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The Sliderule As Paleo-Geek Artifact

timothy posted more than 13 years ago | from the didn't-have-fingers-we-were-too-poor dept.

News 170

hwestiii writes: "Geek identification methods have waxed and waned over the years. Back in the years when it was still not cool to be a geek, they were identified by their pocket protectors and calculators hanging from their belts. And way back in the mists of time, before most of the Slashdot crowd were even an item on their parent's life-project-plan, they were identified by possession of ... slide rules. I'm clearly dating myself by submitting this, but I owned and used slide rules as a teen, just as microelectronics was making cheap calculators possible. Nando times has an interesting link to a community of people around the country trying to keep the memory and spirit of the slide rule alive. Some may be wistful, some may think 'What the hell...?' Take a look." A quick look at Google's image search yielded some cool photos of both slide rules and the classic HP-35 calculator -- I wonder where the HP-35 my dad used to use has gotten to. Does anyone still use slide rules on a regular basis?

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Curta anyone ? (1)

Anonymous Coward | more than 13 years ago | (#102046)

My mother was an accountant. She used a Curta (mecanical Handheld calculator).

I still have it, functional, of course. It is an amazing machine.

History of the curta [] , and a picture of the : model I []



/. will put anything up nowadays, won't they? (1)

Anonymous Coward | more than 13 years ago | (#102047)

How the hell can slide rules be considered news?

Just plain sad. (5)

mosch (204) | more than 13 years ago | (#102050)

A frightening quote from the article:

If California's energy crisis turns computers into pricey paperweights and makes AA batteries as scarce as vacuum tubes, Tom Wyman will still be able to perform vital calculations such as finding the square root of 144 or figuring the value of 2 to the power of 10.

Are American's today really so uneducated that they can't find the square root of 144, or the value of 2^10 without using a calculator?

Apparently the author thinks these are otherwise unsolveable mathematical mysteries... I sincerely hope he's not representative of the average man.


Re:Slide rules used everyday... (2)

ptomblin (1378) | more than 13 years ago | (#102053)

Except most private pilots now-a-days buy a hand held GPS and never use an E6B except during checkrides.


The sliderule site (1)

SiliconJesus (1407) | more than 13 years ago | (#102054)

As mentioned, he has a site with sliderules on it. They didn't reference the site's address, but here it is. [] .

Secret windows code

my first encounter (2)

Imabug (2259) | more than 13 years ago | (#102055)

My first encounter with a slide rule was after a high school math exam (back in 1987). I finished the exam, and walked back to hand it in to my teacher and saw him using one to calculate percentages with one. Intrigued, I asked him about it and he showed me how it worked based on logarithms. I thought it was really cool and asked him where I could get one. He reached into one of his desk drawers, which was full of them, pulled one out and gave it to me. Thrilled, my next stop was to the library to find any books I could get my hands on about how to use one. Taught myself the basics of using a slide rule. I was even using it to do some of my physics homework when I got into university. I hadn't gotten very fast at it, but i could get the right answers. Then I got myself an HP-28S, and the slide rule now sits on my shelf with my collection of artifacts. I still pull it out now and then to play with it and show it to the occasional person that asks about it.

mondo sliderule (1)

jbgreer (4245) | more than 13 years ago | (#102057)

I have a friend who teaches in a local high school. This year one of the math teachers decided to throw out a lot of the older math teaching aids, including a 7 foot slide rule! When my friend heard about it, he immediately thought of me. I've now got my mondo slide rule propped against an upstairs wall, waiting for those really big problems to roll in...

Teaching how to use a sliderule (1)

Basset (6083) | more than 13 years ago | (#102058)

I remember back in college (circa 1991) going into an engineering professor's office and seeing a gigantic wooden sliderule about 5 feet in length. Apparently, the engineering fundamentals program spent the first few weeks using such props to instruct engineers-to-be on the finer points of how to use a sliderule. Now they just teach them how to use a high level language like Matlab, tell them to forget common sense, and always believe the answer that the computer gives them.

Sliderules should be used as part of an engineering appreciation course along with hand calculations and calculators that cost $500.

Re:Just plain sad. (1)

david614 (10051) | more than 13 years ago | (#102061)

>Apparently the author thinks these are unsolveable mathematical mysteries...I sincerely hope he's not representative of the average man.

I hope so too, but I fear he may be....


Re:Java Slide Rule on the web (2)

afniv (10789) | more than 13 years ago | (#102062)

The link: html

n76lima had a space in the link.

"Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"

Re:Java Slide Rule on the web (2)

afniv (10789) | more than 13 years ago | (#102063)

WTH? html []

Oops, and then I added a spaceThere were more spaces than I thought. ;)

"Man könnte froh sein, wenn die Luft so rein wäre wie das Bier"

Oh my god.. (2)

dr_labrat (15478) | more than 13 years ago | (#102064)

"users still had to figure out where the decimal point should go. (Multiply 4 by 5 on a slide rule and the answer is 2, not 20.)"

This would cause problems with some people I know that use calculators to multiply and divide by 10..

What do you mean? (4)

wirefarm (18470) | more than 13 years ago | (#102071)

I can't be the *only* one posting to slashdot from a Kueffel & Esser Duplex 4080-3 rule, can I?


MMDC Mobile Media []

Re:Pilots use them all the time (1)

Luxury P. Yacht (18865) | more than 13 years ago | (#102073)

Good ol' Jeppesen E6B flight computers [] . I've got one that's about 15 years old. Tough as nails and works well too. Actually, I'd be surprised if most airline pilots didn't carry these for backup.

Price analysis of Slide Rules (1)

Therin (22398) | more than 13 years ago | (#102074)

Check out this page [] where there's a detailed analysis of slide rule prices (top quartile, bottom quartile, median) on eBay .

The table is based on rules sold on ebay from December 1999 to June 2000 inclusive.

Re:Slide rules still in use (1)

FeriteCore (25122) | more than 13 years ago | (#102075)

I do the same with my full-featured K-E log-log deci-trig etc. slide rule at the office. Some problems are perfect slide rule problems, this is one of them. Anything involving similar ratios where 2-3 digit precision is fine. Set the rule once and read off the height of the graphic for any column width.

It also elicits wonderful looks from my coworkers.

Re:Sliderules (1)

axler (25402) | more than 13 years ago | (#102076)

In a lot of k-12 schools calculators are bought for *every* student starting out in kindergarden. This boggles my mind for the same reason you point out; You should be able to know about where the answer should be. Using/depending on calculators hinders this process, you rely more on the output of the LCD, then your own brain...

HP48GX user, and damn proud....

