No shoes allowed on the helter skelter. You can buy original '50s, '60s slide rules on ebay. But no one makes them anymore, except ThinkGeek www.thinkgeek.com/gadgets/tool...
My math teacher said (jokingly) that we couldn't use a calculator in class but we could use a slide rule so like the rebel I am I went home, dug up my dad's made in 1900 slide rule(literally ) and brought it to school and he had no choice but to let me use it.😂
Mine said we couldn't use calculator but he didn't said we *could* use slide rule so I'll buy one and try to see if he gets mad or gimme a bonus point because I used it ^^
Mind you, a slide rule still "calculates" an answer. But by the same token, so does your brain. Your teacher effectively banned use of brains. Perhaps he should ban elecronic calculators... allow for the possibility of using mechanical calculators, but ensure you bring your bioorgainc calculator with you.
I remember when I took my A-levels we were in a crossover year and had to have a slide rule AND a calculator for the exams (I borrowed my teacher’s slide rule, they cost a fortune). Later on I bought myself a US-made circular slide rule which was brilliant (it fit in my top pocket), although less accurate than the linear one. I think a lot of young pupils these days would greatly benefit from having to use a slide rule: it would give them a basic understanding of mathematics, which they certainly do not seem to have since the advent of computers and the Internet... I am reminded of a ragmag joke from my university days: how do you tell the difference between an old school engineer and a modern one? Ask them what 3 x 4 is, and the old timer will take a slide rule out of his back pocket, make a few adjustments and say, “about twelve”. The modern fellow will take a calculator out of his breast pocket, tap a few numbers and say, “twelve point zero zero zero”.
agreed, it also teaches them part of why logs are so important, and how they can be useful. introducing kids to logs earlier would help their understanding later.
The story of Noah and the animals after the Flood: After the Flood was over, Noah greeted the animals as they were leaving the ark. First out (being that they were so fast) were the two squirrels. Noah said to them, "May the Lord bless you! Go forth and multiply." And ZIP! Off went the squirrels. Next came hopping up were the two rabbits. Noah said to them, "May the Lord bless you! Go forth and multiply." And HOP, HOP, HOPP! Off went the rabbits doing what rabbits do best. Then slithering out were the two adders (snakes). Noah said to them, "May the Lord bless you! Go forth and multiply." The adders said to Noah, "We're adders and we don't know how to multiply!" Noah replied, "That's okay. If you could just wait until I'm done with the rest to the animals, I will explain it to you. Wait over there by those fallen trees." It took Noah a few days before he was done. Then right after he was finished with the two snails, he exclaimed (snapping his fingers), "That's right, I have to explain things to those adders!" Noah went over to the fallen trees where he told the adders to wait for him, and he saw the two adders with a bunch of little adders. Noah was puzzled and exclaimed, "I thought you said that you couldn't multiply, because you are adders!" To which the adders replied, "Yes, we are adder, but we have learned to multiply by logs."
I imagine a teacher telling this story and then, over the course of a semester, explaining why its funny to the students and thereby teaching them math.
I love slide rules. My late father was a professional physicist who used a slide rule throughout most of his career. I have a small collection, and enjoy using them. One of the benefits, which comes over very well in this demonstration, is that because the user has to work out the scale of magnitude of the answer, he retains a mental picture of the entire process. Thank you for posting this enjoyable and clear demonstration.
I think the slide ruler should be implemented in early education to give people a grasp of what numbers actually are and take some of those "this isn't real" abstract feelings away from them. Just simple stuff, like what was explained in this video.
I think we should be trying to minimize the amount of mystical magical rote processes that kids memorize in math. Im sure shifting a ruler around and reading off numbers gives them about as much numbersense as pushing buttons on a calculator. And there's no way the log addition->multiplication property (while certainly cool) makes more intuitive sense to kids than "A*B is A groups of B"
There is something wonderfully clever about such a simple and easy to manufacture device that was so useful as well. It's neat that you immediately get not just once calculation, but a table of values when you use the slide rule.
Same for me and I still have the thing 40 + years later. I watched this video with the slide rule in front of me... he'll have to go a lot slower so I can catch up and remember how to use it! I'd be lost with logs now, but remember enjoying using them back in the day.
I still have my slide rule from when I was at school in the early seventies. I occasionally take it out of the draw and go down memory lane. Great piece of equipment.
I was not great at maths, and I am still not. But at high school up to 1968, I was great on a slide rule and could get the answers fairly accurately. I knew how to use log tables, but I never understood how they worked. Mind you, it wasn't until I went to teacher's college, that I learnt what numbers meant and why we "borrowed a one, and paid the one back", meaning renaming numbers. You have such infectious enthusiasm. I would have loved to have had a maths teacher like you.
This is the best explanation of how to use a slide rule ever. And I learned to use a slide rule very young (father was an engineer), and long before pocket calculators were even a thing.
+Jnvska The scene from Apollo 13 where they checked Lovell's maths with slide rules back at mission control is one of my favorite uses of period-specific props in film history.
Unfortunately, it was one of the Apollo un-realistic ones. Jim just had to translate angles between the two systems (and account for Swigert's slight misalignment during transposition and docking)- pure addition and subtraction. Not that it didn't make for excellent movie magic!
True, it was movie magic, but the guys in "The Trench" (the row of NASA flight controllers closest to the front of the room) did indeed use slide rules in their daily efforts.
My chemistry teacher had been teaching in the same classroom since 1952; he had a giant slide rule ten feet long above the board with markings big enough for the whole class to see, and used it to make his calculations. He says that slide rules taught important lessons about significant figures that calculators don't.
@@SoloRenegade When you get down on yourself for weakness in mental maths, check in with a young person. They pull out a phone (for the calculator app) for the simplest things. And it seems like most of them do not know what significant figures are. Yo, when we are looking at live results, 40 micro inches per micrometer is plenty accurate. Sure, for your report you should retain figures consistent with your uncertainty, but I do not need that level of specificity for a reality check.
