>> That might explain it, I guess. So if I see something before me that I
>> am inclined to refer to as a "coffee cup", how am I to tell whether or
>> not it actually _is_ a coffee cup in some essential way?
>
> In fact, it could be your doughnut.
>
> (Old topology joke.)

My doughnuts are generally not continuously deformable to coffee cups.
I'd have to poke them with a stick to make that true, and that would
squirt jam everywhere.

Jonathan de Boyne Pollard wrote:
>>> That might explain it, I guess. So if I see something before me that I
>>> am inclined to refer to as a "coffee cup", how am I to tell whether or
>>> not it actually _is_ a coffee cup in some essential way?
>>
>> In fact, it could be your doughnut.
>>
>> (Old topology joke.)
>
> My doughnuts are generally not continuously deformable to coffee cups.
> I'd have to poke them with a stick to make that true, and that would
> squirt jam everywhere.

Would topology have still been the field it is today if doughnuts had
not existed?

--
Peter Moylan, Newcastle, NSW, Australia. http://www.pmoylan.org
For an e-mail address, see my web page.

On 26/08/11 7:36 AM, Peter Moylan wrote:
> Jonathan de Boyne Pollard wrote:
>>>> That might explain it, I guess. So if I see something before me that I
>>>> am inclined to refer to as a "coffee cup", how am I to tell whether or
>>>> not it actually _is_ a coffee cup in some essential way?
>>>
>>> In fact, it could be your doughnut.
>>>
>>> (Old topology joke.)
>>
>> My doughnuts are generally not continuously deformable to coffee cups.
>> I'd have to poke them with a stick to make that true, and that would
>> squirt jam everywhere.
>
> Would topology have still been the field it is today if doughnuts had
> not existed?
>

But when I was a child in England, doughnuts were amorphous lumps and
were definitely not ring-shaped and had no visible hole. It took me a
while before I understood what Americans writers were talking about when
they said "donut-shaped". I don't think I saw a toroidal doughnut until
I was in my twenties.

--
Robert Bannister

"Peter Moylan" > wrote in message
. au...
> Jonathan de Boyne Pollard wrote:
>>>> That might explain it, I guess. So if I see something before me that I
>>>> am inclined to refer to as a "coffee cup", how am I to tell whether or
>>>> not it actually _is_ a coffee cup in some essential way?
>>>
>>> In fact, it could be your doughnut.
>>>
>>> (Old topology joke.)
>>
>> My doughnuts are generally not continuously deformable to coffee cups.
>> I'd have to poke them with a stick to make that true, and that would
>> squirt jam everywhere.
>
> Would topology have still been the field it is today if doughnuts had
> not existed?

All topology textbooks would contain pictures of coffee cups.

Or topologically identical people?

pjk

Why coffee mug is ingested in this conversation. I didn’t’ get it !......

Actually it's in the title of this thread: "doughnut, coffee cup, scissors, pretzel, ..."