why not change conventional current to electron current?

[CatalinaWOW]

...I am infuriated by how often I see torque values in the metric world specified as g-cm...

What's wrong with that? Even if g-cm is not an SI unit of torque, it is 100% blindingly obvious that it means 9.8 mN-cm; and it's also easier for some to intuit about.

Yeah, and poundals, slugs, pounds force and pounds mass are blindingly obvious to some, and easier to intuit for others. 

[Mechatrommer]

Yeah, and poundals, slugs, pounds force and pounds mass are blindingly obvious to some, and easier to intuit for others. 

but sometime lb.f is simply written as lb which may invite pulling hair event during the design process of a metric guy. but i agree, things like plywood size, plumbing etc should be kept imperial. it'll be akward to say 1.2m x 2.4m plywood or give me 2.54 cm or 1.905 cm pipe. but for temperature, it should be degC regardless. human comfort can be stated in 0.1 resolution... but that just me.

[rs20]

Yeah, and poundals, slugs, pounds force and pounds mass are blindingly obvious to some, and easier to intuit for others.

To be clear, I'm not making a metric vs imperial statement here. I was just defending the use of "grams-force" as a more intuitive alternative to Newtons.

[miguelvp]

Yeah, and poundals, slugs, pounds force and pounds mass are blindingly obvious to some, and easier to intuit for others.

To be clear, I'm not making a metric vs imperial statement here. I was just defending the use of "grams-force" as a more intuitive alternative to Newtons.

Easy solution, let's redefine the gram as 1000 times more than now, so, instead of a kilogram being close to 1dm^3 of volume of water, let's call that a gram. It is convention after all.

The thing is that we as human beings can deal with 1 liter, 1 kilogram, 1 second, 1 meter and the other SI units.

One gram not so much (unless you buy and consume things in grams and then no one cares, well unless is saffron I guess).

But nothing prevents us to shift that by 3 orders of magnitude, the math will still work.

Hey the math works for pounds, it's all arbitrary.

Edit: just to be clear what I meant, if we change the definition of a gram to be the same as a kilogram, then a newton would be 1g x m/(s^2) and the current gram-force will really be a milligram-force and no one will use it

[rs20]

just to be clear what I meant, if we change the definition of a gram to be the same as a kilogram, then a newton would be 1g x m/(s^2) and the current gram-force will really be a milligram-force and no one will use it

Well, obviously it's never going to change, but I take your point that it's unfortunate that the kilogram is basically the base measurement of mass. After all, my edit on this post was totally not me remembering this fact and changing "N-cm" to "mN-cm". Honest. 

[Tac Eht Xilef]

By the way the US began adopting the Metric system in 1866 and has taken several formal steps along the way.  It just hasn't outlawed English units.

The US doesn't use English Units, or even the Imperial system. It uses United States Customary units, which in many cases vary significantly from both the original English system (on which it was based but has since diverged) and the slightly more recent Imperial system.

[AndyC_772]

Could someone please clarify exactly what's meant by "English units"?

Here in England, we use metric. Prior to that, we used Imperial measurements.

I've only ever heard the phrase "English units" used by non-English people, which seems... just odd, really.

[Brumby]

Could someone please clarify exactly what's meant by "English units"?

I'm curious also.  I would have thought it was synonymous with Imperial, but I can't recall having heard the expression before.

[miguelvp]

Could someone please clarify exactly what's meant by "English units"?

I'm curious also.  I would have thought it was synonymous with Imperial, but I can't recall having heard the expression before.

Simple, works for us

I do love the base 2 fractions, very convenient.

[IanB]

Could someone please clarify exactly what's meant by "English units"?

I'm curious also.  I would have thought it was synonymous with Imperial, but I can't recall having heard the expression before.

I think it is an incorrect reference to US customary units. US custom varies of course from the Imperial system particularly in liquid measure, where the fluid ounce, pint, and gallon are different sizes from their Imperial counterpart.

Probably the use of "English" for American measures is similar to the way that you find "English" muffins in the bakery, even though you do not find such things in England.

With the reference to fasteners above it is also worth noting that screw threads are also totally different across the Atlantic as well. America does not use the British standard thread sizes such as BSW, BSF or BA.

[d4n13l]

America does not use the British standard thread sizes such as BSW, BSF or BA.

Just FYI, America is also an incorrect reference to the US.

[IanB]

Just FYI, America is also an incorrect reference to the US.

I'm afraid you are going to lose that one. It is widely accepted in the English speaking world that "America" is short for "United States of America" when the context is a country (and by the way, I am not American).

For the continents we specifically use "North America" and "South America", with maybe "Latin America" in the middle.

[denelec]

Why don't we abandon the stupid Philips screws for Torx?

Robertson screws are far superior to Philips.
https://en.wikipedia.org/wiki/List_of_screw_drives#Robertson
No slippage and the screw stays firmly on the screwdriver at almost any angle.
Unfortunately, they are virtually unknown outside Canada. 

[retrolefty]

US custom varies of course from the Imperial system particularly in liquid measure, where the fluid ounce, pint, and gallon are different sizes from their Imperial counterpart.

 So who knows why there is dual usage of the unit name ounces, as used in both mass and volume. Did they run out of unique unit names? 

 Seriously there must be some historical story to explain arriving at that this seemingly stupid decision.

[IanB]

So who knows why there is dual usage of the unit name ounces, as used in both mass and volume. Did they run out of unique unit names? 

Seriously there must be some historical story to explain arriving at that this seemingly stupid decision.

Sure, I know why. One Imperial fluid ounce of water weighs one ounce. This causes a pint to weigh 20 oz and a gallon (160 oz) to weigh 10 lb. It is simple and convenient.

