Auctions, blanks, cups
Listening to a Strange As It Seems episode
about the auction that sold the entire Roman Empire
in 193 AD. In their dramatization, various rich dudes are bidding in millions of sesterces, then one dude ups the ante by bidding in denarii.
Had to look up those units ... apparently the denarius was equal to a daily wage for a working man, and the sestertius was 1/4 of a denarius. So the Den was about 4 dollars in 1930, or 80 dollars now; and the Ses was about one dollar in 1930, or 20 dollars now,
For some reason this led to thinking about the alleged lack of zero in Roman numerals. I can see how you get along without zero in a non-positional system, but how do you represent a zero answer to a subtraction?
Oh. The same way you do it in non-positional money units like LSD. 4/3/- is four pounds, three shillings and nuppence. The dash or blank for nothing has persisted in bookkeeping; I remember finishing off the columns of a handwritten ledger with _ to indicate balance, and putting _ in slots that had no cost or payment. It's still commonly used in forms like income tax returns. The blank line basically means "I didn't overlook this slot. I've entered or calculated the result for this slot, and I know for a fact that nothing goes here."
So that wasn't a mystery at all. The role of zero as 'just another digit' is NOT THE SAME as the role of zero or _ representing an empty slot or an empty spoon or a balanced column or nulled circuit.
The trouble is that we've grown spoiled by the universality
of decimals. We've lost our previous ability to deal with units that represent coins or cups or columns, units with individual personalities like LSD or pints or inches. Our minds are odometers.
When looking up Ses and Den, I bumped into an interesting project called Nova Roma,
an attempt to study Rome and Latin by being
Roman and doing everything the Roman way. It's along the same lines as Society for Creative Anachronism, but seems more scholarly and serious.
Labels: Metrology, Real World Math