Pilots use them all the time (2)

mav[LAG] (31387) | more than 13 years ago | (#102079)

Not airline pilots (someone please correct me if this is true for anything other than Air Zambia) but I know a number of private pilots - both powered and glider - that use them. No batteries, no hard-to-read displays, gives the right answer nice and quickly too :)

A sliderule helped me get named Sexiest Geek Alive (5)

Ellen Spertus (31819) | more than 13 years ago | (#102080)

It was an integral part of my costume, second only to the printed circuit board motif. See [] or go straight to the picture [] and explanation [] .

Re:Slide rules used everyday... (2)

edremy (36408) | more than 13 years ago | (#102082)

Except most private pilots now-a-days buy a hand held GPS and never use an E6B except during checkrides.

Their loss. I'll put money that I can outrun them on a standard E6B for working time/speed/distance. Just dial in your ground speed and read off the time between checkpoint after checkpoint.

Then again, I was annoyed when my examiner made me turn off the VOR receiver for all of my cross country. Hey- he's the one that gave me a route between two VORs. Everyone has the equipment they get used to...


Re: The Sliderule As Paleo-Geek Artifact (1)

The Silicon Sorceror (40289) | more than 13 years ago | (#102083)

I had an experience last semester at my high school where a sliderule really was a paleo-geek artifact. While replacing a row of old lockers, the janitors at our school (HHSS, Ontario) found an old slide rule underneath! It had slid under a locker sometime in the last fifty years or so. Our OAC calculus teacher (OAC is Grade 13, for you crazy Yankees) acquired the rule from the janitors who found it and brought it in to class. Everyone oohed and aahed over it, and the next day one of my friends brought in his dad's old slide rule with a sheet of instructions. I learned how to operate the excavated slide rule and did a whole class with it.

Showing my age: missed pocket calculators altogeth (2)

td (46763) | more than 13 years ago | (#102089)

I was an undergraduate in 1974, and pocket calculators were still controversial -- professors railed against allowing them to be used on exams, etc. -- so kept using my slide rule (it's on a shelf not 10 feet from where I sit, covered in dust.) That year, I got my first account on a UNIX box, which came with dc and bc, and I've never since been tempted to buy a pocket calculator.

Re:One problem ... (2)

jlcooke (50413) | more than 13 years ago | (#102090)

Incorrect. There are various rules on a SR. Two linier rules make for addition. One linier and one geometric make multiplication and division. One linier and one expoential... make a guess.

One Linier and one ossolating (sp?) rule make sin/cos/csc/sec and tan/atan with a bit of work.

At the request to my parents for a birthday present, they had to goto a mesuem gift store's deep storage to get me one.

I didn't know how to speeel engineer, and now I are one.


Quick Draw Slide Rules (1)

Foos (52086) | more than 13 years ago | (#102092)

My math teacher in high school (the best high school teacher that I had) used to tell us about how he and his friends used to carry their slide rules around in holsters. When someone had a math problem, they would would whip out their slide rules from their side holsters and see who could do the computation the fastest!

Geek? (1)

Old Wolf (56093) | more than 13 years ago | (#102093)

It's now cool to be a geek?

Re:Just plain sad. (5)

Old Wolf (56093) | more than 13 years ago | (#102094)

Are "American's" today really so uneducated that they can't use an apostrophe correctly?

Still usefull at Engineering school ! (1)

HiH (61053) | more than 13 years ago | (#102095)

Last semester, I attended a course of Electronic. It was really interesting although the teacher was kind of crazzy. During the exams, calculators were forbidden but slide rules were allowed.

It's sad I could not find one, anywhere..

Re:Pilots use them all the time (2)

sconeu (64226) | more than 13 years ago | (#102096)

I always thought that nuke yield data was classified?

Still have one... (3)

sconeu (64226) | more than 13 years ago | (#102097)

I still have my KK log-log duplex. I need a new index though. The glass cracked.

Re:One problem ... (1)

kvigor (66615) | more than 13 years ago | (#102099)

Of course slide rules can add. Everything they do is addition (*); it just happens that if you do addition using a log scale, the net result is multiplication.

If you use a linear scale (which any decent slide rule had), addition is... addition.

(*) or simple table lookup; typically you'd have a few trig tables to play with as well.

Re:Sliderules (1)

rtaylor (70602) | more than 13 years ago | (#102100)

I see, so you prefer to argue accuracy over precision? I can see your point, but it was never assummed that the values of x.xx and y.yy were measurements or approximations due to measuring. Taken as exact values (as implied by not stating the source or other information), x.xx by y.yy will result in zz.zzzz.

The difference between men and fools (1)

rbrander (73222) | more than 13 years ago | (#102101) the price of their tools.

The Romance of the Slide Rule is very much alive today, the love affair is just transferred to the modern version of the tool.

Slashdotters and Tom's Hardware afficionados who explore every capacity and foible of their machines are following the same urge as slipstick experts who practiced use of the LL/0 scale (which did an e^(-x) operation in one move) just so they were prepared should it come up one day.

I must be almost the same age as "timothy" who started this article - it was slide rules for us up to about grade 12, when the richer kids were all getting calculators that did more than 4 functions...then in University, calculators were suddenly essential (but I carried the Rule to exams in case of battery failure).

What I remember is that most geeky kids were old enough to *learn* to use a slide rule at the start of their teens...right around the time you get coordinated & generally grown-up enough to be allowed to touch precision tools. And slide rules, with their fine machinining, high cost, and smooth movement (metal sucked; bamboo rules...mine still work perfectly after 25 years in the drawer) were clearly *TOOLS*, not toys.

A slide rule was a grown-up possession, a minor Rite of Passage.

I don't think slide rules will ever be forgotten as long as dad's, grandad's and great-granddad's get found in attics. But what worries me is my Dad also taught me dozens of MENTAL calculation tricks that nobody needs any more.

The easiest one was squaring number that ends in five. Chop off the five. Multiply the rest by one greater than itself; tack 25 on the end. (i.e. 35 squared: 3*4=12, the answer is 1225.) The hardest was memorizing ten anti-logs to three places; you can do remarkable estimation-level calcs with that one. (I've long forgotten them.)

Anybody ever done a web page of those tricks?

Me and my Pickett (2)

Mr. Protocol (73424) | more than 13 years ago | (#102103)

My dad is a civil engineer, and used a slide rule daily in his design work. Therefore he made sure that I had a good one. He had other, much more exotic tools too, such as a polar planimeter. This is a wondrous device that lives in a felt-lined case. You put it together, set it on a drawing, and run a little wheel around a closed figure. From a dial, you read off the area of the figure. It's a mechanical integrator. It's gorgeous. He sold it when he retired. OW!

