings and string
* finding the minimum Steiner-tree for any number of nodes using pegs sandwiched between parallel sheets of plastic dipped in a soup solution
* a prime calculator using a pair of lasers and parallel mirrors

In the next chapter, Gadgets Revisited, he presents:

* a way to compute the best-fit trend of a graph using a board, nails, rubber bands, and a rod
* finding the longest path through a network of nodes using segments of string knotted together
* computing the forth power of a number based on the principle of elasticity and the deflection of a bar of aluminum
* or the third power of a number by using the same principle applied to a weight placed on the bar
* light refraction computed with soap film suspended between stepped surfaces
* optimal position for a refinery using a board with holes, string, a brass ring, and weights proportional to the cost of transportation for each source of raw material
* number averaging using interconnected graduated glass cylinders
* cubic polynomial solver using a water tank, a balance beam, two scalepans, and a variety of solids to represent terms of the equation: a cone for x, a paraboloid for x and cylinder for cx, and a sphere for d

Re:More Weirdness (1)

Purity Of Essence (1007601) | more than 6 years ago | (#23041754)

I hit Submit accidentally.

That should have read:

cubic polynomial solver using a water tank, a balance beam, two scalepans, and a variety of solids to represent terms of the equation: a cone for x^3, a paraboloid for x^2 and cylinder for cx, and a sphere for d


In the Tinkertoy Computer, Dewdney covers the well known Tic-Tac-Toe playing Tinkertoy computer built by MIT, as well as a fanciful computer based on ropes and pulleys featuring an inverter, an OR gate, an AND gate, a multiplexer, a flip-flop, and an adder.

Marble adding machine (2, Interesting)

tvelocity (812600) | more than 6 years ago | (#23041802)

This article reminds me of a very interesting video on youtube about a marble adding machine [youtube.com] . It is constructed out of wood, and the creator also has made a video explaining how it works [youtube.com] , in case anyone would like to build one on his own.

ripples! (1)

dwater (72834) | more than 6 years ago | (#23041818)

For those half blind speed readers among you, it's ripples in a tank of water...

Domino Digital Logic (2, Interesting)

jone_stone (124040) | more than 6 years ago | (#23041918)

This article makes me think, of course, of my experiments in domino digital logic [pinkandaint.com]

Prior art (0)

Anonymous Coward | more than 6 years ago | (#23042004)

XORgate? Isn't that what they called the Pentium-bug scandal?

/is very upset that someone else claimed the XORsyst Gamertag on XBL.

Why does everyone screw this up? (1)

CrazedWalrus (901897) | more than 6 years ago | (#23042016)

That would make possible things that are unfeasible with today's computers â" such as rapidly factoring large prime numbers to crack cryptographic keys.


Thanks Bill Gates. That really would be a neat trick.

ions in an electric field (1)

Jeff1946 (944062) | more than 6 years ago | (#23042152)

Ion paths in an electric field were determined by streching a rubber sheet between walls whose edge heights were proportional the electric voltage on those edges. The rubber sheet would obey Laplace's eqn just like electric fields do. If you roll balls down the rubber sheet they will follow the similar paths to ions in the electric field. Conducting solutions can also be used to for a similar purpose for systems that only vary in two dimentions, like a cylindrical lens. Here a small electric probe can be set up to a servo mechanism to follow the field gradient. The probe is slaved to a pen the draws a parallel path of the probe.

XOR gate (2, Insightful)

Jurily (900488) | more than 6 years ago | (#23042196)

used wave patterns to make a type of logic gate called an "exclusive OR gate", or XOR gate."
Why the explanation? Are /. readers braindead nowadays? What kind of "news for nerds" needs an explanation of what a XOR is?

Re:XOR gate (0)

Anonymous Coward | more than 6 years ago | (#23042854)

it was in the article -- they just copied. and from the last entery, I assume just to prove that they actually read it.

Re:XOR gate (0)

Anonymous Coward | more than 6 years ago | (#23043116)

What kind of "news for nerds" needs an explanation of what a XOR is?

Um, they didn't explain what it is. They just expanded the acronym. Had they said that XOR is when one and only one condition is true, then they would be explaining what it is.

LEGO computing (1)

Dan Posluns (794424) | more than 6 years ago | (#23042238)

Any such list is insufficiently researched in my opinion without listing mechanical LEGO logic gates [ikaruga.co.uk] .

Slime mold? (2, Funny)

ibbie (647332) | more than 6 years ago | (#23042670)

Now I feel bad for eating all of those poor things in Nethack.

Fluidics (1)

McGregorMortis (536146) | more than 6 years ago | (#23042770)

Personally, I've always found Fluidic Logic to be fascinating. It's based on the flow of a fluid (usually air) through specially-shaped chambers. Typically implemented in a stack of etched glass plates. But no moving parts, just fluid-dynamics. They can make logic gates, flip-flops, all kinds of things.

Neutrino Computing (0)

Anonymous Coward | more than 6 years ago | (#23043408)

Are neutrinos still thought to travel backward in time? I wanted to build a computer network running on neutrinos but figured its CPU would be maxed out at 100% as soon as you turned it on from running programs in the future. At least you'd get the answers before you asked for them.
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