this post was submitted on 08 Mar 2024
167 points (96.1% liked)

Showerthoughts

29839 readers
1156 users here now

A "Showerthought" is a simple term used to describe the thoughts that pop into your head while you're doing everyday things like taking a shower, driving, or just daydreaming. A showerthought should offer a unique perspective on an ordinary part of life.

Rules

  1. All posts must be showerthoughts
  2. The entire showerthought must be in the title
  3. Avoid politics
    • 3.1) NEW RULE as of 5 Nov 2024, trying it out
    • 3.2) Political posts often end up being circle jerks (not offering unique perspective) or enflaming (too much work for mods).
    • 3.3) Try c/politicaldiscussion, volunteer as a mod here, or start your own community.
  4. Posts must be original/unique
  5. Adhere to Lemmy's Code of Conduct

founded 1 year ago
MODERATORS
 

How come people say 5,000 km and not 5 Mm?
why not just say millions of meters or Mega meters?

you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 1 points 8 months ago

Yeah, the everyday usage is limited to, well, everyday sizes.
As you pointed out there is no difference in everyday usage. But for anything outside of the most trivial of comparisons, the imperial system breaks down hard.

The advantage of the metric system is the possibility to scale both bigger and smaller when you need it, and always does so with a consistent factor. Sure, not needed when you want to know how many 8 cm strips are needed to cover 50cm. But for 1m? With inches and yards you already have to handle two conversation factors. How many sixteenth of an inch do you need to cover a foot? 192. Possible to calculate, but not nice and you'll approximate with 200 if you need to do some calculations in your head. How many feet are in a mile? 5280. And yards? 1760. Do you really know these conversation factors? Do you want to calculate "there's a street light every 30 yards, the street is 2 miles long, that's xx streetlights? Or "there's a street light every 30 meters, the street is 3.2km long, that's 3200/30 = 107 streetlights"?

Oh, and the weird units do actually get used when it is a convenient size.
Cooking uses lots of in-between units for example. Centiliters (cl) are common in cocktail recipes or for shots, in some cookbooks you will find dekagrams, etc.
Hectare is commonly used to give area measurements (it's origin is hekto-are, and "are" in turn is hekto-square meters, though "are" is not commonly used.). Want to convert hectare to square kilometers? Simply divide the number by 100! 3000hectare of forest burned down? That's 30km^2, so 5kmx6km. Easy to visualize. The US customary system makes such conversations really really really hard. How many square feet, yards or miles are in an acre? I just looked at the Wikipedia page and there is no way anyone will be able to convert an area given in acre into "well, it's approximately x by z miles". Or "my house have xx square foot of living space, so that's yy acres".

Btw, no one uses kiloliters, because that's equivalent to cubic meters. Easy conversions!