Mugs - scientifically, like.

There clearly isn't
an optimum shape for a mug. Otherwise we'd have found it by now.
But...

...there must be a
shape which makes sure that the tea (or other hot beverage, take your pick - for
the purposes of this discussion let's assume it's tea) (Earl Grey - in fact,
let's assume it's Green Earl Grey because I haven't had any in a while and I
miss it). (Mmmm).

Where was I? Oh
yeah.

There must be a mug
shape which first cools the tea quickly, then keeps it drinkable for the longest
period of time. Let's make some assumptions (yay! I like this
bit):

1. There is a range
of 'drinkable' temperature - say, 45-30 degrees celsius. Below this, tea is
tepid and nobody wants to drink it. Above it, the tea is too
hot.

2. People's rate of
drinking is related to temperature. Let's assume they drink it fastest at about
40 degrees.

3. Let's assume that
the profile is not allowed to 'bottleneck' - for the purposes of cleaning, the
mug isn't allowed to narrow at the top. Actually, that's a bit harsh - I have
several mugs at home which do just that. But it makes the maths trickier - is
there reflected heat from the insides? - but I guess we'll have to allow it.
Okay. But only a little bit. Great. Now we're going to need a computer to work
this out. Sheesh.

4. Also for the
purposes of practicality, the mug isn't allowed to narrow down to less than an
inch in diameter.

5. But it can be as
tall as you like (you can take practicality too far, you
know).

So the aim of the
game is to keep the temperature of the tea within the drinkable range until it's
all drunk. Now, I reckon it should go something like this: the top should be
flared, like a trumpet. That way, you start off with a big surface area and the
tea will cool quickly. Then, assuming that the drinker starts to sip it while
it's still technically too hot, the mug should narrow down fairly quickly to the
point where the tea is now at the top edge of the drinkable range. Then, the
belly of the mug can maybe open out (just a bit)... although that will increase
the surface area so it might increase the cooling rate (damn), so maybe better
to just go vertically down... until we reach the bottom, when the tea could be
nearing the bottom range of 'drinkable', when the surface should start blending
in to a nice, curvy bottom.

It's possible that
the best shape might involve having a mug that as narrow as possible, so we'll
end up with something like a trumpet balanced on a straw... but hey. It'd be a
fun investigation, anyway. Anyone know any students looking for a project?
There's plenty to do. Yo'd have to find out about the drinkable range. Then
measure people's rates of consumption at different temperatures. Then there's
some juicy simulation work to determine the reflected heat (if you're going to
include narrowing at the top - otherwise you could probably get away without
it). Choice of materials, colours, etc. Finally a bit of design work to pretty
it up a bit.

What fun... for
someone else!



(PS Denby make my favourite mugs - see below!)