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Know How To Use a Slide Rule?
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.
at around 10 years old. I've been using it ever since, and don't plan on ever stopping.
At least a slide rule is more accurate than excel 2007.
At the bottom of the
I prefer to use a tactical nuclear slide rule, myself.
I can use one (only a linear slide rule, though), but I definitely prefer a calculator. The calculator gets you much more precision at a quicker rate.
I did college physics, organic and physical chemistry with my trusty Pickett aluminum log-log slide rule. You needed one for real geek cred in those days.
Some mornings it's hardly worth chewing through the restraints to get out of bed.
When I took HS Chemistry a slide rule was required. The instructor spent a bit of time explaining how to use it and we were quizzed later. While it lacked the precession of modern calculators we managed to solve complex problems. My dad earned an engineering degree back in the 50's using only a slide rule.
When I was 10 years old my father gave me one as a present! It made complicated calculations very easy task. It was even faster than the computer :)
sex is better than war!
Mainly to give rough answers to vaguely complex calculations, to check if this or that engineering decision is sound, or not way off the mark. For me, that's the main interest of a slide rule today: not precise answers, but quick validation of a calculation. For anything more precise, I juse my trusty HP48.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
In case you'd like to work with the real thing, take a look here for some info on places to buy slide rules these days.
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.
Misery loves company. Online misery loves unsuspecting random strangers.
When I started with what they call 'Gymnasium' over here, even pocket calculators were not at hand and the system/360 was not yet introduced ;)
CC.
TaijiQuan (Huang, 5 loosenings)
You youngsters and your simpleton slide rules. Try a real one that makes you use that noggin of yours. http://home.earthlink.net/~apendragn/runish/sliderule/index.html
The poll on that page has a great "Cowboy Neal" option.
I believe that the Government is doing all it can to ensure that toys are 100% safe
Strongly agree
Agree
Dont know
Disagree
Strongly disagree
They should all come with a free set of steak knives
Militant Agnostic: "I don't know, and damn it, neither do you!"
There's a reason we don't use slide rules, abacuses, buggy whips, etc. - we have better tools now. I used to have one when I was a kid back in the '80s, never really figured out what it was for, especially since we had scientific calculators instead.
The only slide rule around here is to not push the kid in front of you.
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I'll give you some oldskool virtual calculators.
Unfortunately I have never had a chance to learn to use a slide rule. I am a third generation math geek and there are plenty of old math books around but not a single slide rule to be found. I feel like I am lacking a certain level of geekness.
It was still taught at school (University?) in the day and age of my parents. Not anymore in my day and age (I was born in 1976, use your slide rule to calculate my age ;-) ). Both my mom and dad still have theirs.
Please tell me when it really works! I got:
77.1*850=65535
The E6-B that every pilot learns to use in ground school is basically a special-purpose circular slide rule.
You see the article and think "the virtual slide rule I created is better than this one!" Too bad my University stopped hosting it (they stop hosting student web pages 6 months after you graduate).
You are reading a copy of my copyrighted post.
I also don't know how to use a Flintlock rifle, trap/clean/spit roast a hare, catch a fish with my bare hands, hitch a wagon to a horse, or build/make/use a butter churn.
Since I live in the 21st century, I don't really lose sleep over those things.
Made it through chem 1, chem 2, and physics back in the day. I keep it around in case there's an extended power failure...
The contest for ages has been to rescue liberty from the grasp of executive power. -- Daniel Webster
I tell ya, nothing like having a trusty E-6 sliderule device in your bag, just in case your batteries die. For some calculations, it is MUCH faster than an electronic flight computer.
Toil is Stupid. Don't be Stupid.
I graduated high school when calculators ran on 4 AA batteries and would run for up to 8 hours. They were just under $150 for one that could add subtract multiply and divide and the big bonus, a percent key for the morons who couldn't move the decimal point two places.
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 fit my shirt pocket and had a pull out sheet with common conversions of weights and measures. I used the table as much as I used the slide.
One of the biggest uses for it was a sanity check of my math. If my math was out in left field for some stupid thing, the slide rule would quickly show my answer wasn't in the ball park.
The truth shall set you free!
the bigger the slide rule, the more accurate the calculation...
"The index line on scale C is always put over the number to be multiplied on scale D"
What's the point of explaining how it works if you don't explain what each of the terms used is?
Damn nerds...
-- Trinity in high heels carrying a whip: The donimatrix - there is no spoonerism
(which I can, BTW, I stole my dad's many years ago, but I think it got lost in a random move), do you know WHY a slide rule works, and how to make a slide rule for addition and subtraction...
Test your net with Netalyzr
I use a circular slide rule at a few times in the week if I need to use a film camera to enlarge images that need to go to film.
They are great for proportions, especially in the print industry. It amazes me how many CSR's cant figure out proportions in this line of work.
I use a slide rule DAILY. It's an extremely useful and (if you know what you are doing) both accurate and fast. For many engineering problems 3 or 4 sig. figs. is plenty enough. The advantages are well-known - the most important being the elimination of "false precision" that you can get with a mindless calculation with a 10-sig-fig calculator.
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
With 24 or so computers in the house, I still keep my now 30+ year old Dietzgen Polymath 1733 at my desk for quick math work. Like an abacus, if you really know how to use a slide rule, you can do basic math much faster than most people hammering on a calculator or PC numberpad.
Steven
What is the point of having such a long rule, if you only see a part of it and cannot move both parts at the same time???????
At least, this one is usable:
http://www.antiquark.com/sliderule/sim/n909es/virtual-n909-es.html
When I entered high-school I was using slide rules (still have some ranging back to great grandfather's). When I left high-school, programmable calculators were the rage.
The E6B is still great for aviation.
