Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ending the Era of the U.S. Survey Foot

nist.gov

Post reply on HN
Print view View original

71–80 of 163 posts

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

#71

Post by analog31 »

hadlock wrote: post #3

Mildly surprising that we are not just using meters at this point.

We are. All of the US standards are based on metric units. A large number of the products that we buy are made from metric components such as screws. CAD software and machine tools can switch effortlessly between unit standards. There are some standards that are so unique that they might as well be arbitrary, such as spark plug threads.

Some building materials still have US dimensions, but if you measure plywood carefully, it's thicknessed in mm. And the "2 x 4" has never been 2 x 4 inches.

So I think we've made great progress towards an age when units of measure don't matter much any more.

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

#72

Post by big_chungus »

mrb wrote: post #39
adamtj wrote: post #29

Earlier quoted context omitted.

That's not hard to imagine. Quick, what's 1/3 of a meter? The sometimes problem with metric is it's base-10. The prime factors of 10 are 2 and 5. Feet are in base-12, which has the prime factors 2 and 3. Three is much more useful than five. There are marks on your measuring tape at exactly 1/3 of a yard or 1/3 of a foot. Metric is often easier and more convenient, but not always. So, in the US, we tend to use metric…

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…

This is also just an anecdote, but I'll second thomk's opinion on woodwork/manual measurement of most kinds. Twelve has one, two, three, four, six, and twelve for divisors, and that is incredibly handy when you're trying to do manual measurement. Even sixteen has one, two, four, eight, and sixteen, making for easier division of pounds to even numbers of ounces; compare this to ten, which has only one, two, five, and ten. People can't eyeball or measure tenths or fifths nearly so easily as thirds and fourths. Even eights are easy to get from measuring a quarter and taking half; good luck eyeballing a fifth. And before all the "we have computers to do it for us" people come out of the woodwork: 1. Not always and 2. High-precision floating-point arithmetic is still computationally expensive and often hard to get right. I think every one has, at one point or another, hit some weird numerical glitch due to floating-point error.

Every schoolboy learns basic unit conversion; I'm not convinced by your tales of hapless relations. It's not that hard to remember eight fluid ounces per cup. It's not that hard to multiply the feet times twelve, add the inches, and divide by twelve to get just feet. It's not that hard to divide the ounces by sixteen to get pounds and ounces. It's not hard to remember that water freezes at thirty-two degrees. I've also never heard someone describe weights as "six pound five" with either meaning; the closest I've heard are descriptions of height as, say, "six foot two". This means six feet and two inches in every case, and everyone understands this.

At this point,

In conclusion, it is sometimes easier. It's just comical to see someone trying to argue that there are literally zero cases where the customary system is sometimes easier.

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

#73

Post by analog31 »

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.

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

#74

Post by thrower123 »

kibwen wrote: post #19
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 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.

Some metric units work well, and are scaled to human everyday measurements, and some are not.

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

#75

Post by thrower123 »

mrb wrote: post #39
adamtj wrote: post #29

Earlier quoted context omitted.

That's not hard to imagine. Quick, what's 1/3 of a meter? The sometimes problem with metric is it's base-10. The prime factors of 10 are 2 and 5. Feet are in base-12, which has the prime factors 2 and 3. Three is much more useful than five. There are marks on your measuring tape at exactly 1/3 of a yard or 1/3 of a foot. Metric is often easier and more convenient, but not always. So, in the US, we tend to use metric…

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…

> My wife's family, who almost all have university degrees

Honestly, this is probably part of the problem.

If you ask the AP Calculus student to calculate these things, they probably don't have that down solid.

If you ask the sweathog vocational tech kid, they will know what the units of measure are and have no problem.

Practice makes perfect.

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

#76

Post by big_chungus »

analog31 wrote: post #71
hadlock wrote: post #3

Mildly surprising that we are not just using meters at this point.

We are. All of the US standards are based on metric units. A large number of the products that we buy are made from metric components such as screws. CAD software and machine tools can switch effortlessly between unit standards. There are some standards that are so unique that they might as well be arbitrary, such as spark plug threads. Some building materials still have US dimensions, but if you measure plywood care…

> the "2 x 4" has never been 2 x 4 inches.

Well, it used to be pretty close, until lumber manufacturers and builders cheaped out. They've been gradually "shrinkflating" by reducing the thickness, conveniently requiring less wood. This went along with the switch to fast-growing garbage pine. I lived for a long time in an early-fifties house, and the quality of the wood was vastly superior to what you'd find today. Though, the newer measurements did make things a pain.

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

#77

Post by ska »

not2b wrote: post #46
ska wrote: post #17

Earlier quoted context omitted.

I believe it is the latter.

In practice, since the difference is so small it does not matter in almost all cases, because no one was in a position to measure accurately enough. If you ask for 100 feet of rope, the difference between the two definitions of "foot" is much tinier than the smallest possible roundoff error you or the sales person will make.

That's fine for measuring most things, but not necessarily for survey work. Your reference points can be quite far away, and you are dealing with angles. So ever pretty tiny changes can be significant.

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

#78

Post by spritecranberry »

zamalek wrote: post #8
hadlock wrote: post #3

Mildly surprising that we are not just using meters at this point.

The situation is far more bizarre than "use" or "not use." As I understand it, America uses something along the lines of "converted metric units" - i.e. the entire imperial system is defined according to metric/SI. Some subset of public records have been, supposedly, converted to metric. If you have a recent car, it should have km/h alongside mph (in a smaller font, or as a different digital readout). You'll find met…

> The situation is far more bizarre than "use" or "not use"... "converted metric units"

You're absolutely right. It's time we removed the quasi-metric garbage and replaced it with proper customary units defined on the same universal constants used by SI units.

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

#79

Post by ska »

oh_sigh wrote: post #53
DoofusOfDeath wrote: post #16

The article left me confused about what it means to have a legally binding redefinition of a term. Does this mean that all existing, legally binding contracts are to be reinterpreted using the new definition of "foot"? Does it mean that any new legal document (contract, legislation, etc.) that uses the term "foot" without further clarification shall be assumed to mean this new definition of "foot"?

As a general point, I don't think contracts can have their terms adjusted after the fact without both parties agreeing to it.

This seems the only reasonable way to do it except for terms deemed unenforceable (which is why you see a lot of boilerplate about severability)

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

#80

Post by Taniwha »

big_chungus wrote: post #76
analog31 wrote: post #71

Earlier quoted context omitted.

We are. All of the US standards are based on metric units. A large number of the products that we buy are made from metric components such as screws. CAD software and machine tools can switch effortlessly between unit standards. There are some standards that are so unique that they might as well be arbitrary, such as spark plug threads. Some building materials still have US dimensions, but if you measure plywood care…

> the "2 x 4" has never been 2 x 4 inches. Well, it used to be pretty close, until lumber manufacturers and builders cheaped out. They've been gradually "shrinkflating" by reducing the thickness, conveniently requiring less wood. This went along with the switch to fast-growing garbage pine. I lived for a long time in an early-fifties house, and the quality of the wood was vastly superior to what you'd find today. Tho…

Here in NZ when we switched to metric nothing changed, 2x4s (well we call the 4x2s) were never quite 2x4, and 50x100s (the metric replacement) are close enough (but still not quite) that nothing really changed
Post reply on HN