Comment by lupire
1 year ago
Meter, second, and kilogram were all chosen to be approximately the scale of a human, and the combined multiplicative units like Pascal, m^3, and Kelvin/Celsius are also numerically 1 in these units.
1 year ago
Meter, second, and kilogram were all chosen to be approximately the scale of a human, and the combined multiplicative units like Pascal, m^3, and Kelvin/Celsius are also numerically 1 in these units.
> Meter, second, and kilogram were all chosen to be approximately the scale of a human,
“Approximately the scale of a human” leaves so much wiggle room that I don’t see how one can defend that claim.
> and the combined multiplicative units like Pascal
You don’t explicitly claim it, but I wouldn’t say the Pascal is “Approximately the scale of a human”. Atmospheric air pressure is about 10⁵ pascal, human blood pressure about 10⁴ pascal, and humans can very roughly produce about that pressure by blowing.
Which is why I have always kinda hated kilogram. Such an ugly unit for it having prefix. Grav should have been correct answer, but instead we ended up with something that is too small... That is in reality gram. For grams we could simply have milligravs or decigravs for 100g equivalents... Not that hard considering decilitres are used and decimetres are kinda tried in schools.
Pascal is pretty small and m^3 is pretty large though. That's why we still often use millibar and liter. They just happen to largely cancel out.
A human is ~1 meter, 1e2 kilograms and 1e9 seconds.