iso paper sizes are delicious: sides are 1:sqrt2 or about 1:1.414

A4 is 210x297mm

A4 folded in half is 148x210 or A5.

A3 is two A4s, or 297x420

go to A0 841x1189 or one square metre.

A-1 (A Minus One) is 2 square metres.

Australia is ~A-43

The visible universe ~A-179

A proton about A139.

A Quark? A151

Presumably A232 is one dimensional though, as it's planck length on the long edge.

Why A4 Paper Is a Mathematical Miracle

YouTube

@jsnell @NanoRaptor yes, and in the comments that’s where I broke the bad news about 2A0 — sadly it reverts from logarithmic to linear

2^180A0 is the universe

A232 is Planck length paper

#planck #a4 #a0 #metric #paper #universesize

Good to see my calculations concurred with @NanoRaptor

No thanks to YouTube though, for making comments non-searchable

It’s next to impossible to search for my own comments, let alone anyone else’s