Or, we are going to spike in concentrated solutions of certain elements that will be later diluted. Sure, young person, you can calculate that you want 0.783 ml of spike solution to get exactly 20 ug/ml final concentration. That is nice. ... But I don't have a 0.783 ml pipette. So how about you calculate the final concentration based on the 1000 ul and 500 ul pipettes that we actually have in the lab and work with that? Common sense has definitely left the chat.
@@FinnMcRiangabra totally agree. I teach similar things in engineering. Why spend 4wks using the high level super precise calculations to get an estimate to within 0.00001" accuracy, when the simple algebra approximation equation gives us an equivalent answer with 0.001" accuracy in less than 5min, but our vendors will only be manufacturing to plus or minus 0.005" accuracy (due to limitations of their equipment, and it costs a LOT more to manufacture to tighter tolerances). Also, machines with moving parts wear out, and something held to much higher tolerances wear out faster than designs that can handle lower tolerances.
Dr. Grimes has a very infectious personality and a delightful enthusiasm for the subject matter. And only he could pull off picking up an electronic calculator in the middle of a lecture on the slide rule. :D
Boy, does this take me back! Remember mastering the stick and the circle. Saved my life repeatedly. Thanks for setting the wayback machine to... Sliderules!
Nice video. Slide rules were sold and used well into the '70s. I used one for my Physics and Chemistry courses and the engineers had them permanately attached to their belts. Calculators were just coming into use and even basic four function calculators were very expensive. The HP-35 revolutionized everything, but still out of reach for many, and were often forbidden for use during exams since they provided an unfair advantage. I still have my Post bamboo core slip-stick!
Fancier slide rules had more scales. Many had trig scales on them so you didn't have to flip open your trig tables book. The scales he was showing are called the C and D scales, many rules had CF and DF (folded scales) to prevent falling off the edge during calculations. All of them had the reciprocal scale, and the square and cube scales.
Once in a while you'll find an old book that has a bizarre notation for logarithms. If you were given the value of log(0.000323) it would be written as '6.509 (- 10)' instead of '-3.491' (what you get if you use a calculator). It was common practice to turn all log values into positive numbers by adding 10 (or 20 or whatever) and then note that you need to subtract the 10 you just added. This is because slide rules (and log tables) are based on positive mantissa values (the fractional part of a logarithm) and using negative mantissas would cause confusion.
I remember my mom always had one of these she kept from her school days. I played with it as a kid and asked mom how it worked. She didn't know. Now I know. Thanks for that. :D
Mathematics is the language of nature. The Slide Rule is one of humanities most elegant expression of that language. The Slide Rule should be taught in all elementary / primary schoolls so that our thinking ape brethren can see the patterns.
I agree, and all math homework should be done by hand even through at least Calc 1 & 2. I see college students who've used fancy calculators and computer programs to solve things for them and they struggle immensely even with the basics.
That is so cool. I've never seen a slide rule but my parents used them and now I know how they work. It's incredible to think of all the things discovered with nothing but a slide rule. I'm sad you can't buy them anymore. :(
+Ali B You can still get functional slide rules on ebay for a decent price. I'd recommend Pickett brand since they were made of aluminum and generally age better than wood or plastic ones.
Your enthusiasm made me feel young again. I kept my slide rule from the '70s to now... I am going to turn 66. Unfortunately, over the years, I forgot how to use it. I had it in a box with memorabilia. Now I am writing my life story to leave to my grandkids. I can put a picture of the sliding rule and tell some of the simple calculations you've shown. this video y o posted 12 years ago. I hope you are doing well and will be forever thankful (well, I can take my gratitude with me of course... I am reaching the expiration date). Regards.
They are a great bit of kit. I'm of the same generation as James, and we I suppose were the first to use calculators, so never grew up with slide rules. I still have my dad's old engineering one though; and they work a treat. All the calculations to see if Concorde would do what it did, were all done on slide rules.
When I started my first job as an electronic technician in research and development in 1972, I brought my slide rule with me to work. Yes the engineering research department had one, four function desktop calculator for the department of 50 engineers to share. Four functions calculators were very expensive in 1972. When I took college chemistry we had a minicomputer with 10 terminals, each having 10 digit accuracy. With the push of a button we could do logs, trig functions etc. to 10 digit accuracy (using nixie tubes) and not use those 3 inch thick books to do the interpolations for more precise answers. My college had a semester course in the use of the advanced slide rules too that included the log-log scales for chemists and engineers. I challenged the course and just took the final exam and got a A in the class. When I started work in 1972, I went out and bought myself a four function calculator for my desk (using vacuum florescent displays) for $400 to put on my desk. I just about caused a riot in the research department. All the engineers asked "why does a technician get a calculator and we don't"? The answer was "because he bought it himself". LOL Then the HP-35 calculator was first introduced that year by the Hewlett-Packard Corporation and provided the four functions of arithmetic, as well as the transcendental functions of trigonometry and logarithms, to an accuracy of over 10 decimal digits, with a two-digit exponent of ten for numbers expressed in scientific notation. The world was never the same after that. The company bought all the engineers that wanted a HP-35 calculator and charged them $400 each with monthly payment payback. Almost all the engineers bought one. In less than a year, HP introduced their HP-45 calculator that did even more than the HP-35 calculator. The HP-35 calculator price was reduced to $300 and the HP-45 was sold at $400. All those engineers were really screwed buying the HP-35. That was when I bought my HP-45 calculator for $400 that I still have today.
Years ago i got one, from someone who didn't know how to use it.. these things always intrigued me, so i was happy with it.. at home, i asked my neigbor how to use it, he was an engineer, he actually used them. I started using it myself as wel.. also at work.. to the astonishment of my colleagues...only 2 actually knew what it was.. Later on.. i started designing my own, for speeds and feeds calculations for metalworking machines.. just great fun..
