I am a civil/structural engineer. I am semi-retired, and I want to keep my mind active. I enjoy machinist work and woodworking as hobbies. At the beginning of this year, I broke 2 fingers on my left hand. My hand was in a cast for several weeks and I couldn't do any of that. I missed the slide rule era in school. I had my Dad's slide rule and determined to learn it. This got me back into relearning a lot of math that I had not used over the years. Your slide rule videos have been a big help. But, I agree with you that numbers and math are fun. I am really enjoying it. And, I am getting pretty proficient with the slide rule. Good luck in your new endeavors.
I wish that I had know what the homework problems were before you released this video. Wasn't inclined to work all 79 problems. And yes, I will pause the video before each of your solutions.
0:28 i would think (and did think) that the SI unit of mass was a gram. i appreciate you clearing up my misconception. (on a completely different topic, i recently had an infection in my foot that required a toe amputation. they used local anesthetic and i was able to watch the doc do the surgery. it was a fascinating procedure. my friends think i am weird for wanting to watch.) 😃
After the French Revolution in 1793 they initially introduced three new mass units to replace the old ones: the "bar" (one cubic meter of water at melting point), the "grave" (one cubic decimeter of water) and the "gravet" (one cubic centimeter of water). This was modified in 1795 and the smallest was renamed from "gravet" to "gramme" - after Late Latin "gramma" for "a small weight" and being 1/24 of an ounce or a bit more than a modern gram (originally from Greek). By then it was deemed unnecessary to have three weight definitions, so the "grave" simply became the "kilogramme". But handling water at defined temperatures is a bit of a hassle, so in reality water of 4°C (greatest density, doesn't change much around it) was used and it was decided to manufacture a metal "original", but since a gram of metal is so small the kilogram was used for it - the "Kilogramme des Archives" of 1799. In the 1860s the originals of the meter and the kilogram showed wear and tear and it was unsure if they could be reproduced accurately enough, so the metre convention decided that the existing ones to be reproduced. The kilogram was reproduced 40 times, one was decided to be the new original and the others were kept as reserves and distributed as national standards. Several decades later it was noticed that these artifacts started to differ from each other ever so slightly, and the kilogram seems to get a bit lighter over time, so the kilogram since 2019 (when it was finally possible to have fine enough measurements to do so) is now again based on nature and defined by the Planck Constant, the meter and the second (which both already were defined by universal constants). So essentially if the French Assembly had decided to use the _grave_ and not the _gravet_ the gram would now be the milli-whatever.
@@sliderulesandmathematics9232 yes, the SI is based on kg, meter and second (although nowadays all are derived from universal constants). Please note that even the c/g/s system has a decimal prefix: it's *centi*meter, gram, second - and the kilogram was used as reference weight for over two centuries in a physical form.
Question, at 7:52 you are calculating 1/9.11 and come up with 0.1098, wasn't there only three significant figures there? I missed how we have four figures in 0.1098
I am a civil/structural engineer. I am semi-retired, and I want to keep my mind active. I enjoy machinist work and woodworking as hobbies. At the beginning of this year, I broke 2 fingers on my left hand. My hand was in a cast for several weeks and I couldn't do any of that. I missed the slide rule era in school. I had my Dad's slide rule and determined to learn it. This got me back into relearning a lot of math that I had not used over the years. Your slide rule videos have been a big help. But, I agree with you that numbers and math are fun. I am really enjoying it. And, I am getting pretty proficient with the slide rule.
Good luck in your new endeavors.
That is really great to hear- this is a lost art and actually quite a bit of fun.
i love my sliderules. welcome to the "Mathematical Anachronist's Club"! if you're interested, you might want to look up *_"The Oughtred Society"_*
@@sliderulesandmathematics9232 not lost. just fading/niche. i suspect it'll never be completely lost (at least i hope not).
I want to add to the thanks for the sliderule videos. I have one with log log scales and they really add to the challenge of using one.
I wish that I had know what the homework problems were before you released this video. Wasn't inclined to work all 79 problems. And yes, I will pause the video before each of your solutions.
I will try to put the problem list in the community section as soon as I get them.
0:28 i would think (and did think) that the SI unit of mass was a gram. i appreciate you clearing up my misconception.
(on a completely different topic, i recently had an infection in my foot that required a toe amputation. they used local anesthetic and i was able to watch the doc do the surgery. it was a fascinating procedure. my friends think i am weird for wanting to watch.) 😃
there is a c/g/s system, but officially it is kg/m/s. At least that is my understanding and verified by a couple of sources.
After the French Revolution in 1793 they initially introduced three new mass units to replace the old ones: the "bar" (one cubic meter of water at melting point), the "grave" (one cubic decimeter of water) and the "gravet" (one cubic centimeter of water). This was modified in 1795 and the smallest was renamed from "gravet" to "gramme" - after Late Latin "gramma" for "a small weight" and being 1/24 of an ounce or a bit more than a modern gram (originally from Greek). By then it was deemed unnecessary to have three weight definitions, so the "grave" simply became the "kilogramme".
But handling water at defined temperatures is a bit of a hassle, so in reality water of 4°C (greatest density, doesn't change much around it) was used and it was decided to manufacture a metal "original", but since a gram of metal is so small the kilogram was used for it - the "Kilogramme des Archives" of 1799.
In the 1860s the originals of the meter and the kilogram showed wear and tear and it was unsure if they could be reproduced accurately enough, so the metre convention decided that the existing ones to be reproduced. The kilogram was reproduced 40 times, one was decided to be the new original and the others were kept as reserves and distributed as national standards.
Several decades later it was noticed that these artifacts started to differ from each other ever so slightly, and the kilogram seems to get a bit lighter over time, so the kilogram since 2019 (when it was finally possible to have fine enough measurements to do so) is now again based on nature and defined by the Planck Constant, the meter and the second (which both already were defined by universal constants).
So essentially if the French Assembly had decided to use the _grave_ and not the _gravet_ the gram would now be the milli-whatever.
@@sliderulesandmathematics9232 yes, the SI is based on kg, meter and second (although nowadays all are derived from universal constants).
Please note that even the c/g/s system has a decimal prefix: it's *centi*meter, gram, second - and the kilogram was used as reference weight for over two centuries in a physical form.
@@Engy_Wuck and we mustn't forget that other project of theirs... metric time.
Question, at 7:52 you are calculating 1/9.11 and come up with 0.1098, wasn't there only three significant figures there? I missed how we have four figures in 0.1098
Correct. Finish the entire equation then trim to proper number of sf. So 1.098 (4) should be 1.10
@@sliderulesandmathematics9232 Ah,that makes sense, thank you. Great vids, I'm watching them all