~~~~~~~
"You are not remembered for doing what is expected of you." - Atul Chitnis
I still have a Pickett metal slide rule with the yellow, not white, background color. I got it in 1964 when I went to tech school.
I also have a little gadget called an Addiator, a mechanical thingie that does addition and subtraction. They are both in the memorabilia box.
These days I use electronic calculators.
Yes, I'm that old.
http://www.sphere.bc.ca/test/circular.html
..
I still can't figure out how to use it
davecb5620@gmail.com
What a complete waste of time and energy this story is...I'm not here for a history lesson or math 101...Geeze!
It's important to know that I forgot what I thought I knew when I thought I knew it all:Now I don't even know whatIknow.
My freshman college physics professor didn't allow calculators on our exams, but he said we could use a slide-rule. So.. My dad lent me his and gave me a quick tutorial. I think I was the only student to show up with one. It actually slowed me down though (probably because I was still getting used to it).
-metric
When my grandad died, he left his "old" slide rules to my dad and me. My dad kept the original wood and cellulose one from the 1940s; I got the plastic one from the 1960s / 70s.
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.
Je fume. Tu fumes. Nous fûmes!
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.
"Can't you see that everyone is buying station wagons?"
An engineer I knew in the early '70s had a metal circular slide rule. Occasionally he would carry it around in both hands, with a matzoh cracker held against its underside with his thumbs. In the midst of a conversation, he would feign taking a bite of the slide rule, pushing the cracker forward at the last instant and crunching into it instead. The effect was startling...
You have too much time on your hands. Why not simulate the abacus while your at it?! I study physics and I have not need for an slide rule. Matlab rules them all and everthing else is obsolete. I can't sit around all day doing mundane calculations. However, from my observations a tutor, calculators are being utilize too much in high school and the students suffer for it. It is one thing using technology to be productive and it is completely another thing to outsource thinking from your brain. Give them the slide rules, let them earn the calculators!
You don't have to be smart to use a Mac, you just have to be smart enough to buy one
for measuring stuff and for drawing straight lines also.
What?
back in the third grade (roughly 1971-72). I was in my local Target when I saw a cheap plastic slide rule on the shelf -- we were just starting to learn multiplication, and the package said that it could do that, so I figured what the hell, and bought it.
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, which got me into trig and pre-calculus.
Later on, I upgraded to a bamboo K&E which I used well into college (mid-80s). Unfortunately it was stolen from my car shortly after I graduated, along with my HP41CV.
The E6-B is a rotary slide rule that pilots use for calculating wind correction angles, time/speed/distance problems, conversion between units (i.e. weight of a certain number of gallons of fuel), and fuel consumption.
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
Fiid - Ryhmes with Squid. Software Engineer
http://www.hpmuseum.org/srinst.htm
Og like pretty pictures.
Yes
It's THAT easy!!!!
I'm 49 years old; In high school my math teachers still had 6 foot long slide rules hanging above the blackboard, but by the time I graduated I was the proud owner of a TI calculator. Within that 2 year (or so) span, pretty much everyone I knew made the jump from only using slide rules to only using calculators. I still, however, have my Kueffel & Esser, made of bamboo, ivory & glass
09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0
And I just don't have any more pine resin to fill it with.
...
All the best scientists use wooden slide rules, not those fancy plastic ones.
-- Tigger warning: This post may contain tiggers! --
i was given one years ago, but somewhere along the way it was lost. does anyone know where to buy one?
it'd be a cool thing to have.
Was xcalc -analog. I think the analog option is long gone now, though.
That reminds me of my favorite engineering prof in college. He had his slide rule mounted in a glass case above his desk. Below the case was a hammer and a sign that read "In case of power failure, break glass."
Ok, back to work.
Namaste
Nice to hear that people still find slide-rules useful in certain applications nowadays. However... A slide rule is good (or better WAS good) for introductory chemistry and physics classes because it forced you to keep track of the exponents for the calculation. That way you didn't (usually) get the ridiculous answers that people sometimes report who are addicted to calculators. But a modern calculator is a God-send for complicated problems that involve lengthy calculations. These are very easy to mess up with a slide rule. With a calculator you can usually do the calculation, twice, much faster than you could with a slide-rule. Generally if your two calcs agree you probably haven't screwed up anything. So far no one seems to have mentioned "circular" slide rules that had certain advantages in that the answer never ran off the end... OC
Slide rules are still in active use by - of all people - snipers. The Mildot Master is a sliderule for determining distances and ballistics for long-range precision shooting when using a rifle scope fitted with a "mildot reticle".
Simple, low-tech, durable and cheap - specialized slide rules are still useful for particular applications where computers are expensive & fragile overkill.
Can we get a "-1 Wrong" moderation option?
I guess everything comes back, but only for people who didn't experience it the first time. Calculators became affordable (barely) when I was in engineering school. I entered with a slide rule and graduated with an HP-45 calculator. While I still have my old slide rule (which was my dad's before me) for sentimental reasons, there's no way I'd ever want to use it again. I couldn't wait to get my hands on a calculator in school, and paid what would be over $1000 in today's dollars, which was an enormous amount of money for a poor college student. I think my monthly rent back then was $140 for the house I was living in.
Get off my lawn you kids.
For some reason, I'm hearing banjo music...
I did not need that visual.
Ben Hocking
Need a professional organizer?
we used cuneiform on clay tablets. And the sexagesimal numbering system (base-60, but meanwhile cue puns...). Decimal is for wimps. You insensitive clods.
"All successful systems accumulate parasites" -- Hal Hixon
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 critical to accuracy. The cursors were real hairs: stretched and sealed under optical quality glass lenses in a carrier designed and built with the same tolerances as a Swiss watch. A good sliderule cost several hundred dollars at the time: the equivalent cost today would be more than most desktop computers.