At school in the 50's and 60's much of the maths and physics required the use of log tables. I still have them in my office. Once at work I used a slide rule, a lovely German one that smelled of sandalwood and had many scales including all the trig functions. I have it here, it's as good as new, but the smell has gone. It is spring loaded, you press in the back and the slider moves, let go and friction holds it - simple. Come the apocalypse, I 'll still be able to do sums.
I started learning to teach myself to use a slide rule in fourth grade, I don't remember how far I got, since I live in the mountains of North Carolina and was more interested in trying to shoot squirrels...never got one thank god, would have had no idea how to clean it. Back to topic, I think at some level spending hours with a slide rule paid off. I wonder about my own children and calculators...they seem to have a bit more trouble with mental math. Good show! Now, if I can find my old slip-stick!
Memories. When I was at school (late 70's) calculators were banned in exams, but slide rules were allowed. I was the only who used a slide rule -- had a huge advantage :-)
Well done video. Circular slide rules avoid the need to use the right index instead of the left because they're the same line on a circular slide rule.
@iamUSAn50 But the scales are from 1 to 10 so you have to adjust the decimal point yourself. I should have done that but I was just reading it off straight from the slide rule.
I have been collecting slipsticks since I was in high school in the early 80s. I still use my K&E Log-log Duplex Decitrig instead of a calculator. I am absolutely fascinated by how the logarithmic scales function... simply amazing. Great video!
My grandpa did his taxes on graph paper with a slide rule and would point out where TurboTax made errors. Amazed me every time! Skill beats tech every day of the week.
I have a handful of them. Post made good utilitarian rules - bamboo with plastic scales. Castel made plastic ones that were quite good though not really rugged. K&E made great ones - mahogany with ivory scales. They are things of beauty and could get one very close to at least 3 significant digits. The CF scales were handy because it began and ended with pi. So, when I went back to school in 1980 and tried to buy a new one, I was chagrined to find they were no longer sold. The world had begun using calculators. With batteries that had a bad habit of dieing in the middle of a Physics exam...
We also had tables of Trig functions and logs so if we needed more than three significant digits we could use logs, interpolate and get awfully close. Until reliable calculators. I have an HP-15C. It isn't for sale...
Don't forget the slide rule maintenance tool. a good number 1 pencil. When the slide got a little stiff you'd pull it out and use the pencil to lay a little graphite lube on the rails.
I saw a sign in a playground once: SLIDE RULES: 1. No climbing up the chute. 2. No stopping midway down the slide. 3. Only one child at a time on the slide. 4. Devices with logarithmically spaced calibrations used for rapid calculations.
In early 70s my college chemistry professor banned electronic calculators, only allowed slide rule to solve math problems in classroom. Improved my math solving, scale reading, and estimating ability.
Hi! I am the Head of Public Enlightenment for the International Slide Rule Museum. Would you be interested in joining one of our meetings online? It would be great to have you!
I have my Dad’s Eugene Dietzgen Co. Multiplex Decimal Trig Log Log slide rule. Slide rules are supposed to yield 3 significant digits but I haven’t achieved that yet. I found the instructions on line for all the calculations it’s supposed to do.
I mentioned the term "Slide Rule" to a fellow engineer at work one time maybe 10 years ago. He didn't have the slightest idea what I was talking about. So, the next day, I brought in my old slide rule that I had used in my college days. There was a time when they were standard equipment for any engineering student and classes were taught on how to use them. Mine was a higher-end model and is still in very good condition.
Gotta thank you for making this video! My grandpa (A former engineer) left behind a stack of these when he died and no one could figure out how they worked. Well, mystery solved! =D
0:35 " slide rulers were big in the 50's, but then again so were rickets" What is this freak talking about? My father, an aerospace engineer, and NASA were using slide-rulers as recently as 1970! Go check out that film: Apollo 13
that was a really good and enteraining discussion of how the slide rule works. my dad showed me as a kid but i did not really understand why it worked. thx man
You can make your own slide rules. Search online for PDFs to download and print. Some are made by folding paper, others you could make by printing them on sticking paper then pasting onto cardboard or wood.
+ Zurviver _ : Lay out your scale interval; call it the x-axis, from x=0 to x=L, the desired length of the rule. Then each number, N, is "plotted" at x = L*frac(log₁₀N), where frac(a) = the fractional part of a. Fred
Actually, Dr. Grime, there are a couple ways to do that, although they are a bit awkward. Let's say you want to add x + y. One way is to use the L scale, using the cursor to find 'proxies' on the C and D scales for x and y on the L scale. (IOW, you find 10ˣ and 10ʸ) Multiply the proxy numbers (10ˣ·10ʸ = 10ˣ⁺ʸ), and read the result, x+y, back on the L scale. Another one I used to use, and which is maybe the ultimate in nerdiness (or "coolness"?). It's in three steps: 1. First divide: x/y 2. Mentally add 1 (OK, this is kinda cheating, but it's an easy thing to do without computing aid), and move the cursor to that value 3. Multiply by y. Result: x+y. And no, my real name *isn't* Rube Goldberg. Fred
I one from a rocket scientist. His name is Bob Loos. When he died one of my relatives was helping clean out his house, and asked if he could have the slide rule. And he gave it to me
I have a slide-rule in my closet. We had to buy one for school in the early 70s. We leaned how to use them is school. We had log tables too. I still have mine. In about 1973 pockets calculators became affordable and within about two years, slide-rules telecom disappeared. I Britain, our school year (grade) was the first to be allowed to use electronic calculators in official exams. That was 1976.
