Jeopardy contestant on Sept 15's hobbies?

The contestant in the middle on Sept 15’s *Jeopardy *was some sort of mathematician, if I heard right, and during the interviews, he said something that sounded like taking 46,000 business cards and making a level 3 tractor.

I wasn’t able to back it up and listen again. Did anyone catch this and know what he was referring to? I’m sure it was something fairly serious, but it sounded utterly absurd.

I have it on DVR, and according to Close Captioning:

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Alex: "You like to fold mathematical origami?

Kevin Knudson: "I am a mathematician and I once took a group of students and we once took 48,000 business cards and folded it into a large fractal like object called a level-3 menger sponge.

Alex: [rollseyes] Oh!!! I once had one of those. [/rollseyes]

I am super bummed that this is not actually what the guy said, because that would have been awesome.

Cool. I think.

About 2/3 down this page, there’s a pic of the finished “sponge” and an internal view here.

I wonder how much water it can absorb?

Probable just a menger amount.

Sounds like a WoW character class.