Genius of Precision
Вставка
- Опубліковано 12 вер 2024
- In this episode we look at the genius manifested of the design of scales on the slide rule- specifically, how do you get the precision of a 20 inch slide rule out of a 10 inch slide rule? The way they did it was beyond clever....
Remember to hit 'Like' and 'Subscribe', your support of this channel is appreciated.
Join our Discord Channel at / discord
Help the Channel by joining our channel as a member
Patreon- / bobthescienceguy
or sending a Paypal for equipment (I do take requests for content)
www.paypal.com...
I did my A Level exams with a slide rule. Five years later I was using a Casio scientific calculator and writing stats analysis programs for THE computer at my college for my Diploma in Management Studies.
I still love slide rules. They designed Vulcan, Blue Steel and Concord, and the ships my grandfathers sailed. I have my father's, with his main engineering formulae printed on its back. He literally did rocket science with those equations and that slide rule.
Before the advent of electronic calculators, the Irish Department of Education used to issue a little yellow book of Logarithm, Trigonometric, Physics and Chemistry Tables for Secondary Schools (High Schools). The Department's genius touch was that we were provided with a clean copy of the 'log book' for the high school graduation (Leaving Certificate) exam, which is the portal exam to third level colleges. Even the fairly average student was aware that if you knew and understood how to use what was in the 'log book', you were already half way to doing ok in the exams. We came to know that little book backwards, and knowing it made us numerate in a way high school students today seldom seem to achieve.
Exactly. We made a grave error in letting calculators in the high school
I had one of those books, imagine its value 200 years ago
@@sliderulesandmathematics9232and now they're letting AI in.
It’s a beautiful object of industrial design. But so is the HP-45. I do agree with the other comments that the Slide Rule and long hand computation give you a superior feel for numbers unlike anything else.
Thank you, Bob, for your video. For those who are unaware, a "10 inch" slide rule has an actual scale length of 25.0 centimeters which is 9.84252 inches. This was because slide rule manufacturers used an international standard scale length of 250 millimeters.
We refer to it as a 10 inch SR because- Murica. But of course you are correct. A 20 inch slide is actually 50cm.
@@sliderulesandmathematics9232What is Murica?
@@pawelpap9 America
Some might be unaware of a concerned with a conversion of a three significant digit number (25.0) to a six significant digit number (9.84252).
Fortunately, Americans in STEM who cling to imperial are fading out of existence.
I've even switched to metric recently for my home projects, and millimeters are way more convenient for measuring and cutting. We are metricating slowly, but it is happening.
I started college in the fall of 1975. Using my savings, I bought a “Bowmar Brain” calculator in the fall of 1974 which I used for my high school physics class. Nobody else in my class had a calculator. By the spring of 1975, both Texas Instruments and Hewlett-Packard came out with “scientific” (notation) calculators.
About half the students in my college Freshman Chemistry class started out using slide rules. After the first examination, almost everyone was using a calculator. After the second examination, all those who had clung to using the slide rules had either switched to using a calculator or dropped out of the class. By the time of the final examination, NOBODY was using a slide rule. For the remainder of my college career, I never saw a slide rule again.
I started high school in 1975 so I just missed it
My first calculator was a Rapidman 800, which was just a "four banger" (four function) with fixed 2 decimal points. My next one was a Novus Mathematician, which was a full scientific calculator that used RPN. Then, I had a couple of Sharp scientific calculators, one of which is still in my desk drawer, along with a Pickett Microline 120 slide rule, which I bought when I started high school in 1967. These days, I have "RealCalc" on my Android phone.
Yes being at college in the early 70s , i always remember seeing a lot of trash bins with slide rules in them , with the introduction of pocket calculators . My college tutor showed me his calculator he bought in the states , it was like a small brick in size, with basic functions he then showed me his scientific calculator it was light years ahead in capacity and functions .