I learned to do basic sliderule operations before high school. Fortunately for me, the first four function calculators arrived on the scene before I faced any critical need for arithmetic. Those were the clunky, heavy things with red displays that could eat up a couple of nine volt batteries in a day's work. But that's another story.
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 along with my trusty CR-2 slide rule. (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, Breitling and others. Once you travel internationally and realize you have an instant currency converter on your wrist, you appreciate how useful they can be. I also have my father's slide rule from the 40s and 50s when he was studying engineering. It does far more than the circular rule (logs, 10 and natural).
There is something very useful about using these tools, they help you get a sense for the order of magnitude of your answer and you can frequently catch stupid mistakes when you are FORCED to consider the order of magnitude as your work the problem quickly and efficiently. Posters that have pointed this out ahead of me are spot on.
It might shock you, after reading all the above, to learn that I'm under 40 and live in North America. :-)
Now I think I'll go back to dozing on the porch.
Lacking <sarcasm> tags,
I use an E6B circular slide rule for flight calculations. They are quicker to use than the electronic version, and have more than enough precision.
Oolite: Elite-like game. For Mac, Linux and Windows
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 crippling.
I still have my trusty K&E (Keuffel and Esser) Deci-Trig sliderule http://www.sphere.bc.ca/test/slide8/260-ke-slides.jpg/ - the one at the top - that my grandfather gave me as a high school graduation present. Really nice piece. Served me very well throughout college physics and chemistry courses. I also had a nice Japanese circular sliderule, but I have since misplaced it. Both of these lost face time when I bought an HP-67 programmable calculator...
Against stupidity, the Gods themselves contend in vain. --Friederich Schiller
After a recent Incident in the billing department, verizon is rumored to be moving their entire accounting system to a series of mechanical slide rules that are operated by squirrels.
NewslilySocial News. No lolcats allowed.
I learned how to use a slide rule for math competitions (I don't know what you Yankees had, but in Texas we had interschool competitions under an umbrella called UIL). Unfortunately, I never got to compete with my newfound knowledge, because that year they phased them out, replacing them with competitions using a newfangled device called a "calculator".
Yes, I'm old. Now git off'n my lawn, you mountebanks.
"I guess the moral of the story is, don't paint your airship with rocket fuel." -- Addison Bain
If Engcom is going to present an online simulation of a slide rule, why show a cheap-looking stock-issue Mannheim?
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 mean, Pickett had eye-ease tinted yellow, and was made of aluminum that wasn't subject to dimensional changes due to humidity, and the scale design and layout... well... nobody with taste or discrimination would get a K & E when they could get a Pickett.
"How to Do Nothing," kids activities, back in print!
As the owner of a 50-year slide rule that is still in great shape, I can say they are cool, at least. But what is even cooler (and a lot more expensive) is the Curta: http://www.webcom.com/calc/Curta_text.html and http://www.vcalc.net/disassy/ !
I have three, two picked up at estate sales, one that belonged to my grandfather.
K&E log log duplex decitrig
Picket ortho-phase duplex
Post 1446 Student model (gave to my daughter)
I use still use them most of the time both to stay in practice, and it also forces you to think more about the problem, keeps the mind limber, but I do also still have my HP-15c for when I am in a hurry.
my old sig is obsolete, and I haven't come up with a stupid enough new one yet
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.
"Oh boy! Are we going to try something dangerous?"
An Engineer is one who, when asked what is 3 times 4, takes out a slide rule, fiddles around for a while and replies "Approximately 12"
It's a mechanical analog computer, you say?
Well then... imagine a Beowulf cluster of these!
in the field of aviation. Student pilots to this day learn how to use a slide rule (though they call it an "E-6B flight computer") to perform the calculations necessary to plan a flight. Most pilots carry one in their flight bag, in the event they need to make a change of plans and calculate, for instance, if they have enough fuel to make it to an alternate airport.
An E-6B is a specialized circular slide rule with some aviation-relevant information printed on the face. Sure, there are electronic calculators by the truckload that do the same thing, but since every student pilot kit comes with an old-fashioned one, most pilots just hang onto it.
'Gymnasium' is what they call 'high school' in some countries.
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i live in a time when there are things called computers running software packages like maple, mathematica, matlab, etc.
Fall 1973, CU Boulder: Engineering freshmen were required to learn to use a slide rule and most students still used them.
Fall 1974: Slide rules were gone.
Physics professor Al Bartlett scoffed at calculators and used to race calculator-wielding students with his slide rule and kick their butts.
I'm not sure about current training, but when I got my pilot certificate in 1999, *every* student had to learn to use an E6B circular slide rule to pass the written flight test. You can use a calculator or computer when you're flying, but to take and pass the written FAA test, you have to be able to run a mechanical slide rule.
By that measure, at least 100,000 Americans know how to use a slide rule.
Nostalgia's not what it used to be.
This is one of the reasons I bought this particular watch (Citizen C300). The rotating bezel is a slide rule, complete with set points for doing certain unit conversions (knots -> statute miles, liters -> gallons).
:-)
Take that you owners of 4-function calculator watches
Don Dugger
"Censeo Toto nos in Kansa esse decisse." - D. Gale
Maybe it's just my monitor, but the scales don't line up exactly. The B and C scales should be exactly the same.
BTW - my old high school Trig/Physics teacher had an accurate mental image of a slide rule in his head and could mentally manipulate the sliders. He could reliably do any calculation to slide rule accuracy in his head - including square and cube roots!
You were 80% angel, 10% demon. The rest was hard to explain. - Over The Rhine
"Math in a song is good."-Linford
I could NEVER remember how to use it!
So much more complicated than a fucking calculator.
