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Ending the Era of the U.S. Survey Foot

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Re: Ending the Era of the U.S. Survey Foot

#131

Post by Svip »

analog31 wrote: post #73
p1mrx wrote: post #55

> In 1959, the relationship of the foot to the meter was officially refined as 1 foot = 0.304 8 meter exactly. We can thank one man for this: Carl Edvard Johansson from Sweden. When making gauge blocks, he decided to round off the inch to exactly 25.4mm, and people around the world used his blocks to manufacture everything. The 1959 change just reflected what industry was already doing. - http://mitutoyo.com/wp-conte…

An interesting factoid is that if you rummage around in a machine shop, you will find a pair of gears in a drawer somewhere, with 50 and 127 teeth. Those are for converting an old fashioned manual lathe to cut metric screw threads.

Just FYI, a 'factoid' is something believed to be true, when it probably isn't. I assumed you meant 'fact', but otherwise your comment could be confusing.

Re: Ending the Era of the U.S. Survey Foot

#132

Post by int_19h »

nwallin wrote: post #108
mrb wrote: post #39

Earlier quoted context omitted.

My wife's family, who almost all have university degrees, who were all born and raised in the US, and who are very familiar with the imperial system NEVER seem to be able to do math with it. They ask me, a European raised with the metric system, for help. Find out how many fl oz of milk are in a measuring cup graduated in units of cups? Ask mrb. Convert my daughter's height from feet/inches to inches? Ask mrb. Conver…

> Find out how many fl oz of milk are in a measuring cup graduated in units of cups? Ask mrb. 8. Volume is base 2. Two tablespoons in an ounce, 8 ounces in a cup, (there used to be other units in between, but nobody used them, like deci in si) two cups in a pint, two pints in a quart, four quarts in a gallon. If you were going to sell me on switching units, it would be based on hexadecimal instead of base 10. > Conve…

> nobody used them, like deci in si

What makes you believe that nobody uses them? Where I'm from, "decimeter" is in use, for example. Centimeters are way more common, sure - but it does come up when eyeballing distances, or in well-established terms such as "decimeter band".

Re: Ending the Era of the U.S. Survey Foot

#133

Post by Someone »

saghm wrote: post #20
kibwen wrote: post #19

Earlier quoted context omitted.

I suppose it depends on what your goals are; despite being officially metric, my Canadian and British friends still seem to exhibit a melange of imperial and metric in everyday life.

I notice sometimes when watching British television that stones are commonly used as a unit of weight, which is interesting because it's imperial, not metric, but I've seen never it used in American contexts.

“1 stone equals 14 pounds” is (also) British. It dates back to Edward III (1350). See https://en.wikipedia.org/wiki/Stone_(unit)#England.

The idea to use physical stones as reference weights is way older.

Re: Ending the Era of the U.S. Survey Foot

#134

Post by pjc50 »

d-sc wrote: post #126
mark-r wrote: post #60

Earlier quoted context omitted.

My calculation shows 12 * 0.0254 = 0.30479999999999996 meters. That may be off a little due to IEEE floating-point inaccuracy.

2 * 4 = 8 so the last significant digit should be an ‘8’

Definitely one to cite in the "overreliance on calculators" - the comment you are replying to should have realised that multiplication can't create digits to the right like that!

(Most desktop calculators do it in BCD which would give the correct result, too)

Re: Ending the Era of the U.S. Survey Foot

#135

Post by anticensor »

thechao wrote: post #30
3fe9a03ccd14ca5 wrote: post #23

Earlier quoted context omitted.

I don’t really mind that we’re not on the metric system. I just wish our measurements were consistent as they increase. E.g. foot, kilofoot, etc. instead of foot, yards, miles.

