Measurements relevant to electricity are a fairly new phenomenon and the pioneers who worked on it mostly impacted the entire world. Similar to how the "decibel" coined by Bell Laboratories is named after Alexander Graham Bell, and at that point the international community was on board with keeping up with the latest research relevant to modern technology.

Humans have been doing things like walking to market and baking bread and weighing witches to see if they'll float for a very long time. There was no international community to manage those measurements.

Then the French and the Europeans and the communists came along with the metric system and Americans said screw you all.

Just like we standardized on kms, nms, etc. Only few countries in the world are using miles, and only conventionally - even US scientists rely on metric system.

The whole metric system is based on constants like kilogram, meter, second, etc. That conveniently correlate with each other and are used almost universally - first they were defined by well-preserved objects (e.g. 1kg steel block), now we define them using physics.

Although we've known a long time about electricity and magnetism, a broad based theory about them is a fairly recent discovery. (maybe 1800s). This was preceded by the metric system which was introduced in 1795 - so a lot of standards were already "established" before measures like volts and amps were defined.

Things like weights and distances, though, are very common measures and every civilization needed them even from ancient times thereby resulting in many different measures. By the time things like voltage and amperes came into broad use (outside of scientific circles), the SI system was already firmly established and there was no reason for alternative measures.

Note that the watt is a standard unit of power in the SI system. However we still use things like horsepower (1 HP = 746 W) and BTU/hr as non-SI unit measures of power. One used even today for engine power output and the other for cooling and/or heating systems. So not quite "standardized".

That's a bit missing his point of there not even existing imperial equivalents to volts and amps, and why that is.

The ship bringing the official kilogram and meter from Europe to the United States sank in 1790 something.

And they apparently didn't order another one.

Voltage is originally not created using in the KMS system with kilo, meter, and second but a unit in the CGS system that has the base in centimeters, gram, and second. That were the customary units in science when the field was created.

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It is when International Electrical Congress (IEC) defined the unit in 1881 it was scaled up for the voltage in the MKS system, International Electrical Congress become International Electrotechnical Commission in 1906 still called IEC, and is still a standard organization for that field.

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So it is units that were very quickly defined within the international agreement before any large-scale adaptation.

This also shows there is no metric system, there are many metric systems. MTS(meter-tonne-second) was used industrially in France and the soviet union in the first half of this century.

What is commonly used today is the SI system which is A metric system, not THE metric system.

The CGS system is still used in for example magnetism. The usage have decreased with MKS standards in 1940 and the SI standards in the 1960s. It has been used longer in theoretical sciences compared to practical engineering.

They are more recent.

There were hundreds of units of distance a long time ago, when there wasn't a lot of communication or cooperation between nations - or sometimes even between cities in a nation (see: China, Rome). As humans spent more time interacting and cooperating, we standardized our measurements; but the US stubbornly refuses to change from the system it uses.

However, electricity was discovered and measured recently enough that competing units of measurement never got established enough for there to be significant argument over which units to use.

The Americans tried to import the kilogram way back when, but the weight they brought with them was stolen by pirates: https://www.npr.org/sections/thetwo-way/2017/12/28/574044232/how-pirates-of-the-caribbean-hijacked-americas-metric-system

It's because of how recent the "invention" of electricity is compared to ideas like distance and weight.

Weights and lengths were things that all sorts of civilizations had to deal with (even the ancient ones) and so those civilizations all individually developed "units" that were convenient for them (or borrowed from their neighbors). So, after you get good and comfortable with your units over a few hundred years, when you meet some other country that says "Hey, your units are weird, why not use ours!" you tend to be like "No way, it is your units that are weird! Buzz off!".

Electricity, on the other hand, (which was invented and commercialized in the last couple centuries) was basically a brand new thing. That meant that the first country that had it was like "Hey, this is how it works and these are the units we use!" and everybody else was like "Okay, cool! Sign us up!".

Electricity is a fairly recent discovery. When it was discovered and formally described by science, the world was already connected to a decent degree, so as the knowledge of electricity was passed along, so were the units.

On the other hand, physical quantities like distances and weights were measured independently by different cultures basically since the dawn of civilization, so every culture developed their own set of units.

If electricity were discovered by say, ancient Greeks and ancient Chinese, we would most likely have two different sets of units for electricity.

>Note that the watt is a standard unit of power in the SI system. However we still use things like horsepower (1 HP = 746 W) and BTU/hr as non-SI unit measures of power. One used even today for engine power output and the other for cooling and/or heating

The US just has a furious hatred for standardisation, don't they ?

They have their own standards, just as many countries have their standards which aren't SI. Continental Europe is more likely to use cl not ml (UK) for capacity even if they're both metric and derived from SI.

While hectares may be used for modern land deeds there are dozens if not 100s of standards around the world for land area.

That's not just a US thing.
Ask anyone in Europe how much power their car has and they will give you the horsepower number. Unless they are driving electric, maybe.

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I wonder how another old one like time has been standardised globaly or if there are any other pre si that are standard

Nope, we're just like any other country

Wait until you find out what the "B" in BTU stands for!

Except for the fact that the US is literally one of two countries that haven't adopted metric.

But yeah, just like any other country

We do use metric, we learn metric in school and metric is exclusively used in science fields and engineering. There are countries besides the U.S. that use both metric and imperial. The U.S. uses U.S. Customary instead of imperial, and we use metric.

I noticed that each wire wrap on a transformer is roughly one volt, so I wonder if that's how one volt of potential acquired that value?

It gets worse. The American British Thermal Unit isn't the same as the Canadian British Thermal Unit.