In Middle School we used Log tables. In High School they deemed us ready for slide rules. Everyone had one and used it every math class ... or tables, and did so well into University.
I remember when my science nerd buddy got one of the first TI/HP calculators (can't remember which one) on campus in 75 ... what a thrill.
@@kaoskronostyche9939 We used log tables in high school math class but a slide rule in electricity, electronics and physics. That was likely HP you had, as TI came a bit later.
As an engineering student, I was darn good at using my slide rule back in the 1960s. I knew all the scales. I still have it. Mine has a belt loop on the case. I could wear it walking around campus. Pretty nerdy huh? I also had a pocket protector, which was actually more than nerdy. Ink pens leaked a lot in those days.
I got very comfortable with my "slip-stick" (I still have it somewhere) while getting my BSEE from 1970-1974. There is no better way to develop intuition about engineering calculations than spending hours every day doing them on a slide rule. In my five decades as a professional, that deep intuition about numbers is arguably the most valuable asset that I acquired during my undergraduate years.
The ability to look at or listen to an analysis and "smell" that something isn't right is especially crucial when time or life and limb is at risk.
Absolutely. I would essentially outlaw calculators in high school in favor of slide rules. When you are working the trades or going to college then you can use calculators to apply the insight you learnt with the sticks
We are hitting the LL scales next, then specialty scales like P and hyperbolic trig
Yes, the Tay Bridge which collapsed in 1979 looked unsafe even to untrained people, some of whom refused to cross it. Lessons were learned, and the later Forth Bridge consequently is very sturdy indeed.
One of the more subtle aspect of the slide rule is the 3 significant digit precision. As a result, many things were slightly 'over' engineered just to make sure...
I remember walking around the U of Illinois campus in the early 1960s wearing this on my belt. We used to have fun seeing how fast we could draw them out of the case.
Boys will be boys. Everything is a challenge
This site is an interesting find. I still have several slide rules from my school days in the '60s. Also had several 'Concise' brand circular rules.
Concise (Japan) STILL makes those circular slide rules….I bought one for my slide rule collection. I didn’t think there was much of a market for those, but they must sell enough of those to make it worthwhile.
Brit here : Slide rules were/are? fine for structural design, as it involves varying factors of safety and empirical strengths of materials. I mainly did highway design, pre-computers, and that did need strings of significant figures. I mainly used 8-figure logarithms, and eventually a crude Friden calculator, which cost £800. A very senior colleague much later gave up his slide rule only because of the constant jeering he got from the youngsters with their fancy calculators. We went completely metric on 1/1/1968, except for the distances on road signs.
Not completely metric. Pints of beer, pounds of flour, etc. Weights and measurements were imperial.
@@pentachronicI agree ; I was trying to to refer to UK civil engineering in particular. Of course we now buy our road fuel solely in litres, but still talk about miles per gallon. I don’t think litres per 100km will ever catch on here, especially with mildly eccentric Britons such as myself.
@@pentachronic I'm a beer drinker from the future and I just wanted to drop in and let you know that a "pint" is *NOT* a unit of measure. A "pint" simply means a glass of beer. A glass of beer is generally about 500 ml, but it varies a lot. If you prefer your beer in a can, you can ask for a "tinnie" instead of a "pint".
@@DemPilafian Legally in the UK a Pi t of beer IS a pint. This is controlled by the weights and measures act. Now you know! www.cityoflondon.gov.uk/supporting-businesses/business-support-and-advice/trading-standards/weights-and-measures#:~:text=Most%20pubs%20use%20what%20are,the%20level%20of%20one%20pint.
@@DemPilafian Legally in the UK a Pint of beer IS a pint. This is controlled by the weights and measures act. Now you know! www.cityoflondon.gov.uk/supporting-businesses/business-support-and-advice/trading-standards/weights-and-measures#:~:text=Most%20pubs%20use%20what%20are,the%20level%20of%20one%20pint.