But I still have my Pickett. It's true that in order to use it, you have to place the decimal point yourself. In scientific calculations this isn't usually too hard, because you start with numbers between one and ten, and figure the exponents separately. The downside is that answers are inexact. You're lucky to be able to carry three significant figures, and you can't even do that if there are more than two or three steps in your calculation. Really, really serious people used very large slide rules with temperature compensation scales (!!!).

The family company had those brute electromechanical calculators with ten-by-ten fields of buttons. Every ten years or so they'd replace the current ones, so when I hit college, I got one of those as a hand-me-down. It must have been almost solid steel, and weighed about forty pounds. I never looked back. Finally I had something that wouldn't reduce a calculation to mush by the fifth step.

Re:Sliderules (1)

Gladiator (77646) | more than 13 years ago | (#102104)

Maybe your calculator's no good. If I for example do 4.44 * 6.66, I get exactly 29.5704 as a result. Seems to be the right answer as far as I can tell.

I have a NUCLEAR BLAST EFFECTS slide rule/b (2)

mesocyclone (80188) | more than 13 years ago | (#102107)

Among the stranger items in my collection is a circular slide rule used to calculate nuclear blast effects. You can calculate crater size, overpressure, distance to second degree burns, instantaneous radiation, broken glass missile velocity, and all sorts of other hideous stuff with this little gadget. It comes in a pocket in the back of "The Effects of Nuclear Weapons" 1964 - US DOD/AEC.

My mother was a 9th grade math teacher, and had a giant Pickett slide rule as a classroom aid. I don't know if we kept it after she died, but it was about 3 feet wide and 6 or 8 feet long.

As a geek of the '60s, I had a full size Pickett, but my favorite "pocket protector" item was a nice little pocket slide rule. I remember engineering and physics courses where the early review was how to keep track of magnitudes and precision while doing slide rule calculations.

I found Dad's slide rule in the attic... (3)

Greyfox (87712) | more than 13 years ago | (#102109)

As a teen I found Dad's slide rule in the attic. By this time they'd mostly been replaced by calculators, but the manual that came with it was enough to figure it out and it really was a pretty simple solution for what it did.

A while back the Navy stopped teaching older navigation styles, I gather because GPS is so much easier to use. And easier to jam. Sometimes progress is not a good thing and can actually do us harm.

I think teaching at least the basics of these older methods of computation would be a good thing. We should preserve at least the knowledge that they're possible and a basic understanding of how they worked. It could be handy, for instance, to know how to find North using just an analog watch and the sun. Or a digital watch. Would have made The Blair Witch Project a much shorter movie though. "Ok, that's north, so the road is that way! Let's go!"

My experience with slide rules (2)

blakestah (91866) | more than 13 years ago | (#102111)

My Dad, sensing the geek in me, taught me how to use a slide rule when I was a wee lad. At the time calculators were around, but were expensive and used batteries fast on their red screens. The LCD calculators came around about 10 years later, and made batteries last a long long time.

I still have that slide rule though, and I can still use it. But DrGenius is generally faster and closer to hand.

The real tool (1)

cadfael (103180) | more than 13 years ago | (#102117)

I keep a slide rule on my desk to remind myself that the computer is nice, but its just a tool. To run a computer, usually you need some arcane kind of information to get it to do what you need (ie, most people could run a computer, but far fewer program them).

For both the computer and the slide rule, the real power behind them is the mind of the user. Sorry to those of you who realize what I am saying about most computer users out there...

-- The Hollow Man

Same with the abacus (1)

Li0n (110271) | more than 13 years ago | (#102118)

Skilled people with the abacus(sp?) can outperform calculators.


Circular slide rule... (1)

Robber Baron (112304) | more than 13 years ago | (#102120)

Somewhere buried away I have a circular slide rule. Pretty neat design actually: concentric freewheeling disks and a transparent pointer so you don't lose your place. The pieces all stay together nicely, rather than having a slider shoot off one end or the other and get lost.

Re:Not so difficult to grasp (1)

Robber Baron (112304) | more than 13 years ago | (#102121)

Once, I asked one of my instructors about their policy regarding programmable calculators and exams. He said if one understands a concept well enough to program it into a calculator, then one's grasp of that concept is such that the presence or absence of a programmable calculator isn't going to make a great deal of difference. I thought that was a cool attitude.

Sliderule - check. HP-35 - check (2)

meckardt (113120) | more than 13 years ago | (#102122)

Yup, I still have the simple slide rule I had for freshman year back in Engineering school. Also have my dad's HP-35 up in storage, although it needs a battery.

Hi everybody. My name is Mike, and I'm a geek.

Re:I have a NUCLEAR BLAST EFFECTS slide rule/b (2)

Artagel (114272) | more than 13 years ago | (#102123)

Actually, there is a story at the University of Chicago about Enrico Fermi that more or less is along those lines.

During test blasts during the Manhattan Project the engineers would set up all sorts of equipment to measure the shock waves in the ground to estimate the energy in the blast of the atomic bomb.

During one blast, Fermi tore a piece of paper into small squares and dropped them on the floor of his bunker. During the blast, he looked at how far/fast the pieces of paper traveled. Then, knowing the distance of the bunker from the blast, and God knows what else was in his head, he used his 6" slide rule and calculated a result that was within 10% of what the monitoring equipment and involved calculations revealed some time later.

The lesson of this was supposedly, the bigger the mind, the smaller the slide rule.

Re:Sliderules (1)

snarkh (118018) | more than 13 years ago | (#102124)

On a calculator doing x.xx * y.yy will display as many digits as will fill the screen. It dosen't mean that any of those digits after 2 decimal places are significant....

What are you talking about? You will get four significant digits after the decimal point on a calculator as you very well should. It is amusing that people rant about other people being ignorant only to demonstrate their own ignorance.

From The Article (2)

MyopicProwls (122482) | more than 13 years ago | (#102129)

Tom Wyman will still be able to perform vital calculations such as finding the square root of 144 or figuring the value of 2 to the power of 10.

Um... I don't think any good geek needs help finding the square root of 144 or the value of 2-to-the-10.


Re:Pilots use them all the time (1)

NecrosisLabs (125672) | more than 13 years ago | (#102131)

Oh yeah! I remember finding one of those nuke slide rules in one of my Dad's (a Civil Engineer) books (on building for nuclear attack.) You'd dial up yield and airburst altitude, and it would return minimum survivable distances for different construction materials. After playing with that for a few minutes, I realized how futile all of those "duck and cover" drills were.

