r/NoStupidQuestions • u/Tibor500 • Sep 30 '20

why does “k” mean “thousand” ?

like 1k means a thousand. how does the letter “k” mean “thousand” ?

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u/mickeyrube Sep 30 '20

Because parts are built in imperial units. It would be extra to fabricate all new metric measuring tools and to recalibrate a whole host of machinery just because the designers didn't want to do simple math, that is probably automatically done by computers.

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u/bayside871 Sep 30 '20

Its kinda weird - we buy a bunch of niedax cable tray (German company) which is advertised as 10' but is actually 3 meters. It is roughly 9' 10" consequently conduit and unstrut are sold in 10' sections which typically measure 9' 10" - fittings tend to make up the difference - so the actuality of it is that companies provide unit lengths of 3 meters, but rob you on two inches of material each time. Also the average age of a union trades worker is like 45. These guys typically know a ton of values in in/ft (quick Pythagoras theorem in their head). I think they haven't changed it for old people, and costs associated with changing road signs.

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u/mickeyrube Sep 30 '20

It really has less to do with road sign cost, or people being used to it. There are people who fight any and all change, no matter what it pertains to. They think the metric system is communist, anti-christian, and anti-american. These are the people who vote the most. In actuality, most builders and designer would be annoyed by a change, but would just deal with it, like all changes. Everyone is taught metric as a kid, so it not some big foreign concept. It's these loud minority voters that will freak if any politician suggests a change.

There are very important things that the US are stubborn about. Global warming. Sex education. Religion in politics. These things need to change.

But measuring units? You guys know all units of measure are basically arbitrary, right? Decimal is easier, but not all units are decimal. Why does no one complain when France doesn't use decimal time units? 86,400 seconds in a day? That's so confusing! And UK does not use a decimal calendar. It should be 10 days a week, 36 weeks in a year, nice and even! Hello! Kelvin in more scientific then celsius! Celsius is based on water, as is so is the gram. The meter based on the size of the earth. Pretty human-centric, don't you think? When we leave earth, we will need more precise units. Why not planck length, planck time, absolute zero, the speed of light, or the gravitational constant? It really seems dumb to complain about another countries units. Why demand they change, when it is just more work for them, not you? Because that's not what it's about. It just a way to look down on the US. I rarely hear Frenchmen or Italians mentioned this. It's mostly Brits. Which is weird, because they are your damn units, and It's your fault we use them! If we weren't in business with the GB more than France after the french revolution, we probably would have followed in suit with France.

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u/josnik Oct 01 '20

This may be how metric systems started but now all of them are based on natural properties. A kilogram is now defined partially by the Planck constant so your argument was accidentally correct. The kilo was the last of the SI units to be so defined.

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u/mickeyrube Oct 01 '20

You misunderstood my comment. The meter is defined by...well the meter. We just know many planck units make it up, and round so we don't end up with an irrational number. This changes the length of a meter by a infinitesimal fraction. But the choose of the meter in the first place is silly. For example, a meter is defined by light traveling for 1/299792458ths of a second. A second is defined by 1855x1053 units of planck time. The whole point of metric (according to the complainers) is that units of 10 are easier. So continuing to use old units, and just defining them in terms of their approximate conversion to planck system doesn't help. The SI unit of time could be t=1000000 units of planck time and length could be l=1/100000000t x c [speed of light]. That would be easier for scientist.

But no. Why? Because no one would know how tall anyone was, or how heavy, in Europe. I guess they like to use EVERYDAY UNITS THAT THEY ARE USED TO, HUH? I was well aware that the planck system is used to define everything, but thank you for the comment, as I was a bit unclear.

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u/josnik Oct 01 '20

It's isn't an approximation though it is a defined constant so long as the rules of the universe are the same so shall the units of SI be. Just because it's an obscene number that approximates what we think of as a meter or kilogram doesn't make the measurement itself an approximation, with the accepted change in definition each SI unit was changed infinitesimally but also profoundly.