I'm 83 and a retired Engineer. Brings back many memories. I bought my first slide rule in 1961. I still have it, along with 3 more.
My first electronic calculator was bought in about 1975, I think. All it could do was add, subtract, multiply, and divide. It cost me £80! Still got that as well.
In about 1997, my daughter's mathematics classroom in high school had a large 8 foot long basic working slide rule on the wall. I asked the teacher if he used it, but he didn't know how to. I offered to teach him, but he declined. I offered to buy it, but my wife vetoed that. Pity. It would look good on the wall of my man-cave.
(Thinks: I believe I could make one in my workshop. Secretly, of course.)
I have a 7 foot Pickett
I also have my father’s (ME U of M 59) and grandfather’s (CE Cornel 25) KE slide rules
I had a student quality slide rule in HS in the 70's. Last year, some slide rule videos crept into my YT feed probably because I did some researching of the fantastic movie "Hidden Figures" where they showed all the slide rules being used during the space program. Anyway, I went on Ebay and found the same model I had and bought one, and bought a little larger one to relearn how to use them and play around with them. It brought back fun memories and the beauty of them. I love watching these videos. Unfortunately, it make me feel old lol
Until very recently I suspect, all airplane pilots were familiar with and used a circular slide rule for routine nav calculations. I have one along with 6in. and a 10in. straight plus a telescopic Otis which I never really got the hang of! Wonderful tutorial.
The e6b
I just got an Otis but haven’t played with it
E6B is "the most reliable computer in the cockpit".
Thanks for this.
I have a British Thornton stored away somewhere but haven't used any slide rule since my first job in R&D at British Steel about the time the first calculators turned me into a lazy sod.
Tried to impress my offspring with the genius of a device that needs human intelligence for its operating system, but....
I got a Thornton or two this week
My K&E Decilon slide rule has Sq1 and Sq2 scales analogous to the scales you demonstrate here, but I had never looked at them until today!
Yes, my dad was a KE fan, me I prefer the picketts or the German tiles with the P scale. I have his 4080-3 from his college days and my grandfathers KE from the 20’s
I also have a very nice KE 20 inch rule
I've never used a slide rule but they were cool to me even when I was a kid at a time where pocket calculators started to appear in my country.
Slide rules gives you a different dimension to the numbers you are looking for. That dimension is in the movement of your hands that feeds back into your brain. That movement gives you an insight to what the numbers are actually doing. It's not about precision but about the engineer feel for the problem. If you want precision you can get it but that is irrelevant most of the time.
I've had the privilege of having a microwaves class where the teacher asked us to make all calculation in our head. It was not about precision but about the feel for the numbers: was that answer about two volts or two hundred? It was not about decimals. By the end of the first hour I came to an appreciation of what he was trying to do even though I was silently mad at him for 'forbidding' pocket calculator. Doing all those rough calculation in our minds was not necessarily faster. It was faster in giving us insight.
I was a student in one of the last classes at the US Naval nuclear power school that was required to use slide rules. (This was in 1977) One or two classes later, they started allowing the use of calculators. I was shocked by the drop in understanding of basic mathematics the resulted from that decision.
We lived with our slide rules back in the 60s. I bought my first TI calculator in 1972 for $275.00, (the only one in engineering dept).. suddenly, I had a lot of friends.
I bet you did
and that you got really good with it.
$275 was pretty serious cash in 1972.
I'm told it is on the order of $2400 today.
My father, who was a professor of Electrical Engineering, had a circular slide rule. He used to challenge his students to a race to carry out a calculation - they using calculators. He used to beat them.
Only use mine for nostalgic fun since the HP-35 calculator came out many years ago. Fun to be reminded of features whose use I'm no longer sure of.
Glad you like the series
I still have my Blundell Omega 605 - with me now for almost 60 years and it still works😂. Original leather case needs re-stitching.