Re:Pilots use them all the time (1)

Bad_CRC (137146) | more than 13 years ago | (#102133)

heh. I forgot about that, and I own one of those too.

kind of a funky metal sliderule thing with a big wheel on it.

I'd say most people who would need to use one more than a few times probably use the electronic version though.


Re:Just plain sad. (1)

Bad_CRC (137146) | more than 13 years ago | (#102134)

If California's energy crisis turns computers into pricey paperweights and makes AA batteries as scarce as vacuum tubes, Tom Wyman will still be able to perform vital calculations such as finding the square root of 144 or figuring the value of 2 to the power of 10.

The truly sad part is that none of these so-called geeks even considered using solar cells instead of AC or batteries in the event of a power outage.

If your thinking is that confined inside "the box" then knowing a few basic mathematical formulas isn't going to be very useful in any practical sense.


Re:Sliderules (5)

starseeker (141897) | more than 13 years ago | (#102135)

This is an indication of a much larger problem we have with eduction in America. We are taught to USE things, not to UNDERSTAND things. In my NOT so humble opinion computers have no place in education before graduate school, unless they are taught as a subject in and of themselves, not as a substitute for thinking. In this I count TI and HP calculators as computers, how be it small and not really general purpose computers.

I am of this opinion for the simple reason that I have fallen into that trap. I did not have any experience of any note with computers before college, except for one programming class in high school where we used rather pathetic machines at school to work. We had no computer at home except a dedicated purpose word processor. My calculator was not capable of symbolic integration or any of the other nifty tricks that the 89 and 92 are capable of. EVEN SO, the calculator could do logs, roots, and other things that I still have no good intutitive feel for. We need to be less concerned with speed in our teaching and mroe concerned with quality. Basic principles and techniques that have been really learned, not just memorized for a test and forgotten, will be of far more use than quickly picking up a broad survey of concepts.

Students, most of them, don't really want to work hard. It's just not fun. That's where teachers and yes PARENTS need to impose a little disicipline. Not too much, because then it is only the threat of the whip which drives the kid and as soon as the whip is gone (college) the effort goes too. But external disicipline is extremely important in the early years. Just be sure that real learning takes place, and real benefits occur. And show the kid what these benefits are. Don't just say "It'll be of use to you in the future." That's fine for you, but a young kid has no concept of his future. He doesn't see the impact of the past on his present, because he hasn't had enought experience to note cause and effect in his own personal life. Show him/her what they've learned, be excited about it, and if they ask what good it is TELL them. Explain to them about the importance of understanding what's going on around you. Explain to them what science, engineering, and other mathematical endevours mean to their future. Don't assume they won't understand. Just be patient, don't underestimate them, and don't overestimate them. Encourage questions. Never belittle a child or scold him for asking a quetion again and again - if he/she really doesn't understand, you WANT them to keep asking rather than surrender to ignorance.

There is a stigma in American society that if you don't advance a grade each year, you are stupid and behind. Behind in what way? I'd say if you falsly promote a student up a grade they'll be behind all their life, not just a year. Yes, social pressures can be cruel. I've lived through being the oddball and nerdy one all my life, and been shunned and made fun of. But you at least learn when to listen to people and when not to. A useful trick, when you deal with hostile people out in the real world.

Actually, I dislike the use of the phrase "the real world" when applied to the world outside school. For a child, the school world can be horribly real. They are trapped there. All too often, real work ethic is ridiculed, and they get mixed messages from all sides. Parents are essential to provide a clear signal, but even they can do nothing when a student is on the playground being shunned.

I am becoming a huge supporter of home schooling. Have activities where childern interact with each other, but keep learning between the parent and child. Both people involved are thus committed to what needs to be done, and the child can work at his/her pace, whether or not that is faster or slower than average. Also, the parent can then make sure that real understanding and absorption are taking placce, not just memorizing.

And also at home, you can keep them free of electronic aids. I have no problem with computers being TAUGHT in education, but I have a big problem with them being USED in education. If schools want to teach computers, they should teach what makes them work, the history of computers, programming languages, and other basics. If they want to teach how to use computers, I have to pieces of advice. Do not teach any math, spelling or other "educational tool" software until college at the earliest, and do not teach just one system. Teach them to be flexible computer users. Explain how a computer virus works, why they need to worry about them, and how to think about security. Teach them the difference between OS and application, and introduce them to all kinds of both. Hard, you'd better believe it. But very much worthwhile.

I would dearly love to see slide rules come back as a tool in teaching. An intuitive understanding of the world is where fundamental breakthroughs come from. It's also a great source of pride and confidence. Slide rules help build intuition, because the user is involved with the process of solveing. A calculator has none of that.

It is probably too late for me - I doubt I will ever develop the intuitive grasp of the world that the great scientists of old had. Indeed, I seriously doubt most people who have let machines do any significant part of their thinking will. Has anyone noticed how large the precentage of foreign nationals is in our highest education setting, graduate school? So few Americans are there. We just don't have the interest, or the intuition, or the training to want to do it. We pride ourselves on being advanced, but the people responsible for so many of those advances used so many simple tools to learn, REALLY learn, the basics. No computers, no calculators. Pencil and paper, and maybe a slide rule. Basics students don't need more than three sig figs - they are learning BASICS.

Pardon the rant. But this is a serious problem. I think home schooling may become more and more the way to really teach students. Make learning a life long excitement, not something to finish and then do something else. We push too hard, too fast. We burn out. I know what that is too. We need to question both our means, and our ends. I pray that someday we will.

I've always wondered (1)

cosmol (143886) | more than 13 years ago | (#102136)

How do you transmit morse code by banging a pipe? Dit's and Dah's are distinguished from each other by the length of the pulse right? By banging on something you can only affect the time between pulses, not the length.

Everyone talking about "Dad's" slide rule. . . (2)

kfg (145172) | more than 13 years ago | (#102137)

makes me feel old. My daughter just turned 21, my slide rules are older than her.

I've got two Picketts. Same as used on Apollo 13. One to go in my pocket protector, on massive job in a holster to hang from my belt. The leather holster is worth more than most calculators these days. Slide rules were serious business back in the old days.

The Picketts are aluminum, but that was a considered a " new high tech" idea. Before that *Bamboo* was the considered the best material to make slide rules from. Used to have a bamboo K&E, and a circular Teledyne, but somebody with taste and no morals stole them.


