Know How To Use a Slide Rule? 388
high_rolla writes "How many of you have actually used a slide rule? The slide rule was a simple yet powerful and important tool for engineers and scientists before the days of calculators (let alone PCs). In fact, several people I know still prefer to use them. In the interest of preserving this icon we have created a virtual slide rule for you to play with." Wikipedia lists seven other online simulations.
I learned how to use my slide rule... (Score:5, Funny)
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No, seriously.
Re:I learned how to use my slide rule... (Score:4, Funny)
And if this one could be with you, what a wonderful world this would be.
Re:I learned how to use my slide rule... (Score:5, Funny)
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What's sad is a good 4 function calculator costs 1/10th a slide rule does.
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At least (Score:5, Funny)
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Try this one [sliderulemuseum.com], it's much better and actually correctly laid out
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Googlefight does not agree. [googlefight.com] I wonder what Netcraft thinks?
Nuclear slide rule. (Score:5, Funny)
Re:Nuclear slide rule. (Score:5, Interesting)
Of course (Score:4, Interesting)
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Re:Of course (Score:5, Funny)
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Worked a treat.
As a matter of fact, it is probably faster to do some computations with it compared to a calculator or a computer if you know how to use it (I have forgotten it completely now) and if you are happy with its precision.
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Student: "May I borrow your calculator?"
Me: "Sure. Here."
Student searches in vain for any operational familiarity.
Student: "Ummm, no thanks."
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If anyone is interested, here are several links to downloadable ebooks and manuals for using slide rules:
My only experience with using a slide rule was back in the 1960s in an 8th grade math class where we spent two weeks learning to use slide rules. We were just 8th graders, but were able to use a few basic features of something that was normally used mostly by scientists and en
back in the day (Score:2, Interesting)
I still use it (Score:2)
Buy your own! (Score:3, Interesting)
My mother recently bought one in a wave of nostalgia. I can certainly understand the physical appeal - the soft susurration of the pieces gliding against each other, the comforting grip of the leather carrying case, the art of perfectly lining up the dashes to the limits of human precision. If computers were that tactilely slick, nerds might rule the world.
Pheh, youngsters. (Score:4, Funny)
Hooray for progress (Score:3, Insightful)
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If you wanted to rebuild society - what would you use? Yes - things like sliderules. Think of it is a method of survival, rather than - we have better why would you bother to learn how to use sliderules.
One of the reasons I thought it was fun to learn morse code back in the day when I got my amateur radio license. Morse code happens to be the most fun
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Around here (Score:5, Funny)
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(website warning: fugly graphics design!)
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You know you're a math nerd when... (Score:2)
Um No. (Score:4, Interesting)
Since I live in the 21st century, I don't really lose sleep over those things.
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Sounds like if the global shit ever hits the fan, you're simply going to DIE, because you have no ability to care for yourself.
Living in modern civilization is no excuse to be ignorant.
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Re:Um No. (Score:4, Informative)
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So knowing how to use a slide rule will save humanity? Nice!
Did you READ the guy's post? A slide rule might not save you, but being able to hunt, kill, clean, and cook an animal would probably be useful, don't you think?
The hilarity is that if civilization does go in the shitter, it's the so-called "hillbillies" who are going to absolutely own everyone's ass.
Do you hear that sound? (Score:3, Funny)
For some reason, I'm hearing banjo music...
I did not need that visual.
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That's pretty 18th century. You need to pick up the pace a bit [ak-47.us].
Again, you're a couple of centuries out of date. Get with the program here [amazon.com].
Alfred Nobel has the thing for you [illegal-fishing.org].
You actually do it the other way around (horse to
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Damn, you lay the sarcasm on thick
All I gotta say is, the amish are gonna pwn us all.
Re:Um No. (Score:4, Insightful)
If you were seriously interested in shooting, you'd find a flintlock pretty interesting; you'd have at least a rough idea of how to operate one, although it might take you a bit of time to use it expertly. You'd at least get some pleasure out of messing around with one, and maybe take some lessons back for shooting modern firearms. If you were seriously interested in cooking, you'd have a pretty good idea of how to clean, split and roast small game, or how to use a butter churn.
