Comment by sgk284 | Hacker News Reader

Comment by sgk284 | Hacker News Reader

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Just like with software, backwards compatibility is a double-edged sword.

You can look at almost any land assignment, building or commercial sale ever in the history of the United States and be able to compare / modify / extend it without any conversions. If my great-great-grandfather claimed 160 acres from the Homestead Act, any documentation from that time is just as easily understood today without any conversions.

Differing units only become an issue when globalization factors in (which is a fairly recent phenomenon). Many fields in the states, such as the sciences, have indeed chosen interoperability over backwards-compatibility, but these decisions are done on a field-by-field basis.

I'm in the camp that it'd generally be better to just rip the band-aid off and switch everything, but in general I value interoperability over backwards compatibility with software too. That said, who am I to tell Microsoft that they shouldn't worry about Windows backwards-compatibility? Who am I to tell farmers that they should measure their land in hectares?

> You can look at almost any land assignment, building or commercial sale ever in the history of the United States and be able to compare / modify / extend it without any conversions.

What state? Are those 160 international acres, or 160 US survey acres?

http://www.pobonline.com/articles/91189-from-the-ground-up-t...

What weighs more - an ounce of feathers, or an ounce of gold? (An ounce of gold because gold is measured in Troy ounces...)

As much as I hate the metric system myself, I don't think it's true that U.S. measuring culture is a self-consistent system that avoids unnecessary conversions.

For example the energy content of fossil fuels tends to be measured in BTU per (whatever), while electrical energy is measured in kilowatt hours. On the other hand, automobile engines are often rated in horsepower.

I find this sort of thing is ubiquitous in engineering. In metric-only countries, the situation is slightly less bad because that system provides somewhat fewer opportunities for mischief.

In imperial vs. metric, I don't think the actual units are as big of a difference as the convention of using fractions vs. decimals.

When doing manual work, e.g. woodworking or metalwork it's pretty convenient to use fractions. You tend to divide things in half or quarters.

With most things not made by hand any more, using fractions and inconsistent units like inches, feet, yards and miles is a nuisance for engineers.

Inches, feet, and yards and miles aren't really inconsistent, becuase they are all related by somewhat reasonsable integer ratios. In this computer age, there isn't even much advantage in replacing all those ratios with powers of ten.

It's when people inflict mixtures of BTUs with h or Joules with eV on us that I get aggravated. Each of those units has its place, but only in particular domains. Worse, the people most likely to use domain-specific units, are the ones most likely to not name the unit they are using.

Engineers are such people.

The SI system helps reduce the risks a little. But only a little, I have seen German engineers measure velocity in degrees.

If you're working with floating point in meters, all it takes is a look at the exponent (e.g. 1.75923e-5) to figure out whether it's micrometers, centimeter or kilometers. Not as practical with a non base-10 unit system.

Who says people should collectively forget what an inch is?

Every other country made unit conversions.

The people will use old units for some time to buy cheese at the counter and all is well.

Yeah, right up until your car lease contract limits you to 2000 Swedish Miles per year. (Note, these are about 6x longer than American miles).

Or you buy fruit at the supermarket in Indonesia in ounces and kg (an ounce is an hg).

I guess anyone who knows what Swedish mil is will specify kilometres instead.

I cannot remember a single time I have seen a contract specifying mil instead of km.

("Mil" == 10km == 10 000m is used here as well only not in formal or scientific contexts that I can think of but maybe that is a difference between Sweden and here.)

My car lease (in Sweden) is in Swedish miles.

2000 miles (i.e. 20k km).

The problem with your argument is that most other countries have converted to metric without any issues regarding the fact that your land used to be 1000 acres and is now 404 Ha.

and for some of these countries, their official records can even be older than the 250 years you'll find in the US.

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