Never (1)

PingXao (153057) | more than 13 years ago | (#102138)

I'll date myself, too. What the hell. I started college about 2 years after electronic calculators became staples. If I had to use a slide rule, it's very possible I would have chosen another profession altogether. The modern calculator heavily influenced my decision to attend an engineering school. I never had a shirt pocket protector. Well, I wore on to a Halloween party once. And I *never* hung my calculator case on my belt, although there certainly was a loop to do that for those so inclined. Back then being a geek wasn't too bad but you had to avoid the label "nerd" at all costs!

When one of my uncles learned where I was going to college, he was proud to give me a couple of slide-rules as a gift. I didn't have the heart to explain the paradigm shift to him, so I graciously accepted them and put them on a shelf in the basement. I never used them. My first trip to the campus bookstore was an eye-opener. Formerly very expensive slide-rules that had sold for hundreds of dollars only a year before were discounted to $15.

Maybe the manufacturers should have sued TI and HP for denying them their revenue stream. Tsk, tsk, if only they had been prescient enough to patent numbers.

I used to use those... (2)

Saint Aardvark (159009) | more than 13 years ago | (#102139)

I'm only 29, but I've used them before. Read on, and hear a tale of wonder and woe...

When I was growing up, I had a set of encyclopedias that had been my mom's when she was growing up. It was called Our Wonderful World, and was published in 1953 or so. (If anyone knows where to get a set, leave a note -- my parents sold them...grr.) It was a great set of books, but the technology was pretty out of date. Between that and the old, old selection of books on science in the libraries of the towns I grew up in, I was forever frustrated that I couldn't find a Foobly67 vacuum tube to build a radio with.

One of the things I read about was how to use a slide rule; that and all the slipstick references (paging Dr. Freud!) in Heinlein made me lust after one. But where the hell to get them?

I ended making my own. Of course, I didn't know carpentry, so I made it from two strips of paper that I had carefully marked out on a sorta-logarithmic scale. It worked pretty well, considering that I guessed at where numbers like 3 and 5 should end up -- I was able to multiply 2 and 3 and come up with 6.3.

This was in high school, and a math teacher saw me demonstrating how to use a slide rule to (vastly interested, I'm sure) friends. He took pity on me, and gave me a couple that he had from the dark days before cheap Taiwanese pocket-sized calculators. I also got a copy of the manual that came with one of them -- they were complicated things! -- and learned about how to do roots, cube roots, sines and cosines. I got relatively accomplished (relatively meaning that any competition was at least ten hours drive away), and used it to discover a wonderful proof of Fermat's last theorem; unfortunately, my pen wouldn't write on the plastic of the slide rule and so it was lost.

I haven't got one now, but this makes me want to check out Ebay and get one. If Heinlein has taught me anything, it's "Keep It In The Family"^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H^H"Keep Your Slipstick Handy" -- you never know when civilization will collapse around you.

Slidrule contest... (2)

Diomedes01 (173241) | more than 13 years ago | (#102140)

I had a professor in college who used to challenge students to contests doing calculations. He used a slide rule, and they could use whatever tool they wanted (they always used a calculator as far as I know).

Now, I had never even seen, let alone used, a slide rule before. However, this guy's fingers would fly over that thing. I can't remember him ever losing while I was there, but he said that he had been bested a few times. The funniest thing was that he was usually done by the time the poor kid had found the ln button on the calculator...


Re:Just plain sad. (2)

Diomedes01 (173241) | more than 13 years ago | (#102141)

Are American's today really so uneducated that they can't find the square root of 144, or the value of 2^10 without using a calculator?
God, I hope not. I'm an American, and I sure as hell know how to do stuff like that in my head. Unfortunately, I know many people that probably could not. Hell, before July 4, a bunch of high school age kids were asked what the Fourth of July was celebrating, and they either didn't know, or thought that it was our independence from France...


Uber-Paleo-Geek Artifact (3)

nagora (177841) | more than 13 years ago | (#102142)

I can go one better: I have a slide rule marked up for calculations in PRE-DECIMAL UK money. where 1 pound=240 pennies. It even does guineas!


Does anyone still use slide rules? (1)

hlh_nospam (178327) | more than 13 years ago | (#102143)

I won a slide rule in a math contest in high school (just after the earth cooled enough to crust over), along with a $100 savings bond. I still have the slide rule. Nice K&E.

I kept a little plastic 6" rule in my car to calculate my mpg up until about 6 years ago. On a particularly hot day that I didn't roll my windows down just a bit, it melted, and I haven't been able to find one to replace it. As near as I can tell, nobody makes them anymore.

I still have my circular rule that I got for use in private pilot ground school. I guess if I ever fly again, I would still use it. (Flying is time consuming and expensive. When I have the money, I don't have the time, and when I have the time, I don't have the money.)

Re:No need to know. (3)

Gordonjcp (186804) | more than 13 years ago | (#102146)

Even the Navy and Coast Guard have ABANDONED teaching or using morse code. (Only old fossil ham radio exclusionary elitists praise it now).

Perhaps in the US, they do not teach or use morse code. But it is still the a fantastically efficient way to communicate, in terms of power usage bandwidth.
A very simple homebuilt transmitter can send an intelligible signal around the world, with an output power of perhaps 1 watt.
Got no transmitter? Use a heliograph. Or bang a pipe. Flash your headlights, whatever...

Re:Sliderules (1)

RatFink100 (189508) | more than 13 years ago | (#102147)

I may be missing something but x.xx and y.yy WILL result in an answer of the form zz.zzzz

E6B (1)

Howl (193583) | more than 13 years ago | (#102151)

My watch has an E6B built in! See Navitimer image []

Re:Circular slide rule... (1)

cosmic_0x526179 (209008) | more than 13 years ago | (#102153)

Yep, I have two of those, one large and one small. Nice thing about circular slide-rules is that the stick was never extended in the wrong direction. "what goes around, comes around" it seems :) Rumor had it that the german rocket scientists were *big* on using circular slide rules during WWII.

Cosmic Ray (another one, not like the other one)

Re:Slide rules used everyday... (2)

Alioth (221270) | more than 13 years ago | (#102156)

I still use my E6-B (manual one) rather than an electronic one or a GPS for figuring time/distance problems - it's just so much faster. Batteries never go dead either!

I'm not some old timer either, I'm not even 30 yet and I've only been flying for 4 years. I do have a GPS (it's nice to have the HSI display when flying IFR), but a mechanical E6B is still a very useful tool. I upgraded from a cheap card one to a nice aluminium one too ;-)

I found slide rules good enough... (1)

dkoyanagi (222827) | more than 13 years ago | (#102157)

for most calculations I do, except when I try to use it to run Doom in deathmatch mode, then slide rules really bog down.