[retrolefty]

So who knows why there is dual usage of the unit name ounces, as used in both mass and volume. Did they run out of unique unit names? 

Seriously there must be some historical story to explain arriving at that this seemingly stupid decision.

Sure, I know why. One Imperial fluid ounce of water weighs one ounce. This causes a pint to weigh 20 oz and a gallon (160 oz) to weigh 10 lb. It is simple and convenient.

 Maybe you missed my point. Does a fluid ounce of mercury weight the same as a fluid ounce of water?

[Brumby]

Sure, I know why. One Imperial fluid ounce of water weighs one ounce. This causes a pint to weigh 20 oz and a gallon (160 oz) to weigh 10 lb. It is simple and convenient.

The metric system also uses water to define mass: 1 litre of water weighs has a mass of 1kg.

[Brumby]

So who knows why there is dual usage of the unit name ounces, as used in both mass and volume. Did they run out of unique unit names? 

Seriously there must be some historical story to explain arriving at that this seemingly stupid decision.

Sure, I know why. One Imperial fluid ounce of water weighs one ounce. This causes a pint to weigh 20 oz and a gallon (160 oz) to weigh 10 lb. It is simple and convenient.

 Maybe you missed my point. Does a fluid ounce of mercury weight the same as a fluid ounce of water?

No, of course not.  A fluid ounce is a measure of volume.

Water is used as the reference to define the volume/weight relationship.

Thereafter you use relative density (aka specific gravity) for comparison of materials.  For liquids, these are almost always related to the same reference: Water = 1.

[IanB]

Maybe you missed my point. Does a fluid ounce of mercury weight the same as a fluid ounce of water?

So who knows why there is dual usage of the unit name ounces, as used in both mass and volume.

I don't think I missed anything. There is "ounce (avoirdupois)" and "fluid ounce". Different names. When using liquid measure we always say "fluid ounce" and not "ounce". We also use the symbol "fl oz" for liquid measure and "oz" for weight.

If I ask for 10 fl oz of mercury I will expect someone to measure it in a measuring cylinder. If ask for 10 oz of mercury I will expect someone to weigh it. No confusion.

[retrolefty]

Maybe you missed my point. Does a fluid ounce of mercury weight the same as a fluid ounce of water?

So who knows why there is dual usage of the unit name ounces, as used in both mass and volume.

I don't think I missed anything. There is "ounce (avoirdupois)" and "fluid ounce". Different names. When using liquid measure we always say "fluid ounce" and not "ounce". We also use the symbol "fl oz" for liquid measure and "oz" for weight.

If I ask for 10 fl oz of mercury I will expect someone to measure it in a measuring cylinder. If ask for 10 oz of mercury I will expect someone to weigh it. No confusion.

 That is all correct. But wouldn't it be better to use two different unit names for those two cases. Seems a mystery to me, and this is not the first time I've asked for a explanation if there is logic or just convention to the use of using fluid ounces and ounces for two different measurements.

[elgonzo]

For the continents we specifically use "North America" and "South America", with maybe "Latin America" in the middle.

Keeping with the theme of commonly misapplied geographic names with regard to the Americas, "Latin America" is actually not the middle part between North and South America. That part is called "Central America". "Latin America" is the collection of countries of Central and South America speaking predominantly latin/romanic languages (hence the name), which also explains why Belize, Jamaica, Guyana, Surinam and perhaps a few other Central/South American countries are not considered to be a part of Latin America.

[miguelvp]

For the continents we specifically use "North America" and "South America", with maybe "Latin America" in the middle.

Keeping with the theme of commonly misapplied geographic names with regard to the Americas, "Latin America" is actually not the middle part between North and South America. That part is called "Central America". "Latin America" is the collection of countries of Central and South America speaking predominantly latin/romanic languages (hence the name), which also explains why Belize, Jamaica, Guyana, Surinam and perhaps a few other Central/South American countries are not considered to be a part of Latin America.

Since when?

Mexico is definitely part of Latin America and it's in the North American Continent.
Cuba and the Caribbean is also Latin America.
Even Brazil (which speak Brazilian Portuguese) is part of Latin America.
I would even venture to say that Latin America included California, Arizona, Texas, and Florida at least until the Spanish lost them.

[elgonzo]

Since when?

Mexico is definitely part of Latin America and it's in the North American Continent.
Cuba and the Caribbean is also Latin America.
Even Brazil (which speak Brazilian Portuguese) is part of Latin America.
I would even venture to say that Latin America included California, Arizona, Texas, and Florida at least until the Spanish lost them.

Yes, right, Mexico and the Caribbean islands are in NA, but not in Central America. Sorry for excluding the north from the latin party. Doh!

[IanB]

Keeping with the theme of commonly misapplied geographic names with regard to the Americas, "Latin America" is actually not the middle part between North and South America. That part is called "Central America".

Thanks for the correction 

[pmbrunelle]

I do love the base 2 fractions, very convenient.

Base 2 is very much for suited for computers. I'm sure that there are computers using binary to store mm dimensions. So mm (or some fraction of one) are already in base two, just the same as "fractional" inches. The choice of the unit and the base are two different issues.

The metric system also uses water to define mass: 1 litre of water weighs has a mass of 1kg.

Unfortunately, this has not been true for over a century. When the kg was defined as the mass of the International Prototype Kilogram, it stopped being possible for anyone to reproduce the kg in their backyard.

SI doesn't facilitate anything versus Imperial units. It's just an arbitrary re-scaling of quantities.

Besides, now that 1 in == 25.4 mm exactly by definition, inches are really just disguised mm.

So why are electrons "negative" anyway? What does it mean...