Paul Schlyter:
But if the distance is irrelevant, why not perform the division
and say 0.67 instead of 20/30? Or at least 2/3 instead of 20/30?
After all it means that the person with 20/30 eyesight has 2/3 or 0.67
of normal visual acuity.

Chris L Peterson:
It's just convention.

Paul Schlyter:
An unnecessary convention which should be removed.

Suppose that I, instead of saying "it's 5 degrees outside", suppose
I would say "it's 35/7 degrees outside". It's the same thing, but
you'd probably ask why I involved that 7 in the temperature, and then
I would reply "it's just convention"... See?

Settle down! What happened? Father Christmas pass you by?

Once you know, as Mr. Peterson said, it's a convention, that's all you
need to know. It is used over practically the whole world and it works.
The world of measurement is full of conventions that, if being
originated today, might be done differently. But there is no need to
change them when everyone knows them. It explains why the general
public uses the English System of measures in the U.S. and some other
countries‹including the U.K., frequently‹its a convention that serves
its purpose!

I was watching a British cooking show on TV the other day. "Add 250 g
of this or that, 500 g of the other and another 200 ml of milk. Roll it
up until it looks like this and cut into two-inch sections. Works.

--
I agree with almost everything that you have said and almost everything that
you will say in your entire life.

usenet *at* davidillig dawt cawm