Those were the days. I remember one exam at university my brand new electronic calculator gave up the ghost. Thank goodness I had my old slide rule at hand. I think that I still have it in a box in the attic - the electronic calculator has of course gone the way of all electronic devices.
Long since misplaced my slide rules & log tables which were part of my life throughout school, my phone has an app which would have flown Concorde or controlled the space missions, but I largely use it for simple arithmetic. So much change in so few years!
I have 4, 3 K+E and my Dad’s Dietzgen super duper log log mondo scale rule. The Dietzgen has a high quality feel to it.
Very cool. I have one Pickett rule, but not the model with these great scales on it.
The Puckett n3 and the Aristo Studio. 0968 are the models I recommend. Plus there is a good virtual slide rule (n3) on the web. Link in the description
I’ve had couple during high school and college in the 1960’s. I still have and use my Diva 6” made in Denmark. I was given this one by an Ag professor at Michigan State for remodeling a room at his house. He didn’t give me any break on grades, in case you are wondering.
Thank God I started with abacus and skipped the slide rule show straight into calculators. Most school was done with paper and pen. Yes, they insisted on pen because errors were counted against your grade. I did see and use ink wells and quill for calligraphy too. Oh! The old days!
I've relied on software devices for calculations for many decades, but I used to have calculator and I was taught to use a slide rule, which I still have. Slide rules are still great for teaching about accuracy.
There were scientific slide rules where a lower line was 1 and the upper line was
times Pi just looking up on the hairline without moving the sliding middle.
And commercial slides where the lower line was 1 and the upper one was times 360 ( daily interest) and mark up or down was easy.
Yeah, and I know how to do slide rule stuff with logarithm tables ( lookup values adding and looking up the reverse value) with pen and paper.
But I’d prefer my Casio scientific calculator or TI- spire CAS app if I had such problems at all.
All I do is throwing SQL results at Pivot tables.
The faber Castell SR had an additional magnifying lens as accessory that could be attached to the clear thingy for improved (lol) precision.
I still have mine. Got me through Caltech in the late 60s. There were Pickett fans and K&E fans. Only the nerdiest hung them on their belts : ) I bought an identical one on Ebay for my granddaughter. I still have my little plastic circular slide rule from then, as well.
Cool. My only experience with a slide rule as a primary calculating device was the e6b flight computer
@sliderulesandmathematics9232 During my first year in grad school (1972), the (Astronomy) department bought a newly available HP-35 calculator for the (12 or slightly more) grad students to share. It was chained to a desk in our grad student lounge : )
And to think calculators are as valuable as paper clips now it seems. I think we all just use the free one on our phones
I prefer the tan/cream colored Pickett n3. Great scales and doubles as a katana
In high school, we lived with our slide rule. No self-respecting person was ever without one!
I got out my 55 year old Picket scale that I used when I took electronics in 1974. I can't say that I know how to use it now but I can't believe I didn't need a magnifying glass to use it back then.
Damn, brings tears to my eyes. I remember quite well when, as an undergrad EE in 1970 something professor Leon Zelby showed us how to use the binomial expansion to get accuracies of 5 decimals from a slide rule. Damned if I remember how ro do that now. He still had his concentration camp tattoo. Wonderful soul.
I had a cheap 6 inch plastic slide rule going through engineering school in the early 1970s. I only needed the basic scales.
I eventually got a Texas Instruments scientific calculator. I could also use the college computer (punched cards in FORTRAN).
In the early '60s, we got three-place answers, but we had to calculate the place, 1.0, 100, or .001. Villanova had an IBM 1620, the size of an upright piano. We used punch cards and made money troubleshooting other students' errors. Now, we use a concrete slide rule for the quantities. I then enter all the numbers into a program to verify the answers. At $265 a cubic yard, we cannot error. BTW; IBM could calculate massive cut and fill jobs, and calculate the offsets, etc.
in th 60's and 70's ,there was the hemmi slide rule made with bamboo and plastics. it was made in japan.with a leather case.
