How come people say 5,000 km and not 5 Mm?
why not just say millions of meters or Mega meters?
Familiarity I guess. Mega isn’t really a widely used prefix outside of computers. We even say tons instead of megagrams.
And yet we say megatons.
Yes, I think it’s a question of use. I can’t think of many examples where you would quickly need to know the measurement to the nearest Mm. Maybe if for some reason you deal with a lot of lunar orbits? Diameters of exoplanets?
Any earth distances we need to know with greater precision, and any stellar distances are probably better measured in light years, etc.
Odometer readings
“I’ve driven 112.326 megameters” takes the same amount of time to say as 112,326 kilometers. 🤷♂️
Jokes on you elite dangerous uses Mm/s for lowest speeds in supercruise before it changes to “c” for relative to light speed
I’ve seen megameters used in the context of astronomical distances, but not terrestrial ones. I think terrestrially, the familiarity of kilometers helps with a sense of scale.
The beauty of the metric system is you don’t lose a sense of scale from using a higher unit because you can intuitively know 1Mm is 1000km.
