3 ms·

That headline is... horrible. What are SI units for if not for this?

slaw 4y ago
I wouldn't complain. At least it is not in football fields, yards, pounds or other American units.
akira2501 4y ago
I happen to agree, but the headline conveys information in the most accessible format. SI just makes a lot of promises that it can't deliver on, because human beings aren't interested in such a unit system. They seem to want just three unit scales, "smaller than me", "the same size as me", and "larger than me." They will fit the entirety of their experience and frame of reference into these three scales, even when they know there are other options. It's probably the reason they punted and let a _kilo_gram be a base unit in the first place, and why everyone represents the distance to the sun in kilometers instead of gigameters; even though they round the kilometer figure down to a point where gigameters would clearly be the most warranted.
- dylan604 4y ago
  Everyone was perfectly fine with "the size of 3 buses".
  - akira2501 4y ago
    As a North American, can I get that expressed in "football fields?"
    - qbrass 4y ago
      62 football fields worth of astroturf. 25 if it's real grass.
- screamingninja 4y ago
  > human beings aren't interested in such a unit system All of them??
  - voxelghost 4y ago
    No, but roughly 18E3 football stadiums worth of them.
- Karellen 4y ago
  > It's probably the reason they punted and let a _kilo_gram be a base unit in the first place, Not quite - it's so that the system is coherent. https://en.wikipedia.org/wiki/Coherence_(units_of_measurement) https://en.wikipedia.org/wiki/Coherence_(units_of_measuremen... which makes a whole bunch of other things simpler. The other option to meter-kilogram-second would have been the centimetre-gram-second, but then you're not using the metre as your base unit for length. Scale is probably the reason for picking MKS over CGS, but it's only moving the weird-base-unit problem around. ISTR reading once that MKS has coherence advantages over CGS with regards to electromagnetism (probably current), but I can't find the reference now.
  - akira2501 4y ago
    It's so that it retains coherence without moving to a non-gram based measurement. You could have easily selected a new unit, or even just given what we call a "kilogram" a non-prefixed name and be done with it. The point is, it's obvious that they didn't define the system on first principles, but allowed "creature comforts" to creep into the scope of the system. For example the needless definition of Hz which conflicts with radians, and the needless definition of the unitless mol. These are obvious conveniences. They're not first-class members of the system.
shirro 4y ago
The kilogram is the SI base unit of mass. Mass is the only one where the base unit has a multiplier for some reason. Expressing quantities in the base unit makes total sense for me as a metric native.
frosted-flakes 4y ago
Your right, it would be much better expressed as "1000 tonnes".

slaw 4y ago

I wouldn't complain. At least it is not in football fields, yards, pounds or other American units.

I happen to agree, but the headline conveys information in the most accessible format. SI just makes a lot of promises that it can't deliver on, because human beings aren't interested in such a unit system. They seem to want just three unit scales, "smaller than me", "the same size as me", and "larger than me." They will fit the entirety of their experience and frame of reference into these three scales, even when they know there are other options. It's probably the reason they punted and let a _kilo_gram be a base unit in the first place, and why everyone represents the distance to the sun in kilometers instead of gigameters; even though they round the kilometer figure down to a point where gigameters would clearly be the most warranted.

dylan604 4y ago
Everyone was perfectly fine with "the size of 3 buses".
- akira2501 4y ago
  As a North American, can I get that expressed in "football fields?"
  - qbrass 4y ago
    62 football fields worth of astroturf. 25 if it's real grass.
screamingninja 4y ago
> human beings aren't interested in such a unit system All of them??
- voxelghost 4y ago
  No, but roughly 18E3 football stadiums worth of them.
Karellen 4y ago
> It's probably the reason they punted and let a _kilo_gram be a base unit in the first place, Not quite - it's so that the system is coherent. https://en.wikipedia.org/wiki/Coherence_(units_of_measurement) https://en.wikipedia.org/wiki/Coherence_(units_of_measuremen... which makes a whole bunch of other things simpler. The other option to meter-kilogram-second would have been the centimetre-gram-second, but then you're not using the metre as your base unit for length. Scale is probably the reason for picking MKS over CGS, but it's only moving the weird-base-unit problem around. ISTR reading once that MKS has coherence advantages over CGS with regards to electromagnetism (probably current), but I can't find the reference now.
- akira2501 4y ago
  It's so that it retains coherence without moving to a non-gram based measurement. You could have easily selected a new unit, or even just given what we call a "kilogram" a non-prefixed name and be done with it. The point is, it's obvious that they didn't define the system on first principles, but allowed "creature comforts" to creep into the scope of the system. For example the needless definition of Hz which conflicts with radians, and the needless definition of the unitless mol. These are obvious conveniences. They're not first-class members of the system.

shirro 4y ago

The kilogram is the SI base unit of mass. Mass is the only one where the base unit has a multiplier for some reason. Expressing quantities in the base unit makes total sense for me as a metric native.

frosted-flakes 4y ago

Your right, it would be much better expressed as "1000 tonnes".