Möbius Bagel: interlocking, endless, doughy rings of math


mob2.jpgOn the website of sculptor and mathematician George Hart, there are step-by-step instructions for how to craft a Möbius strip from a single bagel. I like his thoughts at the very end of the instruction process:

"It is much more fun to put cream cheese on these bagels than on an ordinary bagel. In additional to the intellectual stimulation, you get more cream cheese, because there is slightly more surface area."

Mathematically Correct Breakfast: How to Slice a Bagel into Two Linked Halves (via Serious Eats NY, thanks Laura)



  1. Just when I think I’ve seen the geekiest things on the internet, my world is blow apart.

    Holy Crap that’s nerdy. lol, and I Love it.

    Mazel tov!

  2. I think this is not a Möbius strip. If it were, the cut side would seamlessly become the uncut side, and be traceable all the way around, no? What he has are two totally separate, yet interconnected, loops. Also known as a chain.

  3. If you look closely, there are two boundary components to each of the cream cheese regions. They form a Hopf link and bound an annulus.

    You know that it wouldn’t give you a Mobius band anyway, since it completes to a closed surface on the shiny side of the bagel. That would give an embedded, closed non orientable surface in R^3 – which is impossible.

  4. He doesn’t claim it is a Möbius strip (and it isn’t), although he does leave as an exercise at the end:

    “Topology problem: Modify the cut so the cutting surface is a one-twist Mobius strip.
    (You can still get cream cheese into the cut, but it doesn’t separate into two parts.)”

  5. it’s not a moebius strip, it’s two interlocked rings! pretty cool but i think the purpose of it is to cut a bagel in half in such a way that you obtain a bigger area for buttering :)

  6. “In additional to the intellectual stimulation, you get more cream cheese, because there is slightly more surface area.”

    But, why not just cut it normal, and simply add more cream cheese to the bagel anyway?

    “…this bagel goes to 11.”

  7. To the whingeing buggers who claim that this is not a möbius strip, you’re right – but it’s two, interlocking ones and is therefore twice as good (minimum) and you suck arse.

  8. If you cut a Moebius strip down the length of it, you get a larger strip. But if you cut the strip again down the length, THEN you get two linked rings tied with a knot. But you have to have a very clever bread knife to do it with a bagel. Would it then be called a “Boggle”?

    Adams, Oregon

  9. Jarooooo. Apologies for the correction but this is not two mobius strips either. To be a mobius strip, when you follow it around you realise there is only one side. Have a look for yourself at the picture above. This is clearly just a chain link. It is not possible to make a mobius strip out of a bagel. For anything to make a mobius strip there is one rule; both supposed sides must look identical.

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