More advanced math than numberphile series - I really enjoyed that, especially as a fresh MEng graduate. Really glad that RUclips suggested me this movie. Also, I am a fan of your approach and attitude as a teacher, doc. Actually this made me want to use a slide rule, but I can't find any practical use for it right now. ;)
Great article on the slide rule. I remember using the slide rule..it was a fascinating tool to do calculations. Today we have cheap scientific calculators that do it all automatically. The advantage of using slide rules was that it enabled you to understand math concepts.
+Douglas Fawkes Right! You had to be very careful with roots for example. To calculate the squareroot of 200 for example, you had to calculate sqrt(2) with the sliderule and multiply the result with 10, because 10 is the squareroot of 100. Or when calculating the sine or tangent of small angles (
Yes there were all kind of slide rules other than the basic one. However they certainly made you apply math to the practical everyday things in life..... I kinda miss 'em.
Wow. That was complicated. I think I would have to watch this several times before I actually understood it. Still, the enthusiasm and knowledge that poured from the video made it entertaining non-the-less. Thanks!
Very clear and well presented.. Before we got the slide rule we had to use log tables and antilog tables. You have to wonder about the genius who calculated them in the first place and wrote those out. I made my living by my slide rule.
I had one during my engineer studies in the late 90's. The only thing we did with it was learn to use it though. HP48 was the boss of the day. Sadly, I lost it at some point.
Oh, Nostalgia. I still have all three of my slide rules. Don't use them, just can't bear to part with them. About 10 years ago, I finally got rid of my three Volkswagen bugs, but not my slide rules.
I've been staring at mine blankly for far too long, so thank you for some basic instructions. It'd be nice if geeks had this sort of awesome status again. Then again, being able to use a slide rule today proves pretty geeky, albeit retro.
My school years preceded calculators so we used slide rules. I remember having a circular one, though I don't recall any differences to the straight ones. It was a long time ago!
Circular ones give automatic wraparound at the ends of the scales. This is convenient where it makes sense for the scale. Not all scales make sense to wraparound. The downside with circular rules is they tend to be bulkier. That’s why straight ones tended to be more popular.
For people who like their maths UNPLUGGED. It is not just Think Geek. A Japanese company called Concise still produces a few Circular ones. They supplied one for my collection. I've no idea why they still do Slide Rules as there other wares are things like purses, wallets and small travel items.
There was talk about that when I was working for McDonnell Aircraft in St. Louis but it was determined to let Houston do all the heavy stuff. But I think one did make the trip anyway.
I'm a ruler just like you But I've got better things to do Than sit around and math my head Hang out with the living dead Mark white boards with my prose Cross out at the shows I don't even think about speed That's something I just don't need I've got a straight edge
"Engineers, mathematicians, physicists... you know, cool people!"
That made my day.
Well, they are.
Made mine as well
theRealPlaidRabbit Yeah, you guys really are. :-)
In my opinion, we'd be living in the dark ages if there were only people like me!
Only in your dreams.
Slide rules were often used by computers.
My math teacher said (jokingly) that we couldn't use a calculator in class but we could use a slide rule so like the rebel I am I went home, dug up my dad's made in 1900 slide rule(literally ) and brought it to school and he had no choice but to let me use it.😂
Mine said we couldn't use calculator but he didn't said we *could* use slide rule so I'll buy one and try to see if he gets mad or gimme a bonus point because I used it ^^
Following this comment for updates.
This makes some sense because you can't really use a slide rule without knowing how multiplications work.
Samuel Prevost: Let me know who still sells them.
Mind you, a slide rule still "calculates" an answer.
But by the same token, so does your brain.
Your teacher effectively banned use of brains.
Perhaps he should ban elecronic calculators... allow for the possibility of using mechanical calculators, but ensure you bring your bioorgainc calculator with you.
I've never seen someone look so much like they were going to perform a magic trick.
+MafeefCNT What?
@anticorncob6 Slide rules do sin, cos and tan on the back. But the rules are rather complicated so I didn't want to go into it in this video.
The question is; can you take slide rules into non-calculator tests.
I did it, but that was 4 years ago.
siratthebox the teacher would be to stupid to think you can solve math with it
Yep - I did it for years.
If not, you can still take a watch. Many watches have slide rules
@Felix Carpio modern problems require modern solutions
I asked my grandpa to teach me how to use a slide rule and he is unusually excited. It is all he talks about now. I'm scared.
That's so sweet.
I remember when I took my A-levels we were in a crossover year and had to have a slide rule AND a calculator for the exams (I borrowed my teacher’s slide rule, they cost a fortune). Later on I bought myself a US-made circular slide rule which was brilliant (it fit in my top pocket), although less accurate than the linear one.
I think a lot of young pupils these days would greatly benefit from having to use a slide rule: it would give them a basic understanding of mathematics, which they certainly do not seem to have since the advent of computers and the Internet...
I am reminded of a ragmag joke from my university days: how do you tell the difference between an old school engineer and a modern one? Ask them what 3 x 4 is, and the old timer will take a slide rule out of his back pocket, make a few adjustments and say, “about twelve”. The modern fellow will take a calculator out of his breast pocket, tap a few numbers and say, “twelve point zero zero zero”.
agreed, it also teaches them part of why logs are so important, and how they can be useful. introducing kids to logs earlier would help their understanding later.
The story of Noah and the animals after the Flood:
After the Flood was over, Noah greeted the animals as they were leaving the ark.
First out (being that they were so fast) were the two squirrels. Noah said to them, "May the Lord bless you! Go forth and multiply." And ZIP! Off went the squirrels.
Next came hopping up were the two rabbits. Noah said to them, "May the Lord bless you! Go forth and multiply." And HOP, HOP, HOPP! Off went the rabbits doing what rabbits do best.
Then slithering out were the two adders (snakes). Noah said to them, "May the Lord bless you! Go forth and multiply."
The adders said to Noah, "We're adders and we don't know how to multiply!"
