I just watched The Martian again and noticed something I missed the first time: Watney's notebook has four holes (instead of three) punched in the left margin, which means it's probably A4 in size (though I didn't get a close enough look to be sure).
This is odd since it's an American mission. Is there an official explanation? If not, what's the likeliest explanation?
- By 2035 the US has switched to ISO paper formats and metric measurements.
- Watney stole the notebook from Vogel's personal effects.
- The production designer thought that that particular notebook looked cool.