I have here a yellow Pickett Microline 120, which I bought back in 1967, when I started high school and it still works! 🙂. It's a basic slide rule, which I used in my electricity, electronics and physics classes. I paid $2 for it, IIRC. I also recall my electronics teacher had a slide rule that was customized for electronic calculations and included things like reactance.
Ok. Sure but the batteries for that model are so expensive
you can get them on line on Amazon. Right next to the Kidneys.
First time here. Grew up with slide rules. Father had one to calculate trigonometry and metallurgic properties. As students through middle school, high school and into university until the HP and TI units came out, slide rules and math tables all teh way. Now I have to go dig out my collection of slide rules and see what I have. Cheers!
Cool have fun
The double-length square root scale is a nice feature of the Picketts. I used a Model 4 in high school and college, which I still have.
yes, the n 2/83 has the W scales which are similar.
I still have a Faber Castell sliderule that I bought in 1965 for £5/10 shillings. £5.50 in modern GBP. That was what I earned working 2 weekends in a garage when I was at school. I got a degree in Electrical engineering using it. I lost the rubber ends for mine just as you don't have.
😂😂😂 my teacher from Aviation Academy back in 1983, in Riga. Always tried to maintain, that you can find the size of anything without knowledge of basics, excellent for fast figuring physics, mathematics, music.😂
I still have my slide rule from high school physics in 1970. The kids with the money bought the first of the pocket calculators from Texas Instruments. The teachers told those kids to put them away because, one day, the battery may die and then they'd be stuck. Years later, when I was doing my accounting studies, I bought a calculator. A solar powered calculator. I still have that too. And it still works. But the slide rule is still pretty neat to have.
They are indeed
Have you looked at circular slide rules? I had a 600 inch equivalent with 5 digit accuracy. But I often had to solve the problem with a regular slide rule to make certain I was on the correct spiral scale.
Yes o have a fuller and a precision circular rule
In college I used that Pickett slide rule with the split scales, mine was the standard yellow. In high school I used the standard Pickett "Texas Speed Rule".
the Texas Speed Rule is quite rare and worth around 300 bucks today, if not more.
@@sliderulesandmathematics9232 I used mine a lot in UIL competition so it isn't in museum quality.
So you competed?
@@sliderulesandmathematics9232 yes.. there were some powerhouse teams in my district that were very hard to beat so I never won anything.
You and I should get together first a tips and tricks livestream
I still have my 70s-era slide rules from High School. I still use it occasionally for proportions and conversions.
I started high school in 75. I’m sorry I missed out on the instruction and use in the early 70’s
I have a 66" helical slide rule. Only has the C and D scales plus a log scale. Weird British device but it works.
Yes they get crazy accurate with those long scales.
That was very interesting, it's been years since we had slide-rule classes in Junior high. I've forgotten everything about them. I should probably revisit the skill again. Any suggestions for doing that?
Well I just put this series together. Only two more to go
Still have one. N-500-ES Still use it from time to time. I also use log tables and trig tables. It just depends on how I feel that day.
One of my favorites
I used a K+E 20-inch for the first year of engineering school in 1975. Our “Introduction to Engineering” class spent quite some time teaching us how to use the slide rule. In my second semester, in 1976, relatively cheap Casio scientific calculators became available in my home country, and the slide rule soon became obsolete. Some professors wouldn’t let us use calculators in the exams. They insisted we needed to really learn how to use use the slide rule in case “one day, in your professional career, you are in the middle of an empty field, and the calculator’s battery runs out of juice.” By the end of my second year of engineering school, calculators were widely in use. I still keep my K+E, however, as a reminder of my transition to college. Slide rules were some clever calculation tools, and the only portable calculation tool available to anyone from the 1600’s until about 1970.
