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The Mars Climate Orbiter infamously disintegrated after its trajectory sent it too close to the planet’s atmosphere, due to a calculation error—an error that could have been avoided if everyone used the metric system.

You might ask, “Well, why not have everyone use imperial units?”, to which I would respond:

Map
Seriously..these are the only countries using imperial units.

You might wonder why the rest of the world uses the metric system. Take a look at the following charts, and see if you can make sense of the imperial conversions:

Imperial Chart
Metric chart

If you’re still not convinced…

Answer the following:

Imperial: What is half of the diameter of a 1/32″ hole that’s 4 thou oversized?

Metric: What is half of the diameter of a 0.8mm hole that’s 0.1 mm oversized?

*questions from Michael Good.

If you busted out your calculator and began solving fractions, you’ve already added unnecessary complexity to your design. In the end, both answers result in the same distance when rounded—0.017 inches, or 0.425mm. The metric units just reduce the chance of error and, hopefully, keep your future spacecraft intact.