

Group Theory in the Bedroom: the curious mathematics of mattress flipping - tokenadult
http://www.americanscientist.org/issues/pub/group-theory-in-the-bedroom

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MartinCron
A King-sized mattress could be made square by being just 4 inches wider. Not
only would it make more rotations possible (8) but it would also be easier to
put the sheets on, as it's impossible to put them on the "wrong" way.

Sorry, just a pet peeve of mine.

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coderdude
I would be reluctant to rotate the mattress so that the old feet location is
the new head location.

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litewulf
Why? (Ignoring say foot fungus, is it just squeamishness or is there something
else I should know? ;))

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angusgr
That's quite an amusing extrapolation.

(Kinda O/T) I amused my girlfriend the other day by taking a permanent marker
to our mattress. On one side, I wrote "top to bottom" in the top-left and
bottom-right corners, facing the edges. On the other side, I wrote "side to
side".

Each time you flip, you just look at the bottom corner and it tells you what
to do next.

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jeroen
Why not label the configurations 1, 2, 3 and 4? Less writing and you don't
need to remember which instruction to read.

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angusgr
That'd work, the only catch being that when you see 1 you need to know where 2
is, and it's on the other side of the mattress (I have a latex mattress, it
weighs about 30kg so it's a pain to turn over, even to look. Turning it twice
because you got it wrong with the first movement is a big cost.)

You don't actually need to remember which instruction to read, cos they're the
same on the each side of the mattress. I could have just written "side to
side" on one side and "top to bottom" on the other side, it'd just sometimes
be upside down.

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jcdreads
Perhaps instead of replacing our crappy mattress with a new one I can instead
regale the lovely wife with group theory: "Look, honey. It's our old friend
Z2xZ2xZ2."

Won't she be pleased!

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jeroen
If you don't want to browse through 7 pages, here's the full text:

[http://www.americanscientist.org/issues/id.3465,y.0,no.,cont...](http://www.americanscientist.org/issues/id.3465,y.0,no.,content.true,page.1,css.print/issue.aspx)

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Groxx
A much better reading format, thanks for the link!

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boredguy8
I haven't had a mattress that's symmetrical along all axis. I only ever 'turn'
the mattress 180° parallel to the ground.

