[sci.physics] The physics of coffee cups

cw@vaxwaller.UUCP (Carl Weidling) (10/31/86)

MESSAGE
	It seems to me that a nice thick coffee mug is the proper design
because, when the coffee is 1st poured it is too hot to drink.  The large
mass absorbs a lot of the heat quickly cooling it down to a drinkable level.
After that, the thick walls of the cup insulate the coffee so that it doesn't
keep on cooling quickly.  Is this right?  Maybe a coffee cup has to be made
with the walls in two layers.  The inner layer being thermally conductive
in order to absorb heat quickly, and the outer layer insulative.

Regards,
Carl Weidling
-- 
Cleave yourself to logodaedaly and you cleave yourself from clarity.

john@uwmacc.UUCP (John Jacobsen) (11/02/86)

> MESSAGE
> 	It seems to me that a nice thick coffee mug is the proper design
> because, when the coffee is 1st poured it is too hot to drink.  The large
> mass absorbs a lot of the heat quickly cooling it down to a drinkable level.
> After that, the thick walls of the cup insulate the coffee so that it doesn't
> keep on cooling quickly.  Is this right?  Maybe a coffee cup has to be made
> with the walls in two layers.  The inner layer being thermally conductive
> in order to absorb heat quickly, and the outer layer insulative.

The French have a better solution -- drink out of bevel-lipped bowls.  The
coffee in the center of the bowl stays warm while the coffee at the lips
cools quickly to drinking temperature.  Not a very 'physical' explanation
but it works for me.


John E. Jacobsen
University of Wisconsin -- Madison Academic Computing Center
john@unix.macc.wisc.edu  or  {allegra|seismo|ihnp4...}!uwvax!uwmacc!john

michaelm@bcsaic.UUCP (Michael Maxwell) (11/04/86)

In article <594@vaxwaller.UUCP> cw@vaxwaller.UUCP (Carl Weidling) writes:
>MESSAGE
>	It seems to me that a nice thick coffee mug is the proper design
>because, when the coffee is 1st poured it is too hot to drink.

Well, that depends on a lot of things.  I used to live in Quito, Ecuador, at
an altitude of 9000+ feet.  The boiling point of water is considerably lower
there, and by the time a cup of coffee got to the table it was *just* the
right temperature.  Periodically I'd take a flight down to the Amazon jungle
(altitude ~400 feet).  I don't know how many times I burned by mouth on my
first cup of coffee after arriving...
-- 
Mike Maxwell
Boeing Advanced Technology Center
	...uw-beaver!uw-june!bcsaic!michaelm