52MeowCat t1_iugx86y wrote on October 31, 2022 at 6:32 AM

Reply to comment by Implausibilibuddy in TIL that in ancient times, the carob seed was used to measure the worth of gems and gold since the seeds have a general uniform weight. This is where the word "karat" comes from. by kkoolook

Ok, I looked it up and you're right, it is not based on it it is just that carob seeds can be used to estimate shoe size because of their consistency.

Amaranthine t1_iuh88um wrote on October 31, 2022 at 9:23 AM

I assume barley/poppyseeds are also pretty consistent, which is why UK (and US) sizes are based off that :)

So for anyone wondering what one shoe size is and why it doesn't quite map with centimeters... it's because 1 US size is a barleycorn, which = 1/3 of an inch; close enough that sizes will more or less map to 1cm (2.54cm per inch), but not qute.