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The largest commercial cylindrical slide rule has a scale length of 24m

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Re: The largest commercial cylindrical slide rule has a scale length of 24m

#21

Post by yuubi »

sizzzzlerz wrote: post #12
jedimastert wrote: post #5

I love slide rules. The amount of functionality stuffed into such a simple device is beautiful. Also, turning multiplication/division into addition/subtraction with logarithmic scales felt like a genius level hack when I first learned about it, like the fast inverse square. On a mildly related note, does anyone know if it's possible to construct a logarithmic scale from simple tools? A demonstration I've always wante…

Maybe they focus the "old guy" rays I give off, but so do I. I have a small collection of slide rules, all normal sized linear types, which I still am fascinated with. They're all made between the 1940s and 1960s and aren't terribly rare but the care and precision that went into their manufacture is amazing given that they weren't terribly expensive back in the day. I especially like the one's made of bamboo. Not as…

Less precision, more speed than a digital calculator, in my experience (at least in high school physics class in the early 90s). Makes sense because the slide rule takes one precise movement per number but the digital calculator takes one movement per digit.

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#22

Post by carapace »

jedimastert wrote: post #19
carapace wrote: post #17

Earlier quoted context omitted.

Use a pantograph? https://en.wikipedia.org/wiki/Pantograph Log scale is a linear fractal, self-similar.

That would be useful for geometric scales, which I don't believe a logarithmic scale is

I could be wrong, I haven't had enough coffee yet.

Say you constructed a pantograph where the ratio of the "inner" point to the "outer" point was ... um ... log(5)? for a decimal scale? ( I think you could make a binary scale but I can't think what the ratio would be log2(1)? )

Anyway, you'd start with the pantograph's base and outer point at the ends of your ruler, mark off the inner point, and then repeat on each sub interval, and then again recursively until you ran out of room.

Like I said, I could be wrong about this.

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#23

Post by generalizations »

jedimastert wrote: post #5

I love slide rules. The amount of functionality stuffed into such a simple device is beautiful. Also, turning multiplication/division into addition/subtraction with logarithmic scales felt like a genius level hack when I first learned about it, like the fast inverse square. On a mildly related note, does anyone know if it's possible to construct a logarithmic scale from simple tools? A demonstration I've always wante…

Are slide rules still useful? I mean, are there calculations that are more convenient to do with a slide rule than a calculator?

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#24

Post by kens »

sizzzzlerz wrote: post #12
jedimastert wrote: post #5

I love slide rules. The amount of functionality stuffed into such a simple device is beautiful. Also, turning multiplication/division into addition/subtraction with logarithmic scales felt like a genius level hack when I first learned about it, like the fast inverse square. On a mildly related note, does anyone know if it's possible to construct a logarithmic scale from simple tools? A demonstration I've always wante…

Maybe they focus the "old guy" rays I give off, but so do I. I have a small collection of slide rules, all normal sized linear types, which I still am fascinated with. They're all made between the 1940s and 1960s and aren't terribly rare but the care and precision that went into their manufacture is amazing given that they weren't terribly expensive back in the day. I especially like the one's made of bamboo. Not as…

> always remember that we got to the moon on them.

Well, there were also 5 computers (one analog) onboard the spacecraft, multiple powerful IBM System/360 mainframes computing trajectories on the ground, a Honeywell 1800 assembling code, a whole pile of Univac computers (1230, 494, 495) processing data, and RCA 110A computers for mission control (including one inside the launch platform under the rocket).

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#25

Post by sizzzzlerz »

kens wrote: post #24
sizzzzlerz wrote: post #12

Earlier quoted context omitted.

Maybe they focus the "old guy" rays I give off, but so do I. I have a small collection of slide rules, all normal sized linear types, which I still am fascinated with. They're all made between the 1940s and 1960s and aren't terribly rare but the care and precision that went into their manufacture is amazing given that they weren't terribly expensive back in the day. I especially like the one's made of bamboo. Not as…

> always remember that we got to the moon on them. Well, there were also 5 computers (one analog) onboard the spacecraft, multiple powerful IBM System/360 mainframes computing trajectories on the ground, a Honeywell 1800 assembling code, a whole pile of Univac computers (1230, 494, 495) processing data, and RCA 110A computers for mission control (including one inside the launch platform under the rocket).

