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### Course: Math for fun and glory>Unit 1

Lesson 7: Thanksgiving math

# Borromean onion rings

Borromean Onion Rings, the perfect way to top your Green Bean Matherole! Borromean onion rings were invented by special guest Marc ten Bosch (http://marctenbosch.com). Also shown are gelatinous cranberry cylinder, bread spheres and butter prism, mathed potatoes, apple pie, and pumpkin tau. Mathed Potatoes: http://youtu.be/F5RyVWI4Onk Green Bean Matherole: http://youtu.be/XwIs1nlDQ2I Turduckenen-duckenen: http://youtu.be/pjrI91J6jOw. Created by Vi Hart.

## Want to join the conversation?

• So is 4D time?

Thanks for all the answers to my question. xD
• Not necessarily. You can measure anything you like on any dimension. It is quite common to have three spatial dimensions with time as the 4th, as that is useful when measuring things in our universe. In this context however, I think Vi was referring to a 4th spatial dimension, which would allow you to create the Borromean rings without cutting them.
• Isn't that how the Olympics rings are designed (minus the onion)?
• The Olympic Rings are just 5 rings linked in a line, while these are not actually linked.
• did anyone see on the pi and the tau?
• who's she cooking with at ?
• Marc ten Bosch, the 4 dimensional Frenchman who invented the Borromean Onion Rings.
• How come there isn't a video for the cranberry cylinder or the pi and tau pies?
• I would guess there is one, but she didn't post it on Khan Academy. If you search YouTube for "vi hart thanksgiving cranberry cylinder" it should come up. But there might not be one, so don't hold me responsible. I'm not allowed on YouTube, so I couldn't tell you for sure.
--Blue Leaf
• Can you make a mobius strip using onion rings?
• Yes you can! Make it the same way you would make a Mobius strip out of paper -- make a loop and twist it halfway -- then connect it with a toothpick. After you fry your Mobius onion ring, it will stick together and you can remove the toothpick. The final product will hopefully be delicious.
--Blue Leaf
• At , what is a "gelatinous cranberry cylinder"? Dose anyone know how she made it?
• You can buy a can of cranberry in the store. Personally, I don't like it but thats beside the point. When she refers to it as a "gelatinous cranberry cylinder", she is just giving it a fancy, mathematical name.

Hope that helps!
Ben Doucette