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Rulers of the Ancient World: period correct measuring tools

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Re: Rulers of the Ancient World: period correct measuring tools

#71

Post by arlort »

legitster wrote: post #15
BitwiseFool wrote: post #4

While I am no apologist for the measurement system we use here in the United States, I realized something interesting when trying to explain why almost all of our units consist of easily divisible sub-units. Imagine you needed to split something up into halves, thirds, fourths, sixths, etc.. If you imagine doing this with paper, it's fairly easy. Now imagine Metric, and the need to split something into 10 even pieces…

Yeah, it's crazy to see my dad at work in his shop - the amount of intuition he has of fractional measurements is insane, but he can do the math so quickly. In that specific context, if you were to do the math with decimal measurements it would take longer and leave you with some funky units. It's hard to describe how you work with the fractions - but the lumber and the saw blades and the screws and even the finishes…

> if you were to do the math with decimal measurements

You'd end up building the same intuitions and speed that you have with fractions. It's all just a matter of familiarity

Re: Rulers of the Ancient World: period correct measuring tools

#72

Post by arlort »

BitwiseFool wrote: post #4

While I am no apologist for the measurement system we use here in the United States, I realized something interesting when trying to explain why almost all of our units consist of easily divisible sub-units. Imagine you needed to split something up into halves, thirds, fourths, sixths, etc.. If you imagine doing this with paper, it's fairly easy. Now imagine Metric, and the need to split something into 10 even pieces…

> and the need to split something into 10 even pieces

Why would you need to do that though?

Re: Rulers of the Ancient World: period correct measuring tools

#73

Post by Ekaros »

EnigmaFlare wrote: post #53
saalweachter wrote: post #41

Earlier quoted context omitted.

It's a shame that we entered the era of precision a century or so before we got some good science. We could have chosen so many different, cooler distance units than "one ten-millionth the distance between the North Pole and the equator, on a line passing through Paris". We could have chosen 1 nano-lightsecond! We could have chosen the wavelength of the hydrogen line! We had options, but we didn't even know them in 1…

Instead of having Avogadro's number at all, chemists could just count using numbers like we do for everything else. We already have the prefixes to make 10^+/-24 easy. No need to re-define it, just stop using it. It's nothing more than a conversion factor between two parallel unit systems that somehow both coexist within SI.

Avogadro's number is for making calculations including weight simpler. If I have x grams of carbon how many grams of oxygen I need to burn it all. And then how many grams of carbon dioxide I end up with.

Value is somewhat arbitrary. And could also be tied to some other isotope. It is really about the ratios between all the elements including their isotopes. Picking carbon and there of isotope C-12, and saying this is exactly 12 grams is not unreasonable selection.

Re: Rulers of the Ancient World: period correct measuring tools

#74

Post by inglor_cz »

darby_nine wrote: post #46
legitster wrote: post #22

Earlier quoted context omitted.

Although, it should be noted that the standardization of measurements themselves was mostly done by the founding of the country. Authority of the government to "fix the Standard of Weights and Measures" is in the constitution. From its founding, the US had one of the largest contiguously agreed upon measurement system in the world, sidestepping the problems of European measurement systems which changed border to bord…

[flagged]

While I am frustrated by freedom units sometimes, the truth is that the US simply started too late and the transition costs are too high.

It is a different story to change measuring units in a still-mostly-rural society with relatively few engineers and engineering projects - which describes Europe in the late 19th century.

Re: Rulers of the Ancient World: period correct measuring tools

#75

Post by inglor_cz »

wizardforhire wrote: post #65

I think the coolest thing from an experience perspective as far as a built environment with this is the opportunity to have spaces with different ratios and spacing. I’m reminiscing about realizing from an American perspective why buildings in Europe felt so different. Old buildings sure, but new buildings feel weird! It finally dawned on me that the difference between imperial and metric had made its way to the buil…

Standard table height in Europe is 75 cm, which indeed sounds like a convenient rounding.

What is the value in the US?

Re: Rulers of the Ancient World: period correct measuring tools

#76

Post by saalweachter »

arlort wrote: post #70
BitwiseFool wrote: post #48

Earlier quoted context omitted.

Now we have to wait for the French to have another revolution.

And for people to start growing 6 fingers per hand instead of 5

Duodecimal also has a connection to counting on your fingers.

You've got twelve finger bones/joints. Move your thumb from one to the next as you increment your count.

Bampf, base twelve, no extra fingers needed.

Re: Rulers of the Ancient World: period correct measuring tools

#77

Post by saalweachter »

Ekaros wrote: post #73
EnigmaFlare wrote: post #53

Earlier quoted context omitted.

Instead of having Avogadro's number at all, chemists could just count using numbers like we do for everything else. We already have the prefixes to make 10^+/-24 easy. No need to re-define it, just stop using it. It's nothing more than a conversion factor between two parallel unit systems that somehow both coexist within SI.