True, but my point was that the engineer's who designed the rockets and capsules and towers and just about everything else, including those computers, needed by the space program used their slide rules on a daily basis.

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#26

Post by kqr »

generalizations wrote: post #23
jedimastert wrote: post #5

I love slide rules. The amount of functionality stuffed into such a simple device is beautiful. Also, turning multiplication/division into addition/subtraction with logarithmic scales felt like a genius level hack when I first learned about it, like the fast inverse square. On a mildly related note, does anyone know if it's possible to construct a logarithmic scale from simple tools? A demonstration I've always wante…

Are slide rules still useful? I mean, are there calculations that are more convenient to do with a slide rule than a calculator?

Sure. One undeniable advantage they have is when it comes to scaling multiple numbers by the same factor (for example in the kitchen.) You just set it to the scaling factor and then don't touch it again. Reading off a scaled number is as easy as it gets.

There are other softer benefits too, such as making the quantities in the computation somehow more... visceral.

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#27

Post by HarryHirsch »

generalizations wrote: post #23
jedimastert wrote: post #5

I love slide rules. The amount of functionality stuffed into such a simple device is beautiful. Also, turning multiplication/division into addition/subtraction with logarithmic scales felt like a genius level hack when I first learned about it, like the fast inverse square. On a mildly related note, does anyone know if it's possible to construct a logarithmic scale from simple tools? A demonstration I've always wante…

Are slide rules still useful? I mean, are there calculations that are more convenient to do with a slide rule than a calculator?

Don't pilots have them in the cockpit? Easier to calculate remaining fuel on a slide rule than on a calculator, because the analog nature gives a plausibility check.

Wikipedia has an article: https://en.wikipedia.org/wiki/E6B

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#28

Post by Someone »

jedimastert wrote: post #5

I love slide rules. The amount of functionality stuffed into such a simple device is beautiful. Also, turning multiplication/division into addition/subtraction with logarithmic scales felt like a genius level hack when I first learned about it, like the fast inverse square. On a mildly related note, does anyone know if it's possible to construct a logarithmic scale from simple tools? A demonstration I've always wante…

Using straight edge and compass:

  - draw a line
  - pick two points on the line
  - label them 1 and 10
  - bisect the segment to get √10
  - bisect the halves to get 10^¼ and 10^¾
  - etc.
You can’t do much better, as the logarithms of rational numbers tend to be transcendental.

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#29

Post by jerf »

abecedarius wrote: post #16
jerf wrote: post #10

Earlier quoted context omitted.

"Pen and paper, compass and straight edge," Compass and straight edges compute what are called the constructible numbers [1], which have 0, 1, and anything obtainable via addition, subtraction, multiplication, multiplicative inverse, and square roots of positive numbers. These will not allow you to get to logarithms. You can't avoid having to calculate them numerically; from there you may also create approximations t…

OTOH the first log table was computed by taking successive square roots of 10. Then you use the binary expansion of each number on your scale, right? So compass-and-straightedge doesn't seem crazy, since square roots are easier that way than numerically by hand.

The original question seemed to be asking about how to make a real chart, that is, with real paper, pens, compass, straightedge, etc. In the real world, taking successive roots is going to bleed accuracy pretty quickly, and when you feed that inaccuracy back in to the e^x function, it's going to bite pretty hard. I don't think it's practical to get the requisite level of accuracy this way.

Re: The largest commercial cylindrical slide rule has a scale length of 24m

#30

Post by syntaxing »

I never got to use a slider ruler but I got a couple of gems from my older coworkers that were catalogue slide ruler (not sure what its called). There was one that you pulled a couple sleeves and it gave you the clearance hole for the corresponding screw. It's kinda crazy how functional these manual lookup tables were and designing it must of been a form of art.
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