But my Trig teacher INSISTED on slide rules becaUse of something about factors LOL.
I was like that is so old.
So I like failed Trig completely.
ALL SLIDE RULES ARE GOING TO HELL!
I'd rather have my TI-30 anyday!
How do people learn to use them so easily, anyway?
You never know how long the 21st Century is going to last.
I'm pretty sure I know how long it's going to last.
... no, I had to carry round a book of four figure tables everywhere.
The slide rule is the true Nerd's Spreadsheet
Since the sliding scale is not aligned properly with the fixed ones, it is a few percent shorter in my browsers here at work (Opera, Internet Explorer 6.0), it shows that 4x2=8.05. The slide should be extended another decade and there ought to be a means to move both slider and rule together so that one can view results greater than 10.
The US government have made it clear that we have no inalienable rights; any we do not defend vigorously will be taken.
I still have my EE dad's Kueffel&Esser and Pickett aluminum rules! Ever hear of a "nomograph"!?
Still have mine with the (synthetic) leather case and some of the box. picture
Get yourself a Curta calculator. I've got three... :-)
Or a Gilson Atlas - the only commercial slide rule with five digit accuracy (a sixty foot slide rule in a spiral). Got one of those as well...
No sig today...
I have about 25 or so slide rules, including a 4 ft. long one used for classroom instruction which hangs above my desk at home.
I used a 6in. magnesium slide rule until I got into college when it was broken by a classmate. Watching that moron step on my backpack and hearing the glass guide snap was like watching someone shoot a puppy.
I have a Pickett N 3P-ES on my desk at work. When people ask what it is I tell them it's the backup system in case the mainframe goes down.
Anyway, when everyone else was dealing with graphing calculators and believing whatever their HPs told them, I was visualizing the graphs and numerical relationships in my head. I had a much better head for numbers, approximations and telling if the answers I got passed the 'smell test'.
Knowing how to use a slide rule for an engineer or scientist is like knowing how to program in LISP if you are a programmer. You may never actually use it in your day to day work, but you will benefit from the knowledge and you will be a better professional for it.
Sig? What sig? Do I have to have a sig!?!?
Didn't use it all that much, though. I bought it 'cos it rocked.
I piss off bigots.
I carry a 6" Pickett slide rule in my pants pocket, and have 10" slide rules on my desks at home and work. They have a lot of advantages over calculators:
Precision is a nonissue, IMO; I'm a physicist, and I essentially never need to multiply or divide numbers with more than three sig figs of precision. As far as speed, the most time-consuming step of any numerical calculation is checking your answer in as many ways as you can think of; the actual operation of doing a multiplication or a division takes negligible time either device.
If I'm going to do a calculation, my preferred tools are a computer or a slide rule. An electronic calculator is essentially the worst possible way to do a numerical calculation, because it's so hard to detect mistakes. It's really, really easy to hit the wrong key, or transpose digits, and not notice it. Also, you're looking at your calculation through a keyhole on that tiny little screen, which means you can't see whether all the steps fit together properly. Even if your calculator allows you to scroll back and forth, you're still looking at it through a keyhole. Computer software is nice, because you can look at a whole screenful of data. On a slide rule, I write out the calculation on paper, estimate the answer, write it down, and then get a more precise answer on the slide rule; that way, it's almost certain that I'm not messing up.
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My freshman college math teacher used a Curta for routine calculations.
My entire 1974 tax return went into purchase of an HP 45. The slide rule didn't get much use after that, but I kept it around because it would work without batteries.
Oliver's law of assumed responsibility: If you're seen fixing it, you will be blamed for breaking it.
...well, a circular slide rule, that is...
Everybody in my high school advanced math class had to buy one back in the dark ages so we would get the school group rate. By all indications the pig in the "genuine pigskin carrier" wasn't optimally fresh and class was funky for a few days.
Mr. Chula used to always praise the virtues of the slide rule. The big advantage is that they force you to think about your input and output, rather than blindly accepting results. That helps you to catch errors like using the wrong decimal placement and getting value off by a factor or so. With calculators, if you make small input errors, you usually don't pick them up (I notice this when I'm paying bills).
I swear to God...I swear to God! That is NOT how you treat your human!
I have slide rules and use them today. For some tasks, they are easier and faster than a calculator. My K&E Analon rule also helps you to remember formulas and the Pickett is light weight and durable (even if it is an ugly green).
;)
Knowing how to use a rule also helps you realize if a calculator answer is right or wrong. Since so much of using a rule is in your head, sharing that with a calculator is beneficial.
Yes, I also have a pair of electronic rules -- HP-35 and HP-67 calculators. Oops. Just dated myself
Banjo - The more I know about Windoze, the more I love *nix
Funny enough, the first thing I bought via ebay was a nice Pickett slide rule, around my senior year in high school. It was a pretty good find - it had the original slide case, and even the manual. I didn't use it for actual work, though I did fiddle with it enough to figure out the basic operations. I recall I even managed to approximate pi to a couple decimal places with it.
:P
Needless to say, I didn't go on many dates in high school.
I read an article in the Toronto Globe and Mail about seven years back about this guy who runs a site - Slide Rule Universe - for getting slide rules of all ilk. He damn near makes a living off it. Who knew?
They're way too far into slide rules there. Gotta love 'em for it. I am not affiliated - just jealous.
http://www.sphere.bc.ca/test/sruniverse.html[17] Leary, T., White, C., Wood, P. R., Bhabha, W. D., and Wirth, N. Lambda calculus considered harmful. In Proceedings
I have one from a school auction. I thought of refurbishing it. Half the paint is gone, including lines, numbers.
Never trust a man wearing a coat and tie!
