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LEGO Difference Engine
Andrew Carol ^ | 2/9/2006 | by Andrew Carol

Posted on 02/09/2006 6:26:12 PM PST by zeugma

Building A Calculating Machine Using LEGO

Small picture of the difference engine.
Carol's LEGO Difference Engine 2. (click for larger image)

History

Before the day of computers and pocket calculators all mathematics was done by hand. Great effort was expended to compose trigonometric and logarithmic tables for navigation, scientific investigation, and engineering purposes.

In the mid-19th century, people began to design machines to automate this error prone process. Many machines of various designs were eventually built. The most famous of these machines is the Babbage Difference Engine.

Because of engineering issues as well as political and personal conflict the Babbage Difference engines construction had to wait until 1991 when the Science Museum in London decided to build the Babbage Difference Engine No.2 for an exhibit on the history of computers.

Babbage's design could evaluate 7th order polynomials to 31 digits of accuracy. I set out to build a working Difference Engine using LEGO parts which could compute 2nd or 3rd order polynomials to 3 or 4 digits.

There is a lot more coming to this page over the next few weeks.

More details on how it works, and more pictures. Including pictures of the engine broken into its basic adder units as well as close ups of the important mechanisms.

Do you want to contact me about the machine?
I am available at: aecarol@coastside.net ..and... aecarol@woz.org

Select the Source Link


TOPICS:
KEYWORDS: computers; denmark; lego; vavage
This isn't really news or anything, but I just saw this referenced on SlashDot, and just couldn't resist posting it because it is just Too Freaking Cool.

I can also tie this into current events if you squint just a little bit at it. You see, Lego is a product of Denmark. Given the issues that the country is currently having with whacked out muslims, (is there any other kind?), I figure Lego is tangentially topical.

1 posted on 02/09/2006 6:26:14 PM PST by zeugma
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To: ShadowAce; N3WBI3
Tech pings?
2 posted on 02/09/2006 6:28:45 PM PST by zeugma (Muslims are varelse...)
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To: zeugma

That tie-in is a major stretch, since it is 'Mentos Cool'(TM), we're good to go. :-)


3 posted on 02/09/2006 6:29:03 PM PST by Riley ("What color is the boathouse at Hereford?")
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To: Riley
Thanks! I just couldn't resist.
4 posted on 02/09/2006 6:34:02 PM PST by zeugma (Muslims are varelse...)
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To: zeugma

Very cool- thanks for the post.

BTW mechanical computers didn't die out with Babbage. Every office in the US had mechanical adding machines not very many years ago- they could add, subtract and multiply.
The main guns on the Iowa class battleships are directed by mechanical ballistic computers.
WWII US subs had mechanical fire control computers linked to the periscopes and on-deck binoculars through a Torpedo Bearing Transmitter (TBT) system. Compute the enemy's course and speed, Triangulate their position, enter the sub's course and speed, turn the crank, and it plots the bearing and range for the torpedo shot. Pretty nifty, eh?


5 posted on 02/09/2006 6:39:17 PM PST by Ostlandr ( Hey! Where'd my tagline go?)
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To: zeugma

You must not live with siblings. Younger, rug cruising, siblings destroy Lego creations because it's fun; older siblings destroy Lego creations to see if they can upset you, and, because it's fun. How do you propose to keep the difference engine in one piece, because you know, friends destroy Lego creations because... it's fun.


6 posted on 02/09/2006 6:39:33 PM PST by concentric circles
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To: concentric circles
Younger, rug cruising, siblings destroy Lego creations because it's fun; older siblings destroy Lego creations to see if they can upset you, and, because it's fun

Moms destroy your Lego creations because the floor is filthy & she need to clean.

(That's where most of mine went, anyway. :-)

7 posted on 02/09/2006 6:51:53 PM PST by MamaTexan (I am NOT a ~legal entity~, nor am I a *person* as created by law!)
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To: MamaTexan

You need this, cleans and sorts!

8 posted on 02/09/2006 7:18:55 PM PST by concentric circles
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To: concentric circles
You need this, cleans and sorts!

ROFL!

Now THAT is a useful invention!

9 posted on 02/09/2006 7:31:10 PM PST by MamaTexan (I am NOT a ~legal entity~, nor am I a *person* as created by law!)
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To: Ostlandr
Da, very cool. My folks had a grocery store when I was a but a wee lad. We had mechanical Sweeda registers. One of our meat pricing machines (a Hobart I think) was a really early model, that actually had about an ounce of gold in it as contacts!

I saw an article about a museum attempting to actually build an 'Analytical Engine' about a year or so ago. They were attempting to machine the thing out of the same material Babbage would have used. It turns out that it was not as easy as one would think even using modern machine tools because the tolerances had to be so tight. That's one reason I thought the Lego version was so cool.

10 posted on 02/09/2006 7:32:43 PM PST by zeugma (Muslims are varelse...)
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To: concentric circles
Well, I'm an AFL (Adult Fan of Lego), which essentially means I'm still about 10 years old inside. :-) My friends aren't allowed to tear up my creations.
11 posted on 02/09/2006 7:34:09 PM PST by zeugma (Muslims are varelse...)
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To: Peanut Gallery; sionnsar

ping


12 posted on 02/09/2006 7:41:51 PM PST by Professional Engineer (It's a bunch of hot air, crap flows down hill, and electrons go wherever they darn well please.)
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To: zeugma
And to keep the thread alive just a bit longer... I thought the following comment contributed on /. was interesting...

"On two occasions, I have been asked [by members of Parliament], 'Pray, Mr. Babbage, if you put into the machine wrong figures, will the right answers come out?'

I am not able to rightly apprehend the kind of confusion of ideas that could provoke such a question."

Charles Babbage (1791-1871)

Sounds like politicians haven't changed in ages.

13 posted on 02/09/2006 7:47:21 PM PST by zeugma (Muslims are varelse...)
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To: Marcus _Aurelius-180

It was electro-mechanical. Yeah, platinum is better, but it normally sells at a 15-20% premium to gold, and gold has the advantage that it doesn't corrode. It was a nice bit of hardware. Once we upgraded to more modern hardware, I recovered the gold with a bit of teenage elbow grease. :-)


16 posted on 02/09/2006 9:27:47 PM PST by zeugma (Muslims are varelse...)
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To: Marcus _Aurelius-180
From what I understand, there are still some analog computers still in use, as the can do "fuzzy" logic, and has been useful in simulating chaotic systems. I believe analog computers were used by Benoit Mandelbrot while at IBM doing whatever it was he wanted to do as an "IBM Fellow".
17 posted on 02/09/2006 9:30:51 PM PST by zeugma (Muslims are varelse...)
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To: fnord; phantomworker; sd-joe; Jack Black; TXBSAFH; SouthernBoyupNorth; Ichneumon; ...
Thanks to Professional Engineer for the ping!


Geezer Geek ping.

This is a very low-volume ping list (typically days to weeks between pings).
FReepmail sionnsar if you want on or off this list.

20 posted on 02/10/2006 2:30:13 PM PST by sionnsar (†trad-anglican.faithweb.com† | Libs: Celebrate MY diversity! | Iran Azadi 2006 | Is it March yet?)
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To: sionnsar
I had the pocket version. :-)


21 posted on 02/10/2006 2:47:08 PM PST by JoeSixPack1
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