25 November 2008

On foods of genus one

It seems that some people describe the torus as the shape of a bagel, and others as the shape of a doughnut.

I wonder if this is somehow correlated with geography; bagels are more common in some places, doughnuts in others.

7 comments:

intrinsicallyknotted said...

How about Cheerios? (Or Froot Loops, or any other toroidal cereal of your choice.) I can't think of any non-breakfast foods of genus one, and I can't think of anything with more holes except for fancy bagels and doughnuts.

Todd Trimble said...

Lifesavers (technically, a food).

Veky said...

In Croatia, both bagels and doughnuts are of genus zero. So we describe torus as a tyre. :-)

hdur said...

Here in Chile we don't even know what a Bagel is. I like to describe the torus as a inner tube.

David said...

I can't think of anything with more holes except for fancy bagels and doughnuts.

Pretzels!

intrinsicallyknotted said...

David, if you consider that a pretzel is formed by rolling out a sphere of dough and then twisting it, I'd say it's still of genus zero. Of course, after sticking the ends together and baking it, it could be argued that it is now a three-hole torus, but the act of sticking the ends together is not a continuous transformation, and I don't think there is a topological concept of "baking" a topological space. So I refuse to accept that a pretzel has holes!

Michael Lugo said...

In Philadelphia, pretzels are of genus two.