I'm fairly certain in saying I was the only kid in school who even knew what a slide-rule was -- outside of kids of engineers.
Ruby Neural Evolution of Augmenting Topologies
As a moderately young college math/computer teacher, I've never had a slide rule, but wish I had. I've looked for, and failed to find any way to get one. Where can you get one these days?
We know where leadership by an anti-intellectual "strongman" who scapegoats minorities and likes boisterous rallies goes
I just realised I haven't used a calculator in 10 years (i.e. ever since I started using a computer for work full-time), even though I have a very nice HP-42s sitting in the closet. The calculator app and spreadsheet on my computer are just more convenient. The UI of the calculator app still could stand improvement, though (e.g. I'd like to be able to select a number in any application, and then right-click and do unit conversions, or send it to the calculator faster than with copy/paste).
Do calculators still get used in the office (or basically anywhere except school)?
On the up side it did solve the problem of people with calculators that can do all the physics and calculus problems that are around today. Maybe it wasn't such a bad idea.
I was in college in the transitional years when sliderules were still used in class but electronic calculators were making inroads. I had my basic Pickett sliderule and could get reasonable results.
When I started my college career, the ultimate calculator was the HP35. All the engineering students that could afford it paid their four hundred dollars to get the calculator, which was somewhat on the bulky side.
About seven years later, you could get a credit card sized calculator that could do all the HP35 could do, plus basic statistics, all for forty dollars.
Damn that was funny - I missed that in the GP post
I keep seeing posts about how engineering so much better and more elegant under slide rules.
;-)
Not sure about that. It certainly took longer. And don't forget there *were* specialized mechanical calculators if engineers reallhy needed to pile on some significant digits. 10 digit precision was available way back at the end of the 19th century.
IMHO, waxing rhapsodic over slide rules is just silly nostalgia. If they were such ubergoodness, they wouldn't have fallen out of favor.
Some older engineers I have known tell me it took a month to design a low pass filter back in the 1950's.Today I can design a 250 tap digital filter in a day. And it'll be adaptive to changing signal conditions. *AND* if I wanted to another day will have it spitting out a live view of it's own response curve on a VGA signal you can hook up to any monitor.
Why not take it further? Some of the REAL feats of enginering (think pyramids & cathedrals) throughout history were done with no calculating devices at all other than someone's brain and a bunch of alges and plumb bobs.
You can have my HP RPN calculator when you pry it from my cold, dead hands.
I know how to use a circular aviation slide rule (both e6b style and completely circular jeppesen)
Way better in real world applications than electronic doodads. I'm not even an old fogey, but still prefer the slide rule. No batteries and doesn't crap out in extreme cold or humidity.
My Father bought me a nice circular slide rule when I entered High School (I an not saying when that was...).
Talk about total nerd-cool! You could carry through when chaining calculations without shuttling the slide. Now that rules! Unfortunately, I misplaced it about fifteen years ago. It was still in perfect condition. At least I still have my HP32S.....
I used to drive the math teacher in my grammar school crazy by using slide rule. At that time all other pupils had calculators. Heck, *I* had a calculator. I just loved showing off and driving my teacher. By the way, my calculator was beautiful piece made in Soviet union. Programable and with Reverse Polish Notation ;-)
Both of these web slide rules have the K scale, so the fact that they're missing the "turn slide upside down" isn't a huge loss, but it's still a limited imitation of the real thing. It's also missing the "sling the slide rule so the slide flies out at your fellow students" feature that was very popular in junior high..., though it does retain the "girls will think you're geeky" aspects.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I taught myself to use one in junior high back in the 70s, but I have no idea what I ever did with it. Wish I still had it.
(posting anonymously cuz I had to undo someone's stupid moderation.)
~treeves
How long would you have to stay down there?
Strangelove:
Well let's see now ah, searches within his lapel cobalt thorium G. notices circular slide rule in his gloved hand aa... nn... Radioactive halflife of uh,... hmm.. I would think that uh... possibly uh... one hundred years. On finishing his calculations, he pulls the slide rule roughly from his gloved hand, and returns it to within his jacket.
Muffley:
You mean, people could actually stay down there for a hundred years?
Strangelove:
It would not be difficult mein Fuhrer! Nuclear reactors could, heh... I'm sorry. Mr. President. Nuclear reactors could provide power almost indefinitely. Greenhouses could maintain plantlife. Animals could be bred and slaughtered. A quick survey would have to be made of all the available mine sites in the country. But I would guess... that ah, dwelling space for several hundred thousands of our people could easily be provided.
Slashdot: stuff for news, nerds that matter, matter for news, stuff that nerd
I must admit, I never really got logarithms until I learned to use a slide rule.
That stood me in good stead when I was learning to fly, because at that time the "standard" tool for calculating things like estimated time enroute was a circular slide rule called an E6B.
Well, we actually use cardboard slide rules at work all the time.
Most of all, the famous Trane Ductulator for sizing ductwork, with a rotating "slide" on an 8-1/2"x11" piece of cardboard that reads out friction loss, air velocities, and equivalent rectangular sizes for circular duct sizes and flow quantities of standard air.
We also use gas company-issued cardboard slide rule for sizing and calculating pressure drops of gas piping.
Significant digits in those cases can be less than two, e.g the difference between 12" dia and 14" dia duct (no one uses 13" dia) or the choice between 1-1/2" or 2" pipe.
I've seen electronic calculators with the required functions, and they're much clumsier than the cardboard slides.
Only recently, since I've developed macro functions in spreadsheets that can easily account for different materials (and if I ever need to finish extending it, different fluids), have I mostly quit using the cardboard calculators. And I really only use the spreadsheet because it means automatically having a record of the calculations.
I'll just go and try to find where I put my trusty British Thornton
Once I was a four stone apology. Now I am two separate gorillas.