I love the 20 inch KE and use it regularly. Great accuracy and clear numbering
Maybe I should dig out my 8 inch circular slide rule. .I had trouble with my high school Physics teacher when I wanted to use it instead of doing hand math to 3 and 4 decimal places.
Thanks for the video.
You are welcome!
I saw a much larger slide rule someone had ... I think it was something like effective 50m or more, printed with the scales spit around a drum. Made years ago by, I think it was a German company if I recall correctly. These were quite popular for, e.g. use in banking in the 1940s ... want to calculate that 30 year multi-million dollar loan, and be quite accurate ... yeah, 50m or so long slide rule.
Sounds like a fuller calculator. The scales are 41 feet long
Wright Brothers first flight, Dec 17, 1903 > Chuck Yeager X-1, breaks sound barrier Oct 14, 1947 > less than 44 years, all with slide rule
I really enjoyed your video, thank you 😊
My mind is very non- mathematically inclined, but it looks very interesting to the point of being good fun.
Speaking of ruler…maybe there’s an etymological link to ‘rules’. The Latin root designated a measuring rod. Just a reminder for those who think they can be clever with the interpretation of Law. A rule does not bend. If it can be bent, it loses its value and is not Law.
(Sorry about my rant 😄).
Glad you enjoyed it!
Thank goodness for the invention of the electronic calculator.
You may have missed why slide rules are such superb tools. If you just use an electronic shoveler you’ll never know if you have made a huge mistake. Slide rules however force you to determine the order of magnitude estimate and then a rough idea of the first few digits. For example, what are the square roots of 2, 20, 200 and 2,000? On a calculator you might not determine if you have left of a zero or even typed in the 2 correctly.
@@Trevor_Austin Perhaps you meant that slide rules WERE superb tools when they were the only option. I don't know anyone who continued to use tnem once electronic calculators came out.
I do for many things, especially trig.
Not really. Calculators and computers only make people unwilling to think.
Do they have cos / tan / arccos etc?
Could they be laser printed?
Hi Bob, I've never found any explanation of how the logarithmic scales were actually marked in the first place. Most slide rules say they're "engine divided". What does that mean, and how was it done? I'd love to see a video about it.
There was a device called a ‘dividing engine’ that calibrated the markings on engraved rules. Pickett used a dividing engine to create a template and then used it for a photo printing process.
americanhistory.si.edu/collections/nmah_1802358 here is a dividing engine
1973 Engineering colleges still used slapsticks by 1976 they were history. I kept my picket for decades in 66 my first was bamboo simple 12" starter
Wow. Used slide rules in high school physics. Calculators when I got to college (1971).
When I started work, we had a one of the cylindrical extending models. Unfortunately, calculators were just coming into use, so it never got used properly
The big ones were fuller calculators. I got mine from the UK
There's something extra when you learn about how to use tools like these "slipsticks", nomographs and such, that you don't get from a calculator or computer. They're more visual, literally hands-on, and I think they promote a better way to visualize the math in your mind.
Plus there are some things like tables and radioactive decay that are actually easier on the slide rule. I’m starting statics in May and plan to use mine for vectors
They seem complex - how long did it take to get used to them?
Really not very. I’ve been using them for a couple of years but it took me an afternoon or two to get the concepts down. It makes sense to me
I just missed using the slide rule - calculators just came out cheap for use to buy.
I used a Pickett slide rule for years as a C-141 Flight Engineer. Then, they issued HP 41CV calculators which I used until I wrapped up my Air Force career.
STILL have mine and left high school in 1969. I thought it may come in handy some time, then they brought out scientific calculators. 🥴
Does anyone know of a Post/Hemmi Slide rule that also works in 20" scales on a 10" rule similar to the 2/83N?
I had to use a slide rule in high school. Hand held calculators came out when I graduated.
I had to take university physics using a slide rule. Luckily they gave 90% credit on answers that were orders of magnitudes off if you showed your work but did the slide rule manipulation wrong.
“Physics ?” - we had to do “Natural Philosophy “ - the same thing - I think !