Not Quite A Slide Rule (2)

BoarderPhreak (234086) | more than 13 years ago | (#102160)

I still have my slide rule from childhood... I got it because it looked cool and seemed pretty useful and I wanted to learn it. Pretty simple, and really neat actually.

In mechanical drawing, you really learn how powerful not only slide rules, but normal, scaled (triangular) rulers can be. For example, to divide a distance into equal parts, just line up "0" with the beginning of the distance, then tilt the ruler down a ways. Make check marks at each centimeter/inch mark along the ruler's edge. Now take your T-square and triangle, line up the last mark with the end of your distance to establish your angle. Just slide your triangle over to each check mark and transpose that to your distance... Voila - evenly broken up along it's length into as many parts as you wanted... (It's easier to show this than explain it)

Re:Just plain sad. (1)

Beowulf_Boy (239340) | more than 13 years ago | (#102162)

Are American's today really so uneducated that they can't find the square root of 144, or the value of 2^10 without using a calculator?
Yep, I passed Algebra 2 with an A, and we were tought Square root meant that funny little button on the calculator, and thats about it.

My Slide Rule (1)

Senor Wences (242975) | more than 13 years ago | (#102163)

In eighth grade, perhaps because of my pestering interest, my pre-algebra teacher gave me a nice slide rule. I took it home, with the manual and carrying case it came with, and figured out how to do pretty basic math with it: multiplication, division. From what I understand, my uncle was quite the slide rule wizard back in the day. Supposedly people were able to crank on them as fast as others now use calculators. What an interesting progression, from abacus to adding machine to slide rule to calculators to computers....

Re:Pilots use them all the time (1)

VE3THX (247076) | more than 13 years ago | (#102165)

Good ol' Jeppesen E6B flight computers. I've got one that's about 15 years old. Tough as nails and works well too. Actually, I'd be surprised if most airline pilots didn't carry these for backup.

I still regularly use my Jepp E6B for flight planning even though electronic means are at my disposal. I also have a flight computer slide rule on my Citizen wristwatch that I have also used while in flight. All it is is a C/D scale slide rule with a few extra fixed references for fuel and oil weight, unit conversion, etc.

I have a close friend in Ottawa who loves slide rules of all kinds. I fondly remember him demonstrating some of the more rare and obscure ones at a science fiction convention a couple of years ago. My favourite was the one that calculated the damage/blast range for nuclear weapons!

Classroom slide rool use (2)

MarsCtrl (255543) | more than 13 years ago | (#102167)

Although I'm not adept enough with my Pickett slide rule to rely on it entirely (especially in classes where 3 decimal precision is considered essential, and time is limited), there is one situation where I have found it quite useful - classes where a calculator is not allowed. Most teachers only make such a restriction to keep students from using built-in cheat functions on some calculators to skip difficult problems, and having my slide rule helps me to do the simple math that I am supposed to have learned by now. Plus it's great for impressing girls.

and then there are those of us... (1)

celerity02 (256071) | more than 13 years ago | (#102168)

...who are too young to even remember what the things look like without going to look them up. :)

I'm 17, starting college this fall, and can honestly say that I have never had the experience of seeing someone have to use one outside of things like the movie Apollo 13...

Not age dependant... (1)

kurisudes (258390) | more than 13 years ago | (#102170)

I am 20 and used one in high school for math too... (i guess people did think of me as a geek using a slide rule for the provincial (final) instead of the programmable graphing ones given... But I know and understand math better as a result of not using crutches (except for making games and chat programs to talk to somebody beside you on those TIs in chemistry class ;)

Diver's Watches (1)

TheSHAD0W (258774) | more than 13 years ago | (#102171)

Keep your eyes peeled when browsing around jewelry stores; some mid- and high-range diver's watches have built-in circular log-log calculators around the bezel.

Slide rules used everyday... (4)

Mumbly_Joe (302720) | more than 13 years ago | (#102174)

.. by private pilots!

We use a tool called an E6B, invented originally (I think) by the army, which has a circular slide rule on one side of it.

The circular slide rule is pre-marked with conversions that are interested to pilots, such as gallons/gas->pounds and gallons/oil->pounds, and it it frequently used (in flight, with one hand) for computing distance covered.

There's a tons of other conversions, and of course, you can do any other mathematical operation that a slide rule can do.

Aviators are the only people I know who still use these slide rules -- but every student pilot where I flew was issued one and had to use it for the examinations.

Mumbly Joe

Meta (2)

blair1q (305137) | more than 13 years ago | (#102175)

It might also be interesting, while conducting a dig for slide rules, to conduct a dig for the first time the subject of the archaeology of slide rules came up on Usenet. Should be early '80s net.misc, or so. There could be a whole taxonomy of wistful ruminations on the slipstick. The Well, CompuServe, in fact any BBS whose archives survive in paleontological context... would be kind of useless. dejanews was kind of useless, too. They don't go back far enough. I guess you'd have to start the "recorded history" of the net somewhere around 1990.


Learn from the past. (1)

Martigan80 (305400) | more than 13 years ago | (#102176)

I think that it is good for people to still practice using the slide rule, it might help solving some problem down the road just like people who learn Latin can understand some words in an unknown language.

...and not just by pilots. (1)

hoegh (306704) | more than 13 years ago | (#102177)

The principles used in a sliderule is in use not just in aviation, but also in more down-to-the-earth tasks.

Being a little over average recommeded weigth I use one to calculate the energy contribution from fat in foods in the supermarket. It is to nifty little paperwheels with logaritmic scales joined by a clip, and given away for free. If it wasn't for my granddad giving me a sliderule back when I was playing with Lego for fun, I wouldn't have recogniced this lowtech paper-wheel as a modern incarnation of a sliderule.

So, even now people who wouldn't know a logaritm even if they saw one, are using sliderule for everyday lowtech tasks.

Re:Just plain sad. (1)

bzcpcfj (308756) | more than 13 years ago | (#102178)

"Apparently the author thinks these are otherwise unsolveable mathematical mysteries... I sincerely hope he's not representative of the average man."

Of course he's not representative. The average modern American thinks a "square root" is some genetically engineered tuber.

xcalc -analog (2)

dlleigh (313922) | more than 13 years ago | (#102181)

I still miss the -analog flag to xcalc. Under the X window system, if you run "xclock -digital" you get a digital clock, while "xclock -analog" gives you an analog clock. The command "xcalc" gives you a calaculator. Long ago some sneaky individual programmed it so "xcalc -analog" would give you a working slide rule. This feature is not in current version, but I wish it would make a comeback.