I was given a Night hawk watch, (for aviators) with a circular slide rule bezel on it and an instruction book. I was so excited, I started playing with it until I discovered that they had stretched the scale around the low end so the characters would look nice and calculations were off by 2%. Totally unacceptable. I just hope the fuel calculations made by some aviators with it did not drop out of the sky. Alas it died on me about 1 1/2 weeks ago and I missed a flight from Minneapolis to Chicago. So there were at least 2 flight risks involved with having it.
P.S. when I was in engineering school you would see slide rules on the belts of ping pong playing students, 15 years later, I went back to school, the same ping pong table had students playing with scientific calculators hanging from thier belts. Some things never change.
...my grandpa just gave me the slide rule he used in school and it has a genuine "Made in Occupied Japan" sticker on the case. I can't remember the brand or model, but it's in a nice case and really is a beautiful thing. It is machined which is, according to the manual, much better than the painted ones. Just my two cents...
http://www.bynarystudio.com
Did you ever try to do 2 * 2 using 4-figure tables?
log10 2 = 0.3010
log10 2 = 0.3010
10 ** 0.6020 = 3.999
2 * 2 = 3.999. QED.
Je fume. Tu fumes. Nous fûmes!
in the mid-1970s, and discarded it with relief as soon as the TI-30 "slide-rule" scientfic calculator came out. For me, a "slipstick" was a PITA. Now, I just use Linux scientific calculator software and Excel for any complex or lengthy calculation I'm likely to have to repeat.
Tech Public Policy stuff
Smith's Charts http://cgi.www.telestrian.co.uk/cgi-bin/www.telestrian.co.uk/smiths.pl are still alive and kicking the world of RF engineering. I don't think there is a HAM (Amateur Radio operator) who doesn't know how to use a Smith's Chart.
My physics teacher in high school could do incredible math in his head because he'd used a slide rule so much that he had virtual one in his brain. It was pretty neat to seem him calculate square roots of random numbers in his head. That would be my reason for learning how to use one.
I'm a young'n, being in my mid 20s.
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.
I learned how to use a slide rule in tenth grade. My geometry class was one of those combined ones, where half the students have up to that point taken two years of math ("pre-algebra" and "elementary algebra"), and the other half have taken one year ("algebra 1") and learned roughly three times as much, so then the school district throws them all together for geometry, and the results are predictable: no C grades, lots of As and Bs on the one hand and Ds and Fs on the other. The latter category slow the course down to a real crawl, and since I was also taking Algebra II the same year (in order to get ahead so I could take the AP Calc as a senior), the Algebra II teacher had me in OHML (a competitive math team thing, semi-extracurricular). So in order to let me absorb the geometry faster, my geometry teacher halfway through the year agreed to let me study at my own pace and take the tests when I was ready. I finished the remaining two quarters in nine weeks, and after that he gave me other stuff to do. The slide rule was one of those things. Non-euclidean geometry was another, and at least as valuable. It was a great opportunity for me. The school district really should split that class in half and put the algebra 1 students into a geometry course that moves faster and covers more.
Cut that out, or I will ship you to Norilsk in a box.
I'm in my (late) 30's now. Back when I was a kid some "old" person was making fun of us youngones because we didn't know how to use a slide rule. I went to the closet, where we kept my great grandfather's slide rule (plus his portable transit and other things) I learned how to use it, but once calculators were common enough I didn't see the point that much.
"In fact, several people I know still prefer to use them."
Yeah, Amish those days.
only they were called a "proportion wheel" instead of a "circular slide rule." I used my "straight" slide rule in Physics and Math, then used it to help scale photos and set type in my design classes. Yep, before PageMaker and the LaserWriter, when you made bluelines and shot film of those to burn plates.
Everyone in my school had to learn to use a slide rule.
The main thing I notice about slide rules versus calculators, is that in many computations, the user is required to be aware of certain techniques, often involving logarithmic properties. And in many calculations, you see a *range* around a solution, not just a number popping up like on a calculator.
Slide rule users tend to have a natural ability to estimate the magnitude of a solution, and do not find sigfigs and scientific notation (with a single digit mantissa) to be an unusual idea.
One nonobvious consequence of electronic calculators has been to push the understanding of log properties from early grade school arithmetic, into at least middle school territory, and I know for a fact that many College Algebra students today have difficulty with logarithms. In the slide rule era, there was *no way* a student would get out of grade school math without naturally being very comfortable with logarithms, and how to relate multiplcation to the sum of logs.
-fb Everything not expressly forbidden is now mandatory.
Props to the creators of the virtual slide-rule, but I have a real one, thanks.
I'd lost the one that got me through elementary and high school. In college, one of my favorite physics profs thought that was unacceptable (even though by then we all had calculators), and gave me one of hers. Turned out to be the same model as the one I'd lost! I still use it on occasion, just so I don't forget how.
Yes, I'm old.
I own a few slide rules, and know how to use (most of the) scales on them. I keep one
of my favorites on my desk at work, and even use it occasionally. (If you care, it's
currently a late-model K&E 4081-3 LogLog Duplex DeciTrig, "like my Dad used to use",
although it is sometimes a Post 1461 Versalog. I own a plastic DeciLon and a beautiful
plastic Faber 2/83N and an aluminum Pickett or two and a few others, but I like the
classic laminated wood rules. Somehow they just FEEL like precision instruments.)
My work doesn't call for much on-the-fly number-crunching, and I find that my slide
rule that actually gets the most use is a Concise 28N, a little pocket-sized plastic
disk that hardly even looks like a slide rule. As a result, it's easieast to carry
with me everywhere, and easiest to hold in one hand and shift the inner disk with my
thumb. It's a snap to figure gas mileage, restaurant taxes and tips, or the cheapest
cereal or cat food or just about any bulk grocery items.
