That family must have the best picnics!
To think about it another way, imagine if you took a mobius strip and constructed a semicircular lump of bread on the surface, extending it around until it connects back to itself. You've made a bagel!
Now take the mobius strip out of the middle, and the gap it leaves is the cut you're asking to make.
I wonder if I could sell bagel-sized silicone mobius strips for baking.
However, I of course have no bagels or bagel accessories on the one day I read about mathematically correct bagels :(
So yeah, added to my grocery list too!
After a couple minutes of back and forth an epiphany was realized that if they were pre-cut all the way through they'd get jumbled up and then we'd spend way too much time rifling through halves to find a matching one.
Either way, bravo!
Someone please ask Professor Shewchuk (UC Berkeley) and Professor Demaine (MIT) to look at this! Perfect geometric problem for both of them.
I mean yeah, that was the point of my remark.
To write something on topic as well:
There was a fun little challenge on puzzles.stackexchange I think, which relied on the same construction as this article. I couldn’t find it, but it went like this:
“You’re stuck on top of a tall building with nothing but a saw. There’s a ladder fastened to the side of the building, but it’s unfortunately not long enough to reach the ground; in fact it goes about half the height of the building from the top. Challenge is to get on the ground “safely”. You can cut into the ladder with your saw in any way you like and you can assume that the resulting pieces will be rigid, but won’t break under load.”