Not so difficult to grasp (2)

OpenSourced (323149) | more than 13 years ago | (#102184)

I was introduced to the "spirit of the slide rule" by some works of Robert A. Heinlein, in which some characters had to do something or other with them slide rules. It seemed like a big deal. I was young, calculators were all over, and I wondered what the fuss was all about.

Being a good writer, however, Heinlein finally managed somehow to get his point across, and I found that using a slide rule could give you a better uhmmm... let's say manipulation ability of the involved mathematical concepts. I even learnt to use an old one of my father, and loved the simplicity and power of the design. Somehow fascinating, but sorry no graphics display :o) So I kept with the HP. I remember going to math and physics exams with that 64K calculator filled up with all the theory, as text. I never had a teacher tech-savvy enough to know that calculators could carry full pages. That was a neat trick that slide rules still have to learn :o)


One Gaint Slide Rule (1)

Quizme2000 (323961) | more than 13 years ago | (#102185)

When teaching us logs in HS, My Math TeacherAir Force Flight Engineer had constructed a gaint slide rule and mounted on the wall where he would show the "real" way to do it. Just about cut of his thumb a few times though. I later used a slide rule when taking the math portions of the SAT (didn't help much, very simple).

One problem ... (3)

s20451 (410424) | more than 13 years ago | (#102186)

There's a great scene in Apollo 13 where a group at mission control frantically works with slide rules to calculate information before a computer on the ship is shut off.

Yes, that was a cool scene from a cool movie. However, the calculation they were performing was addition (from Lovell's line to the effect of "check my addition"), and I'm told that this is something slide rules can't calculate.

Feynman and Logarithms (5)

s20451 (410424) | more than 13 years ago | (#102187)

There's this cool chapter in the book "Surely you're joking, Mr. Feynman" in which the Nobel-laureate physicist Richard Feynman describes how he could calculate all kinds of complicated expressions in his head, simply by being very familiar with log tables and basic arithmetic. Unfortunately, in the calculator age this skill has been lost.

Example: Someone asks Feynman to calculate e to the power 3.3, and then to the 3:

"I happened to know three numbers -- the logarithm of 10 to the base e ... which is 2.3026 (so I knew that e to the 2.3 is very close to 10), and ... I knew the log of 2 to the base e, which is .69315 (so I also knew that e to the 0.7 is nearly equal to 2). I also knew e (to the 1), which is 2.71828. The first number they gave me was e to the 3.3, which is e to the 2.3 -- ten -- times e, or 27.18. I knew I couldn't do another one; that was sheer luck. But then the guy said e to the 3, that's e to the 2.3 times e to the .7, or 10 times 2. So I knew it was 20.something, and when they were worrying how I did it, I adjusted for the .693."

This is covered by fair use, I hope. But seriously - go get the book. It's an excellent read.

Mmmm... sliderules... (2)

Guppy06 (410832) | more than 13 years ago | (#102188)

I love my TI-92+. How could you not love the most poweful calculator on the face of the planet? It's a graphing calculator and a book of integration tables all rolled into one, with the added advantage of being able to solve ordinary differential equations (symbollicly, even). A real life-saver when you've got a lot of partial differential equations to do in your homework. I've yet to see anything better on the market.

However, different teachers have different policies about calculators. Some won't allow graphing calculators because they can store text (so can the old TI-68 scientific, but it doesn't look like a graphing calculator). Some will allow graphing calculators, but not ones the size of a VHS tape, complete with QWERTY keypad (even though the TI-89 has the same capabilities in a normal-looking design).

I'm fine with these policies for the most part, but it begins to irk me when, say, they won't allow calculators that can store text, but will allow a crib sheet. Or they won't allow a calculator that can do symbollic integration, but they will allow a book of integration tables. These sound an awful lot like "I won't allow technoligical aids because I don't understnad them."

When I find I have a particularly anal-retentive teacher, having my father's old sliderule handy is greaty for making a loud statement without saying a word, sticking out like a sore thumb in a room full of people pushing buttons. As long as you don't have notes written on it or anything, there's nothing they can say about you using it.

As for figuring out how to use it, my father had a pair of small books on their use, one of which was a book my grandfather got from the War Department while he was in the Navy. They're not hard to learn (easier to learn than most scientific calculators if you already know a thing or two about logarithms, as there's no different button layouts to get used to or Reverse Polish Notation), and I find they also help reinforce ideas about logarithms (you can SEE why log(a*b) = log(a) + log(b)).

While I'm not a rabid collecter with 300 sliderules (what a freak... now if he collected calculators... :) ), I'm glad I've got mine.

TI30 (1)

index5 (412769) | more than 13 years ago | (#102189)

I have a TI 30 that sort of still works. Cool laser beam red leds...

Re:Same with the abacus (1)

archen (447353) | more than 13 years ago | (#102191)

but the graphing sucks =P

Sliderules (3)

Registered Coward v2 (447531) | more than 13 years ago | (#102194)

The real beauty of using a sliderule was that you developed a feel for the numbers and what the results should be. After you had some experience estimating magnitude, if someone came up with some calculations, they'd either feel right or you'd get a gut feeling that something is wrong. I am still amazed that people can multiple two three digit numbers in the form of x.xx and y.yy) and come up with zz.zzzz or however many places their calculator displays. Or misplace a decimal point and not realize the result is wrong. People assume because the work has been done by a bunch of electrons that it must be right.

While I would not want to go back to only using a sliderule, the one thing that I did learn was how to estimate results in my head - a tool that has been very useful over the years.

Spreadsheets and handheld calculators are great - you can do more more quickly than you ever could with a slide rule.
You can also make bigger mistakes more often.

Re:I found Dad's slide rule in the attic... (3)

Registered Coward v2 (447531) | more than 13 years ago | (#102195)

One of my favorite pastimes at sea was celestial navigation. I found a lot of satisfaction in shooting the stars and getting a nice position fix. Part of the fun was knowing that I practicing a centuries old art much the same as the earliest navigators. (Although I must admit I also enjoyed knowing my fix would be used to reset the multi-million dollar ships inertial navigation system.)
That, to me, was what set sailors apart from everyone else: no matter where you were, or what side of the cold war you were on, you shared a long heritage and a common mistress - the sea. Even nominal enemies could share beers, swap lies and toast those on permanent patrol. It was why, when the Glomar Explorer raised a Russian nuke we buried, at sea with honors, those we found inside.

Somewhere Megellan and Vasco da Gama must be smiling.

