[perl4ever]

A meter seems to me linked to the human body just as much as the foot.

"The metre was originally defined in 1793 as one ten-millionth of the distance from the equator to the North Pole along a great circle"

That factor of ten is because we have ten fingers. There's no cosmic significance to ten or ten million. Or to the size of a line of longitude on our particular planet.

And a meter is almost exactly a yard, or three feet anyway.

[jeroenhd]

The use of the decimal system is kind of funny because for the longest time large parts of Europe used a 20 based system for a lot of common math. You can still see this in French, where 99 is spelled out as "four times twenty and nineteen". Even in English you can find the remains of the 20-based system, because of the way numbers are expressed: twenty-one, but not tenny-one or even one-teen; twenty-five but not onety-five but fifteen.

The foot is directly based on a person's body part (which caused major issues when bordering jurisdictions used different sizes for a "foot"). The denomination used for meters is a lot more disconnected, its basis focused on the planet instead of on a body part. The choice for the decimal system is much more akin to the choice of 3/12/8/10 in the imperial system.

You can also quickly run into issues if you assume a meter is almost exactly a meter, there's a 9% difference there. The difference can quickly add up, and plenty of international orders have been messed up that way. The distances are similar enough that they serve the same use in day to day expressions, but they're certainly not "almost exactly" the same.

[perl4ever]

>its basis focused on the planet instead of on a body part

It was based on both, and both measurements are completely determined by the happenstance of life on earth rather than the laws of nature.

>which caused major issues when bordering jurisdictions used different sizes for a "foot"

The meter has also had varying definitions leading to slightly different values. Obviously if you are going to base it on the size of the earth there is going to be some uncertainty and of course that's not the current definition.

I'm not really trying to convince you or anybody that meters are not superior to yards, just that it's hard to explain why without appealing to prejudice and/or making categorical statements that are false.

>The choice for the decimal system is much more akin to the choice of 3/12/8/10 in the imperial system.

Is it correct to call SI the decimal system? Powers of ten time units never caught on above seconds.

[oblio]

> There's no cosmic significance to ten or ten million.

Cosmic? No. But social? For sure. 99.99% of math the layman will encounter is in base 10.

[perl4ever]

Picture some American saying there's no point in knowing languages other than English because 99.99% of the people you will encounter know it.

https://en.wikipedia.org/wiki/British_Standard_Whitworth

[oblio]

Thankfully we're slowly getting rid of that abomination and replacing it with something reasonable:

https://en.wikipedia.org/wiki/ISO_metric_screw_thread

A classic: https://www.youtube.com/watch?v=pikrntjcbyw