Imperious measurements

[mirrorshard]

vashti linked to a US-authored guide to building a tin-can wireless antenna. The measurements are all in inches, which got me thinking.

How do you measure 1.21" in any meaningful manner? The rulers I have here are almost all marked out in thirty-secondths on the inches side, and whilst one has tenths for half its length, it doesn't go any finer than that. I don't even think you could fit another ten subdivisions into one of those and still be able to use it. Possibly with a special magnifying section, I suppose...

Best answer gets a cookie.

Comments

[dasquian.livejournal.com]

I can get you to 1/400th of an inch with the rulers you have!

We're essentially trying to solve x/10 + y/32 = 21/100 where x and y are both integers (ignoring the trivial full inch for now).

This resolves to 80x + 25y = 168, which is clearly unsolvable. However, it's very close to 80x + 25y = 170 which gives us x = -1 and y = 10. So if you measure 1/10th of an inch back, then 10/32nds of an inch forwards, you get 0.2125 of an inch.

So I've, um, proved you can't measure it exactly with your two rulers alone. I guess you already knew that ;p *slumps*