I own calculators too, a high-end model with more buttons than I understand, and even a
cheapie with just the basic functions. And they get used at the appropriate times. But
their UI is very ill-suited to the task of quickly evaluating bulk food prices while
pushing a shopping cart. My pilot friends tell me the same thing, that their onboard
computer is capable of computing airspeed, fuel consumption and lots of other things,
but that their round E6-B is their favorite tool for such calculations because it's far
easier to use with one hand while flying the plane with the other.
People talk about the importance of slide rules, tradition, math skills and the elusive
"feel" of numbers and their precision and magnitude. And they're right, these are all
important skills that I still wish were emphasized more in school. But it seems to me
that the thing that's overlooked the most is the importance of selecting the appropriate
tool. You wouldn't swat a fly with a bazooka, and you wouldn't use a slide rule to
balance your checkbook. But they're perfect for lots of calculations, and it really is
a shame that they have become so marginalized.
The right tool for the right job!
I have two, both acquired recently. I grew up with calculators (I'm 38), but I did have one as a kid. Never learned how to use it then.
A couple years ago I got curious and decided to learn about them. Got the same one I had before, then found the one company still making them and bought their top-of-the-line model. I do actually use them occasionally.
Slide rules are fun. They require some actual mathematical knowledge to use correctly. And you don't need seventeen digits of precision for most things. What better geek toy could you ask for?
Oh, wait... an abacus. I have one of those too. And I know how to use it.
Ob. plug for FOSS software. After having used Matlab in school, I just started using Octave. I was pleasantly surprised by how compatible the two are. In fact, the GNU Octave developers actively strive to make their updates follow updates to Matlab, so that the two can be as drop-in compatible as possible.
Nice for people who want a powerful but easy-to-use calculation package without going through the hassle of trying to buy Matlab --heck, to even find out what the actual price is on that web site, you have to log in!
Of course, a slide rule is also Free and Open Source. I remember finding the idea of a slide rule being very cool, and making my own out of two strips of cardboard by drawing marks according to logarithms.
404555974007725459910684486621289147856453481154 in hex is "You sank my Battleship?"
[GPG key in journal]
I had probably dozens of small, cheap sliderules when I was a kid. They were available for a few dollars in any drugstore. In the very early 70's, I bought a nice Post Versalog, which I expected to use for decades. I used it through high school and couple years of college, then I sold one of my guitars and bought an HP-35. I remember taking a mandatory "Engineering Computation" course my first year in college. The course had a fearsome reputation, but turned out to be pretty easy if you were already quick with a slide rule.
:-)
I still have the Versalog---it's outlasted the HP-35. Doesn't get a lot of use anymore, though.
I have concluded while trying to read this thread that posting a slid rule question on Slashdot is akin to throwing gasoline on a fire. You're going to get lots of flames and you won't be able to control it.
When I decided to go back to school in the 90s, I took my slide rules with me.
I didn't have a calculator and so I used the slide rule on tests and for homework.
I think that some of the profs had never even seen one before.
As a first-order approximation, perhaps. But to propagate an orbit you need to use differential equations. Have you ever tried doing the simplest Runge-Kutta algorithm on a slide rule?
Many mathematical advances were brought by people trying to invent easier methods to calculate orbits, for instance Gauss invented the least squares method to calculate an asteroid's orbit. Perhaps this is just a coincidence, but we didn't leave the Earth's atmosphere until after digital computers were invented.
While not exactally the same, it is the same group.. I remember back in early school years using a slide rule like device for finding guitar chords. I think it was from yamaha. Damned if i lost it over the years, never dreamed it would be come 'antique' in my life time and something to save. Now we have pocket chord finders and digital tuners.
---- Booth was a patriot ----
I don't know if it's good or not, but xcalc from I think X11R3 and earlier had a sliderule mode -- I built it once to take a look. It also had a regular calculator, so I could type in math problems on the calculator and watch this sliderule jerk around as it showed the result on it. It was fairly crude, I think using raw X line draw commands for everything but the numbers (which use some font.)
The index line on scale C is always put over the number to be multiplied on scale D. The answer is then read off scale D, below the multiplying, number on scale C, using the cursor line for ease and accuracy e.g. set the 1 on scale C over the 2 on scale D (note: this is not the first 2 you can see as this is actually representing 1.2, it's the larger 2). You can now read off 4, 6, 8, 10 etc. on scale D under the figures 2, 3, 4, 5 etc. on scale C (Use the cursor line to find the answer). Then if you slide the 10 on scale C over 2 on scale D you can read multiplication answers of 2 x 5, 6, 7, 8 & 9 beneath each number, so completing the scale (Use the left or right hand index,depending on the numbers to be multiplied)
I'm old enough to be one of those who was in college before the advent of hand held calculators, when all science/engineering students were intimately familiar with their slide rules.
9/11 Eyewitnesses to Explosive WTC Demolition 1 of 2
I'd never bothered to learn a slide rule before, but playing with the online emulations, it is obviously much faster to use than digital calculators for most purposes.
Here's the key question: how would a girl react if on a date the guy pulls out a slide rule to figure the tip? It's probably a given that the typical girl would either wallow in humiliation or label you a freak at that point, but what about a geek girl?
I used a slide rule in my Celestial Mechanics class. We were calculating some orbit to the moon (yes, orbit, since we were going to the altitude of the moon, not the actual moon... two-bodies, y'understand) but I digress. I got an A, but The Professor called me into his office.
:'( It's not often that an orbit is the co-star of a plotline.
"You did the equations correctly, but your answer was not correct. You had 60.42 (or something) and the answer was 60.4235. Why is that?"
