A Matter of Degrees

[andrew at cee.hw.ac.uk]

Harrison Sherwood writes:
> Isn't this yet one more example of the mysticism/science,
> Medieval/Enlightenment, East/West dichotomies central to M&D?

Thank you. If you keep pushing the same dumb question someone comes up
with the right smart answer.

> (Query, for one who left his _Historia Mathematica_ in his other suit:
> Who first determined that the standard subdivision of a circle should be
> 360 degrees? Pythagoras? Some Arab algebra-walloper or another,
> perhaps?)

I seem to recall somwehere from the depths (probably via Carl Boyer's
History of Maths which I read 20 years ago) that 360 degrees were used
in Egyptian astronomy and related to use 60 as a base (not the base as
it was mixed base) in the Babylonian counting system.

> My memory is a little flawed on the details, and Web-searches are
> shooting blanks, but wasn't the meter originally based on a certain
> subdivision of the distance from the Equator to the Pole?

Yes, there were supposed to be 10000 km along a great cricle from
equator to pole. Of course there are not because the Earth is not
round.

> And is this
> not suggestive? Does this not bring us, as it were, full circle? Why not
> a *metric* geometry? Why isn't a degree of terrestrial arc a certain
> number of kilometers, perfectly divisible by 10?

Well, you see the earth isn't round . . . But there are units of angle
call gradians with 100 gradians to the right angle. Relates quite
nicely to the km for great circle distances, I guess.

> For the same reason that we here in the Yoo Ess are still fighting the
> metric system: the Old Way, borne out of medieval weights and measures
> that evolved from the village marketplace, seemingly irrational and
> atavistic, is actually a whole lot more convenient to use than the
> newfangled sciento-fascist metric system: It's as simple as this: How
> many whole numbers can 12 be divided by? Now how about 10? Ever tried to
> buy a quarter of a Metric Dozen of dinner rolls?

Thing is you can usually buy as many rolls as you want, no matter how
big your dozen is, as `twere.

<Cue debate on family vs party size and what exactly constitutes an
individual fruit pie . . .>


Andrew Dinn
-----------
How do you know but ev'ry bird that cuts the airy way
Is an immense world of pleasure clos'd by your senses five