Noah replied, "That's okay. If you could just wait until I'm done with the rest to the animals, I will explain it to you. Wait over there by those fallen trees."
It took Noah a few days before he was done. Then right after he was finished with the two snails, he exclaimed (snapping his fingers), "That's right, I have to explain things to those adders!"
Noah went over to the fallen trees where he told the adders to wait for him, and he saw the two adders with a bunch of little adders.
Noah was puzzled and exclaimed, "I thought you said that you couldn't multiply, because you are adders!"
To which the adders replied, "Yes, we are adder, but we have learned to multiply by logs."
Clever. It wasn't until the end that I realised the 'adders' was a pun.
This is one of the most clever jokes I have ever seen.
Normally, I don't approve of religious humour, but I'll let this one, umm, slide.
I imagine a teacher telling this story and then, over the course of a semester, explaining why its funny to the students and thereby teaching them math.
You perfectly described how a slide rule works lmao
I love slide rules. My late father was a professional physicist who used a slide rule throughout most of his career. I have a small collection, and enjoy using them. One of the benefits, which comes over very well in this demonstration, is that because the user has to work out the scale of magnitude of the answer, he retains a mental picture of the entire process. Thank you for posting this enjoyable and clear demonstration.
I think the slide ruler should be implemented in early education to give people a grasp of what numbers actually are and take some of those "this isn't real" abstract feelings away from them. Just simple stuff, like what was explained in this video.
My roommate is a high school math teacher and he isn't allowed to teach algebra and geometry without a calculator. Ugh.
Clifton Hall It's an EU human rights ruling, no child shall be subject to the traumatic stress of having to actually understand numbers.
857frank what, seriously
zoranhacker No.
I think we should be trying to minimize the amount of mystical magical rote processes that kids memorize in math. Im sure shifting a ruler around and reading off numbers gives them about as much numbersense as pushing buttons on a calculator. And there's no way the log addition->multiplication property (while certainly cool) makes more intuitive sense to kids than "A*B is A groups of B"
There is something wonderfully clever about such a simple and easy to manufacture device that was so useful as well. It's neat that you immediately get not just once calculation, but a table of values when you use the slide rule.
Oh crap. I went to school in the 70's when calculators were just coming out (and were very expensive) and we actually learned how to use a slide rule.
One of my teachers still had one of those giant classroom demo sliderules hanging from the top of the chalkboard.
Same for me and I still have the thing 40 + years later. I watched this video with the slide rule in front of me... he'll have to go a lot slower so I can catch up and remember how to use it! I'd be lost with logs now, but remember enjoying using them back in the day.
I still have my slide rule from when I was at school in the early seventies. I occasionally take it out of the draw and go down memory lane. Great piece of equipment.
I was not great at maths, and I am still not. But at high school up to 1968, I was great on a slide rule and could get the answers fairly accurately. I knew how to use log tables, but I never understood how they worked. Mind you, it wasn't until I went to teacher's college, that I learnt what numbers meant and why we "borrowed a one, and paid the one back", meaning renaming numbers.
You have such infectious enthusiasm. I would have loved to have had a maths teacher like you.
This is the best explanation of how to use a slide rule ever. And I learned to use a slide rule very young (father was an engineer), and long before pocket calculators were even a thing.
My grandpa, who worked with Neil Armstrong and Buzz Aldrin, still has a Slide Rule! I was SOOOOOO intrigued by it... And confused too XD
Cool!
My calculus teacher uses his in class
+Jnvska The scene from Apollo 13 where they checked Lovell's maths with slide rules back at mission control is one of my favorite uses of period-specific props in film history.
Unfortunately, it was one of the Apollo un-realistic ones. Jim just had to translate angles between the two systems (and account for Swigert's slight misalignment during transposition and docking)- pure addition and subtraction. Not that it didn't make for excellent movie magic!
True, it was movie magic, but the guys in "The Trench" (the row of NASA flight controllers closest to the front of the room) did indeed use slide rules in their daily efforts.
My Grandad gave me his slide rule before he passed away. Very happy to see you made a video and I can now actually use it. Thank you
My chemistry teacher had been teaching in the same classroom since 1952; he had a giant slide rule ten feet long above the board with markings big enough for the whole class to see, and used it to make his calculations. He says that slide rules taught important lessons about significant figures that calculators don't.
as well as the value and applications of logs
@@SoloRenegade When you get down on yourself for weakness in mental maths, check in with a young person. They pull out a phone (for the calculator app) for the simplest things. And it seems like most of them do not know what significant figures are. Yo, when we are looking at live results, 40 micro inches per micrometer is plenty accurate. Sure, for your report you should retain figures consistent with your uncertainty, but I do not need that level of specificity for a reality check.
Or, we are going to spike in concentrated solutions of certain elements that will be later diluted. Sure, young person, you can calculate that you want 0.783 ml of spike solution to get exactly 20 ug/ml final concentration. That is nice. ... But I don't have a 0.783 ml pipette. So how about you calculate the final concentration based on the 1000 ul and 500 ul pipettes that we actually have in the lab and work with that?
Common sense has definitely left the chat.
@@FinnMcRiangabra totally agree. I teach similar things in engineering. Why spend 4wks using the high level super precise calculations to get an estimate to within 0.00001" accuracy, when the simple algebra approximation equation gives us an equivalent answer with 0.001" accuracy in less than 5min, but our vendors will only be manufacturing to plus or minus 0.005" accuracy (due to limitations of their equipment, and it costs a LOT more to manufacture to tighter tolerances).
Also, machines with moving parts wear out, and something held to much higher tolerances wear out faster than designs that can handle lower tolerances.
@@FinnMcRiangabra And microinches don't even exist. One is equivalent to 25.4 nm.