I still have a six-foot Pickett slide rule used for teaching purposes! Got to find a way to unload it.
as in sell it?
I just bought a 7 foot pickett N-500 teaching rule for $450 with shipping. Hope that gives you some idea of what it is worth. You can see it in the background of this and other vidoes.
@@sliderulesandmathematics9232 thanks for that. I will miss it. Been a part of my teaching career from the beginning. 😥
I am getting ready to start mine (in about 3 years) and that is why I got mine. I'll be using it in the class room. Swing by the 'slide rule fan club' on facebook and see if there are teachers looking for one there. Do you know the model of the Pickett? Mine is an N-500
You pulled out the Faber Castell, and I had to back away because I started drooling on my keyboard.
Wait til you see the fuller calculator
@@sliderulesandmathematics9232 Never used a Fuller so it won't have quite the same effect.
Concord was designed in the early 60's using only slide rules.
It was indeed, as was the SR 71
I carried an aristo in college. I started college in 1959. Not sure when I bought the aristo.
Great slide rule
@@sliderulesandmathematics9232still have the aristo. One nice thing about the slide rule is that "all" of the answers are available, so you can visualize how thing vary in and around your answer. Calculators only give a number.
absolutely
Impossible to follow this guy with his super small scale and unreadable scales as well as his super rapid changing locations before one can read any of the scales. I had to use a slide rule for surveying classes in spring 1972. The number of digits were to few to get accurate values of small angles with the trig functions. We had to do calculations long hand on paper. By the way, all the Apollo moon shots used slide rules to perform almost all the calculations.
My 50 or so year old Pickett slide rule works fine. It never needs batteries.
I have a mini sun-dial wristwatch. Runs great.
Does anybody know a place to buy a new slide rule?
Not new mostly but eBay is where I get mine
Did anybody else have a giant working slide rule positioned at the front of the room inmhigh school math class? For demonstration purposes.
I have one in my living room. I use it for big problems
In addition to the class textbook we also used the big CRC book of of trig & logarithmic tables. Math was heavy.
Can’t see a thing… 😮
Master
Slide rule porno click bait and I fell for it? To find Bob the Science Guy I watch on your other debunking channels? I have my fav old school Pickett on display. I was a Math Lab asst in college in '70, '71' and taught slide rule to the general class.
PRECISION!
True I will change it
ps: I remember being too lazy to remember my multiplication tables and using a rule....LOL
Many pilots still use circular slide rules as they don't need batteries.
The E6b
@@sliderulesandmathematics9232 Yes, that is one of them, mine is the Airtour "CRP-1 Computer"
IT I.S. 2 muCH for me, sir
Watch it a second time. It will come your way you.
cool
Geeks!
Absolutely!
Or dork! As in Doric! 😂
who knew
The shadow knows.
I have ---- wait a minute. Who the hell cares if I have an old slide rule or not!
We do
@@sliderulesandmathematics9232 Ok. Well actually I have a couple of the finest slide rules ever... somewhere in my stuff. See, my dad was a real (early) rocket scientist. I'm serious. He worked at White Sands and also at the ICBM missile base in the Marshall Islands, a good while ago.
fantastic!
@@sliderulesandmathematics9232 Hello again. I don't know if something odd is going on with youtube, but I no longer see my longer comment to which you replied "fantastic!".
I see it.
Your 20" is most likely a half-metre
Yep
What a madness! Just use the metric system which fits to all other basic units of physics, this nonsens would be obsolete...
Murica
this has nothing to do with the units of measure, but with the fact that the scales on the ruler are logarithmic and not linear
#’s are dimensionless
The slide rule is a calculation tool, and has nothing to do with units of measurement. They were used all over the world, including in countries which use the metric system as standard. It is the analogue equivalent of the pocket calculator, therefore your comment is the equivalent of saying "just use the metric system and calculators will be obsolete".