[tempodox]

Fascinating!

However, I get the cringes every time an article about space exploration uses those atavistic units like Royal Hangnails (length), Princely Bladders (volume), Regal Farts (speed) and Fornicating Fever (temperature) for measurement. Hasn't the metric system arrived yet on planet USA?

[jamesmontalvo3]

While I'm an American engineer who prefers working in metric, since this is a space-related article I have to point you to this: https://s-media-cache-ak0.pinimg.com/736x/69/ae/01/69ae0104b...

[Someone1234]

And I have to point to this: https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...

[RankingMember]

@mitchty, I don't see how the Beagle probe relates unless parallel but different measurement systems caused that, and I'm not seeing anything to indicate this (but let me know if I'm missing something, I'm curious).

[aguywithamum]

"The primary cause of this discrepancy was that one piece of ground software supplied by Lockheed Martin produced results in a United States customary unit ('American'), contrary to its Software Interface Specification (SIS), while a second system, supplied by NASA, that used those results expected them to be in metric units, in accord with the SIS."

[RankingMember]

That's in reference to the Beagle 2?

[aguywithamum]

Yeah, that's in reference to the failure of Beagle 2. It's on the page that was linked by Someone1234 (https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_...).

[mitchty]

And? Someone output things in non SI units to something that expected SI.

Shit happens. Want me to point to the Beagle probe? Space isn't easy.

[aguywithamum]

The point being that his particular failure could've possibly been avoided if we were not using two parallel measurement systems...

[mitchty]

How so? If I build something that doesn't conform to specifications, what does it matter if it happened to be unit conversions? They could have skipped a decimal point and not noticed, because they didn't conform to the specification. More importantly it never got checked or tested or simulated further on up the chain to catch the issue.

Look at the Araine 5. Unit conversions had nothing to do with a computer saying "gimbal an engine 90 degrees".

I'm sorry but this canard of two units being the problem is missing the entire point.

Its an engineering issue and management failure. Just like the space shuttle O rings before them, space is hard. Distilling things down to "america should have used metric cause reasons" is trying to pass off complex problems with bite sized quotes. The only issue is it is wrong.

[mturmon]

This is a smart comment. It sucks to have to keep repeating this comment every time someone trots out this supposedly easy example.

Sure, the units issue was the root cause, but the resulting navigation errors should have been acted upon. They were noticed ("The discrepancy between calculated and measured position, resulting in the discrepancy between desired and actual orbit insertion altitude, had been noticed earlier by at least two navigators, whose concerns were dismissed."), but the issue wasn't acted upon. This is a management and budget problem.

Even if the units are given as SI, there are always interface issues -- which coordinate system to use, where the origin is, does z point up or down, degrees or radians. It can be hard to appreciate unless you have had experience with hard-to-find failures due to subtle numerical problems.

As you say, space is hard.

[wtetzner]

Not necessarily. One part of the code could have been using meters, and another using kilometers.

[dweinus]

Ignoring the idiotic patriotism, that image is incorrect: Russia, China, and India have all placed landers on the moon.

[juliangregorian]

Not people though.

[venomsnake]

And imagine what would you have been able to do if you used sane measurement system ...

[kchangnyt]

I'd love to use metric. It'd save a slew of annoyances converting back and forth, and it's the easiest thing to screw up, because no one has an intuitive sense of a millionth of an inch. But as long as I work at the New York Times and New York is part of the United States and the United States isn't metric, I'm stuck with inches, miles, pounds and gallons.

[blfr]

Why? Units are mostly arbitrary anyway. Actually, having more than one system is a good reminder of that. And Fahrenheit is supposedly more efficient for describing weather.

http://isomorphism.es/post/3767526267/fahrenheit-versus-cels...

[Someone1234]

That's just a blatant rationalisation because people don't like change. There's nothing natural about understanding either metric or imperial, so suggesting that humans inherently are born with more understanding of one is silly.

Metric only wins in my book because it is much easier to convert units (there are no magic numbers for conversion factors). However I'd laugh at anyone who suggest metric is better because people inherently internalise it better, just as I laugh at people who suggest the same for imperial.