Dr. Grimes has a very infectious personality and a delightful enthusiasm for the subject matter. And only he could pull off picking up an electronic calculator in the middle of a lecture on the slide rule. :D
I have looked for slide rule instructions before. This is the most concise, most useful explanation I have ever seen.
Boy, does this take me back! Remember mastering the stick and the circle. Saved my life repeatedly. Thanks for setting the wayback machine to... Sliderules!
Nice video.
Slide rules were sold and used well into the '70s. I used one for my Physics and Chemistry courses and the engineers had them permanately attached to their belts. Calculators were just coming into use and even basic four function calculators were very expensive. The HP-35 revolutionized everything, but still out of reach for many, and were often forbidden for use during exams since they provided an unfair advantage.
I still have my Post bamboo core slip-stick!
I remember, we used to have a State Math Contest. And slide rules were banned.
Fancier slide rules had more scales. Many had trig scales on them so you didn't have to flip open your trig tables book. The scales he was showing are called the C and D scales, many rules had CF and DF (folded scales) to prevent falling off the edge during calculations. All of them had the reciprocal scale, and the square and cube scales.
Once in a while you'll find an old book that has a bizarre notation for logarithms. If you were given the value of log(0.000323) it would be written as '6.509 (- 10)' instead of '-3.491' (what you get if you use a calculator). It was common practice to turn all log values into positive numbers by adding 10 (or 20 or whatever) and then note that you need to subtract the 10 you just added. This is because slide rules (and log tables) are based on positive mantissa values (the fractional part of a logarithm) and using negative mantissas would cause confusion.
I remember my mom always had one of these she kept from her school days. I played with it as a kid and asked mom how it worked. She didn't know.
Now I know.
Thanks for that. :D
@HaslamCorp Yup, they are both the same scale. Benford and the slide rule both use the logarithmic scale.
For so long time have I wondered how to use the slide rule. Thank you for giving me the answer.
Mathematics is the language of nature. The Slide Rule is one of humanities most elegant expression of that language. The Slide Rule should be taught in all elementary / primary schoolls so that our thinking ape brethren can see the patterns.
I agree, and all math homework should be done by hand even through at least Calc 1 & 2. I see college students who've used fancy calculators and computer programs to solve things for them and they struggle immensely even with the basics.
I suck at math and even I must appreciate the elegance that is the simplicity and beauty of a slide rule!
That is so cool. I've never seen a slide rule but my parents used them and now I know how they work. It's incredible to think of all the things discovered with nothing but a slide rule. I'm sad you can't buy them anymore. :(
+Ali B You can still get functional slide rules on ebay for a decent price. I'd recommend Pickett brand since they were made of aluminum and generally age better than wood or plastic ones.
I absolutely loved your presentation! Thank you for the explanation, it was exceptional.
Your enthusiasm made me feel young again. I kept my slide rule from the '70s to now... I am going to turn 66. Unfortunately, over the years, I forgot how to use it. I had it in a box with memorabilia. Now I am writing my life story to leave to my grandkids. I can put a picture of the sliding rule and tell some of the simple calculations you've shown. this video y o posted 12 years ago. I hope you are doing well and will be forever thankful (well, I can take my gratitude with me of course... I am reaching the expiration date). Regards.
I learned how to use a slide rule as a kid when I read an old George Gamow book on the subject. I used to love his books.
It's always nice watching your videos because of our common interests and your enthusiasm.
I'm on a numberphile binge. Funny meeting you here.
That takes me back. I used slide rule and a book of tables all the time back in the late 60's early 70's. A great piece of kit.
James, along with your other videos, these ones showcasing gadgets and tools have added an extra something to your uploads.
Very cool, keep it up :)
They are a great bit of kit. I'm of the same generation as James, and we I suppose were the first to use calculators, so never grew up with slide rules. I still have my dad's old engineering one though; and they work a treat. All the calculations to see if Concorde would do what it did, were all done on slide rules.
Found a slide rule at my local Goodwill for 8 bucks a few hours ago. Came with a nice leather scabbard. Now I just have to practice with it.
When I started my first job as an electronic technician in research and development in 1972, I brought my slide rule with me to work. Yes the engineering research department had one, four function desktop calculator for the department of 50 engineers to share. Four functions calculators were very expensive in 1972. When I took college chemistry we had a minicomputer with 10 terminals, each having 10 digit accuracy. With the push of a button we could do logs, trig functions etc. to 10 digit accuracy (using nixie tubes) and not use those 3 inch thick books to do the interpolations for more precise answers. My college had a semester course in the use of the advanced slide rules too that included the log-log scales for chemists and engineers. I challenged the course and just took the final exam and got a A in the class. When I started work in 1972, I went out and bought myself a four function calculator for my desk (using vacuum florescent displays) for $400 to put on my desk. I just about caused a riot in the research department. All the engineers asked "why does a technician get a calculator and we don't"? The answer was "because he bought it himself". LOL Then the HP-35 calculator was first introduced that year by the Hewlett-Packard Corporation and provided the four functions of arithmetic, as well as the transcendental functions of trigonometry and logarithms, to an accuracy of over 10 decimal digits, with a two-digit exponent of ten for numbers expressed in scientific notation. The world was never the same after that. The company bought all the engineers that wanted a HP-35 calculator and charged them $400 each with monthly payment payback. Almost all the engineers bought one. In less than a year, HP introduced their HP-45 calculator that did even more than the HP-35 calculator. The HP-35 calculator price was reduced to $300 and the HP-45 was sold at $400. All those engineers were really screwed buying the HP-35. That was when I bought my HP-45 calculator for $400 that I still have today.
"You know, COOL PEOPLE!"
Years ago i got one, from someone who didn't know how to use it.. these things always intrigued me, so i was happy with it.. at home, i asked my neigbor how to use it, he was an engineer, he actually used them.