"Well, I can only see about 4 digits on my slide rule." I produced my 12" Yellow Pickett.
"You used a slide rule?" This was the guy who used a slide-rule and non-diimensional equations to tell the Apollo 11 Tiger Team where The Eagle had landed, as they forgot to account for the thrust of the docking spring, sheesh.
He reached into his desk and produced the exact same slide rule. Needless to say we formed a camaraderie from then on.
He has recently passed away, and will not be able to see the flights of fancy he inspired in my fictional writing.
May all your mechanics be celestial, Professor Harm.
Did a college paper on accounting machinery once and that was a factoid from my research. Also did a research paper on the slide rule in high school back when we were waiting for simeone to invent the pocket calculator.
Too lazy to create a sig...
As good a scifi writer Asimov was, he never could predict shit.
Of course, in his "future" people didn't have computers, let alone pocket calculators. Instead, they had the slide rule of the future: the analytical rule!
I realize this isn't a vote--that has already taken place YEARS ago. I just wanted to jump on the bandwagon of people who realize that slide rules suck.
http://widgets.yahoo.com/gallery/view.php?widget=40705
How do people learn to use them so easily, anyway?
Like this. When I was at high school, the use of slide-rules wasn't actively discouraged, and electronic calculators were not permitted (and in any case were still prohibitively expensive). We were expected to be able to use books of tables. Not much fun, and that in itself was motivation to learn how to use a slide-rule.
It's still worth knowing. In my first year at Uni, the batteries in my HP48G+ died in the middle of an exam, but I was able to get by with my K&E Log-Log Decitrig slide-rule.
We learned to use slide rules and were required to use them in high school physics (which I took as a junior). Or, it might have been in chemistry which I took as a sophmore. In the physics class, we also had a four-banger calculator at the front of the room that we could use, until someone dropped it. It was large with plasma-segment digits for the display (the big, glowing, orange ones).
We understood well what two- and three-digit precision was. Slide rules also made it pretty easy to understand logarithms. I still think about a slide rule scale when estimating the log of a number from 1 to 10.
My slide rule was a relatively cheap Sterling model, but I was a high school student after all.
When I was a senior, I was given a TI SR-51 calculator as my first calculator. Of course the SR meant ``slide rule.'' It had all of the functions found on a slide-rule and also did hyperbolic trig functions.
The next year, when I was a freshman at Ga Tech, there were still people on campus with slide rules on their belts. Of course, we carried our calculators on our belts, too. The cases had a loop for that purpose.
My roommate, who was an older PhD student, used a slide rule throughout my time at Tech, even in the late 70s. I don't think he actually had a calculator, but I don't remember for sure.
P.S. The SR-51 died before it was two years old and I bought an HP-25 and then upgraded to an HP-25C soon thereafter.
Unless you burn at the same time all books and kill all people with any basic scientific knowledge, your scenario is a pointless exercise best suited for a bad SciFi book or movie.
IANAL but write like a drunk one.
... I think most people would prefer to die quickly and painlessly.
The person that is ignorant is the one that can't live in the society where he was born, somebody accumulating useless knowledge is not any better for doing this, as you clearly are implying.
IANAL but write like a drunk one.
There is this thing called progress which makes life easier.
IANAL but write like a drunk one.
When I was a high school math teacher in the mid 1970s one classroom had one of those monster slide rules above the chalk board. On the first day of class students would ask: "What is that?" to which I'd reply: "It is a manual calculator? Do you want to race?".
:-)
I'd write a messy looking problem on the board that was ideally suited for a slide rule: multiplication and division with four significant digits and no addition. Anyone who has used a slide rule knows that such a problem is not fair competition -- heavily loaded in my favor.
I'd have an answer before the students would be halfway through entering their numbers, and the majority of them would make an input error.
The slide rule is an analog computer. It's probably the best example of an analog computer to show a student curious about analog computers. A slide rule teaches a lot about the nature of calculation, not merely providing the result of the calculation. I have several slide rules, and I still use my Pickett Log Log computer, even though command line Perl or Python would probably be faster in most cases for the kinds of calculations I do at work. Why then do I reach for the slide rule? I like the kinesthetic experience of moving the slide and the cursor, thinking through the result. I also have a Keuffel & Esser compensating polar planimeter. The tracer arm traces around a planar figure, and the cylindrical slide rule mechanism in the base calculates the area of the planar figure. As a math graduate student, I read Felix Klein's remarkable book Elementary Mathematics From An Advanced Standpoint, and there was an essay on how the polar planimeter worked. By measuring a linear measure (dimension one), the planimeter is able to calculate area measure (dimension two). At first glance, it doesn't make any sense. How can the planimeter take one dimensional data as input and render two dimensional data as an output? The answer involves Green's Theorem from calculus. It's subtle and elegant and mind-blowing. Engineers before the digital computer was invented would use the planimeter for numerical integrals, after graphing the function to be integrated at the same scale as the planimeter. Cartographers still use planimeters in map-making for calculating areas of countries. Modern planimeters have a computer in the base, rather than a cylindrical slide rule, but the principle is the same.
People have been smart for much longer than I've been alive. Sometimes it's nice to see examples of the way smart people thought who did not have access to the same tools I have at my disposal. There's something worthwhile about looking at a problem that way. I'll prototype Perl programs in AWK, because if it works in AWK, I know I haven't overPerlified the program. Doing a problem with old tools sometimes shows that you have a deeper understanding of the solution.
"Indeed, it is wise never to consider any form of electronic data as final." --Arnold Robbins
For those interested in playing around with a slide rule, the book An easy introduction to the slide rule by Isaac Asimov (1965) could be very helpful.
Here is a (modern) review of the book; here is a list of second-hand copies.