The US should switch, there are no legitimate arguments against it except perhaps [short term] costs. Certainly not "because F is easier to understand." It is only easier because you grew up with it and are used to it...

[coderzach]

> However I'd laugh at anyone who suggest metric is better because people inherently internalise it better

I disagree. Once you've been taught a base ten counting system, units that change based on orders of magnitude is very easy to understand. Since almost everyone has a base ten counting system internalized, metric is MUCH easier.

[finnh]

But 12 is evenly divisible in thirds and quarters. Actually pretty useful for a bunch of things. Really it's just too bad we have 10 fingers instead of 12.

[anigbrowl]

Yep, but 10 fingers is what most of us have. I like 12 too but unless you can persuade people to start counting in astrological symbols instead of decimal digits then metric is the way to go.

[moron4hire]

I think, if you don't even know that the US doesn't use "Imperial" units, but that the system of units is actually called "US Customary", then you don't know enough about systems of units to be able to comment on the issue.

Don't get me wrong, I like the metric system. But US Customary units aren't that hard to deal with. Seriously, we're software developers, we don't memorize shit. We create type definitions and routines to convert between them.

The same arguments you make for why it's not that big of a deal to switch are the same arguments for why it's not that big of a deal to not switch.

[enraged_camel]

>>There's nothing natural about understanding either metric or imperial

That's not true at all. The metric system is more intuitive because it is a Base 10 system, which is very intuitive and natural for humans because we have ten fingers. Base 10 also makes things a lot easier because calculations are simply a matter of adding/removing zeroes/decimals.

[Rusky]

10 fingers/base 10 isn't inherently any more "natural." There are cultures that use(d) base 12 (and count using the 12 finger segments on one hand) and probably others.

And base 12 is way more divisible.

[rquantz]

And yet, the US will never convert to a system of measurement invented by the French. Remember freedom fries?

[rquantz]

I'm not allowed to edit this anymore, so let me reply instead. To those downvoting I ask: do you think this comment wasn't serious? You think there aren't at least 47 senators who would filibuster a bill to, say, convert the US highway signs to metric because it's "unamerican"?

[mitchty]

Well to be sure we were going down that route. Then Reagan got elected. Take that what you will.

[solve]

Primitives, real intellectuals turn their noses at anything other than http://en.wikipedia.org/wiki/Planck_units

[tempodox]

Wow, this is really cool. I'm afraid I have been one of the primitives up until now :)

[mintplant]

This sounds like a perfect example of bikeshedding.

[moron4hire]

That's all it really is. Arguing over metric or US Customary is just pseudo-intellectualism.

[saucetenuto]

Yes it has! It conquered our soda industry and then gave up.

[mturmon]

Interestingly, "liter" is a customary metric unit, but not an SI unit. SI requires you to use units of length-cubed for volume.

In this respect (partial antiquation in the wake of unit redefinitions) liters have something in common with the quart.

[RankingMember]

"Yeah I'll have a quart of Coke" certainly sounds weird.

It is strange now that I think about it that we have imperial measurements for milk but metric measurements for sugary drinks/beer.

[vonmoltke]

Beer and soda bottled or canned for individual servings still use imperial units (12oz/16oz/20oz). Oddly, water bottled for such has mostly moved over to metric. Keg beer also still uses imperial.

[Sami_Lehtinen]

In Finland you can always order 0,568 liter beer. (Imperial pint) Or traditional large beer which is 0,5 liter or euro beer which is 0,4 liter. You decide.

[RandallBrown]

I usually buy/order sugary drinks and beer by the ounce or pint.

Other than 1 and 2 liter bottles of pop, I can't really think of any time I would buy pop or beer using the metric system.

[vidarh]

Cans of soda are most commonly 330ml.

[RandallBrown]

In the US, they're mostly 12 ounces.

[kabdib]

Are you kidding? It was traumatic enough when we switched from cubits, scruples and fortnights.

And what good is a system of measurement that you can't use to bamboozle customers? ("That's not an ounce, ma'am, that's a Troy ounce...")

If we move to anything, it's going to be Donald Knuth's Potrzebie system (see http://en.wikipedia.org/wiki/Potrzebie). It seems more well thought out than most.