And base-2, rather than the computer-unfriendly base-10. Aaaaactually ... with a bit of squinting the U. S. customary volume system(s) define a complete set of base-2 nouns (which could be used as prefixes): tbspn oz jill gill cup pint quart half gallon peck kenning bushel rundlet barrel hogshead butt tun Where each item below the next item is exactly 2x the previous one. It turns out there's also some base-3 stuff (…

Added binary teaspoon and dessert spoon, also renaming a few units:

    tspn
    dspn
    tbspn
    oz
    jill
    gill
    cup
    bottle
    quart
    half
    gallon
    peck
    jimmyjohn
    bushel
    rundlet
    barrel
    hogshead
    butt
    tun

Re: Ending the Era of the U.S. Survey Foot

#136

Post by zokier »

mark-r wrote: post #61
oneplane wrote: post #13

Earlier quoted context omitted.

I think that's what they did in Canada and it worked out great as far as I can tell (except that they had a silly clock based on 10 hours instead of 12 IIRC which had little to do with metric units and nobody wanted it nor was it compatible with the rest of the world).

I once tried to imagine a metric time system, with a deciday of 14.4 minutes. I realized that it would never catch on, because a half-hour TV show would have to be cut to 28.8 minutes losing at least 2 commercials.

14.4 minutes is a centiday btw. For decimal time I think milliday is the most reasonable unit, being very close to conventional minute.

In practice Mars might be the best opportunity for enacting decimal time, because Earth based units would be bit awkward on Mars.

Re: Ending the Era of the U.S. Survey Foot

#137

Post by zokier »

jonas21 wrote: post #111
mark-r wrote: post #61

Earlier quoted context omitted.

I once tried to imagine a metric time system, with a deciday of 14.4 minutes. I realized that it would never catch on, because a half-hour TV show would have to be cut to 28.8 minutes losing at least 2 commercials.

They actually tried this, during the French Revolution: https://en.wikipedia.org/wiki/French_Republican_calendar It didn't catch on then either.

And again in the 90s https://en.wikipedia.org/wiki/Swatch_Internet_Time

Re: Ending the Era of the U.S. Survey Foot

#138

Post by zamfi »

Svip wrote: post #131
analog31 wrote: post #73

Earlier quoted context omitted.

An interesting factoid is that if you rummage around in a machine shop, you will find a pair of gears in a drawer somewhere, with 50 and 127 teeth. Those are for converting an old fashioned manual lathe to cut metric screw threads.

Just FYI, a 'factoid' is something believed to be true, when it probably isn't. I assumed you meant 'fact', but otherwise your comment could be confusing.

That is indeed one sense of the word factoid, but in common North American usage it also can mean “small or trivial piece of information”, which is the sense I believe the parent poster is using.

Re: Ending the Era of the U.S. Survey Foot

#139

Post by zokier »

mark-r wrote: post #112
jessaustin wrote: post #106

Earlier quoted context omitted.

How would one use the diameter to determine weight? Do we square it then divide by four?

In metric, the weight of water in grams is equal to the volume in cubic centimeters, by definition. The volume of a cylinder is the area of the circle times the length. The area of a circle is pi * r^2. So my description above skipped a step or two.

> In metric, the weight of water in grams is equal to the volume in cubic centimeters, by definition.

Just to clarify this is not exactly true. It was the original idea, but pretty quickly they realized that it wasn't a practical definition and kilogram ended up being defined by a standard reference object which was carefully stored in a vault in Paris and thus being disconnected from the meter and the density of water. Finally in 2019 kilogram was redefined again in terms of natural constants in the great SI unit upheaval. Although sadly the new definition is not very intuitive to understand.

Re: Ending the Era of the U.S. Survey Foot

#140

Post by doctor_eval »

irrational wrote: post #98
Taniwha wrote: post #82

Earlier quoted context omitted.

nah, a mm is an incredibly useful unit for woodworking, it's a little less than the width of a saw cut, it's just about the right precision for most woodworking

It's not the precision. It's the divisibility. 10 can only be divided in half. It can't be divided into thirds, quarters, sixths or twelfths evenly and that ability is invaluable. This is the same reason why, in the old days of grid layouts, grids were 12 columns wide and not 10.

What’s so special about thirds, sixths or twelfths?

10cm = 100mm; 100mm can easily be divided by 2, 4, 5, 8 (=12.5), 10, 20, 25, ...

That’s a nice thing about metric. If you don’t like the units you can multiply them

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