It's a very cool visualization in any case.
It's a very cool visualization in any case.
I have literally never heard the term “megameter” used in conversation and I’m pretty sure if you said it in any metric country you would get blank stares.
I think it’s much better to pick a unit that makes the most sense for the bulk of your readings and abuse it instead of changing units on me. Imagine if it went from 999mg to 1g, now imagine it trying to settle between them. Or you are weighing a dozen items that are all expected to have a weight of about 1g and need to log the results - think of the unnecessary cognitive overhead the changing units would cause.
I just cooked a recipe where it asked me for 100 grams of a paste, 90 grams of a liquid, 70 grams of a powder, 30 grams of a spice, 15 grams of another liquid. Do people in other countries have measuring spoons in gram size? And do you always tell people whether you meant by volume or weight? Tablespoons, teaspoons, cups and ounces just seems easier than having to measure a fraction of some large number.
Grams are a mass measure. A recipe calling for X grams of Y requires a scale to be accurately followed. Volumetric measurements, e.g. teaspoons and ounces, are easier to follow, but they're less accurate. (Canonical example is salt. Ask for a mass measurement of salt, and you'll always get the same amount of it. Ask for a volumetric quantity, and your mileage [hehe] will vary based on what type of salt is used.)
All road signs, the distance indicator on the entertainment system in planes, etc. are always set out like that (e.g. 1617 km to Cairns, or 11,980 km to Dubai).
From my point of view (whole life in a country that is exclusively metric), it would be really strange to see this kind of distance written in millions of metres or megametres. Would feel totally unintuitive.
Our current system is basically the social consensus of what is easiest.