Avogadro's number is for making calculations including weight simpler. If I have x grams of carbon how many grams of oxygen I need to burn it all. And then how many grams of carbon dioxide I end up with. Value is somewhat arbitrary. And could also be tied to some other isotope. It is really about the ratios between all the elements including their isotopes. Picking carbon and there of isotope C-12, and saying this is…

And now that we actually know how big particles are, we could work the other direction [if restandarizing an industrialized civilization wasn't impossible] -- pick an arbitrary number of particles that is a nice number for some reason or another (eg, 4!!), take the simplest thing that has mass (monatomic hydrogen), and declare your unit of mass to be equal to 4!! hydrogen atoms.

Sure, it's not easy for a primitive scientist to take a box of an exact number of hydrogen atoms and weigh them, but any advanced civilization should know exactly what a hydrogen atom masses.

Re: Rulers of the Ancient World: period correct measuring tools

#78

Post by mauvehaus »

inglor_cz wrote: post #75
wizardforhire wrote: post #65

I think the coolest thing from an experience perspective as far as a built environment with this is the opportunity to have spaces with different ratios and spacing. I’m reminiscing about realizing from an American perspective why buildings in Europe felt so different. Old buildings sure, but new buildings feel weird! It finally dawned on me that the difference between imperial and metric had made its way to the buil…

Standard table height in Europe is 75 cm, which indeed sounds like a convenient rounding. What is the value in the US?

Anywhere between 28" and 30" is in the accepted range, though 28" will feel a little low to most people. I had a table at 31" once, and every time I sat at it, I felt like a kid sitting at the grown-up table.

A good reference for stuff like this is Human Dimension and Interior Space:

https://archive.org/details/humandimensionin0000pane

Re: Rulers of the Ancient World: period correct measuring tools

#79

Post by EnigmaFlare »

Ekaros wrote: post #73
EnigmaFlare wrote: post #53

Earlier quoted context omitted.

Instead of having Avogadro's number at all, chemists could just count using numbers like we do for everything else. We already have the prefixes to make 10^+/-24 easy. No need to re-define it, just stop using it. It's nothing more than a conversion factor between two parallel unit systems that somehow both coexist within SI.

Avogadro's number is for making calculations including weight simpler. If I have x grams of carbon how many grams of oxygen I need to burn it all. And then how many grams of carbon dioxide I end up with. Value is somewhat arbitrary. And could also be tied to some other isotope. It is really about the ratios between all the elements including their isotopes. Picking carbon and there of isotope C-12, and saying this is…

Let me try to do it without Avogadro's number approximately:

  m_oxygen / m_carbon = (n_oxygen * A_oxygen) / (n_carbon * A_carbon)
  m_oxygen = x * (2 * 16) / (1 * 12)
  = 2.7 x
and more accurately:

  m_oxygen / m_carbon = n_oxygen * m_oxygen / n_carbon * m_carbon
  m_oxygen = x * (2 * 26.567 yg) / (1 * 19.945 yg)
  = 2.664 x
Can you do it more easily using Avogadro's number?

Re: Rulers of the Ancient World: period correct measuring tools

#80

Post by Ekaros »

EnigmaFlare wrote: post #79
Ekaros wrote: post #73

Earlier quoted context omitted.

Avogadro's number is for making calculations including weight simpler. If I have x grams of carbon how many grams of oxygen I need to burn it all. And then how many grams of carbon dioxide I end up with. Value is somewhat arbitrary. And could also be tied to some other isotope. It is really about the ratios between all the elements including their isotopes. Picking carbon and there of isotope C-12, and saying this is…

Let me try to do it without Avogadro's number approximately: m_oxygen / m_carbon = (n_oxygen * A_oxygen) / (n_carbon * A_carbon) m_oxygen = x * (2 * 16) / (1 * 12) = 2.7 x and more accurately: m_oxygen / m_carbon = n_oxygen * m_oxygen / n_carbon * m_carbon m_oxygen = x * (2 * 26.567 yg) / (1 * 19.945 yg) = 2.664 x Can you do it more easily using Avogadro's number?

Where did you get the A_oxygen and A_carbon in first part?

Take the same calculation, use 12,01 for carbon and 16,00 for oxygen. Values in one reference book, get 2,66444629475 or the 2,644.

Avogadro's number is just number of atoms in the mole. Making atomic masses sensible numbers.

Carbon dioxide is actually relatively bad example as both values are close to integers. Chloride with atomic mass 35,45 starts to be more reasonable example where you have pretty simple number.

As shown dealing with very small numbers like counting together masses of neutrons, protons and electrons and then removing binding energy gets very tiny numbers. Which make calculations more error prone or even complex to do by hand. Using atomic masses which include Avogadro's number makes it much simpler process.

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