I started using it myself as wel.. also at work.. to the astonishment of my colleagues...only 2 actually knew what it was..
Later on.. i started designing my own, for speeds and feeds calculations for metalworking machines.. just great fun..
At school in the 50's and 60's much of the maths and physics required the use of log tables. I still have them in my office. Once at work I used a slide rule, a lovely German one that smelled of sandalwood and had many scales including all the trig functions. I have it here, it's as good as new, but the smell has gone. It is spring loaded, you press in the back and the slider moves, let go and friction holds it - simple. Come the apocalypse, I 'll still be able to do sums.
Scientific notation really helps, as well, with keeping track of decimal places.
Thanks for the video. I'm always amazed at who came up with this stuff.
All these years and now I’m 😎 cool. Glad to see the slide rule rules.
I love watching you videos! The thing i love the most is that you always grin! You're so passionate about math! :)
I started learning to teach myself to use a slide rule in fourth grade, I don't remember how far I got, since I live in the mountains of North Carolina and was more interested in trying to shoot squirrels...never got one thank god, would have had no idea how to clean it. Back to topic, I think at some level spending hours with a slide rule paid off. I wonder about my own children and calculators...they seem to have a bit more trouble with mental math. Good show! Now, if I can find my old slip-stick!
Memories.
When I was at school (late 70's) calculators were banned in exams, but slide rules were allowed. I was the only who used a slide rule -- had a huge advantage :-)
To this day, these things intrigue me. My brother had one in the late 70s when he was studying Mechanical Engineering.
Well done video. Circular slide rules avoid the need to use the right index instead of the left because they're the same line on a circular slide rule.
@iamUSAn50 But the scales are from 1 to 10 so you have to adjust the decimal point yourself. I should have done that but I was just reading it off straight from the slide rule.
This is DEFINITELY worthy of a Numberphile video. Perhaps with a clearer script and better camera work.
The main objective of this device is to make you smart enough to do the calculations by hand and ignore the machine altogether
FINALLY! I couldn't find a good guide to understand slide rules. You are awesome!
I have been collecting slipsticks since I was in high school in the early 80s. I still use my K&E Log-log Duplex Decitrig instead of a calculator. I am absolutely fascinated by how the logarithmic scales function... simply amazing. Great video!
My grandpa did his taxes on graph paper with a slide rule and would point out where TurboTax made errors. Amazed me every time! Skill beats tech every day of the week.
I have a handful of them. Post made good utilitarian rules - bamboo with plastic scales. Castel made plastic ones that were quite good though not really rugged. K&E made great ones - mahogany with ivory scales. They are things of beauty and could get one very close to at least 3 significant digits. The CF scales were handy because it began and ended with pi. So, when I went back to school in 1980 and tried to buy a new one, I was chagrined to find they were no longer sold. The world had begun using calculators. With batteries that had a bad habit of dieing in the middle of a Physics exam...
We also had tables of Trig functions and logs so if we needed more than three significant digits we could use logs, interpolate and get awfully close. Until reliable calculators. I have an HP-15C. It isn't for sale...
+ Joe Burks: And don't forget the aluminum ones that Pickett made!
Fred
Don't forget the slide rule maintenance tool. a good number 1 pencil. When the slide got a little stiff you'd pull it out and use the pencil to lay a little graphite lube on the rails.
Cool! I've wondered for years about how slide rules work! Thanks
@TyYann You can buy original '50s, '60s slide rules on ebay. But no one makes them anymore except Think Geek.
Does think geek still make them?
I saw a sign in a playground once:
SLIDE RULES:
1. No climbing up the chute.
2. No stopping midway down the slide.
3. Only one child at a time on the slide.
4. Devices with logarithmically spaced calibrations used for rapid calculations.
Your video is excellent. I'm going to get my I slide rule out I haven't seen it in years. Thanks.
I used to use a slide rule in precalculus and such. They're very handy!
Wow, I was just researching this late last night and now you made a video explaining what it is! That's quite cool :P
Thank you!
In early 70s my college chemistry professor banned electronic calculators, only allowed slide rule to solve math problems in classroom. Improved my math solving, scale reading, and estimating ability.
Hi! I am the Head of Public Enlightenment for the International Slide Rule Museum. Would you be interested in joining one of our meetings online? It would be great to have you!
Thanks for sharing how they work, I always wondered. So simple, but so clever.
I have my Dad’s Eugene Dietzgen Co. Multiplex Decimal Trig Log Log slide rule. Slide rules are supposed to yield 3 significant digits but I haven’t achieved that yet. I found the instructions on line for all the calculations it’s supposed to do.
This slide ruler I've seen in a movie "The wind rises" by Hayayo Miyazaki from Ghibli, Japan. And surprised to see this. Amazing calculator. 🤓🤓🤓
I love your enthusiasm for maths :D
I mentioned the term "Slide Rule" to a fellow engineer at work one time maybe 10 years ago. He didn't have the slightest idea what I was talking about. So, the next day, I brought in my old slide rule that I had used in my college days. There was a time when they were standard equipment for any engineering student and classes were taught on how to use them. Mine was a higher-end model and is still in very good condition.
@@ShootBigBucks There is nothing more to the story. He didn't know what a slide rule was, so I brought one in and showed him.
Gotta thank you for making this video! My grandpa (A former engineer) left behind a stack of these when he died and no one could figure out how they worked. Well, mystery solved! =D
0:35 " slide rulers were big in the 50's, but then again so were rickets" What is this freak talking about?
My father, an aerospace engineer, and NASA were using slide-rulers as recently as 1970! Go check out that film: Apollo 13
you saved my life. actually. oh my goodness, thank you soooooo much! you're the first person who explains it well!
that was a really good and enteraining discussion of how the slide rule works. my dad showed me as a kid but i did not really understand why it worked. thx man
You can make your own slide rules. Search online for PDFs to download and print. Some are made by folding paper, others you could make by printing them on sticking paper then pasting onto cardboard or wood.