Still using mine (1)

Satellite Designer (449600) | more than 13 years ago | (#102196)

Perhaps not regularly, but... A couple of months ago my son came into my basement office with a question about his chemistry homework. After he'd gotten the concept straight, he asked if he could sit down at my (LinuxPPC) desktop machine and do the calculations. OK, fine. His next question was "Can you check my work?". He's now at my desktop, my laptop and my HP-42S are upstairs in my backpack, but I'm prepared for just such an emergency: my K+E Deci-Lon (1968 model) is on the shelf above the computer!

Apollo 13 (4)

SilentChris (452960) | more than 13 years ago | (#102198)

There's a great scene in Apollo 13 where a group at mission control frantically works with slide rules to calculate information before a computer on the ship is shut off. Going down the row seeing them raise their thumbs and say "checks out, flight" is one of the better scenes in the movie.

Sliderules (1)

Blue Aardvark House (452974) | more than 13 years ago | (#102199)

I'm a little young for the slide rule era; I have never owned or used one. I do remember the old HP-35 from when I was a kid. Thinking it was so powerful, a little handheld "computer".

Today, I still bring my HP-48GX to work. That's my modern-day slide rule.

Java Slide Rule on the web (2)

n76lima (455808) | more than 13 years ago | (#102200)

I found this site months ago and find it to be a useful tool in TEACHING slide rule use. html

Re:Sliderules (1)

TXG1112 (456055) | more than 13 years ago | (#102201)

On a calculator doing x.xx * y.yy will display as many digits as will fill the screen. It dosen't mean that any of those digits after 2 decimal places are significant....

Re:Pilots use them all the time (1)

petecarlson (457202) | more than 13 years ago | (#102202)

"Flight computers" as they are often called are still in use all over the world. They have mostly been replaced by GPS, but any pilot with any sense still caries one on their knee board. I think they are still tought in ground school but am not sure.

Pencil and paper? (1)

jrp2 (458093) | more than 13 years ago | (#102203)

Wonderful thread.

One thing I haven't see in this thread is mention of people still using pencil and paper for calculations! Even that seems to be a lost art. No, I am not talking about "high math", but the simple stuff (ya know, multiplication and division, etc.). At work when I do math on the back of paper (often the back of a napkin or some meeting handout) people look at me like I am some sort of Luddite. Yeah, I'll use xcalc, etc. if it is handy and I am in a hurry, but make a point out of using pencil and paper often enough that I don't lose the touch.

I often think when doing job interviews if I should give them ten math problems (not too hard, but hard enough to test their skills) and not let them use a calculator. This might separate the wheat from the chaff, but worry I might not find many under 35 pass ;)

graduation presents (1)

linuxjoel (458276) | more than 13 years ago | (#102204)

Here at the University of Missouri-Rolla the standard is the HP49G, but you can still buy slide rules in the bookstore. People get them all the time for graduation, but I've never once seen someone use one. When my dad graduated with a CS degree from here 15 years ago, he used an HP-35 -- it doesn't work any more, so he recently bought a 49G. -- Raise Up, Out of my office so I can blaze this L.

Re:No need to know. (1)

LIeut. Chile Relleno (463989) | more than 13 years ago | (#102207)

I disagree. "Unlearning" the foundation stones of today's technology does have the drawback of leaving you vulnerable when the underpinnings of the new technology go awry. You get things like kids who can't tell an off-by-several-orders-of-magnitude answer spit out by a calculator from a correct one.

Instead of laughing at the Ptolemaic view of the Solar System, just try to imagine figuring it out yourself from watching the skies night after night. Though wrong, it was a work of genius. Then think what you'll have to do if the power grid goes down for a week.

The many uses of a rule (1)

RumbaFlex (465472) | more than 13 years ago | (#102210)

I've got a sliderule to gauge the diameters of pipes. And waddayaknow it's great for cleaning pipes too! Nothing takes the resin out of my bowl like this sliderule.

I also got this screwdriver that i've had since i was eight years old, I'm now twentyfour and it's all worn down and ragged. However it now fits into any screws encountered in a computer cabinet (or almost any other screw in electronic devices)..
It's one of the few consumer-items I can honestly say I have put to full and good use.

Yes, Pilots and graphic designers use em all the t (1)

Air-Op (465781) | more than 13 years ago | (#102211)

Pilots use circular logarithmic calculating devices... that are basicly slide rules. they are cheep and made out of cardboard. used to calculate fuel and wind stuff. I guess the graphic designers use em for proportions... I just saw em in the art section of my school bookstore.

Re:Pencil and paper? (1)

sagman (465807) | more than 13 years ago | (#102212)

Agree with your comment re: pencil and paper. Some folks have mentioned that slide rules require an order-of-magnitude-awareness to be developed by users and I agree completely. Understanding the size of the numbers with which you're working is important, and comes in handy during day-to-day life. There are other advantages to slide rules, too. For instance, the slide rule introduced students to logarithms, usually around 7th grade or so here in the US. Nowadays the first exposure that students have to logarithms comes in their second semester of calculus, when they're learning how to do definite integrals of x^{-1} w.r.t. x. *If* they take Calculus, and *if* they learn how to integrate at all. So students are often tasked with learning some skills with logarithms at the same time they're learning calculus, which tends to steepen the learning curve a bit. For me, when I finally learned the definition of the logarithm base E, it was something of a religious experience, since I'd been blindly using logs for years before. I understood the *algebra* of logarithms through constant use, but being able to use the definition to prove all the rules was just awesome. Today this is probably a rare, if not extinct, experience. For engineers, they may coast right by the calculus stuff but later on, if they work with something like Laplace or Fourier Transforms, they'll encounter the same logarithmic algebra all over again. And I've seen students struggle with this while wondering if things would'nt be much easier if they'd chucked the calculators in favor of the old slide rule long ago. There may be some debate over whether having the skills that a slide rule (or pencil and paper) teaches is important. Or whether the preparation for further education that it provides is something that we need today. Call me old-fashioned, but it's a matter of education, and I think we've lost something valuable in the switch from the slide rule to the calcualtor. One wonders if the Mars Climate Orbiter mission would have succeeded if the contractors had been using slide rules. Did they push the wrong conversion button on their calculator? Had someone had an order-of-magnitude idea about the numbers they should have gotten, perhaps they'd have caught the error in time...

sliderule (1)

witchonthemoor (465813) | more than 13 years ago | (#102213)

The sliderule had one huge advantage over the electronic calculator: you had to actually understand something about math to use it. My experience with my students now, (yes, I am THAT high school math teacher -- the one everybody tries not to get) is that few have any idea how those magic boxes work. Worse, most don't care. Incidently, if you think you got ridiculed for owning one as a guy, you should have tried it in the pre-feminist 60's as a girl.
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