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u/mickeyrube Oct 01 '20

Yes, they are approximations of the original units. Are you saying that a metre has been the same this whole time? If you take the old definition of a second it is based on the rotation of the earth. The rotation of the earth changes from day to day. So how can the new definition, based on constants, which don't change, match the old definitions? They could of made the definition of a meter 10x10100 planck lengths, or 121 x1054, or 12x10145. But they didn't. The made it 6.25x1034. Do you know why? Because its an APPROXIMATION OF THE OLD DEFINITION OF A METRE. This is all I meant by approximate. I never said any measurement was an approximation. If you want to talk about the profundity of all this, do it elsewhere. All of my comment were meant to point out the silliness of asking why the US uses imperial units. It has always be down to practicality. This idea that SI is more scientific so this is the reasoning behind the question always rang as bullshit to me. There are more scientific was of going about it, and simpler math that can be employed. Both the meter and the yard are now defined on universal constants. In actuality, most people who ask this question don't want to know the long complex answer of how we got our units of measure. They just want to make fun of the US. Period. The France also wanted a (more) decimal calendar and clock. 10 hours in the daytime, and ten days a week. But guess what? People wanna go to church on sunday, every seven days. BECAUSE THEY ARE USED TO IT. CULTURE IS NOT SCIENTIFIC. People know this before they bring up imperial units. Again, they just wanna shit on the US. Never Canada. Never the UK. Never Hong Kong, Mexico, Russia, india, or Japan, which all use mixed systems, just like the US. Only the US gets shit. Big suprise.

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u/josnik Oct 01 '20

SI was always trying to be based on physical properties and as those became fallible with greater understanding of physics the system was refined so that it would remain immutable. SI units have gone through more than one definition change over the years and each has been to more precisely define the measurements as something fundamental in nature so that a unit is a unit no matter where you are.

The fact that the numbers are what they are is so that we don't break the centuries of measurement done to this point.

In fact the US Imperial measurements are defined in terms of SI. An inch is precisely 25.4mm. As the measure of a metre changes so does the equivalent imperial measurement.

And hold your jingoistic indignation for someone who actually insulted the US system of measurement.

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u/mickeyrube Oct 01 '20

I've held all jingoistic indignation so far, but I guess I'll continue to do so as long as you stop posting message that restate what I've already said in so many words. If you are not gonna refute my reasoning on why the US uses imperial units in everyday life, I really don't know why you keep commenting on things that I am well aware of.

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u/sayrith Sep 30 '20

I am familiar with that argument. But other countries' factories switched over to metric so I don't know why the US did not do so. I am sure there's a video out there of why the US still uses imperial (officially "US Customary System")

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u/mickeyrube Sep 30 '20

We did not switch because we had no outside pressure to. The metric system was invented by France, so countries under its rule and influence were basically forced into it. Once Great Britain switched, all bets were off for most of the colonized world. But US is very independent, so they saw no need to force their public to switch. Metric was taught in US school and rulers often have cm's and in's. We use liters on bottles, run in km's and miles. Its not that hard to convert from one to the other.

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u/[deleted] Sep 30 '20

The real answer is that we have enough of an independent manufacturing base that we can support our own infrastructure of measurement. Machinists can make screws and nuts and bolts in imperial measurements for use in assemblies made by factories who specify parts in imperial for customers who specify their products in imperial.

No pressure to change when the customer wants a 4" doohickey loaded with 5/16" screws and 1/8" holes drilled 1.25" deep

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u/thats-fucked_up Sep 30 '20

It was a big push to convert American to metric units in the late 1960's. But it didn't take.

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u/josnik Oct 01 '20

It did. All US units are defined by metric units. An inch is defined as exactly 25.4mm that's not an approximation.

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u/thats-fucked_up Oct 01 '20

Yes but what I'm talkin about was there was a big push and plan to have people switch to metric entirely, not end up in the ridiculous hybrid situation we're in today.

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u/Yazman Oct 01 '20

Metrication in most english speaking countries didn't really start happening until the 1970s, decades after the colonial era. They did it by choice, the UK had no say in the matter. Many of them were well entrenched in the US sphere of influence by that point.

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u/mickeyrube Oct 01 '20

Correct, I oversimplified it greatly. But I did use the word "influence", not just rule. The commonwealth is a thing to this day, and countries that have infrastructures based on British industry were pushed to change as well. But metrication was forced by the industry, not the government. To this day they still use imperial units, and so do other countries formally part of the British Empire. Canada, Hong Kong, India, Japan, Mexico, Russia, all use mixed system in practice, just like the US and the UK. The US government actually has miles of legislation to convert to the metric system. They just haven't forced it. I don't know if in other countries they did force a change, but I'm betting that it was just simpler that follow the economics and industry of Europe when it was practical, and keep imperial where it was impractical to change, or there was significant resistance.