Or write a program to generate the scales. They represent mathematical formulas, after all.
I literally drew the scale on graph paper using a calculator. It's not the most accurate, but it still works for integers.
How did you draw the scale? I’m missing where to place the numbers at
+ Zurviver _ : Lay out your scale interval; call it the x-axis, from x=0 to x=L, the desired length of the rule.
Then each number, N, is "plotted" at x = L*frac(log₁₀N), where frac(a) = the fractional part of a.
Fred
"cool people"
@anticorncob6 No adding or subtraction on a slide rule.
Actually, Dr. Grime, there are a couple ways to do that, although they are a bit awkward. Let's say you want to add x + y.
One way is to use the L scale, using the cursor to find 'proxies' on the C and D scales for x and y on the L scale. (IOW, you find 10ˣ and 10ʸ)
Multiply the proxy numbers (10ˣ·10ʸ = 10ˣ⁺ʸ), and read the result, x+y, back on the L scale.
Another one I used to use, and which is maybe the ultimate in nerdiness (or "coolness"?). It's in three steps:
1. First divide: x/y
2. Mentally add 1 (OK, this is kinda cheating, but it's an easy thing to do without computing aid), and move the cursor to that value
3. Multiply by y.
Result: x+y.
And no, my real name *isn't* Rube Goldberg.
Fred
You can make an additive slide rule out of two ordinary rulers with evenly spaced calibrations (inches or centimeters).
That was . . . awesome LOL I really want a slide rule now!!!
A magical digital display shows "Error"
I one from a rocket scientist. His name is Bob Loos. When he died one of my relatives was helping clean out his house, and asked if he could have the slide rule. And he gave it to me
I have a slide-rule in my closet. We had to buy one for school in the early 70s. We leaned how to use them is school. We had log tables too. I still have mine. In about 1973 pockets calculators became affordable and within about two years, slide-rules telecom disappeared. I Britain, our school year (grade) was the first to be allowed to use electronic calculators in official exams. That was 1976.
More advanced math than numberphile series - I really enjoyed that, especially as a fresh MEng graduate. Really glad that RUclips suggested me this movie.
Also, I am a fan of your approach and attitude as a teacher, doc.
Actually this made me want to use a slide rule, but I can't find any practical use for it right now. ;)
first i thought someone stole numberphile video and was thinking about reporting :D
Nope, it's just me.
Thanks for the class. Very clear
Great article on the slide rule. I remember using the slide rule..it was a fascinating tool to do calculations. Today we have cheap scientific calculators that do it all automatically. The advantage of using slide rules was that it enabled you to understand math concepts.
+Douglas Fawkes
Right! You had to be very careful with roots for example. To calculate the squareroot of 200 for example, you had to calculate sqrt(2) with the sliderule and multiply the result with 10, because 10 is the squareroot of 100.
Or when calculating the sine or tangent of small angles (
Yes there were all kind of slide rules other than the basic one. However they certainly made you apply math to the practical everyday things in life..... I kinda miss 'em.
My grandfather did not work with Neil Armstrong or Buzz Aldrin but he is good at using one.
Good at using a Neil Armstrong? Or a Buzz Aldrin? Or both?
Wow. That was complicated. I think I would have to watch this several times before I actually understood it. Still, the enthusiasm and knowledge that poured from the video made it entertaining non-the-less.
Thanks!
today my dad gave me an antique slide rule, made in 1900, and now i can learn to use it :D
The B-52 bomber, which is still in service, was designed using these...
Very clear and well presented..
Before we got the slide rule we had to use log tables and antilog tables.
You have to wonder about the genius who calculated them in the first place and wrote those out.
I made my living by my slide rule.
He seems so happy
I had one during my engineer studies in the late 90's. The only thing we did with it was learn to use it though. HP48 was the boss of the day. Sadly, I lost it at some point.
Oh, Nostalgia. I still have all three of my slide rules. Don't use them, just can't bear to part with them. About 10 years ago, I finally got rid of my three Volkswagen bugs, but not my slide rules.
Idaho Spud Why'd you rid yourself of the VW bugs? They're awesome cars...
I've been staring at mine blankly for far too long, so thank you for some basic instructions. It'd be nice if geeks had this sort of awesome status again. Then again, being able to use a slide rule today proves pretty geeky, albeit retro.
Thanks!
Cool! I love these videos.
@orangetj1 This channel is also on iTunes for download. It has a different name on iTunes, search for "Quite Easily Done".
Brilliant! Thanks.
Excellent video. This guy makes mathematics really fun and interesting.
My school years preceded calculators so we used slide rules. I remember having a circular one, though I don't recall any differences to the straight ones. It was a long time ago!
Circular ones give automatic wraparound at the ends of the scales.
This is convenient where it makes sense for the scale. Not all scales make sense to wraparound.
The downside with circular rules is they tend to be bulkier. That’s why straight ones tended to be more popular.
For people who like their maths UNPLUGGED.
It is not just Think Geek. A Japanese company called Concise still produces a few Circular ones. They supplied one for my collection. I've no idea why they still do Slide Rules as there other wares are things like purses, wallets and small travel items.
There was talk about that when I was working for McDonnell Aircraft
in St. Louis but it was determined to let Houston do all the heavy stuff.
But I think one did make the trip anyway.
@aznlalaland Straight edge? Isn't that metalheads who don't drink? Because I'd love to make a video about that!
I'm a ruler just like you
But I've got better things to do
Than sit around and math my head
Hang out with the living dead
Mark white boards with my prose
Cross out at the shows
I don't even think about speed
That's something I just don't need
I've got a straight edge
Euclidean geometry with straight edge and compass?
Is that a moral compass?
Im a metalhead that doesnt drink! :D