If you are seriously interested in math, you are bound to find the slide rule intriguing.
Aside from idle curiosity, it is also true that taking the difficulty out of processes is not always an unmixed blessing, especially in education.
My daughter just started middle school, and one of the key math skills she is being taught is "number sense". This topic basically amounts to cognitive strategies for looking at a set of calculations and determining if certain possible results are reasonable. What is interesting is that this hole in math education was left by the removal of the slide rule from the curriculum.
The brain is a curious and largely unreasonable thing; it obstinately refuses to work in ways that seem like it should, yet performs brilliantly in ways it seems impossible that it might. For example, when I was a student, I experimented with using a tape recorder instead of taking notes, on the theory I could play the lecture back during what otherwise was down time. Aside from the obvious deficiencies of only having audio, I was disappointed to discover that at least for me, listening over and over to information doesn't do anything for recall. On the other hand, I was delighted to find that if I wrote down information as I heard it, mainly concentrating on the speaker but letting my hands semi-automatically follow along, my recall was so improved I seldom needed to refer to the notes I was taking. Something about the process of completing the circuit from input to output caused the information to stick.
In many other instances, I have found that trivial manual effort has unexpected rewards. I recently wanted to review probability theory, and I found it helpful to work through even trivial problems that I could see how to solve right away. It wasn't enough to have the insight, doing the work improved my comprehension and retention.
The lessons in number sense given by the slide rule are largely of the same kind. You'd think you could do as well having a superior calculating tool that effortlessly gives you more precision than you need. All you need to do is ignore the superfluous digits. It may even work that way for you, but I suspect many people's brains won't acquire the same skills.
Still have mine... (Score:2)
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Pocket slide rule (Score:2)
I found the traditional slide rule large and bulky and often I would try to use the wrong index so my answer was off the scale off the other end (those who use them know what I'm talking about) so I was the owner of a circular slide rule. It
nerd phallus (Score:5, Funny)
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I presume you meant it as a joke, but it is true. You get more accuracy with a larger slide rule.
If you double the size of the slide rule, you double the accuracy for most tasks.
No, and what the hell is the index line? (Score:5, Insightful)
What's the point of explaining how it works if you don't explain what each of the terms used is?
Damn nerds...
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Re:No, and what the hell is the index line? (Score:5, Informative)
First, the term "index" has the old-school meaning of the number "1" and it appears at either end of the C scale. On the left side of C it means 1, and the right side it means 10, but there are no actual decimal points involved (you're on your own for order of magnitude with this device) so they're equivalent at either end. Also, for multiply and divide, you don't need that hairline slider that covers all the bars; that's only useful if you need to align two values on non-adjacent rules. Just slide the center bar (the one that holds scale C) back and forth.
The other important point to note is that you'll see numerals 1-9 between 1 and 2; those are just convenience markers for 1.1 through 1.9. That first (smaller) 2 you see, reading from left to right, is really 1.2 not 2.0.
So to multiply 6x2, we can go either direction, starting at 2 and multiplying by 6, or starting at 6 and multiplying by 2. To start at 2, slide the center part of the bar so that the right-hand "index" (1) of scale C is directly above the 2.0 on scale D. Now to "multiply" you don't do anything; you just read the result, which is found on scale D, directly under the 6 you wanted to multiply. Here you'll see 1.2 is directly under the 6.
Wait, though, we used the right-hand index, which is 10 not 1, so we need to multiply the result by 10. So 1.2 becomes 12 (which is why I said you have to do your own decimal point management). To start at 6 instead, slide the right-hand "index" (1) of scale C directly above the 6 on scale D; your answer will on D again, directly under the 2.0 of slide C. Again, we used the right-hand index of 10, not 1, so we multiply the 1.2 by 10 to get 12.
How did I know to use the right-hand index rather than the left-hand index? Well, if you slide the left-hand index of C all the way to 2.0 on D, you'll notice that the 6 you need to multiply is off the edge of the device--an overflow, if you will--so you must essentially work with 10 rather than 1 and move the decimal at the end.
With this extremely trivial example, you should be able to follow the rest of the terribly-written instructions FTFA for divide (although you can do significantly more with a slide rule than just multiply and divide).
