Ever wonder why scientists and news sites reporting on science often use the metric system? Metres and kilometres and other things that are spelled funny? Well, mainly because an overwhelming percentage of the planet use the metric system.
In fact, there are only three countries that do not: Myanmar, Liberia, and the United States of America.
So next time you think to yourself that you wish reporters would get with the program and use miles or whatever, take a look at the map above.