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.
But only in regards of nuclear bombs. Maybe it’s because of the scientific origins of these fields. Probably the same reasons why Americans measure firearm munition in mm.
Firearm’s ammunition is a mixed bag because many military sizes are standardized with the rest of NATO. 5.56, 7.62, and 9 mm sure; but then you get a bunch measured in caliber .308, .45, .50.
megaton, megawatt, megapascal, megacandela (for military flares), megahertz, megajoule, megaohm, megabequerel
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.
To be fair, mass is weird because the base unit is kg (yes, the name includes a prefactor). I have no idea how they managed to fuck it up that badly.
nobody will stop you, i’ve seen some publications use gigagrams instead of thousands of tons
I’ve always found that strange. I guess a kilogram is a lot closer to “human scale” than a gram, maybe that’s why they picked it.
My physics teacher once told us that this was due to the influence of disciplines that calculate with huge masses, say in astrophysics the weight of a planet or the the amount of oxygen within it. Don’t know how much of it is true but the basic tenet of everyone preferring the numbers that they work with on a daily basis having as few prefixes as possible as it makes mentally handling and remembering them easier.
That unit is used a lot in the space game Elite Dangerous. Never saw it used before that, but it made sense because it’s the next jump up in large units, and it also helps keep the UI clean looking.
I wish we would. It sounds awesome to say.
As a KSP player I use megameters all the time lol.