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I read through the multiplication instructions, and I can't even come close to getting any kind of answer at all.
And if you can use one... (Score:2)
Of course (Score:5, Interesting)
They are also just good things to have around. A good slide rule (Aristo, Nestler, Faber-Castell, etc) is just such a fantastically well-made device that you really need to see it to appreciate. The precision is something you don't see these days. Even a lowly Pickett is nicely made.
Brett
Used!? (Score:2)
Steven
Stupid virtual rule slide! (Score:2, Informative)
At least, this one is usable:
http://www.antiquark.com/sliderule/sim/n909es/virtual-n909-es.html [antiquark.com]
Calculate my age (Score:2)
The E6B [wikipedia.org] is still great for aviation.
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Circular Slide Rule .. (Score:2)
I still can't figure out how to use it
no calculators (Score:2)
-metric
I have (Score:4, Informative)
I soon got the hang of using it (and it can be quicker than a calculator sometimes), but I knew the general principle from before anyway. The main thing you have to remember is the slide rule only ever gives you the mantissa; you have to work out the exponent yourself. This means you have to do a rough mental calculation. People often put too much trust in calculators. When I was filling in order forms by hand in a previous job, I never used a calculator -- and I never got called out on a wrong total.
Old School (Score:2)
I taught myself how to use one (Score:2)
As promised, the slide rule was quite useful for multiplication and division. On the back of the slide, there were sine, log, and tangent scales -- that led me to look those things up in Dad's copy of Machinery's Handbook [industrialpress.com], which got me into trig and pre-c
Pilots know how to use slide rules. (Score:5, Informative)
It's preferred over digital devices because they still work when the batteries go flat, they are easy to use with one hand, and some models are actually smaller.
http://en.wikipedia.org/wiki/E6B [wikipedia.org]
I found this page easier to understand (Score:2)
Og like pretty pictures.
Still have one. (Score:2)
where to find a real one (Score:2)
it'd be a cool thing to have.
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Slide Rule Universe [sphere.bc.ca]
I feel bad (Score:5, Interesting)
Mildot Master (Score:5, Insightful)
Simple, low-tech, durable and cheap - specialized slide rules are still useful for particular applications where computers are expensive & fragile overkill.
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Never again (Score:2)
When I was in school... (Score:2)
I used to know all that stuff.... (Score:2)
The sliderule was essential to my Dad's work, back in the day. He used it heavily in the thermodynamics engineering of jet engine parts, and later when working on the design of the Apollo heat shield.
A good sliderule in the 1950s was ivory laminated on teak, ebony, or lignum vitae, with a magnifying hairline cursor. The wood was selected for stability despite changes in humidity: ideally it would never warp, crack, expand or contract. The ivory surface was needed for the fine, closely calibrated lines cri
I happen to have a few lying around. (Score:2)
I carry a circular slide rule in my briefcase for checking quick calculations and the various basic problems that pop up that are 'multiply/divide' ratio style problems. Here is a photo of this story's page [flickr.com] along with my trusty CR-2 slide rule [flightstore.co.uk]. (Many basic items, from time and distance to power or area calculations.) The circular slide rule is still a basic tool used by pilots (when things that take batteries fail) and you can even purchase watches that have them built in from companies like Citizen, Seiko
Useful experience (Score:2)
Now I think I'll go back to dozing on the porch.
E6B (Score:2)
'course. Still use 'em! (Score:2)
Especially when I need to check the valve sizes a jr.engineer gets the GIGO fancy pgm to spit out to 10 decimals.
It is easy to slip decimals in general calcs on slide rules, so we used to be very careful about magnitudes. Electronic calculators keep everything very neatly, so we now lose a feel for magnatudes. The crutch becomes crippli
Verizon (Score:2)
I have (and still can, I suppose) (Score:2)
Yes, I'm old. Now git off'n my lawn, you mountebanks.
Why such a feeble one? (Score:2)
Please, at the very least, show a Log-log Duplex Decitrig to illustrate the virile power of the device.
And believe me, a slide rule was a badge of manhood (why do you think we carried them in holsters dangling down from our belts?) and there was intense rivalry and claims and counterclaims between the Keuffel & Esser faction and the Pickett & Eckel fans.
