Let's say you have a standard bagel (one that is NOT pre-sliced). How can you cut this bagel into two interlocking rings? The rings must never be broken.

  • 4
    $\begingroup$ georgehart.com/bagel/bagel.html $\endgroup$ – skv Nov 6 '14 at 9:01
  • $\begingroup$ @skv That's an answer ;-) $\endgroup$ – Joe Nov 6 '14 at 9:44
  • $\begingroup$ :) Yes, I just did not feel good about writing that out as an answer because it was not nearly mine, also I could not modify anything there to make it sound like I have added value, so just left it there $\endgroup$ – skv Nov 6 '14 at 9:49
  • $\begingroup$ The answer @skv posted is the only one that can fulfill the requirements, I think.. $\endgroup$ – Andrea Gottardi Nov 6 '14 at 10:56

Ok Just to ensure that this question gets an answer I am posting this, and attributing it to community.

Credits to http://www.dailymail.co.uk/sciencetech/article-2232924/How-make-Mobius-bagel-Sliced-just-right-breakfast-snack-makes-linked-halves-curious-mathematical-properties.html

The basic concept is to consider the third dimension and visualize four key points. Center the bagel at the origin, circling the Z axis.

A is the highest point above the +X axis. B is where the +Y axis enters the bagel. C is the lowest point below the -X axis. D is where the -Y axis exits the bagel.

Cut through the line ABCDA. Then turn the bagel over and make the same cut again. Here is a video showing how to cut the bagel.

enter image description here

  • 1
    $\begingroup$ I changed the image because I think it would be useful to show the line you need to cut through, as well as the final result. $\endgroup$ – pacoverflow Nov 6 '14 at 14:48
  • $\begingroup$ Is the red line just the other end of the same cut? That is, 180 degrees opposite the black line? $\endgroup$ – TheRubberDuck Nov 6 '14 at 15:20
  • $\begingroup$ @EnvisionAndDevelop You have to turn the bagel over and make the same cut again - I edited the answer to reflect that and included a link to a video. $\endgroup$ – pacoverflow Nov 6 '14 at 15:34
  • $\begingroup$ Why\how is there 'slightly more surface area'? $\endgroup$ – Mazura Nov 7 '14 at 10:31

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.