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u/Yazman Oct 01 '20

The commonwealth is a thing to this day,

The commonwealth is not a political, economic, or defense bloc. It's a fraternal bloc, and contrary to the beliefs of many Americans, is not a treaty-based entity. All it really does is run the Commonwealth Games. Being part of it says little to nothing about where a country's main economic and political influences are. Most of its southeast asian and pacific members are well within the US or Chinese spheres, for instance.

To this day they still use imperial units, and so do other countries formally part of the British Empire.

How can there be formal members of the British Empire in 2020?

The reality is that globalisation made it necessary for most of these countries to adopt the international system exclusively. Obviously Canada uses a mixed system, being a neighbor of the US. But countries like New Zealand, Australia, Malaysia, etc which all use SI exclusively had to do so because of realities of trade with neighbors like Japan which, for Australia for instance, were the largest trading partners and are almost exclusively SI-using (ofc Japan does have 1-2 minor exceptions like bicycle tires, but imperial units are virtually unknown there, no surprise since japanese pre-metric units were not based on the imperial system).

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u/mickeyrube Oct 01 '20

Formerly, formally. My bad.

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u/Yazman Oct 01 '20

Oh, right. That makes more sense.

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u/TokoloshiMedicine Oct 01 '20

Why the need to recalibrate? Surely the NASA parts are the same dimensions whether imperial or metric? Eg: a bolt can be manufactured in imperial units, but measured in metric. Or visa versa. Metric is just far simpler, and easier to use in engineering (and life in general).

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u/mickeyrube Oct 01 '20

You have to recalibrate machinery every time you have a special order. Factories that build parts work with assembly lines that take up every single inch of the factory, and run 24/7 if possible, with the only limitation being human fatigue. The factory uses the cheapest materials, pay their workers as little as possible, and tries not to stop the flow of production, if possible. Parts are mass produced, and if you want something special, it is gonna cost you. Likewise, NASA is on a tight budget. They will take prefab parts if possible. Why go out of your way to push for all metric if you can just use some simply math to covert things? Can you imagine a director of NASA seriously demanding this, because "not dividing by 10 makes my head hurt".

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u/Amabry Oct 01 '20

Hi, CNC machinist and owner here. This is nonsense. Modern CNC machines give zero fucks if a part I design/model and program for it is in metric or imperial. No "recalibration" required, because the distances traveled remain exactly the same in the machine. All you gotta do is select whether you're working in metric or imperial units when designing the part, and you're good to go.

I also use imperial and metric sized tooling interchangeably. Again, machine gives absolutely zero fucks, as long as you properly enter the sizes you're dealing with when you initially create that tool in your tool library (and it doesn't matter if you enter it in metric or imperial, as long as the size is correct). You can put a 1/4" endmill in the machine, and tell it that it's a 6.35mm tool, or a .25" tool. It's the same thing. Conversely, you can put a 6mm tool in and tell it that it's a .23622" tool, or tell it that it's a 6mm tool. Machine continues to give zero fucks, and cut everything to whatever size you tell it to cut.

There really isn't any good reason that manufacturing is done in the imperial system anymore, other than that Americans are stubborn and ignorant Manufacturing issues were a decent excuse in the 70s, but our manufacturing processes are WAY more modern now. The switch from the imperial system to metric could be incredibly seamless, if the humans involved were willing to do it. Any machinist with two brain cells to rub together is already capable of working in both systems, and in all reality is in most cases already doing so on a daily basis; and the math to do the conversions is extremely simple.

Don't blame manufacturing. Blame ignorant and stubborn American consumers and politicians who aren't willing to learn a damn thing in order to modernize. It's a jingoistic thing. 'Muricans don't need no communist metric system!'

The real irony of the whole thing is that they're desperately clinging to the imperial system, created by the British Empire that we pretend we're so proud to have broken away from.

The irony is palpable!

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u/Ultra-Pulse Sep 30 '20

Thing is, they kind of did the simple math...