But it was really no contest. I me
No, but I was an English major (Score:2)
I was an English major, so there wasn't much cause for me to learn how to use a slide rule. I do, however, still have and use the English department's equivalent: a paperback Roget's Thesaurus.
I think my dad has a slide rule somewhere still. Hell, knowing him, he probably still uses it.
Aviation E6B (Score:2)
By that measure, at least 100,000 Americans know how to use a slide rule.
Oh yeah! Well... (Score:3, Interesting)
Late to the party, but still love slide rules (Score:3, Interesting)
Dad was an engineer. I learned how to use a slide rule for basic math in first grade, just because "it was neat" -- after all, if dad the engineer uses one, it must be cool.
One of my math classes "required" a TI-82 (Jr. High), since some of the problems were of the "push these buttons in this order to graph this equation" type. After that, most kids went out and bought the latest and greatest TI graphing calculators. I was given a TI-86 when they were first released, as "the calculator that will do anything you need it to through college" by my parents. It was neat for a while, some of the games were cool, and programming in assembly for it was kinda fun - at least much more so than paying attention in Early American Literature. But I didn't use it for my math classes. I was the nerd in the back of the room using dad's old slide rule while everyone else was punching buttons on their calculators.
I continued using a slide rule for most problems until my senior year in college, when I switched over to a TI-89 because I was extremely lazy and it made the statistics class much easier (it did all the work anywhere where we weren't required to "show our work").
I still have it, and still use it out in the shop on occasion. My TI-86, TI-89, and HP-48G+ sit gathering dust.
Re:Of course (Score:5, Insightful)
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Re:Of course (Score:5, Interesting)
E.g., divide 52 by 7 on a calculator, and it will spit out 7.428571428571, a completely correct although ridiculous answer when dealing with real-world quantities, since it blows away the precision of the input numbers. Slide rules require you to constantly consider the number of decimal places that you want, and encourage you to only write down the correct number of digits (so you might do the same result and put down 7.4).
Personally, I think some of the best engineering ever accomplished by man has been conducted mostly by slide rules. I wouldn't go so far as to say that we've necessarily regressed since then -- computers are great, don't get me wrong -- but it's not right to simply write off slide rules. They had very distinct benefits and I think students would be well suited if they were kept around as a pedagogical tool.
Re:Of course (Score:4, Informative)
A slide rule enforces estimating a reasonable answer before hand, and encourges arranging computations for economy of calculation. I think there is a big benefit to critical thinking skills in praticing basic computation with a slide rule.
That said, computers have made it possible to do what was formerly impossible due to computational expense. Integrated circuits would not be where they are if you couldn't burn many flops running spice. Cars would weigh more and get less gas mileage without mechanical simulations because they would have to be over-built in order to simplify strength calculations. Pre-computer-simulation camera optics suck when compared to modern computer optimized lens, ditto for antennas.
I once met a guy whose mother was a computer.... that was her job title: "computer". She worked for a university research department, where row upon row of "computers", mostly women, sat in front of mechanical calculators all day long, 40 hours per week, cranking through tablets of computations for various numerical models. Modern electronic computers enable solutions to problems there were too expensive to attack before, and life *is* better as a result.
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Re:Of course (Score:5, Funny)
I was in the last class in my high school that learned how to use a slide rule. I was in the first class in my college where owning a scientific calculator was required for entry.
As a freshman my Econ professor asked the class if anyone with a calculator would do a division for him. I was carrying an inexpensive plastic slide rule in my back pack. I did the division and said the answer. As he turned to thank me he did a double take and said "What is this?" taking the slide rule from me and holding it up. I said "Its new, a solar powered calculator that never needs batteries." "What will they think of next?" he pretended to marvel.
The point of that whole story is that about 15 people probably had pulled out a calculator and started to do the division and I was able to beat all of them by several seconds.
Yep (Score:2)
77.1*850=65535
Just for haha's I got out my trusty old Concise circular No. 300 and checked this. You only get three sig fig's, so it actually comes out to ~65500.
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For dumb Americans: (Score:3, Informative)